Home

GScnd v1.29 User Manual

1. Communication with photometer You must first open communications with the Open command and finish by closing communications with the Shut command The XYZ command measures light and returns the CIE 1931 XYZ values You may then also download the radiant spectrum of the measurement using the SPC command cgphotometer open pr650 1 Open communications with the photometer The PR650 should be connected to serial port COM1 cgphotometer shut Shut communications with the photometer idstr cgphotometer ID Obtain the identification strings Typically GScnd cgPhotometer v1 29 Compiled Nov 6 2008 PhotoResearch Spectra Colorimeter Model PR 650 SN 60954201 xyz cgphotometer X YZ Measure light and return the CIE 1931 XYZ values spc cgphotometer SPC Return the spectrum of the last measurement cgplaymovie Key lt x y w h gt Key The identification numberof the movie to play x y w h Where it should appear on the display This command plays a movie that has been opened with the cgopenmovie command If you omit the x y w h parameters the movie will play full screen Otherwise it appears at the requested position The position is affected by the cgalign command You cannot interrupt the movie once it has been started cgplaymovie 7 Play movie number 7 cgplaymovie 33 0 0 320 240 Play movie number 33 at position 0
2. gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 74 59Hz gt gt r rgb cgloadbmp 1 Demo3 bmp 10 gt gt cgdrawsprite 1 0 0 gt gt cgflip 0 gt gt cgcoltab 10 rgb gt gt cgnewpal Cogent Graphics display window We loaded file Demo3 bmp into sprite 1 with the colours starting at palette index 10 The image palette colours were returned in array rgb We then drew the sprite and executed a C 8 GScnd user manual v1 29 6 November 2008 flip to make it visible Then we loaded the palette array rgb into our display palette with the cgcoltab command and displayed the colours with cgnewpal C9 GScnd user manual v1 29 6 November 2008 We can check the contents of the rgb array gt gt rgb rgb 1 0 0 0o 0 0 Here we can see that there are two colours in the Demo3 bmp palette the first is maximum red 1 0 0 and the second is black 0 0 0 Now let us set up the following colours in the palette 10 100 red 11 000 black 12 010 green 13 000 bDlack 14 110 yellow 15 000 black 16 00 1 blue 17 000 black gt gt rgb 100 000 010 000 110 000 001 000 gt gt cgcoltab 10 rgb gt gt cgnewpal Now make sprites 1 to 4 all from the Demo3 bmp file but respectively starting at palette indices 10 12 14 and 16 gt gt cgloadbmp 1 Demo3 bmp 10 gt gt cgloadbmp 2 Demo3 bmp 12 gt gt cgloadbmp 3 Demo3 bmp 14
3. gt gt cgtouch calibrate ERR cgTouch Calibrate No cogent graphics screen E 33 GScnd user manual v1 29 6 November 2008 However in our example the calibration screen appears and you are asked either to press and hold the displayed cross or to press the escape key on the keyboard to abort the calibration Cogent Graphics display window n calibration Press amp hold the cross o If you press the escape key at any time during the calibration control returns from the command and the following message appears on the matlab console ERR cgTouch Calibrate User abort However if you press and hold the cross then it becomes red after half a second Cogent Graphics display window If you continue to press for a further half second the cross disappears and you are asked to release the touch if you remove the touch instead you go back to the white cross Cogent Graphics display window sn calibration Release the touch or E 34 GScnd user manual v1 29 6 November 2008 Once you release the touch the second calibration point is displayed Cogent Graphics display window Press amp hold the cross or Altogether there are five crosses which have to be pressed upper left upper right lower left lower right and centre and then the calibration process is complete You can obtain an array describing the calibration using the following form of the command gt gt Touch
4. GScnd user manual v1 29 6 November 2008 You can also record eye position data in the background for a period of time and then retrieve the information later To start recording use the command gt gt cgtracker start Then at the end of the period you can retrieve the data using the following command gt gt eyearray cgtracker stop eyearray will then contain an array of eyedat structures each one corresponding to a separate eye position You may store up to eighty minutes of data if the eye camera is running at 60Hz 40 minutes at 120Hz or 20 minutes at 240Hz GScnd user manual v1 29 6 November 2008 Using sound The sound interface has a time resolution of approximately 40ms and so it is not reliable for psychophysics studies where highly accurate sound synchronisation is required However for many applications it provides a useful addition to the display commands Using the sound system can introduce some variability in the frame rate and you may find that frames are off by up to 4mS when you check for dropped frames Sampling rate channels and sample size The sound interface uses digital sound the sound waves are converted into numerical form by sampling the waveform at a specific frequency 0 57 Waveform numerical value 1 T T T T T 1 0 2000 4000 6000 8000 10000 11025 Sample number The figure above shows a sound wave of a frequency of 21 Hz 21 cycles per second A one second portion o
5. cedriver CLEAR Clears all driver fixes currently in force No info message G 6 GScnd user manual v1 29 6 November 2008 cgellipse cx cy w h lt Col gt lt f gt CX Cy Co ordinates of the centre of the ellipses w h Widths and heights of the ellipses Col Optional The colours for the ellipses When in palette mode Col must be an n x 1 single column array containing the palette index for each item When in direct mode Col must be an n x 3 array containing the RGB levels 0 to 1 for each item T Optional draws filled rather than hollow ellipses This function draws ellipses with centres on the co ordinates x y and widths and heights defined by w and h The ellipses are drawn on the current destination as set by cgsetsprite If you include the Col argument each ellipse will be drawn in the requested colour otherwise the current drawing colour as set by egpencol will be used If the optional f argument is used filled ellipses will be drawn Otherwise hollow ellipses are drawn using the current line width as set by egpenwid The arrays cx cy w h and Col must have the same number of entries When in direct mode where Col is an n x 3 array n gives the number of entries cgellipse 0 0 20 10 Draws a hollow ellipse centred on 0 0 with width 20 and height 10 cgellipse 0 0 10 10 f Draws a filled circle of radius 10 centred on
6. Frq 1 0 5 Resets the playing frequency for SND buffer number 1 to be half the original value Matrix lt SamplesPerSecond lt BitsPerSample gt gt cgsound GetSND Key Matrix Returned Matlab matrix containing the sound sample Mono sounds are returned as a 1 x n array stereo sounds asa 2 xn array The individual values range from 1 to 1 SamplesPerSecond Optional returned original playing frequency of the SND buffer BitsPerSample Optional returned sample size of the SND buffer 8 or 16 Retrieve a SND buffer as a matlab matrix Mono sounds are returned as a 1 x n array stereo sounds as a 2 x n array The individual values range from 1 to 1 Optionally you can also retrieve the playing frequency and sample size of the SND buffer as well mat cgsound GetSND 1 Retrieve SND 1 as matlab array mat mat sps cgsound GetSND 7 Retrieve SND 7 as matlab array mat and the playing rate samples per second as variable sps mat sps bps cgsound GetSND 7 Retrieve SND 7 as matlab array mat and the playing rate samples per second and sample size bits per sample as variables sps and bps respectively H 1 GScnd user manual v1 29 6 November 2008 cgsound Info or cgsound Info 0 or cgsound Info Key Key The ID number of the SND buffer for which information is required Lists information about the sound system A s
7. SYSMEM Lets you specify that system rather than video memory should be used See the Graphics Drivers section for further details This function loads up a sprite with identification number Key with an image from the named file If you want you can scale the sprite using the Width and Height values to be whatever you please If you want to use the underlying gprim library functions you may optionally use the returned RASKey value to identify the raster used for this sprite The BMP file should be in uncompressed Windows bitmap BMP or Windows Device Independent Bitmap DIB format cgloadbmp 3 Demo bmp Creates a new sprite with ID number 3 The sprite is the same size as the supplied image file Demo bmp RASKey cgloadbmp 3 Demo bmp 30 40 Creates a new sprite with ID number 3 The sprite will be 30 units wide and 40 units high The units depend on the current co ordinate system as selected by cgscale The underlying gprim raster identification key for this sprite is stored in RASKey cgloadbmp 3 Demo bmp 100 0 Creates a new sprite with ID number 3 The sprite is 100 units wide and the height will be calculated so that aspect ratio of the original image is maintained cgloadbmp 3 Demo bmp 0 100 Creates a new sprite with ID number 3 The sprite is 100 units in height and the width will be calculated so that aspect ratio of the original image is maintained G 13 GScnd
8. csd cggetdata CSD Requests the CogStdData structure gpd cggetdata GPD Requests the GPrimData structure ras cggetdata RAS RASKey Requests the data for RAS number RASKey dib cggetdata DIB DIBKey Requests the data for DIB number DIBKey gsd cggetdata GSD Requests the GscndData structure spr cggetdata SPR SPRKey Requests the data for Sprite number SPRKey myd cggetdata MVD MVDKey Requests the MOVData structure for MOV number MVDKey mve cggetdata MVE MVEKey Requests the Movie structure for movie number MVEKey In general you can use the cgGetData function in the following way gt gt csd cggetdata CSD This command returns the CogStdData structure to the matlab variable csd You can look at the individual members of the CogStdData structure by typing esd as below gt gt esd csd Version 125 CogStdString CogStd v1 29 Compiled Nov 6 2008 Here you can see that the csd structure has two members The first is called Version and it has the value 125 The second is called CogStdString and it has the value CogStd v1 29 Compiled Nov 6 2008 The rest of this manual gives a description of the different data structures and the members they contain J 1 GScnd user manual v1 29 6 November 2008 CogStdData structure The CogStdData structure contains data from the CogStd library It contains the following members Version The version number
9. A LON publication GScnd v1 29 User Manual Written by J Romaya W D C N 6 November 2008 Terms and conditions Cogent Graphics is provided to you free of charge under the following conditions 1 Acknowledgement Acknowledgement from users helps us justify the time we are spending further developing and maintaining this free software Therefore we request that when you use Cogent Graphics for your experiments you include the following statement in your publication This experiment was realised using Cogent Graphics developed by John Romaya at the LON at the Wellcome Department of Imaging Neuroscience 2 Copying This package may be distributed freely as long as it is distributed in its original form It may not be sold without permission 3 Liability The package is distributed as it is without any warranty implied No liability is accepted for any damage or loss resulting from the use of these routines GScnd user manual v1 29 6 November 2008 Cover The Three Graces 1814 1817 by Antonio Canova 1757 1822 In Greek mythology the Three Graces Euphrosyne Aglaia and Thalia bestowed joy beauty and elegance on mankind Please try to bear this in mind when you design your experiments Table of Contents Introduction A Known bugs and limitations A l Update history A 2 General description A 9 Installation A 9 DirectX Installation AY DirectX and refresh rate A 9 Matlab Installation A 12 Cogent Graphics In
10. GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 85 03Hz The Display 640x480x8 85 03Hz should now indicate that we are in 8 bit or palette mode the 8 in 640x480x8 indicates this You can close the graphics screen with the cgshut command gt gt cgshut The window that you opened above was a sub window on the desktop To open a full screen window in palette mode use the command below gt gt cgopen 1 8 0 1 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 75 00Hz This time the whole display goes black Remember that at this point you can do one of two things 1 Minimise the black full screen window by holding down the Alt key and pressing the tab key The minimised window is now represented by a blank rectangle on the system toolbar You can restore it by clicking on this blank toolbar You can issue the egshut command from the matlab console to shut the window The blank rectangle on the system toolbar may not disappear until you select it 2 Exit the program by holding down the Ctrl key and pressing the C key At this point you may want to try altering the refresh rate You can use the DirectX control panel to set the fixed refresh rate as described in the Introduction under the heading DirectX and refresh rate Close your graphics screen first with a cgshut command set the forced refresh rate with the DirectX cont
11. This command makes the current colour table visible It is only available in palette mode You may optionally receive a timestamp indicating the precise time that the colour table became visible using the S variable This timestamp gives you a time in seconds since you made your initialising call to cgopen Currently the precision of the timestamp is 0 001S 1mS cgnewpal Makes the colour table visible at the next VBL cgnewpal I Makes the colour table visible immediately S cgnewpal Makes the colour table visible and records the time it became visible in variable S G 15 GScnd user manual v1 29 6 November 2008 cgopen Res BPP RefRate Monitor lt Alpha gt or cgopen HPix VPix BPP RefRate Monitor lt Alpha gt Res Standard graphics resolutions Values are 1 640 x 480 3 1024 x 768 5 1280 x 1024 2 800 x 600 4 1152 x 864 6 1600 x 1200 HPix VPix Individually specified horizontal and vertical pixel resolutions BPP Bits per pixel 0 bits per pixel is used when you do not know what values are available It will first try 32 then 24 then 16 bits in that sequence until it successfully opens a screen 8 bits per pixel gives only 256 different colours on the screen at any time This mode is memory efficient and you can perform special graphics effects with it 16 bits per pixel gives thousands of colours on screen at any time and is fairly memory
12. before and after you run the sample script These dropped frames are obviously undesirable and they could have serious consequences for your experiment if they occur at a critical point in your stimulus The dropped frames cannot be eliminated altogether but by following the methods described in this section it should be possible to reduce them to a frequency of about one dropped frame per million frames If your experiment is sensitive to dropped frames you should always monitor the timestamps of your cgflip and cgnewpal commands and you should be prepared to ignore any trials where a frame has been dropped Cogent Graphics has been designed to work with Windows 2000 a multi tasking operating system In such an operating system there are many tasks competing for your PCs resources even though you may not be aware of them There may be anti virus software running on your PC and there will be operating system tasks running to monitor the keyboard mouse and network and to control disk activity when you save data to files All of these other tasks can potentially interfere with your Cogent Graphics script Practically this can result in a Dropped Frame Steps have been taken in the larger cogent distribution to eliminate this effect when you issue the start_cogent command you should no longer see these dropped frames By issuing the start_cogent command your matlab session is given a higher priority than all these other tasks When you
13. structure contains the following members CR When in direct colour mode this member is a COLORREF structure described below which contains the colour definition in terms of red green and blue components PV When in palette mode this member contains the palette index number of the colour Otherwise this member is set to 1 The COLORREF structure contains the following members Red The red component of the colour ranging from 0 to 255 Grn The green component of the colour ranging from 0 to 255 Blu The blue component of the colour ranging from 0 to 255 Movie structure The Movie structure also comes from the GScnd library It describes a movie and contains the following members MOV Key The ID number of the underlying gprim MOVData structure Filename The name of the movie file For example gt gt mve cggetdata MVE 3 mve MOVKey 1 Filename movie avi Here we can see that movie structure 3 has an underlying gprim MOV of ID number 1 and that it was created from movie file movie avi J 8 GScnd user manual v1 29 6 November 2008 Multiple Displays GScnd user manual v1 29 6 November 2008 Introduction You can set up Cogent Graphics so that the display appears on a different monitor to your matlab screen This can be a somewhat tricky operation and I have found that different systems need fiddling about with until
14. 3 cgsound open 40 44100 Open the sound device with some selected specified settings Channels 2 default BitsPerSample 16 default SamplesPerSecond 44100 Attenuation 40db Device 0 default H 3 GSend user manual v1 29 6 November 2008 cgsound Pan Key Balance Key The ID number of the SND buffer to modify Balance Multiplication factor for new playing frequency Changes the stereo balance of a SND buffer You enter a value between 1 left speaker only and 1 right speaker only A value of zero selects neutral balance equal volume for left and right speakers If you find you cannot isolate a single speaker channel you probably have surround sound selected Take a look at the section Troubleshooting sound for the way to correct this cgsound Pan 5 1 Set the stereo balance for SND 5 so that the sound comes out of the right speaker only cgsound Pan 5 0 Set neutral stereo balance for SND 5 cgsound Play Key lt LoopFlag gt Key The ID number of the SND buffer to play LoopFlag Optional Set this value to make this sound loop continuously This command plays a SND buffer If you include the optional LoopFlag and set it to 1 the sound will loop continuously If you get a regular click on a looped sound there is probably a discontinuity between the end and start of the sound See the Troubleshooting sound sectio
15. 640 h 480 f 0 Here we can see that Raster 0 the display screen has a width of 640 pixels and a height of 480 pixels The f 0 value indicates that video memory is being used for this raster J 5 GScnd user manual v1 29 6 November 2008 DIB structure The DIB structure also comes from the gprim library It describes a DIB Device Independent Bitmap and contains the following members FName The filename of the DIB Ww The width of the DIB in pixels h The height of the DIB in pixels C The number of colours in the DIB palette For example gt gt dib cggetdata DIB 1 dib FName demo w 320 h 240 c 256 Here we can see that DIB 1 was loaded from file demo bmp It has a width of 320 pixels and a height of 240 pixels and is a palette based image with 256 colour entries MOV Data structure The MOVData structure also comes from the gprim library It describes a movie and contains the following members Filename The name of the movie file For example gt gt myd cggetdata MVD 1 myd Filename movie avi Here we can see that MOVData 1 was created from movie file movie avi J 6 The GScndData structure contains data from the GScnd library named cgData It contains the following members GScnd user manual v1 29 6 November 2008 GScndData structure Version The version number of the GScnd libra
16. TRNBLT problems using transparency SYSMEM smoothing of enlarged sprites and miscellaneous driver problems Do not use this call in a general way as it can adversely affect graphics performance Rather use the gt SYSMEM argument in individual calls to cgmakesprite cgloadbmp and cgloadarray specifically where it is required CLEAR clears all fixes currently in force You can use to cancel a particular fix For example cedriver MIRROR cancels a previous call to cgdriver MIRROR HIDE If present suppresses the informational message for this call This function can be used to fix bugs in your graphics card driver An information message of the form Driver MIRROR is displayed on the matlab console unless the HIDE argument is used Use the drivertest utility to discover which fixes need to be applied on a particular machine The cgopen command now looks for a file named cginit m on the matlab path If such a file exists it is executed This provides a mechanism to automatically apply driver fixes on a per platform basis simply insert the appropriate cgdriver calls for your PC and save cginit m in the cogent graphics toolbox cgdriver MIRROR Applies the MIRROR driver fix An info message will appear on the matlab console cgdriver TRNBLT HIDE Cancels the TRNBLT driver fix No info message will apear on the matlab console
17. gt cgflip Cogent Graphics display window We can make the ghostly apparition even fainter for example a 25 75 blend gt gt cgdrawsprite 1 0 0 gt gt cgdrawsprite 2 0 0 0 25 gt gt cgflip Cogent Graphics display window N B Alpha blending is available only in Direct mode not in Palette mode D 2 GScnd user manual v1 29 6 November 2008 Alpha blending also works with the cgblitsprite command gt gt cgdrawsprite 1 0 0 gt gt cgblitsprite 2 0 120 360 240 0 120 0 5 gt gt cgflip Cogent Graphics display window Alpha performance issues You may have noticed a small but perceptible time lag after issuing the alpha blending commands in the above exercises This occurs because Alpha blending is a time consuming operation A more technical explanation follows Alpha blending programmer s notes You may find that when you use alpha blending in an animation script everything happens too slowly and you get jerkiness and dropped frames If this happens you may be able to solve the problem by using a special form of the cgopen command for example cgopen 1 0 0 0 Alpha This form of the command optimises the graphics system for alpha blending and you should notice a corresponding increase in performance But you should note that the synchronisation of the cgflip command may be different to the standard graphics mode If this is important for your experiment double check the graphics synchronisation for
18. gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgloadbmp 1 Demo bmp gt gt cgdrawsprite 1 0 0 gt gt cgflip 0 0 0 B 32 GScnd user manual v1 29 6 November 2008 Cogent Graphics display window The Demo bmp image is 320 x 240 pixels one quarter of the size of the screen However we can scale it to full screen size if we require gt gt cgloadbmp 1 Demo bmp 640 480 gt gt cgdrawsprite 1 0 0 gt gt cgflip 0 0 0 Cogent Graphics display window Notice here that we re used sprite number for this example The old smaller image was discarded when we reloaded sprite 1 with this bigger image We could also have used either of the commands below to scale the bitmap to full screen width or height supplying a zero for width or height means that the aspect ratio of the image should be maintained when calculating the size of the image gt gt cgloadbmp 1 Demo bmp 640 0 gt gt cgloadbmp 1 Demo bmp 0 480 B 33 GScnd user manual v1 29 6 November 2008 You may find that you get a warning message with the cgloadbmp command gt gt cgloadbmp 1 Demo bmp 640 480 WRN GPrim gAddRAS System rather than video memory used This warning occurs because your graphics card does not have sufficient memory resources to create the sprite Instead system memory has been u
19. gt gt cgloadbmp 4 Demo3 bmp 16 Now draw the sprites evenly spaced horizontally and display them gt gt cgdrawsprite 1 240 0 gt gt cgdrawsprite 2 80 0 gt gt cgdrawsprite 3 80 0 gt gt cgdrawsprite 4 240 0 gt gt cgflip 0 Cogent Graphics display window The same Demo bmp file has now been transposed to four different positions in the palette and each position has been given a different colour C 10 GScnd user manual v1 29 6 November 2008 Loading an image from the matlab workspace When in palette mode an extra argument StartIndex is required when using the cgloadarray command which is shown here in its full form lt RASKey gt cgloadarray Key aw ah Pix Val lt PalRGB lt StartIndex gt gt lt sw sh gt lt SYSMEM gt StartIndex You can choose where the image colours will be in your display palette this value 0 to 255 defines the starting palette entry for the array image colours The array must use a palette to define the colours i e the PalRGB argument must be present This is useful because once you have defined your PixVal array of palette indices going from 0 to n where n is the size of the PalRGB palette you can then load that image into a sprite starting at any palette entry you may require without having to change the individual PixVal elements Consider the example below gt gt PixVal 01234567 8 gt gt PalRGB 00 0 100 010 110 001 101 011 111
20. left centre with the cgalign I c command and draw a blue square aligned so that its left edge on 0 0 The vertical alignment is still centred on the centre of the screen Cogent Graphics display window You should also read Drawing multiple items later on in this section so you know how to draw many rectangles efficiently with a single command B 12 GScnd user manual v1 29 6 November 2008 Ellipses and circles You can use the cgellipse command to draw ellipses and circles cgellipse cx cy w h This command draws a hollow ellipse with the current drawing colour and the current line width as set by cgpen The centre of the ellipse is at co ordinate cx cy and the ellipse width and height are defined by w and h cgellipse cx cy w h f This command draws a filled ellipse In this example we set the screen width to 30 degrees set the drawing colour to white and draw a filled ellipse centred on the screen with width 20 degrees and height 10 degrees gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgscale 30 gt gt cgpencol 1 1 1 gt gt cgellipse 0 0 20 10 f Then set the pen to blue and draw a filled circle of diameter 10 degrees Next set the pen to black and draw a filled circle of diameter 2 degrees Then we set the pen to red and the line width to 1 degree and draw a hollo
21. nx 1 single column array containing the palette index for each item When in direct mode Col must be an n x 3 array containing the RGB levels 0 to 1 for each item Draws filled rectangles on the current destination as set by cgsetsprite If you include the Col argument each ellipse will be drawn in the requested colour otherwise the current drawing colour as set by egpencol will be used The arrays x y w h and Col must have the same number of entries When in direct mode where Col is an n x 3 array n gives the number of entries cgrect Fill the whole of the current destination with the current drawing colour cgrect 0 0 100 200 Fill in a rectangle 100 units wide by 200 units high aligned on the point 0 0 cgrect 100 100 100 100 100 50 50 100 1 0 0 0 0 1 Draws two filled rectangles in direct colour mode One is drawn with aligned on 100 100 with width 100 and height 50 in colour 1 0 0 red The other is drawn aligned on 100 100 with width 50 and height 100 in colour 0 0 1 blue cgrect 100 100 100 100 100 50 50 100 1 2 Draws two filled rectangles in palette mode One is drawn aligned on 100 100 with width 100 and height 50 in palette index 1 The other is drawn aligned on 100 100 with width 50 and height 100 in palette index 2 G 20 GScnd user manual v1 29 6 November 2008 cgrotatesprite Key dstx dsty lt dstw dsth gt Rotation lt
22. there was a memory leak in the cgloadarray function This meant that memory resources were depleted each time the function was called If the function was called many hundreds of times it would eventually use up all available memory resources and cause the system to seize up This bug has now been fixed in v1 18 2 Two new functions have been added to the samples the utility functions equil which matches equiluminant colours by a flicker method and PerfTest which measures the graphics performance of your PC when using Cogent Graphics Changes v1 16 to v1 17 1 Bug fix the time in microseconds as returned by cgFlip and cgNewPal wrapped round to a negative value after 35 47 an unacceptably short interval These functions now return a floating point double in units of seconds Changes from v1 15 to v1 16 1 Bug fix There was a bug in the functions that draw multiple lines and ellipses This bug meant that the sample scripts starspal m and starsrgb m did not work under Windows 98 This bug has now been fixed 2 The cgLoadBMP function has been changed You may now set the required sprite width or height to be zero The aspect ratio of the original bitmap is used with the other dimension to calculate the required size Changes from v1 14 to v1 15 1 Bug fix Sample script dartboard m did not work on dual monitor setup when both displays were set to direct colour mode although it did work when they were set to pa
23. 0 0 cgellipse 100 100 100 100 100 50 50 100 1 0 0 0 0 1 f Draws two filled ellipses in direct colour mode One is drawn with centre 100 100 with width 100 and height 50 in colour 1 0 0 red The other is drawn with centre 100 100 with width 50 and height 100 in colour 0 0 1 blue cgellipse 100 100 100 100 100 50 50 100 1 2 Draws two hollow ellipses in palette mode One is drawn with centre 100 100 with width 100 and height 50 in palette index 1 The other is drawn with centre 100 100 with width 50 and height 100 in palette index 2 G 7 GSend user manual v1 29 6 November 2008 lt S gt cegflip lt VBLFlag gt or lt S gt cgflip lt R G B gt or cgflip lt RGB gt Direct colour mode or lt S gt cgflip lt PI lt ImFlag gt gt Palette mode S Optional Timestamp in seconds for the page flip Itis not possible to obtain a timestamp in immediate mode VBLFlag Optional If present no pageflip will occur but the function will wait until the next vertical blanking period This argument must be v or V Used for animation timing R G B or Optional If present the offscreen buffer will be cleared to this colour RGB R G and B represent the red green and blue components of the colour respectively and take values from 0 to 1 This argument is only valid in direct colour mode The RGB form is a 1x3 array of R G amp B values PI Optional If
24. 0 0 gt gt cgplaymovie 1 0 0 320 240 Cogent Graphics display window Here the alignment mode is set to right bottom and the movie is scaled to 320x240 pixels half the normal size The cgflip command clears the previous screen B 52 GScnd user manual v1 29 6 November 2008 We can even flip the image horizontally by setting the width to be 320 instead of 320 gt gt cgalign l b gt gt cgplaymovie 1 0 0 320 240 Cogent Graphics display window mia che In a similar way we can flip vertically by using 240 for the height rather than 240 gt gt cgalign r t gt gt cgplaymovie 1 0 0 320 240 Cogent Graphics display window B 53 GScnd user manual v1 29 6 November 2008 Finally to complete our sequence we can flip horizontally and vertically at the same time This is the same as a 180 degree rotation gt gt cgalign l t gt gt cgplaymovie 1 0 0 320 240 Cogent Graphics display window l When we have finished we should free up the memory taken up by the movie by issuing a cgshutmovie 1 command You may open more than one movie at a time if you want to play them in quick succession but it is probably better to just keep one open at a time if you can B 54 GScnd user manual v1 29 6 November 2008 Sprite rotation You can rotate sprites arbitrarily using the cgRotateSprite command cgrotatesprite Key dstx dsty lt dstw dsth gt Rotation lt Alp
25. 0 320 240 gt gt ceflip 0 0 0 Cogent Graphics display window B 42 GScnd user manual v1 29 6 November 2008 We can copy the lower left corner by setting the alignment mode to right top gt gt cgalign r t gt gt cgblitsprite 1 0 0 160 120 0 0 320 240 gt gt ceflip 0 0 0 Finally copy the upper right corner by setting the alignment mode to left bottom gt gt cgalign l b gt gt cgblitsprite 1 0 0 160 120 0 0 320 240 gt gt cgflip 0 0 0 Cogent Graphics display window B 43 GScnd user manual v1 29 6 November 2008 Drawing multiple items Sometimes you may wish to draw many hundreds of items You could do this by drawing each item individually in a loop but matlab is rather slow at loop processing and you will get much faster drawing speeds if you can draw all your items in a single function call The following functions accept arrays for their arguments to make this possible cgdraw cgrect cgellipse cgarc Consider the following example gt gt x rand 1 1000 640 320 gt gt y rand 1 1000 480 240 gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt ceflip 1 1 1 gt gt cgpencol 0 0 0 gt gt cgdraw x y gt gt cgflip Cogent Graphics display window The first two lines set up two arrays each containing 1000 elements The x array contains ra
26. 13 2000 WARNING INCONSISTENT VERSION NUMBER GPrim v1 03 Compiled Jun 13 2000 Glib not set by ginit WARNING INCONSISTENT VERSION NUMBER GScnd cgVers v1 29 Compiled Nov 6 2008 GScnd cgBlitSprite v1 29 Compiled Nov 6 2008 If you want to see a short description of any command type the command with a question mark string as its argument to see a usage guide gt gt cgvers ERR GScnd cgVers Usage ERR GScnd cgVers cgVers lt U gt U prints usage description too In this case you can see that cgvers can optionally be called in the form cgvers U This command will print the usage guide for every possible command in the GScnd suite of functions It is rather lengthy so won t repeat it here If you make a mistake typing in any command try looking at the usage guide use the format to see where you have gone wrong B 3 GScnd user manual v1 29 6 November 2008 Opening and closing graphics This tutorial is for direct colour graphics mode You should set your Windows desktop to 32 bit mode using the display control panel see the Palette mode section in the introduction First of all prepare for Cogent by typing the cgloadlib command gt gt cgloadlib Now open a graphics screen using the egopen command gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 75 24Hz Cogent Graphics display window The Cogen
27. Alpha gt or cgrotatesprite Key srcx srcy srcw srch dstx dsty lt dstw dsth gt Rotation lt Alpha gt Key Identification number of the sprite to draw srcx srcy Co ordinates defining the position of the rectangle on the source sprite srcw srch The width and height of the rectangle on the source sprite If you specify a negative value for srcw the image will be flipped horizontally and a negative value for srch flips the image vertically Negative values for both srcw and srch rotate the image by 180 However if you choose negative values for both srcw and dstw or srch and dsth they cancel each other out dstx dsty _ Co ordinates defining the position of the rectangle on the destination dstw dsth You may optionally define the width and height of the rectangle on the destination if it differs from the source sprite dimensions If you specify a negative value for dstw the image will be flipped horizontally and a negative value for dsth flips the image vertically Negative values for both dstw and dsth rotate the image by 180 However if you choose negative values for both srcw and dstw or srch and dsth they cancel each other out Rotation Specifies an anticlockwise rotation in degrees Alpha Performs a translucent copy Alpha takes values from 0 completely transparent to 1 completely opaque When omitted the default value is 1 completely opaque This function rotates an arbitrary rectangle from a
28. BaudRate lt c1 c2 c3 c4 gt or cgtracker Shut or cgtracker Calibrate lt BckCol ForCol gt or eyedat cgtracker eyedat or cgtracker start or eyearray cgtracker stop TrackerID Currently the only eyetracker supported is ASL5000 ASL model 5000 control unit PortNum Serial port to which the eyetracker is connected 1 to 8 Mode Set this value to 1 if the eyetracker is operating in On Demand mode the currently recommended mode Set it to O if the eyetracker is operating in Continuous mode BaudRate Baud rate for the serial port Default value is 57600 although the following other values are also technically possible 9600 19200 38400 cl c2 c3 c4_ Calibration co ordinates of Target points 1 and 9 If these optional values are used the eye data will be in cogent screen co ordinates Otherwise they will be in arbitrary units BckCol Optional colour definitions for the calibration screen These should be ForCol specified as red green and blue colour levels 0 to 1 eyedat This is a structure containing the current eye data eyedat X Eye X co ordinate eyedat Y Eye Y co ordinate eyedat Pupil Pupil radius eyedat Status Status as returned by ASL5000 control unit Zero means normal reading Other values indicate special conditions see ASL manual If the calibration co ordinates c1 c2 c3 c4 were supplied when communications were opened the X and Y val
29. ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound cgSound Open Channels BitsPerSample SamplesPerSecond Attenuation Device cgSound Pan Key Balance cgSound Play Key lt LoopFlag gt cgSound Shut cgSound Stop Key cgSound Vol Key Volume cgSound WavFilSND Key WavFilNam lt Memory gt For full listings use cgsound or cgsound command To get a full listing for a specific command type the following gt gt cgsound devs ERR GScnd cgSound Usage ERR GScnd cgSound cgSound Devs You can also get a full listing for all commands using the following command gt gt cgsound ERR GScnd cgSound Usage ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound cgSound Devs cgSound Free Key Key ID number of sound to free 1 to 10000 cgSound Vol Key Volume Key ID number of sound to play 1 to 10000 Volume 0 to 1 cgSound WavFilSND Key WavFilNam lt Memory gt Key ID number of sound 1 to 10000 WavFilNam name of wav file to load Memory optional storage type 1 hardware 2 software E 31 GSend user manual v1 29 6 November 2008 Using a touchscreen A touchscreen can be used instead of the mouse as an input device Currently only a single family of touchscreens is supported Tyco
30. G B These arrays contain the colour of each colour to be loaded into the colour table The R G B arrays contain the red green and blue components respectively The R G B components take values from 0 to 1 The R G and B arrays must each contain the same number of elements and the number of elements taken together with the first palette index must not exceed the palette size normally 256 RGB This n x 3 array contains the same information as the separate R G and B arguments above This command loads colours into the colour table The colours are not displayed until a call is made to the cgnewpal command cgcoltab 1 1 0 0 Sets colour 1 in the palette to maximum red cgcoltab 2 0 1 0 Sets colour 2 in the palette to maximum green cgdraw x y lt x2 y2 gt lt Col gt x y Co ordinates of the points to draw or if x2 y2 are present the co ordinates of the start of the lines to draw x2 y2 Optional Co ordinates of the ends of the lines to be drawn Col Optional The colour for each point or line When in palette mode Col must be an n x 1 single column array containing the palette index for each item When in direct mode Col must be an n x 3 array containing the RGB levels 0 to 1 for each item This function draws points at the co ordinates x y or if x2 y2 are present draws lines from x y to x2 y2 Lines are drawn with a width as set by cgpenwid The points or l
31. GScnd user manual v1 29 6 November 2008 Hollow ellipses gt gt cgellipse x y w h rgb gt gt cgflip 5 5 5 Cogent Graphics display window Rectangles gt gt cgrect x y w h rgb gt gt cegflip 5 5 5 B 50 GScnd user manual v1 29 6 November 2008 Lines these show up better on a black background gt gt cgflip 0 0 0 gt gt cgdraw x y x2 y2 rgb gt gt ceflip 0 0 0 Cogent Graphics display window And individual points these also show up better on a black background gt gt cgflip 0 0 0 gt gt cgdraw x y rgb gt gt ceflip 0 0 0 B 51 GScnd user manual v1 29 6 November 2008 Movies Movie files should be in Microsoft avi format You should download the sample movie file movie avi from the website and then follow the commands below gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim_ v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 59 96Hz gt gt cgopenmovie 1 movie avi gt gt cgplaymovie 1 Cogent Graphics display window We first open a graphics window and then load the movie file movie avi as movie number 1 Then we play the movie The movie plays moving graphics and audio While the movie is playing nothing else can be done we cannot interrupt the movie until it has stopped The destination rectangle can be positioned and scaled as well gt gt cgalign r b gt gt ceflip 0
32. HIGH or REALTIME priority level for your experiment if you are experiencing dropped frames Consult the Dropped Frames and System Tuning sections of the graphics manual for a fuller treatment of this issue and remember to reset the priority to NORMAL at the end of your experiment To return the current priority level gt gt s cogstd spriority a NORMAL To set the priority level to HIGH from a current level of REALTIME gt gt s cogstd spriority high s REALTIME s cogstd sUserID Arguments This function takes no arguments Return values S The function returns the name of the current login as a text string Description Use this function to get the name of the current login gt gt s cogstd sUserID S hrhqe2 1 4 GScend user manual v1 29 6 November 2008 Data Values GScnd user manual v1 29 6 November 2008 Introduction The cgGetData function can be used to obtain matlab data structures from the underlying Cogent Graphics libraries This data may be of use in some script applications so this method has been provided to access it A deeper knowledge of the libraries may be required to understand some of the data members of these structures and in that case you should consult the programmer s manuals for the cogstd and gprim libraries which are available from the web distribution pages The cggetdata function has the following forms
33. Here we have opened a palette mode window and set the palette colours 0 to 7 to be red green yellow blue magenta cyan and white respectively Next let us set up some co ordinates gt gt x rand 1 1000 640 320 gt gt y rand 1 1000 480 240 gt gt w 1 fix rand 1 1000 29 gt gt h 1 fix rand 1 1000 29 The x and y arrays each contain 1000 random co ordinates from 320 to 320 and 240 to 240 respectively The w and h arrays each contain 1000 values from 1 to 30 Now let us use these co ordinates to draw 1000 rectangles in palette index 7 white on a background of palette index 0 black gt gt cgflip 0 gt gt cgpencol 7 gt gt cgrect x y w h gt gt cgflip 0 Cogent Graphics display window C 12 GScnd user manual v1 29 6 November 2008 The cgrect command used above is identical to that used in direct colour mode The same holds true for all the other commands for cgdraw and cgellipse provided the items are all drawn in the current drawing colour If the items are all to be drawn in different colours there is an important difference in palette mode Instead of defining a colour as an rgb triplet as we do in direct colour mode we must define the colours as a single column array n x 1 of palette indices as shown in the example below gt gt PalInd 1 fix rand 1000 1 6 99 gt gt cgflip 0 gt gt cgrect x y w h PalInd gt gt cgflip 0 Cogent Graphics displ
34. Let us create and select a new sprite the same size as the screen gt gt cgmakesprite 79 640 480 You may find that you get a warning message when you try to execute the cgmakesprite command gt gt cgmakesprite 79 640 480 WRN GPrim gAddRAS System rather than video memory used This warning occurs because your graphics card does not have sufficient memory resources to create the sprite Instead system memory has been used This will still work although the performance may be compromised However you may be able to get round this if you make your screen smaller from the Display control panel Try resizing your screen to 800 x 600 pixels and start again The section immediately below tells you how you can do this You can open the Display Properties dialog box at the Settings tab by clicking Start pointing to Settings clicking Control Panel double clicking Display and then clicking the Settings tab Then in Screen area click the desktop size you require 800 x 600 B 27 GScnd user manual v1 29 6 November 2008 Once you have successfully created the new sprite you can select it and copy the previous sprite into it four times gt gt cgsetsprite 79 gt gt cgdrawsprite 78 160 120 gt gt cgdrawsprite 78 160 120 gt gt cgdrawsprite 78 160 120 gt gt cgdrawsprite 78 160 120 Select the offscreen area as the destination again and clear it with a cgflip command just to make sure that the offscreen bu
35. Points Pan Tilt Tracking Data File lt NOT OPEN gt Disk Manual Auto Pupil Dian XDAT 363360 K bytes free Comment Time 11 54 30 Elapsed 00 03 46 Units Cm Depending on your setup you should be able to see the cogent calibration screen on the Scene monitor of your eyetracker equipment If you can then you should move your mouse over the Scene POG window so that the crosshairs in the Scene monitor lie over each point in turn and then click the left mouse button to store the point and move onto the next one until all nine points have been entered If you do not have a Scene monitor or you cannot see the cogent calibration screen in the Scene monitor then you can still enter suitable calibration points blind Move the mouse over the Scene POG window and watch the Scene X Y values and enter the following points Target point 1 40 40 Target point 2 130 40 Target point 3 220 40 Target point 4 40 120 Target point 5 130 120 Target point 6 220 120 Target point 7 40 200 Target point 8 130 200 Target point 9 220 200 GScnd user manual v1 29 6 November 2008 At any rate this part of the calibration gives you the c1 c2 c3 c4 calibration co ordinates that you need to enter into the open command to receive the eye position in screen co ordinates The values for cl c2 c3 c4 are the co ordinates for target points 1 and 9 in sequence Target point 1 cl c2 Tar
36. SDFilenumber These variables are initialized to CGSD and 1 respectively DriverFlags Records which driver fixes are currently enforced Binary sum of 1 MIRROR 2 TRNBLT 4 SYSMEM J 3 GScnd user manual v1 29 6 November 2008 The COL structure contains the following members CR When in direct colour mode this member is a COLORREF structure described below which contains the colour definition in terms of red green and blue components PV When in palette mode this member contains the palette index number of the colour The COLORREF structure contains the following members Red The red component of the colour ranging from 0 to 255 Grn The green component of the colour ranging from 0 to 255 Blu The blue component of the colour ranging from 0 to 255 You can access these substructures in the following way gt gt gpd DrawCOL CR ans Red 255 Grn 255 Blu 255 Here we are looking at the DrawCOL CR substructure of the gpd GPrimData structure J 4 GScnd user manual v1 29 6 November 2008 RAS structure The RAS structure also comes from the gprim library It describes a Raster and contains the following members W The width of the raster in pixels h The height of the raster in pixels f Flags if this value 1 then the raster is using system memory For example gt gt ras cggetdata RAS 0 ras w
37. We have changed palette index 10 the background to 1 0 0 red palette index 13 the triangle to 0 1 0 green and palette index 17 the dots to 0 0 0 black C 6 GScnd user manual v1 29 6 November 2008 Sprites and transparency The command to make a sprite in palette mode is similar to that for direct colour mode but the RGB colour is replaced by a palette index The command to set the transparent colour for a sprite also takes a palette index rather than a TCol value Consider the example below gt gt rgb 00 0 100 010 110 001 101 011 111 gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 85 03Hz gt gt cgcoltab 10 rgb gt gt cgnewpal gt gt cgflip 14 gt gt cgmakesprite 1 200 200 11 gt gt cgsetsprite 1 gt gt cgpencol 12 gt gt cgpenwid 16 gt gt cgdraw 100 100 100 100 gt gt cgdraw 100 100 100 100 gt gt cgsetsprite 0 gt gt cgdrawsprite 1 0 100 gt gt cgtrncol 1 11 gt gt cgdrawsprite 1 0 100 gt gt cgflip 10 Cogent Graphics display window We load our palette with the colours black red green yellow blue magenta cyan and white starting at palette index 10 and then use the cgflip command to set the offscreen area to palette index 14 blue Then we make our sprite setting a background palette index of 11 red and draw a cross in palette index 12 green We then copy th
38. as set by cgpen The command has two forms cgpolygon x y This command draws a filled polygon in the current drawing colour as set by cgpen The vertices corners of the polygon are held in arrays x and y cgpolygon x y Xoffset Yoffset This command draws a filled polygon The meanings of x and y are the same as in the previous form The Xoffset and Yoffset terms allow you to move the polygon by an offset without having to redefine all the x and y values In this exercise we define a triangle in the arrays x and y gt gt x 0 5 5 gt gt y 6 15 2 5 2 5 gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgscale 30 gt gt cgpencol 1 1 1 gt gt cgpolygon x y gt gt ceflip 0 1 0 After opening the graphics and scaling the screen at 30 degrees wide we set the drawing pen to maximum white draw the triangle on the offscreen area and then display it with the cgflip command clearing the offscreen area to maximum green Cogent Graphics display window B 16 GScnd user manual v1 29 6 November 2008 gt gt cgpolygon x y gt gt cgpencol 1 1 0 gt gt cgpolygon x y 0 2 gt gt cgflip We then draw the white polygon again set the drawing colour to maximum yellow and then draw the polygon again offset by 0 2 i e two degrees higher than the white polygon The cgflip command simply disp
39. between 1 and 8 is expected here Mode The eyetracker can be set up to send eye position only when requested On Demand or in Continuous mode You must let cogent know how the eyetracker is set up Specify Mode 1 for On Demand or Mode 0 for Continuous Currently On Demand is recommended Mode 1 There is currently a bug in the ASL software which means that Continuous mode does not work properly when you do a subject eye calibration See Connecting to your Cogent PC in the Eyetracker setup section for a bit more detail BaudRate Here you tell cogent the speed of the serial connection to the ASLS5000 This should be the number 57600 c1 c2 c3 c4 These values are optional If you don t put them in then the values for eye position that you receive will be in arbitrary units However if you put the correct values in here then you will read the eye position in the same co ordinates that you are using for your screen You need to go through the calibration procedure to get the numbers that you should use You get these numbers when you do the Set Target Points part of the calibration as described below in the section Setting the Target Points This part of the calibration only needs to be done once even if you use different subjects So typically you might use the command as shown below gt gt cgtracker open ASL5000 7 1 1 57600 46 55 219 214 When you have finished using
40. concerning the use of this function while cogent mouse logging is going on Use this function with caution 5 The samples have been modified so that pressing the escape key terminates the script This is necessary because Ctrl C doesn t always work when running a tight animation loop on a dual monitor system Changes from v1 08 to v1 09 1 The cgOpen command has been updated so that multiple displays can be used This manual now contains a section on Multiple Displays Changes from v1 07 to v1 08 1 The functions cgDraw cgRect and cgEllipse have been modified so that they accept array arguments This provides a huge increase in speed when drawing large numbers of items 2 A new function has been added cgMouse which allows the user to quickly and easily obtain a mouse pointer position in the current co ordinate system At the moment this function has not been fully integrated with the rest of cogent and there may be some problems concerning the use of this function while cogent mouse logging is going on Use this function with caution Changes from v1 06 to v1 07 1 New function cgGetData allows access to virtually all internal data values from the Matlab workspace 2 New function cgPhotometer communicates with the PhotoResearch PR 650 spectra colorimeter Colorimetric and spectral measurements can be obtained A 7 GScnd user manual v1 29 6 November 2008 Changes from v1 05 to v1 06 The main change has
41. could have a look at some of the sample scripts mentioned in this manual and try to see how they have been done If you want to program animated graphics you must think of the graphics display in the same terms as movie film i e an animated sequence is composed of a sequence of still frames So in order to create movement on the screen you must draw each frame in the sequence one after the other This is obviously not a job you can accomplish by typing out successive commands into Matlab using the keyboard and so invariably you must write a Matlab script for your animation Consider the Matlab script shown below function Example cgloadlib cgopen 1 0 0 1 kd 1 0 while kd 1 kd cgkeymap end OMDATNAUBWNE 11 cgshut 12 return You should create the matlab script shown above using the matlab editor and save it as a file named Example m In general you should name your script files exactly as the function name Please note that the numbers 1 12 at the left should NOT be included They simply indicate the line numbers for descriptive purposes When you run this script type Example from the Matlab console the screen will go black because a full screen Cogent Graphics display has been opened When you press the escape key the screen will be closed Line by line the script does the following Defines this script as a Matlab function named Example Initializes Cogent Graphics Opens a full screen graphics disp
42. gt gt cgflip 0 0 1 Here the cgflip 0 0 1 command clears the offscreen area to maximum blue You can also use the form cgflip 0 0 1 However nothing appears on the monitor screen until you call ceflip again gt gt S ceflip S 19 0860 The screen now turns blue This time we have used the S cgflip form of the command This form of cgflip returns a timestamp indicating precisely when the offscreen area appeared on the monitor The timestamp is a value in seconds since the cgopen command was executed At the moment the second timer increments in steps of 0 001 i e it is accurate to 1 millisecond The value returned above represents a time of 19 0860 seconds since the cgopen command as issued Prior to v1 17 this function returned the timestamp in units of microseconds but there was a bug in these values which meant that the timestamp became negative after 35 minutes This bug has been fixed from v1 17 onwards where the return value is in units of seconds Another form of this command allows you to wait for the start of the next display frame This facility is useful when presenting stimuli for short periods of time measured in individual frames To wait until the next display frame without flipping use the command ceflip v B 7 GSend user manual v1 29 6 November 2008 Co ordinate system Cartesian x y co ordinates are used with the origin the point 0 0 at the centre of the screen Horizontal x co ordinates increase
43. gt gt cgsound matrixSND 10 bth 48000 When you play it you will hear the lower frequency 100Hz sound from the left speaker and the higher frequency 500Hz tone from the right speaker gt gt cgsound play 10 1 gt gt cgsound stop 10 N B each of the Ift and rgt arrays are single row arrays with 48 000 values Hft LL L2 L3 L4 eese L47999 148000 ret RI R2R3R4 eee R47999 R48000 and the bth array is a two row array with 48 000 values in each row bth LIL2 L3 L4 wees L47999 148000 R1 R2 R3 R4 occ eeee R47999 R48000 You can verify this using the matlab size function gt gt size lft gt gt size bth ans ans 1 48000 2 48000 cgsound is strict about the dimensions of sound matrix arrays and it will only accept matrices with one row for mono sounds and matrices with two rows for stereo sounds You should note that this is different from the format which matlab expects for the matlab sound command which expects a matrix with two columns for a stereo sound To play the same matrix using the matlab sound command you must transpose it using the operator gt gt sound bth 48000 GScnd user manual v1 29 6 November 2008 Modifying sounds as they play Once you have loaded a sound you may change its volume playing rate and stereo balance either before or after you have started it playing First of all create a matrix using the sinwav function described earlier The matrix mat in the example belo
44. in nanometres The second column gives the radiant power in Wm sr nm 1 Finally you should close down communications with the Shut command and then 0 0000 0 0000 0 0000 0 0000 disconnect and pack away the photometer gt gt cgphotometer shut A whole set of colorimetry utilities are available which allow you to perform display calibrations and analyze them as well as plot CIE diagrams and radiant spectra You can download these utilities from the Cogent Graphics website GScnd user manual v1 29 6 November 2008 Using the eyetracker The eyetracker must be correctly set up as described in the section Eyetracker Setup and you must be familiar with the operation and calibration of the eyetracker before you attempt to use it Please consult a member of the computer support staff before you use the instrument so that you are happy about using it correctly There is a sample script available named Tracker which is described elsewhere in this manual which gives a realtime demonstration of using the eyetracker To open communications with the eyetracker you can use the command below cgtracker open TrackerID PortNum Mode BaudRate lt cl1 c2 c3 c4 gt The following arguments must be supplied TrackerID Currently the only supported eyetracker is ASL5000 PortNum You must tell cogent where the serial connection to the ASL5000 comes in This should be one of the serial ports usually COM1 or COM2 A number
45. introduced the following commands cgsound vol Key Volume cgsound pan Key Balance cgsound frq Key Factor Key Volume Balance Factor This value identifies the sound you want to play A value between O no sound and maximum volume The volume command is also affected by the Attenuation setting of the cgopen command the attenuation is a negative value in decibels which sets the volume scaling between the 0 and 1 vaules above the default attenuation being 50db Stereo balance can take any value between 1 left channel only to 1 right channel only A value of zero sets neutral stereo balance Multiplication factor for altering the frequency of the sound Resulting sampling rate must be within the range 100Hz to 100 000Hz E 25 GScnd user manual v1 29 6 November 2008 Getting information about the sound sub system The egsound devs command which lists the available sound devices on your system has already been described Once you have opened the sound device you can get some general information with the cgsound info command gt gt egsound open cgSound v1 29 Compiled Nov 6 2008 Sound library DirectSound v9 DX9 0 Compiled Nov 6 2008 Primary Sound Buffer 2x16x48000 Vol Att 50 0 gt gt cgsound info cgSound Info DirectSound v9 Flags DSCAPS_CERTIFIED This device has been certified by Microsoft DSCAPS_CONTINUOUSRATE All sample rates between 8000Hz and 96000Hz ar
46. not create a file but sets the default name components Defname and Defnumber as used in form 1 described above You may use this command to put all screen dump files in a subfolder by setting Defname appropriately For example if you set Defname to ScreenDumps AA and Defnumber to 1 then files created using form 1 of the command above will be in subfolder ScreenDumps and will be named AAO0001 BMP AA00002 BMP etc Consider the following sequence gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 59 91Hz gt gt mkdir ScreenDump A graphics screen is opened and a new subfolder is created named ScreenDump gt gt cgscrdmp ScreenDump aa 1 The default filename and filenumber for screen dumps are set to ScreenDump aa and 1 gt gt cgscrdmp gt gt cgscrdmp Two files are created in the ScreenDump sub folder named aa00001 BMP and aa00002 BMP The command is slow and takes a moment or two to execute gt gt cgscrdmp ExtraSD A file named ExtraSD BMP is created in the top directory gt gt cgscrdmp Another file is created in the ScreenDump sub folder named aa00003 BMP E 6 GScnd user manual v1 29 6 November 2008 Animation I include here a short section on how to program animations This is a very varied topic and I intend here just to get you started Once you have completed this sections you
47. of standard functions which are used internally by Cogent Graphics as well as other functions which you may find useful One of these functions cogstd sPriority has already been mentioned under the sections on dropped frames and system tuning Short descriptions of a selection of these helper functions follow Identification functions These functions allow you to obtain information about currently installed software the PC being used and to identify the current login It is advisable to save these parameters with your experimental data along with other values which you can obtain from standard Matlab functions such as the date and time of day of the experiment Although you might never use these data they can be extremely useful if you later want to check the details of a particular test n cogstd sDXVer Returns the version number of the currently installed version of DirectX multiplied by 100 s cogstd sMachineID Returns the name of the PC and network ID as a text string s cogstd sOSID Returns the name of the currently installed operating system as a text string s cogstd sUserID Returns the login name of the current user System functions These functions are used for system tuning and obtaining the elapsed time at any point in your experiment You should exercise care when using these functions n cogstd sGetTime t Obtains and or sets the master timer s cogstd sPriority Lev Obtains and o
48. of your monitors Display 2 Dell P1110 on Matrox Graphics Millennium G200 Colors True Color 32 bit 7 1280 by 1024 pixels Use this device as the primary monitor tend my Windows desktop onto this monitor Identify Troubleshoot Advanced Vu VE Remember to click Apply and to reboot the system before using your new settings K 8 GScnd user manual v1 29 6 November 2008 Kyetracker Setup GSend user manual v1 29 6 November 2008 Eyetracker introduction Cogent Graphics can communicate with the departmental eyetrackers using the Applied Science Laboratories ASL model 5000 control unit This manual is not intended to document the use of the eyetracker itself and you should acquaint yourself with the operation of the eyetracker before attempting to use it with cogent The sections which follow deal with setting up the eyetracker and connecting it to your cogent PC This information is correct as of 30 J uly 2002 Eyetracker software The eyetracker requires a separate PC for its operation and there is an ftp site where you can download the latest ASL eyetracker software for it ftp asluser aslftp a s 1 com pub You can download the latest manual for your eyetracker from ftp asluser aslftp a s 1 com pub manuals You should also download the latest version of the eyepos program from the following directory ftp asluser aslftp a s 1 com pub eyepos e5wi
49. only valid in direct colour mode PI Optional If present the sprite will be cleared to this palette index PI represents the palette index and takes values from 0 to 255 This argument is only valid in palette mode SYSMEM Lets you specify that system rather than video memory should be used See the Graphics Drivers section for further details This function creates a new sprite with identification number Key with dimensions Width and Height You may also optionally set the whole sprite to a colour using R G B or to a palette index using PI If you want to use the underlying gprim library functions you may optionally use the returned RASKey value to identify the raster used for this sprite cgmakesprite 5 640 320 Creates a new sprite with ID number 5 and size 640 x 480 units cgmakesprite 5 640 320 1 1 1 Creates a new sprite with ID number 5 and size 640 x 480 units The whole sprite is cleared to colour 1 1 1 white This form is only available in direct colour mode cgmakesprite 5 640 320 12 Creates a new sprite with ID number 5 and size 640 x 480 units The whole sprite is cleared to palette index 12 This form is only available in palette mode G 14 GSend user manual v1 29 6 November 2008 lt x y bd bp gt cgmouse lt sx sy gt Sx sy Optional Set the mouse position to sx sy Sx sy are in local co ordinates as set by cgscale x y bd bp Optional M
50. palette mode and so the StartIndex argument has been added 35 This means that array palette indices from 0 to n will be offset to palette entries 35 to n 35 in the sprite G 12 GSend user manual v1 29 6 November 2008 lt Args gt cgloadbmp Key Filename lt Width Height gt lt SYSMEM gt or lt Args gt cgloadbmp Key Filename StartIndex lt Width Height gt lt SYSMEM gt Args RASKey or RASKey RGBPal RASKey Optional This gives the ID number of the raster that has been created for this sprite The raster is created by the underlying gprim library and should not be required by most users of the GScnd suite RGBPal Optional This returns the palette of the loaded bitmap file if it has one The palette is returned as an array of n x 3 values where n is the palette size Key The identification number to use for this sprite Filename The name of the BMP image file to use for the sprite StartIndex Required in palette mode This gives the starting palette index for the image colours Width Height Optional The width and height of the sprite to create If omitted the sprite will be created so that its pixel size is the same as the supplied image array Otherwise you may optionally set the sprite width and height using these values If either Width OR Height is zero the aspect ratio of the image is used to calculate the value as a ratio from the other non zero dimension
51. port remember to free it using the following command cgsignal Shut E 39 GScnd user manual v1 29 6 November 2008 Matlab scripts GScnd user manual v1 29 6 November 2008 Sample scripts Matlab script files have a m file extension Matlab scripts are text files containing matlab commands which can be run as matlab programs The Cogent Graphics library is a set of additional matlab commands and these can therefore be used in matlab scripts You may download a set of sample scripts from the Cogent Graphics website When you decompress this file you should have a new folder named Samples which contains the matlab sample scripts If you want to run one of these scripts you should run matlab and then change directory to your Samples folder The sample programs were modified in v1 17 to take into account the bug fix of Cogent Graphics timing and so it is worthwhile to make sure you have downloaded the latest version of the sample programs from the website Animation examples There are several animation examples which have direct mode and palette mode variants Some examples give accurate timing information along the top of the screen indicating the total time elapsed the number of frames drawn the refresh rate and the number of dropped frames These examples are therefore of use to check that your version of Cogent is working properly on your machine The timing statistics are shown at the top of the screen P
52. sprite If you specify a negative value for w the image will be flipped horizontally and a negative value for h flips the image vertically Negative values for both w and h rotate the image by 180 This optional value controls translucency and is described in the Alpha blending section of this manual B 24 GScnd user manual v1 29 6 November 2008 The next example creates a sprite and copies it onto the screen gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgpencol 1 1 1 gt gt cgmakesprite 123 100 100 1 0 1 gt gt cgdrawsprite 123 0 0 gt gt cgrect 0 0 6 6 gt gt ceflip 0 0 0 Cogent Graphics display window We open the graphics as usual and set the drawing colour to white 1 1 1 Then we make a sprite with Key 123 100 pixels square initialised to colour 1 0 1 magenta Then we draw the sprite onto the centre co ordinates 0 0 of the offscreen area We also mark the centre of the offscreen area with a small white square of side 6 pixels before the cgflip command You should see that the square magenta sprite is centred under the white square This is because the default alignment is horizontal and vertical centering Now set the alignment mode to left and top gt gt cgalign l t gt gt cgdrawsprite 123 0 0 gt gt cgalign c c gt gt cgrect 0 0
53. sprite to the current destination as set by egsetsprite The destination may be scaled to the specified width and height if required and flipped horizontally and vertically The sprite placement with respect to x y depends on the current alignment mode as set by cgalign cgrotatesprite 1 0 0 30 Copy sprite 1 to the point 0 0 with an anticlockwise rotation of 30 degrees cgrotatesprite 1 0 0 100 200 20 Copy sprite 1 to the point 0 0 with an anticlockwise rotation of 20 degrees The destination rectangle will be stretched if necessary to a width of 100 pixels and a height of 200 pixels The image will also be flipped horizontally as selected by the 100 argument cgrotatesprite 2 0 0 60 70 50 80 120 140 25 Copy a rectangle 60 units wide by 70 units high from position 0 0 in sprite 2 to the co ordinates 50 80 on the current destination and double the width and height to 120 units wide by 140 units high The image is flipped horizontally and rotated anticlockwise by 25 degrees cgrotatesprite 1 0 0 30 0 5 Copy sprite 1 to the point 0 0 with an anticlockwise rotation of 30 degrees and a translucency value of 0 5 G 21 GScnd user manual v1 29 6 November 2008 cgscale or cgscale ScrWidDeg or cgscale SrcWidmm ObsDstmm No arguments Selects pixel co ordinates ScrWidDeg Optional Specifies the width of the screen in degrees of visual angle Selects degrees of visua
54. that only one display is available for use In order to use both displays we must first click on the ghosted out 2 display to select it and then select the Extend my Windows desktop onto this monitor box Display Properties 24 x Background Screen Saver Appearance Web Effects Settings Drag the monitor icons to match the physical arrangement of your monitors 1j 2 Plug and Play Monitor on Matrox Graphics Millennium G200 Colors 256 Colors 640 by 480 pixels I Use this device as the primary monitor IV Extend my Windows desktop onto this monitor Identify Troubleshoot Advanced twee ay Next click on the OK button to accept this setting When we next use cgopen 1 0 0 1 we find that two displays are now available gt gt cgopen 1 0 0 1 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Available devices 1 DISPLAY 1 Matrox Graphics Millennium G200 2 DISPLAY 2 Matrox Graphics Millennium G200 K 4 GScnd user manual v1 29 6 November 2008 However this is not the end of the story Unfortunately hardware accelerated graphics are only available on display 1 so we must use display 1 for our Cogent Graphics and use display 2 for our windows screen To do this select display 2 as shown above and then select Use this device as the primary monitor You will probably also want to adjust the Screen area and Co
55. the display is right In this section I will describe how I have set up the displays on a number of computers in my lab I hope that one of these case studies resembles your setup Recommendations Your multi monitor system should be set up so that all screens are in direct colour mode 15 16 24 or 32 bit colour Otherwise if you use palette mode Cogent Graphics any other screen that is in 256 colour mode will be affected by the Cogent Graphics palette The cgMouse function works correctly with single and dual monitor systems If you have more than two monitors however cgMouse may behave unpredictably To avoid this use the display control panel to position your Cogent Graphics monitor so that it is the right most and bottom most monitor on the system K 1 GScnd user manual v1 29 6 November 2008 Single Monitor Display If you open the Displays control panel and then click the Settings tab you should see the Display Properties dialog box Display Properties This shows the display properties on a system that has only one display When you use the cgopen 1 0 0 1 command to list the available devices you will see a single device listed the Primary Display Driver gt gt cgloadlib gt gt cgopen 1 0 0 1 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Available devices 1 display Primary Display Driver On a system like this you can only open a Cogent Graphics
56. the text is all neatly aligned with the left hand side of the white box along the vertical line x 200 This is because we selected left horizontal alignment The vertical alignment mode was top alignment so the top of the first line was on the y 40 line the top of the white box Now let us try something else B 20 GScnd user manual v1 29 6 November 2008 gt gt cgpencol 1 1 1 gt gt cgalign c c gt gt cgrect 0 0 400 80 gt gt cgpencol 0 0 0 gt gt cgalign r t gt gt cgtext And Caesar s spirit ranging for revenge 200 40 gt gt cgtext With Ate by his side come hot from hell 200 20 gt gt cgtext Shall in these confines with a monarch s voice 200 0 gt gt cgtext Cry havoc and let slip the dogs of war 200 20 gt gt cgflip 0 0 0 And Caesar s spirit ranging for revenge With Ate by his side come hot from he Shall in these confines with a monarch s voice Cry havoc and let slip the dogs of wa This time you should see that the text is all neatly aligned with the right hand side of the white box along the vertical line x 200 This is because we selected right horizontal alignment Notice especially above that the apostrophes within the string must be typed twice as in Caesar s and in monarch s This is to differentiate them from the sign for the end of the string If you make a mistake here and just put a single apostrophe Matlab snivel
57. this with the aid of the task manager and you should be prepared to uninstall programs if necessary Possible candidates for conflict are anti virus software the windows update utility X terminal servers or any program which accesses the network You could also try disabling items from the taskbar such as the system clock and CD writer software icons Potentially any program may be A18 GScnd user manual v1 29 6 November 2008 causing the conflict and you should try to eliminate possible programs by reference to the task manager one by one until the conflict is resolved My final suggestion is to create a clean operating system devoid of unnecessary programs either by reinstalling or by creating a bootable clean operating system on a separate partition If you use a separate partition then you can also disable any hardware that is causing a problem by using the device manager in the System control panel Graphics drivers You may notice some discrepancies between the graphics described in this manual and what actually appears on your PC screen These discrepancies may in some cases be so severe that you cannot create the display that you desire Sorting out these problems requires a good working knowledge of the Windows operating system If you feel unsure about this then seek help from the system manager for your PC Usually these issues can be resolved by following the following steps 1 Ensure that you have installed the latest drive
58. to play 1 x n mono or 2 x n stereo matrix of data values 1 to 1 optional What data size to use 8 or 16 optional The sampling rate for the sound If you do not specify a value cgsound will assume it is the same rate as was specified in the egsound open command optional If you have a soundcard with hardware memory then you can elect to load this sound into hardware memory by specifying 1 for this value Alternatively you may specify 2 to load the sound into software memory Software memory is located in the PC s RAM memory space rather than on the soundcard If no memory type is specified the sound will be loaded into hardware memory if it is available or software memory if not E 22 GScnd user manual v1 29 6 November 2008 Creating a stereo sound matrix You may have noticed from the specification of the egsound matrixSND command that you can specify a stereo sound matrix Here is an example of how to do it First create the sound for the left stereo channel a sine wave of frequency 100Hz duration 1 second at a sampling rate of 48 000Hz using the sinwav function you created earlier gt gt lft sinwav 100 1 48000 Next create the right stereo channel sound 500Hz same duration 1 second same sampling rate 48 000Hz gt gt rgt sinwav 500 1 48000 You can then create a composite stereo matrix gt gt bth Ift rgt You can then load up this matrix into cgsound as follows
59. to the right and vertical y co ordinates increase upwards Two types of units can be used pixels and visual angle The default is to use pixel co ordinates Consider a screen which is 640 pixels wide and 480 pixels high The co ordinates of the centre and corners of the screen will be 320 240 320 240 However you may want to use co ordinates with visual angle as the units One advantage of doing this is that it is easier to ensure that the subject of you experiment sees the same sized stimuli on different occasions perhaps using different displays If you know the screen width in degrees for the set up you want to use you can set that directly or you can set the screen width and observer distance in millimetres Suppose that the screen is 32 degrees wide and 24 degrees high The co ordinates of the centre and corners of the screen will now be You use the cgscale command to set the co ordinate system cgscale On its own selects pixel co ordinates cgscale 32 Sets visual angle co ordinates with the screen width set to 32 degrees cgscale 400 600 Sets visual angle co ordinates with screen width 400mm and observer distance 600mm B 8 GScnd user manual v1 29 6 November 2008 Drawing pen The cgpencol and cgpenwid commands set the colour and line width respectively for subsequent drawing operations cgpenwid 5 Sets the line width to 5 units The units are either in pixels or in degrees depending on which co ordinate sys
60. up Co Modem Options iy afe amp Scanners and Scheduled Sounds and System Users and Cameras Tasks Multimedia Passwords 29 object s Then select the Audio tab of the Sounds and Multimedia Properties and click on the Volume button in the Sound Playback section Sounds and Multimedia Properties 12 x Sounds Audio Hardware r Sound Playback K _ Preferred device aE r Sound Recording Preferred device A Creative B AudioPCI z Volume Advanced r MIDI Music Playback a Preferred device a Microsoft GS Wavetable SW Synth ha Volume About I Use only preferred devices GScnd user manual v1 29 6 November 2008 The Playback Control panel should appear Make sure that the Advanced Controls item on the Options menu is ticked as shown below and then click on the Advanced button of the Playback group E Playback Control Mme Options Help CD Audio MIDI Line In Balance Balance Balance b FM o F el e fa Volume Volume Volume T Mute T Mute T Mute Advanced You should now see Advanced Controls for Playback Control similar but not necessarily identical to the figure below In the Other Controls group you should see a tickable box labelled Spatial as below or maybe Surround sound or some similar classification depending on your soundcard Make sure it is clear not checked as shown below and then click on
61. use the stop_cogent command the priority is returned to normal If you are using the wider cogent distribution this should be all you have to do if you find that you are experiencing significant numbers of dropped frames while using the full cogent distribution you should contact a member of the computer support staff to discuss the problem If you are not using the full cogent distribution you can still raise the priority of your matlab session to a higher class using the following command cogstd spriority high You can return the priority to normal using the following command cogstd spriority normal Typically you would use the command in the following way to run the sample script ballsrgb at a high priority cogstd spriority high ballsrgb cogstd spriority normal If you still find there are significant numbers of frames being dropped you should contact a member of the computer support staff They should then examine your PC and go through the steps described later under System Tuning in order to rectify the problem A17 GScnd user manual v1 29 6 November 2008 Synchronisation When using a CRT Cathode Ray Tube or standard monitor display the cgflip and cgnewpal commands should be synchronized to the top left corner of the display You can check this by running a script to flash the screen black and white and also generate a simultaneous external signal on the parallel port A dual beam oscill
62. used to set the transparent colour of a sprite 5 The following commands can accept a colour as an RGB triplet when in normal graphics mode or as a palette index when in 8 bit mode cgflip cgmakesprite cgpencol 6 cgflipQ now has an immediate mode of operation in palette mode where it does not wait for the VBL This is to allow cgnewpal and cgflip to occur during the same frame cgflip does not return a timestamp in immediate mode 7 The cgloadarray and cgloadbmp commands are only available in direct colour mode A 8 GScnd user manual v1 29 6 November 2008 General description The GScnd suite of graphics functions allows you to present graphic stimuli from within a Matlab program It is provided so that you can design your own experiments for use in clinical testing of patients psychophysics scanning and eeg You should be able to run your experiment on any PC running the Windows operating system You may present images lines rectangles ellipses and polygons with accurate timing and fully integrated within the Matlab environment Installation The GScnd suite can be installed on any PC running the Windows operating system This includes Windows 95 Windows 98 and Windows 2000 In addition DirectX Matlab and Cogent Graphics must be installed on the PC DirectX Installation The PC should also have DirectX installed DirectX allows the program to work with the huge variety of graphics cards that are available
63. user manual v1 29 6 November 2008 cgloadlib lt U gt U Optional This form of the command is used to unload all the graphics libraries from the matlab workspace It should not be necessary to use this command under normal circumstances This function loads all the graphics libraries into the Matlab workspace and makes them available for use You should start every matlab script with this command if you want to use graphics cgloadlib Loads up the graphics libraries into the Matlab workspace ready for use cgloadlib U Unloads the graphics libraries from the Matlab workspace It should not be necessary to use this command under normal circumstances lt RASKey gt cgmakesprite Key Width Height lt R G B or RGB gt lt SYSMEM gt or lt RASKey gt cgmakesprite Key Width Height lt PI gt lt SYSMEM gt RASKey Optional This gives the ID number of the raster that has been created for this sprite The raster is created by the underlying gprim library and should not be required by most users of the GScnd suite Key The identification number to use for this sprite Width Height The width and height of the sprite to create R G B or Optional If present the sprite will be cleared to this colour R G RGB and B represent the red green and blue components of the colour respectively and take values from 0 to 1 The RGB form is a 1x3 array of R G and B values This argument is
64. will be used in subsequent calls to cgtext cgfont Arial 20 Loads up the font named Arial at a size of 20 ready for cgtext cgfont Arial 10 90 Load Arial font size 10 to be drawn vertically upwards cgefreesprite Key Key The name of the font you want to use This function deletes the specified sprite cgfreesprite 2 Deletes sprite number 2 G 9 GSend user manual v1 29 6 November 2008 dat cggetdata DataType Selector or specifically csd cggetdata CSD or gpd cggetdata GPD or ras cggetdata RAS RASKey or dib cggetdata DIB DIBKey or gsd cggetdata GSD or spr cggetdata SPR SPRKey or mvd cggetdaa MVD MOVKey or mve cggetdata MVE MVEKey dat returned A matlab structure containing the data requested DataType A character string requesting a particular type of data CSD requests the CogStdData structure GPD requests the GPrimData structure RAS requests a RAS structure DIB requests a DIB structure GSD requests the GScndData structure SPR requests a Sprite structure MVD requests a MOVData structure MVE requests a Movie structure Selector If a RAS DIB Sprite MOVData or Movie structure is requested this value contains the Key identifier for the specific structure required This function returns data f
65. your stimulus and make appropriate compensation for it So why not use this form of cgopen all the time The answer is that while this special graphics mode is much faster for alpha blending it is also slower for other operations such as cgdrawsprite cgblitsprite and cgflip so you should only use it when you really need it Alpha blending performance also depends heavily on the speed of the processor that you are using I would recommend that you only use alpha blending on a 1GHz PC or a faster PC If you find that your stimulus is almost running fast enough but not quite then it will probably run well on a more powerful PC Remember too that you can get an apparent boost in performance by using a slower refresh rate if your stimulus performs poorly at a refresh rate of 85Hz you may find switching to 60Hz cures the problem Finally you may find that you can boost performance by using a different bit depth for the screen Try using 16 bits in the cgopen command for example D 3 GScnd user manual v1 29 6 November 2008 Alpha blending programmer s notes This section is provided for the benefit of graphics programmers Do not worry if you do not understand it DirectDraw does not support alpha blending more specifically I have not found any graphics card drivers that support the DDFXCAPS_BLTALPHA special effects property So alpha blending must be done by the processor in a custom written function With up to date fast processors the alp
66. 0 1 gt gt cedraw 160 120 160 120 gt gt cedraw 160 120 160 120 gt gt cgpencol 1 1 1 gt gt cgdraw 90 0 gt gt cgdraw 90 0 gt gt cgdraw 0 70 gt gt cgdraw 0 70 gt gt cgpencol 0 0 0 gt gt cgfont Arial 14 gt gt cgtext To sleep perchance to dream 0 0 The lines above employ all the drawing commands described up to now apart from one the cgdrawsprite command We start by drawing a red rectangle with cgrect then draw a green filled ellipse with cgellipse Then we draw a yellow triangle with cgpolygon All these figures are centred on the centre of the sprite Next we draw blue lines across the principal diagonals of the sprite using egdraw and we use cgdraw again to draw four white dots B 26 GScnd user manual v1 29 6 November 2008 Finally we draw some text using cgtext The point of this rather tedious procedure is to demonstrate that all these commands can be redirected to the sprite we have selected sprite 78 Now select the offscreen area as the destination and clear it with a cgflip command The screen should remain black at this point This is just to convince you that the offscreen buffer really is clear at this point gt gt cgsetsprite 0 gt gt ceflip 0 0 0 Now we draw sprite 78 into the offscreen area with a cgdrawsprite and display it gt gt cgdrawsprite 78 0 0 gt gt ceflip 0 0 0 Cogent Graphics display window Now for the cgdrawsprite command
67. 0 with width 320 units and height 240 units Position is dependent on the cgalign command settings G 18 GScnd user manual v1 29 6 November 2008 cgpolygon x y lt X Offset Y offset gt x y These arrays hold the co ordinates of the vertices corners of the polygon There must be equal numbers of elements in arrays x and y XOffset Yoffset Optional Offset to be applied to the x y co ordinates This provides a quick way of moving the polygon without having to adjust all the x y array elements Draws a filled polygon on the current destination as set by cgsprite in the current drawing colour as set by cgpencol x 10 0 15 Draw a filled polygon in the current drawing colour The y 0 20 5 polygon has the following vertices cgpolygon x y 10 0 0 20 15 5 x 10 0 15 Draw a filled polygon in the current drawing colour offset y 0 20 5 by 10 units in the x axis and 20 units in the y axis The cgpolygon x y 10 20 resulting polyon has the following vertices 0 20 10 40 5 25 G 19 GSend user manual v1 29 6 November 2008 cgrect lt x y w h lt Col gt gt x y w h Optional Position x y width w and height h of the rectangles If omitted fill the whole destination The position of the rectangle is defined by x y but is modified by the cgalign setting Col Optional The colours for the rectangles When in palette mode Col must be an
68. 000 gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgloadarray 1 3 3 Pix Val PalRGB 20 240 240 gt gt cgflip 0 gt gt cgdrawsprite 1 0 0 gt gt cgflip 0 gt gt cgcoltab 20 PalRGB gt gt cgnewpal Cogent Graphics display window Once again the familiar 3 x 3 colour square appears this time on a palette mode display Although the original array uses palette entries O to 8 to define the image we have read it in starting at palette entry 20 so it uses entries 20 to 28 in our display palette We then use the cgcoltab and cgnewpal commands to set the display colours to match the array palette GScnd user manual v1 29 6 November 2008 Drawing multiple items You should first work through the Drawing multiple items in the Direct Colour section before starting this description which specifically addresses differences between direct and palette mode when drawing multiple items Drawing multiple items in palette mode is very similar to the method used in direct colour mode If the items are all to be drawn in the same colour there is essentially no difference Consider the following example gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 74 59Hz gt gt cgcoltab 0 0 00 100 010 110 001 101 011 111 gt gt cgnewpal
69. 08 Next type the cgvers command gt gt cgvers CogStd mex v1 29 Compiled Nov 6 2008 GPrim mex v1 29 Compiled Nov 6 2008 GLib not set by ginit GScnd cgdata mex v1 29 Compiled Nov 6 2008 GScnd cgvers mex v1 29 Compiled Nov 6 2008 GScnd cgalign mex v1 29 Compiled Nov 6 2008 GScnd cgcoltab mex v1 29 Compiled Nov 6 2008 GScnd cgdraw mex v1 29 Compiled Nov 6 2008 GScnd cgdrawsprite mex v1 29 Compiled Nov 6 2008 GScnd cgellipse mex v1 29 Compiled Nov 6 2008 GScnd cgflip mex v1 29 Compiled Nov 6 2008 GScnd cgfont mex v1 29 Compiled Nov 6 2008 GScnd cgfreesprite mex v1 29 Compiled Nov 6 2008 GScnd cgloadarray mex v1 29 Compiled Nov 6 2008 GScnd cgloadbmp mex v1 29 Compiled Nov 6 2008 GScnd cgmakesprite mex v1 29 Compiled Nov 6 2008 GScnd cgnewpal mex v1 29 Compiled Nov 6 2008 GScnd cgopen mex v1 29 Compiled Nov 6 2008 GScnd cgpencol mex v1 29 Compiled Nov 6 2008 GScnd cgpenwid mex v1 29 Compiled Nov 6 2008 GScnd cgpolygon mex v1 29 Compiled Nov 6 2008 GScnd cgrect mex v1 29 Compiled Nov 6 2008 GScnd cgscale mex v1 29 Compiled Nov 6 2008 GScnd cgsetsprite mex v1 29 Compiled Nov 6 2008 GScnd cgshut mex v1 29 Compiled Nov 6 2008 GScnd cgtext mex v1 29 Compiled Nov 6 2008 GScnd cgtrncol mex v1 29 Compiled Nov 6 2008 GScnd cgphotometer mex v1 29 Compiled Nov 6 2008 GScnd cggetdatamex v1 29 Compiled Nov 6 2008 GScnd cgmouse mex v1 29 Compiled Nov 6 2008 GScnd cgkeymap mex v1 29 Compiled Nov 6 2008 GScnd cgopenmovie mex v1 29 Compiled Nov 6 2008 GS
70. 1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgscale 30 gt gt cgpencol 1 0 0 gt gt cgrect 0 0 20 20 We next set the drawing colour to blue and draw another square side 10 degrees centred on a point 5 degrees up and 5 degrees right of the middle of the screen These co ordinates have been chosen so that the top right corners of both squares coincide We then use th flip command to see what we have drawn gt gt cgpencol 0 0 1 gt gt cgrect 5 5 10 10 gt gt cgflip Cogent Graphics display window GScnd user manual v1 29 6 November 2008 The rectangles just drawn were centred on the x and y co ordinates This is because the default alignment mode when we call cgopen is to centre horizontally and vertically However we can alter the alignment of the rectangles using the cgalign command gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgscale 30 gt gt cgalign r c gt gt cgpencol 1 0 0 gt gt cgrect 0 0 10 10 gt gt cgalign l c gt gt cgpencol 0 0 1 gt gt cgrect 0 0 10 10 gt gt cgflip Here we set the alignment mode to right centre with the cgalign r c command and draw a red square with its right edge on 0 0 the centre of the screen Then we set the alignment mode to
71. 50 0 150 0 gt gt cgdraw 0 100 0 100 gt gt cgpencol 10 gt gt cefont Arial 200 gt gt cgtext Black 0 0 gt gt cgflip 10 Cogent Graphics display window We have cleared the whole display to palette index 17 white and then drawn an ellipse in palette index 11 red Then we drew a cross in palette index 12 green and then some text in palette index 10 black Finally we issued a cgflip command to display our graphics and set the offscreen area to palette index 10 black C 5 GScnd user manual v1 29 6 November 2008 The drawing commands cgdraw cgrect and cgellipse are similar whether in palette mode or in direct mode as seen above but there is a difference when it comes to drawing multiple items with different colours for each item You should read Drawing multiple items later on in this section to find out how the commands change when in palette mode Now let us continue with some other drawing commands gt gt x 50 0 50 gt gt y 25 61 25 gt gt cgpencol 13 gt gt cgpolygon x y gt gt cgpencol 17 gt gt cgdraw 90 0 gt gt cgdraw 90 0 gt gt cgdraw 0 70 gt gt cgdraw 0 70 gt gt cgflip First we set up a triangular polygon and draw it in palette index 13 yellow and then we draw four dots in palette index 17 white Now let us change these colours gt gt cgcoltab 10 1 0 0 gt gt cgcoltab 13 0 1 0 gt gt cgcoltab 17 0 0 0 gt gt cgnewpal
72. 6 red offscreen is 7 green Onscreen is now 7 green offscreen is 8 yellow Onscreen is now 8 yellow offscreen is 9 blue Onscreen is now 9 blue offscreen is 10 magenta Onscreen is now 10 magenta offscreen is 11 cyan Onscreen is now 11 cyan offscreen is 12 white Onscreen is now 12 white offscreen is 5 black At this point the display is filled with palette index 12 which is currently set to white Let us now change the colour to yellow gt gt cgcoltab 12 1 1 0 gt gt cgnewpal C3 GScnd user manual v1 29 6 November 2008 cgnewpal and cgflip synchronisation In order to avoid flickering the cgnewpal and cgflip commands are usually both synchronised with your monitor display Each command waits until the end of the current display frame before changing the palette or copying the offscreen area to the visible screen respectively This could cause a problem if you wanted to complete both actions on the same display frame To get around this the cgflip command can operate in immediate mode in which case it does not wait for the end of frame period You can therefore issue the following command sequence S cgnewpal cgflip T The cgnewpal command above is synchronised to the end of frame period and the timestamp for the display is taken at that command The cgflip command takes place immediately afterwards It is not possible to obtain a timestamp for the cgflip command in immediate mode However your graph
73. 6 6 gt gt cgflip 0 0 0 B 25 GScnd user manual v1 29 6 November 2008 Some graphics cards cannot make a sprite which is wider than the screen using video memory and they have to use system memory for the sprite instead If this happens you will get a warning message on the matlab console gt gt WRN GPrim gAddRAS System memory required for wide sprite Drawing into sprites You can select a sprite as the destination for drawing commands using the cgsetsprite command From then on all drawing commands will occur in that sprite Remember to reset the destination back to the offscreen area though when you are finished by issuing a cgsetsprite 0 command cgsetsprite Key This command selects the sprite with ID Key for subsequent drawing operations If Key is zero then the offscreen area will receive drawing operations This next exercise creates and selects a sprite that is one quarter the size of the screen gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgmakesprite 78 320 240 0 0 0 gt gt cgsetsprite 78 Then we perform some graphics commands gt gt x 50 0 50 gt gt y 25 61 25 gt gt cgpencol 1 0 0 gt gt cgrect 0 0 160 120 gt gt cgpencol 0 1 0 gt gt cgellipse 0 0 160 120 f gt gt cgpencol 1 1 0 gt gt cgpolygon x y gt gt cgpencol 0
74. 8 000 Then you should open the sound device as follows gt gt cgsound open 1 16 48000 And you should ensure that all your sounds follow this format 2 The cgsound frq Key Factor command seems to work best when you use values for Factor which are less than 1 I have found that there can be a substantial time delay if you set Factor to be greater than 1 If you need to synchronize sounds with something else such as visual displays and it is important to have a synchronisation of better than 100mS then it is imperative that you check the synchronisation physically and independently using some arrangement such as a dual beam oscilloscope to check the delay in implementing sound commands on your PC You may find that the delay is negligible for your experiment and can be ignored or you may find that there is a constant delay which you can then take into account Or you may decide that cgsound cannot deliver the performance you require and you should then investigate alternative methods of generating your sound stimulus You might for example build a customised electronic circuit to generate your sounds and have it triggered by a signal output from the PC You should at least be aware that cgsound has limitations in performance and you should have some idea of how they might affect your experiment You should also be aware that using sound may introduce some variability into the Cogent Graphics frame rate Individual frames may be off b
75. Are defined from ellipse with starting angle 10 degrees and end angle 90 degrees Now try the following example gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgpencol 1 0 0 gt gt cgpenwid 20 gt gt cgarc 0 0 400 400 45 90 gt gt cgflip 0 0 0 Cogent Graphics display window If you are using Windows 95 98 ME you will notice that the arc has rounded ends If this is a problem you will have to upgrade to a more recent version of Windows B 14 GScnd user manual v1 29 6 November 2008 We have used cgpencol to set the drawing colour to red and cgpenwid to set the line width to 20 Then we used cgare to draw an arc of an ellipse The ellipse was centred on 0 0 with width 400 and height 400 i e a circle of radius 200 We drew an arc from starting angle 45 degrees to ending angle 90 degrees In a similar way we can draw a filled sector gt gt cgpencol 0 1 0 gt gt cgpenwid 20 gt gt cgarc 0 0 400 400 90 135 S gt gt cgflip 0 0 0 Cogent Graphics display window You should also read Drawing multiple items later on in this section so you know how to draw many arcs or sectors efficiently with a single command B15 GScnd user manual v1 29 6 November 2008 Polygons You can use the cgpolygon command to draw filled polygons The current drawing colour is used
76. It is important to set the display on your PC correctly for each tutorial because the sub window mode used in many of the examples cannot change the display Al4 GScnd user manual v1 29 6 November 2008 mode for you You should select Control Panel from the Start menu of Windows and then double click the Display control panel Display Then choose the Settings tab In the colours menu you can select from 32 bit or 24 bit which result in direct colour modes or you can select 256 Colors sic for palette mode The 16 bit setting can be selected too and will result in a direct colour mode but the colour definition is inferior to 24 and 32 bit modes When choosing between 24 and 32 bit colour modes you may find that 32 bit mode is perhaps unexpectedly faster than 24 bit mode In general my advice is to select 32 bit for direct colour mode and 256 Colors for palette mode Display Properties 2 x Background Screen Saver Appearance Effects Web Settings Display SONY Multiscan 20se on Matrox MGA Millennium r Colors Screen area True Color 32 bit Less Pa More 1152 by 864 pixels Advanced A15 GSend user manual v1 29 6 November 2008 Display timing There are three subjects to consider regarding display timing display complexity dropped frames and synchronization Please read all three following sections if your experiment requires timing accuracy
77. Matlab to search this new folder for commands Run matlab and then select Set Path from the File menu lt Student Edition gt MATLAB Command Window Open selection ne of these commar The MATLAB Path dialog will appear The exact appearance will vary depending on your version of Matlab Set Path fe EAMATLABEGp1itoolboximatlabigeneral a G EAMATLABEp1itoolboximatlablaps EMATLAB6Gp1itoolboximatlabilang EAMATLAB6p1 itoolhoximatlablelmat E MATLAB6p1itoolboximatlablelfun G EAMATLABE6p1itoolboxtmatlabispectun EAMATLAB6Gp1itoolboximatlabimatfun SQ EAMATLABE6p1itoolboxtmatlabidatafun EAMATLAB6p1 itoolboximatlabiaudio EAMATLAB6p1itoolboximatlabipolyfun A13 GScnd user manual v1 29 6 November 2008 Click on the Add Folder button select the MATLAB toolbox CogGphTB folder and click OK Browse for Folder 2 x Add Folder to Path CogGphTs notebook H sys H toolbox H stats zi cma You should make sure it is at the top of the list if necessary select it and then click on the Move To Top button and finally click the Save button This will complete the Cogent Graphics installation on your PC gprim and CogStd The GScnd suite of commands uses two underlying libraries named gprim and CogStd It should not be necessary for you to use these libraries Palette mode Most of the time you will probably write Cogent Graphics scripts using direct colour m
78. Pars cgtouch calibrate Later on you can set the same calibration parameters without having to repeat the calibration in the following way gt gt cgtouch calibrate TouchPars Remember though that a calibration is only valid for a particular screen resolution and refresh rate and if you use a different display resolution or refresh rate you should recalibrate However if you are always using the same display resolution in your script you can set up your touchscreen calibration in the following way format short e cgopen TouchPars cgtouch calibrate The format command ensures that numbers are displayed with the correct number of significant digits and the second line with no trailing semi colon causes the returned array of calibration parameters to be output to the matlab console TouchPars 2 6407e 004 2 6375e 004 4 6467e 002 1 0279e 000 Incidentally if you want to reset the number format to the default matlab setting simply type format without any extra arguments on the matlab console command line You could then modify your script in the following way to make it fully automatic cgtouch calibrate 2 6407e 004 2 6375e 004 4 6467e 002 1 0279e 000 E 35 GScnd user manual v1 29 6 November 2008 Touchscreen co ordinates The following command obtains the current touchscreen co ordinates xyz cgtouch touch The returned array xyz is a n x 3 matlab arr
79. Prints out version information for all GScnd commands on the console cgvers U Prints out a full usage guide for all GScnd commands on the console cgvers C Prints out a copyright message for all GScnd commands on the console G 27 GScnd user manual v1 29 6 November 2008 cgsound functions GScnd user manual v1 29 6 November 2008 cgsound Devs Lists the sound devices available on the system cgsound Devs Lists available sound devices cgsound Free Key Key The ID number of the SND buffer to free Deletes a SND buffer and releases the resources it uses so they are free to be used elsewhere cgsound Free 1 Frees the SND buffer number 1 cgsound Frq Key Factor Key The ID number of the SND buffer to modify Factor Multiplication factor for new playing frequency Changes the playing frequency of a SND buffer You enter the factor by which to alter the playing frequency There are limits to the value you can specify for Factor The final playing frequency may range from 100 to 100 000 samples per second If the original sampling frequency set when you call cgsound MatrixSND or cgsound WavFilSND was 2 000 samples per second then you may set Factor to any value between 100 2 000 0 2 to 100 000 2 000 50 You may notice a decrease in performance if you use a value for Factor greater than 1 cgsound
80. Program equil vN NN J Romaya WDCN UCL The large upper rectangular region flashes alternately between two colours named Colour 1 and Colour 2 Underneath there are controls for colour 1 on the left and for colour 2 on the right There is a square showing the colour and then four slider controls for red green blue and grey respectively Move the mouse into the triangle boxes and then press a mouse button to increase or decrease a colour level Use the left mouse button to change a step per click or the right button for continuous change The big triangle changes the value in steps of 10 and the small triangle in steps of 1 Colour levels are displayed as a number from 0 to 1 by default but if you select 255 Mode they are displayed as numbers from 0 to 255 You may also change the flash period in multiples of 2 frames Only even periods are possible because the program displays colour 1 for n frames and then colour 2 for n frames giving a period of 2n You should aim to reduce the flicker to a minimum Sometimes it helps to desaturate the colour by adding grey as it can be hard to find the equiluminance point with a highly saturated colour To stop the script press the Esc key F 10 GScnd user manual v1 29 6 November 2008 Drivertest This utility tests your PC for various graphics card driver bugs Correct Correct wo identical bo above each containing the you may need to apply the MIRROR driver fix to contin
81. REQUENCY Frequency control supported DSBCAPS_CTRLPAN Pan control supported DSBCAPS_CTRLVOLUME Volume control supported DSBCAPS_LOCHARDWARE Hardware buffer DSBCAPS_STATIC Static buffer Memory size 1411200 bytes Channels 2 BitsPerSample 16 SamplesPerSecond 44100 GScnd user manual v1 29 6 November 2008 Finally you can retrieve a sound as a matlab workspace array gt gt mat sps bps cgsound GetSND 7 This commands loads mat with the sound values array sps is the samples per second and pps is the bits per second Optimising sound performance In general the sound system under Windows has a delay of about 20 100mS which cannot be reduced because it is built in to the DirectSound libraries used by the operating system Bearing this in mind you should also follow the guidelines below to ensure that delays are kept to a minimum 1 Try to make all your sounds have formats which match the playback format The playback format is set when you make the call to open the sound system cgsound open Channels BitsPerSample SamplesPerSecond Device A ttenuation The critical values here are what you choose for Channels BitsPerSample and SamplesPerSecond Ideally you should be able to plan to make all your sounds follow the same format whether they come from wav files or from Matlab workspace arrays Let us suppose that you choose a master format of Channels 1 mono sound BitsPerSample 16 SamplesPerSecond 4
82. SND 9 to be 0 5 If you are using the default attenuation in the cgsound Open command 50db then the nominal attenuation for a volume of 0 5 will be 25db cgsound WavFilSND Key WavFilNam lt Memory gt Key The ID number of the SND buffer to create WavFilNam Name of wav file to load Memory Optional If your soundcard has its own memory area you can specify l to force the sound to be stored there Otherwise specify 2 to use PC memory If you do not specify a value here the sound will be stored in the soundcard s memory unless there is none available in when it will use PC memo Load up a sound from a wav file Specify Memory 1 if you want the sound to be loaded into the memory area of your soundcard if it has one cgsound WavFilSND 2 Sound1 wav 1 Create a new SND buffer number 2 with the sound in file Soundl wav The sound will be stored in the soundcard s dedicated memory area cgsound WavFilSND 3 Sound2 wav Create a new SND buffer number 3 with the sound in file Sound2 wav The sound will be stored in the soundcard s dedicated memory area if possible otherwise it will be stored in PC memory H 5 GScnd user manual v1 29 6 November 2008 CogStd helper functions GScnd user manual v1 29 6 November 2008 Introduction A library named CogStd is also included with the Cogent Graphics libraries This library provides a number
83. al Make sure that you are familiar with the operation of your eyetracker before you attempt to interface with your cogent PC L 3 GScnd user manual v1 29 6 November 2008 Connecting to your cogent PC Your cogent PC should be also be connected to the ASL model 5000 control unit using the PC serial port usually a male 9 pin D type connector on the back of the PC This connects to a similar male 9 pin D type connector on the back of the ASL model 5000 control unit labeled Serial Out 2 The cable wiring between these connectors should be identical to the other cable Pin Pin 2 2 3 3 5 5 The wiring should be exactly as shown above with pins 2 3 and 5 connected to corresponding pins on both connectors i e no reversal of pins 2 and 3 Once you have connected your cogent PC to the ASL model 5000 and you have started the e5Win exe program you should check that your cogent PC is connected properly You should download the file spv9906 exe from the ASL website at ftp asluser aslftp a s 1 com pub spviewer Copy this file into a new folder and expand it You should then run the file Viewer exe E5000 Serial data output viewer COM port COM Baudrate 57600 x Output format C Stream OnDemand Normal Uncalibrated Target Points Pupil Diameter Scene Plane Horizontal Position Vertical Position Single Continuous Stop Clear ICOM
84. alibrate it yourself You can also set the stereo balance gt gt cgsound pan 1 1 Setting the pan to 1 outputs the left sound channel only You should have no output from your right speaker See the notes below under Troubleshooting Sound if you get output from your right speaker Setting pan to 1 outputs the right sound channel only gt gt cgsound pan 1 1 GScnd user manual v1 29 6 November 2008 To get a neutral stereo balance with sound from both channels set pan to zero gt gt cgsound pan 1 0 You can also set intermediate values between 1 and 1 to achieve intermediate stereo balance Finally you can modify the playing frequency of the sound The following command doubles the frequency gt gt cgsound frq 1 2 You can halve the frequency using a similar command with 0 5 rather than 2 as the argument gt gt cgsound frq 1 0 5 There are limits to the value you can apply In our case the original frequency of the sound was 48 000Hz You can only set values such that the resulting sampling rate of the sound falls within the limits of 100Hz to 100 000Hz 100 48 000 0 002083 100 000 48 000 2 083 If you try to set a value outside 0 002083 to 2 083 you will get an error message gt gt cgsound frq 1 3 ERR cgSound Frq SampRate 48000 Factor must be 0 0021 to 2 083 You can select the original frequency with a 1 gt gt cgsound frq 1 1 This section has
85. align If Alpha is defined a translucent copy is made cgblitsprite 1 0 0 60 70 50 80 Copy a rectangle 60 units wide by 70 units high from position 0 0 in sprite 1 to the co ordinates 50 80 on the current destination cgblitsprite 1 0 0 60 70 50 80 Copy a rectangle 60 units wide by 70 units high from position 0 0 in sprite 1 to the co ordinates 50 80 on the current destination The image is flipped vertically cgblitsprite 2 0 0 60 70 50 80 120 140 Copy a rectangle 60 units wide by 70 units high from position 0 0 in sprite 2 to the co ordinates 50 80 on the current destination and double the width and height to 120 units wide by 140 units high cgblitsprite 2 0 0 60 70 50 80 120 140 Copy a rectangle 60 units wide by 70 units high from position 0 0 in sprite 2 to the co ordinates 50 80 on the current destination and double the width and height to 120 units wide by 140 units high The image is flipped horizontally cgblitsprite 1 0 0 60 70 50 80 0 25 Copy a rectangle 60 units wide by 70 units high from position 0 0 in sprite 1 to the co ordinates 50 80 on the current destination A translucent copy is performed with the result being 75 of the current destination and 25 of the source sprite number 1 G 3 GSend user manual v1 29 6 November 2008 cgcoltab PI R G B or cgcoltab PI RGB PI Palette index for first colour This argument can take values from 0 to 255 R
86. all the arguments and Device must be the last one Otherwise you can specify as many arguments as you wish in any order The Attenuation value applies to the cgsound vol command which is described below in the section Modifying sounds as they play When you are finished with the sound device you should shut it gt gt cgsound shut GScnd user manual v1 29 6 November 2008 Playing a sound file You should have downloaded an example sound file named Soundl wav when you downloaded this document You should use this file for this exercise First open the sound device gt gt cgsound open cgSound v1 29 Compiled Nov 6 2008 Sound library DirectSound v9 DX9 0 Compiled Nov 6 2008 Primary Sound Buffer 2x16x48000 Vol Att 50 0 Secondly load the Sound1 wav file into sound buffer number 6 gt gt cgsound WavFilSND 6 Sound1 wav Thirdly play the sound gt gt cgsound play 6 This has introduced two new commands WavFilSND and play cgsound WavFilSND Key Filename lt memory gt Key Your identification number for this sound This can be any number from 1 to 10 000 You use this Key to identify this sound If a sound with this identification number already exists then this new sound will replace it Filename The name of the wav file containing the sound memory optional If your soundcard has hardware memory then you can elect to load this sound into hardware memory by specifying for this
87. and that you may have on your PC DirectX is a Microsoft product and is distributed free of charge from the following web address http www microsoft com downloads If you have Windows 2000 installed on your PC it should not be necessary to install DirectX However you will need it if you have Windows95 or Windows98 When you reach the Microsoft download URL mentioned above select the operating system you have on your PC either Windows 95 or Windows98 and then select the Keyword Search selection button Type DirectX into the Keywords box and start the search A bewildering array of possibilities will appear for you to choose from such as those shown below l DirectX 9 0a End User Runtime Microsoft DirectX 9 0a End User Runtime will update your current version of DirectX the core Windows technology that drives high speed multimedia and games on the PC Date 3 26 2003 Popularity 1 English download ae DirectX 8 0a for Windows 95 98 and Me Tap into the fun on your computer with this update to the multimedia system services for Microsoft Windows Microsoft DirectX 8 0a delivers fast performance for DirectX enabled games and other rich media software programs Date 2 5 2001 Popularity 4 English download You should select the most recent of the items named DirectX n nn Runtime although currently Cogent is only guaranteed to run under DirectX9 In the case shown above you would select DirectX 9 0a If you are in a
88. at value in seconds e g gt gt cogstd sGetTime 0 resets the master time value to 0 0 seconds Note that a call to cgopen resets the master time to 0 0 seconds 1 2 GScnd user manual v1 29 6 November 2008 s cogstd sMachineID Arguments This function takes no arguments Return values S The function returns the name and IP address if available of the PC you are using as a text string Description Use this function to get the name and IP address of the PC you are using gt gt s cogstd sMachineID S ignoramus 109 34 56 102 s cogstd sOSID Arguments This function takes no arguments Return values S The function returns the name of the currently installed operating system as a text string Description Use this function to get the name of the operating system on your PC Operating systems issued post February will not be recognised gt gt s cogstd sOSID Ss 4 Microsoft Windows 2000 Service Pack 3 Build 2195 I 3 GScnd user manual v1 29 6 November 2008 s cogstd sPriority Lev Arguments Lev The prority level to use for your experiment choose NORMAL HIGH or REALTIME or omit this argument to just return the current level Return values S The function returns the previous priority level NORMAL HIGH or REALTIME Description Use this function with caution and only if you need to You may need to set a
89. at you want to check sound or display synchronisation You can generate a TTL level signal OV to 5V using the parallel port but that requires installation of a driver Alternatively you can use cgsignal to generate signals on the serial port 12V to 12V Remember that these are not TTL level signals and do not try to use them in that way They can however be used as input for an oscilloscope to check timing and synchronisation The DTR and RTS serial port pins are used to generate signals Most PCs nowadays have a D type 9 way male serial port The signals appear on the following pin numbers DTR pin4 GND pin5 RTS pin7 A convenient way to make a signal cable to connect to your PC is to use a 9 way female D type socket available from RS part number 465 362 or Farnell part number 150 730 Socket view Solder bucket view It is also handy to have a suitable casing such as RS part number 483 792 or Farnell part number 609 109 eh Ij g4 TE E 37 GScnd user manual v1 29 6 November 2008 You should make the connections shown below to get two outputs from the serial port Output consisting of GND and DTR and Output2 consisting of GND and RTS Serial port connector solder bucket view Output Output2 How you make up Output1 and Outputz2 is up to you I use BNC connectors RS part 455 624 which plug directly into our oscilloscope E 38 GScnd user manual v1 29 6 November 2008 Generating si
90. ave an animation loop in the script the while loop from lines 10 to 18 in which we draw each successive movie frame of our animation Each frame consists of a white circle of variable size As the animation progresses the circle increases in size until it reaches the edge of the screen and then it starts again at a point For each frame the size of the circle is defined by the variable siz which is modified as necessary during each pass of the loop This loop carries on ad infinitum until the user presses the escape key This example now shows the general principles of animation using Cogent Graphics 1 Create a Matlab script for your animation 2 Do some initial preparation for the animation initialize some variables prepare some graphics etc 3 Have an animation loop in your script 4 During each pass of the loop write a new movie frame and then make it visible Make sure that each frame differs from the previous frame in the appropriate way 5 Have some mechanism for ending the loop and returning control back from your script E 8 GScnd user manual v1 29 6 November 2008 Using the photometer Cogent Graphics can communicate with the departmental photometer the PhotoResearch PR 650 Spectra Colorimeter The photometer should be connected to a serial port on the PC The PR 650 comes with a black communication cable which plugs into a circular 12 pin socket on the PR 650 and has a D type 25 way socket on the oth
91. ay where n is the number of points currently touched n 0 There are no touches on the screen n 1 There is a single touch on the screen n 2 There are two touches on the screen The xyz values returned are as follows xyz 1 x co ordinate in cogent graphics screen co ordinates xyZ 2 y co ordinate in cogent graphics screen co ordinates xyz 3 Amount of pressure exerted 0 to 1 Not all touchscreens are capable of returning the pressure value and only touchscreens fitted with the 2500G gaming controller are capable of returning two points Here are some examples of returned xyz arrays with interpretations xyz Empty matrix 0 by 3 No touch xyZ 78 44 0 6078 Single touch Co ordinates 78 44 Pressure 0 6078 xyz 296 61 0 7234 Double touch Point 1 296 61 Pressure 0 7234 45 148 0 3245 Point 2 45 148 Pressure 0 3245 If there is no Cogent Graphics screen but there is a low level gprim screen then gprim screen co ordinates are returned Otherwise if there is no graphics window open at all the x and y positions are returned in the range O to 1 with 0 0 in the bottom left corner of the screen The xyz co ordinates work correctly even in sub windowed mode and even if you subsequently move the sub window after a calibration E 36 GScnd user manual v1 29 6 November 2008 Making a signal cable Sometimes it may be useful to generate a signal coming out from your PC The most likely requirement for this is th
92. ay window Here we have defined an array PalInd which contains a random sequence of 1000 numbers taking values from 1 to 7 This is used to define the palette indices for the rectangles In a similar way we can draw hollow ellipses gt gt cgflip 0 gt gt cgellipse x y w h PalInd gt gt ceflip 0 Cogent Graphics display window C 13 GScnd user manual v1 29 6 November 2008 Filled ellipses gt gt cgflip 0 gt gt cgellipse x y w h PalInd f gt gt cgflip 0 Cogent Graphics display window Filled sectors use larger width and height gt gt w 1 1000 1 rand 1 1000 49 gt gt h 1 1000 1 rand 1 1000 49 gt gt a1 1 1000 rand 1 1000 360 gt gt a2 1 1000 rand 1 1000 360 gt gt cgflip 0 gt gt cgarc x y w h al a2 PalInd S gt gt cgflip 0 Cogent Graphics display window 7 C 14 GScnd user manual v1 29 6 November 2008 Holow arcs gt gt cgflip 0 gt gt cgarc x y w h al a2 PalInd gt gt ceflip 0 Lines gt gt x2 x 30 gt gt y2 y 30 gt gt cgflip 0 gt gt cgdraw x y x2 y2 PalInd gt gt cgflip 0 Cogent Graphics display window C 15 GScnd user manual v1 29 6 November 2008 Or dots gt gt ceflip 0 gt gt cgdraw x y PalInd gt gt cgflip 0 Cogent Graphics display window C 16 GScnd user manual v1 29 6 November 2008 Movies Movies are not currently supported in pa
93. b 0 1 1 1 You can also set several colours at the same time with the cgcoltab command gt gt r 01010101 gt gt g 0011001 1 gt gt b 00001111 gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 85 03Hz gt gt cgcoltab 5 r g b gt gt cgnewpal Or using a single array gt gt rgb 000 100 010 110 001 101 011 111 gt gt cgcoltab 5 rgb Co GSend user manual v1 29 6 November 2008 In both of the above examples we have set up eight palette entries using the r g and b arrays starting at entry number 5 OMAANDMN 10 11 12 0 0 0 1 0 0 0 1 0 1 1 0 0 0 1 1 0 1 0 1 1 1 1 1 black red green yellow blue magenta cyan white Now let us use the cgflip command to set the display surface to each of the palette indices in turn Note that in palette mode the cgflip command takes a single palette index rather than the RGB triplet which it uses in direct colour mode Remember that the cgflip command clears the offscreen buffer to the index so the display actually lags behind the command by one command as shown below in italics gt gt cgflip 5 gt gt cgflip 6 gt gt cgflip 7 gt gt cgflip 8 gt gt cgflip 9 gt gt ceflip 10 gt gt cgflip 11 gt gt cgflip 12 gt gt cgflip 5 Onscreen is now 0 black offscreen is 5 black Onscreen is now 5 black offscreen is 6 red Onscreen is now
94. been additional support for 8 bit graphics and the completion of various previously missing functions The cgLoadArray function has changed substantially and you should consult this manual in further detail about this function 1 The cgColTab matlab call now accepts a single n x 3 RGB argument as well as separate R G and B arguments 2 The cgFlip command has been extended so that you can simply wait until the start of the next display frame without doing a pageflip 3 The cgLoadArray command now takes a single PixVal argument rather than the previous separate R G and B arguments It is also possible to define a palette based array as well as a direct mode rgb array and arrays can now be loaded in palette display mode 4 The cgLoadBMP command now works in palette mode 5 This manual now has a new section of sample matlab scripts Changes from v1 04 to v1 05 The main change has been the addition of support for 8 bit graphics 1 The cgopen command has been changed In v1 04 the format was cgopen mod ref mon Now the format is cgopen res bpp ref mon The graphics mode mod argument has been replaced by separate resolution res and bits per pixel bpp arguments 2 The cgpen command has been replaced by two new commands cgpencol and cgpenwid 3 The cgmakesprite and cgloadarray commands have been changed The transparent colour TCol argument has been dropped 4 There is anew command cgtrncol This can be
95. cnd cgshutmovie mex v1 29 Compiled Nov 6 2008 GScnd cgplaymovie mex v1 29 Compiled Nov 6 2008 GScnd cgscrdmp mex v1 29 Compiled Nov 6 2008 GScnd cgarc mex v1 29 Compiled Nov 6 2008 GScnd cgblitsprite mex v1 29 Compiled Nov 6 2008 GScnd cgtracker mex v1 29 Compiled Nov 6 2008 cgsound mex v1 29 Compiled Nov 6 2008 Library not opened GScnd cgsignal mex v1 29 Compiled Nov 6 2008 GScnd cgtouch mex v1 29 Compiled Nov 6 2008 GScnd cgrotatesprite mex v1 29 Compiled Nov 6 2008 GScnd cgdriver mex v1 29 Compiled Nov 6 2008 GScnd cgloadlib mex v1 29 Compiled Nov 6 2008 The egvers command checks that all the components are present and also that the version numbers of all components match Depending on the version of matlab and the version of windows you are using the file extensions may be mex or mexw32 or mexw64 If one of the components is not present you will get the following message gt gt cgvers Load failed for mex file E matlabR 12 toolbox CogGphTB cgVers mex The specified module could not be found Invalid MEX file If this happens you must again re install Cogent Graphics from the web distribution B 2 GScnd user manual v1 29 6 November 2008 If one of the components has the wrong version number you will get a warning message informing you of the fact Your experiment may nevertheless run but it would be safer to re install Cogent Graphics from the web distribution gt gt cgvers CogStd v1 03 Compiled Jun
96. cy w h al a2 lt Col gt lt ArcType gt CX Cy Co ordinates of the centre of the ellipses for which the arcs are drawn w h Widths and heights of the ellipses for which the arcs are drawn al a2 Start and finish angles for the arcs Angles are measured in degrees increasing anticlockwise Zero is a horizontal line going to the right from the ellipse centre Col Optional The colours for the arcs When in palette mode Col must be an n x 1 single column array containing the palette index for each item When in direct mode Col must be an n x 3 array containing the RGB levels 0 to 1 for each item ArcTyp Optional A default draws hollow arcs S draws filled sectors This function draws hollow arcs or filled sectors with centres on the co ordinates x y and widths and heights defined by w and h and start and finish angles defined by al and a2 The arcs are drawn on the current destination as set by cgsetsprite If you include the Col argument each arc or sector will be drawn in the requested colour otherwise the current drawing colour as set by egpencol will be used If the optional ArcType argument is S filled sectors will be drawn Otherwise or if ArcType is A hollow arcs are drawn using the current line width as set by cgpenwid The arrays cx cy w h and Col must have the same number of entries When in direct mode where Col is an n x 3 array n gives the number of entr
97. d 2 right justified AlignY Vertical alignment mode 0 top 1 centre 2 bottom ColTable An array of COLORREF structures described below containing the current palette Size of the array is given by PalSize PalSize The number of entries in the palette Flags This contains binary flag values Currently the only flag used is 2 If this is set then the flip function cannot be synchronized with the vertical blanking interrupt NextRASKey The ID number of the next Raster NextDIBKey The ID number of the next DIB MouseX MouseY Mouse position in pixels 0 0 is the top left of the screen increasing to the right and downwards These values are updated only when the mouse is read MouseS MouseP Mouse button state MouseS has the mouse buttons that were down when the mouse was last read MouseP has the buttons that have been pressed and possibly released since the previous time the mouse was read Button values are the arithmetic sum of 1 left button 2 middle button 4 right button MouseS can also include 8 Control key down 16 Shift key down KeyS KeyP Key state each is an array of three values containing the bitwise map of keys down and pressed since the keys were last read SDFilename These two variables are combined to create a filename for the SDFilenumber screendump file when none is supplied to the cgScrDmp command The filename is SDFilenameNNNNN BMP where NNNNN is the five digit value of
98. d PixVal arguments If you want you can scale the sprite using the sw and sh values to be whatever you please If you want to use the underlying gprim library functions you may optionally use the returned RASKey value to identify the raster used for this sprite This function may be used in palette display mode in which case the PalRGB and StartIndex arguments must be present N B This command can fail under Windows 95 98 ME if the source image is much smaller than the destination sprite cgloadarray 3 100 100 Pix Val Creates a new sprite with ID number 3 The sprite is the same size as the supplied image which is 100 pixels square The colour of each pixel in the image is defined by the Pix Val array which contains 10 000 x 3 elements 100x100 10 000 RASKey cgloadarray 3 100 100 PixVal PalRGB 0 50 20 Creates a new sprite with ID number 3 The sprite will be 50 units wide and 20 units high The units depend on the current co ordinate system as selected by cgscale The image is palette based and the palette is contained in the PalRGB argument The supplied image is 100x100 pixels and Pix Val must therefore contain 10 000 elements Array palette indices will be loaded with no offset StartIndex 0 The underlying gprim raster identification key for this sprite is stored in RASKey RASKey cgloadarray 3 100 100 PixVal PalRGB 35 50 20 Creates a sprite as in the previous example but this time the display is in
99. display on the one screen You may open a sub window on the display using zero as the device number for egopen or you may open a full screen display using one as the device number for cgopen K 2 GScnd user manual v1 29 6 November 2008 Single graphics card dual display Some graphics cards such as the Matrox Millenium G200 have a multiple display capability On such systems the Display Properties dialog box looks like this Display Properties fia Background Screen Saver Appearance Web Effects Settings Drag the monitor icons to match the physical arrangement of your monitors Display 1 Plug and Play Monitor on Matrox Graphics Millennium G200 Colors Screen area igs More 1280 by 1024 pixels True Color 32 bit a M Use this device as the primary monitor Extend my windows desktop onto this monitor Identify Troubleshoot Advanced The display properties box shows that there are two displays on this system numbered 1 and 2 However only display number 1 is enabled because display number 2 is ghosted out When we use the cgopen 1 0 0 1 command to list available displays we get something like this gt gt cgloadlib gt gt cgopen 1 0 0 1 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Available devices 1 DISPLAY1 Matrox Graphics Millennium G200 K 3 GScnd user manual v1 29 6 November 2008 Once again it appears
100. driver MIRROR Some graphics drivers cannot handle a blit which mirror flips a sprite either horizontally or vertically while simultaneously stretching the sprite If you apply this fix the blit is done in two stages The first stage creates a mirror image of the same size and the second stage performs the enlargement Applying this fix causes a small performance overhead but only in those cases where it is specifically required If your graphics card driver needs this fix it should be applied in a file named cginit m and placed in the Cogent Graphics toolbox for your PC cgdriver TRNBLT This solves a problem in some graphics card drivers when blitting a sprite with transparency Subsequent calls to cgrect which use the same transparent colour index draw the rectangle incorrectly as colour index zero When this fix is applied an extra blit is executed after each blit that uses transparency This extra blit is a non transparent blit and that seems to restore the correct operation of subsequent calls to cgrect Applying this fix causes a small performance overhead but only in those cases where it is specifically required If your graphics card driver needs this fix it should be applied in a file named cginit m and placed in the Cogent Graphics toolbox for your PC cedriver SYSMEM This call should be used with caution as it causes a big performance overhead After this call all new sprites are created in system memory rath
101. e TCol Transparent colour for the sprite Omit this argument to set no transparency Valid values are as follows n selects black 0 0 0 r selects maximum red 1 0 0 g selects maximum green 0 1 0 y selects maximum yellow 1 1 0 b selects maximum blue 0 0 1 m selects maximum magenta 1 0 1 selects maximum cyan 0 1 1 w selects maximum white 1 1 1 This argument is only valid in direct colour mode PI Transparent palette index for the sprite 0 to 255 Omit this argument to set no transparency Only valid in palette mode Set the transparent colour of a sprite cgtrncol 23 1 0 0 Set the transparent colour of sprite 23 to be 1 0 0 maximum red cgtrncol 17 22 Set the transparent palette index of sprite 17 to 22 cgtrncol 32 Sets no transparency for sprite 32 cgvers lt Mode gt Mode Optional Mode can be U for usage or C for copyright Prints out version information for all GScnd commands on the matlab console This is useful for checking what version of the library you are using It also prints out a warning if there are any inconsistencies in the version numbers of the various components When called with the U argument you get a usage guide as well for all commands giving a synopsis of the arguments that can be passed to each command The C argument prints a copyright message for each command cgvers
102. e supported DSCAPS_PRIMARY16BIT 16 bit primary buffers supported DSCAPS_PRIMARY8BIT 8 bit primary buffers supported DSCAPS_PRIMARYMONO Monophonic primary buffers supported DSCAPS_PRIMARYSTEREO Stereophonic primary buffers supported DSCAPS_SECONDARY16BIT 16 bit secondary buffers supported DSCAPS_SECONDARY8BIT 8 bit secondary buffers supported DSCAPS_SECONDARYMONO Monophonic secondary buffers supported DSCAPS_SECONDARYSTEREO Stereophonic secondary buffers supported Sampling rate range 8000Hz to 96000Hz All buffers Total 64 Free 63 Static buffers Total 64 Free 63 Streaming buffers Total 64 Free 63 HW memory Total 0 Free 0 Largest 0 The command lists the properties of the currently opened sound device Furthermore you can also obtain some information about the primary buffer of the device which tells you the quality of the sound it puts out gt gt cegsound info 0 cegSound Info 0 information about primary sound buffer Flags DSBCAPS_LOCSOFTWARE Software buffer DSBCAPS_PRIMARYBUFFER Primary buffer Memory size 32768 bytes Channels 2 BitsPerSample 16 SamplesPerSecond 48000 If you have opened a sound by using the egsound matrixSND or cgsound WavFilSND commands you can also obtain information about that sound gt gt cegsound WavFilSND 7 Sound1 wav gt gt egsound info 7 cgSound Info 7 information about secondary sound buffer 7 Flags DSBCAPS_CTRLF
103. e mono or stereo how many bits to use per sample 8 or 16 and the samples per second value 11025 22050 44100 Hz When you play any sound it will be converted and played at the playing format This means that you can play a variety of sounds all of which may be recorded in different formats mono stereo 8 16 bit 10 000Hz 100 000Hz etc Opening and closing the sound device You may have several sound devices on your system You can choose any of these for sound output You can list the available devices using the command below gt gt cgsound devs Available devices 0 Primary Sound Driver 1 SB PCI The default device is always number zero Here you can see that there is a single soundcard called SB PCI and that is given the number 1 You can open a sound device using the following command gt gt cgsound open cgSound v1 29 Compiled Nov 6 2008 Sound library DirectSound v9 DX9 0 Compiled Nov 6 2008 Primary Sound Buffer 2x16x48000 Vol Att 50 0 The command actually takes a number of optional arguments cgsound open Channels BitsPerSample SamplesPerSecond Attenuation Device Channels 1 mono sound or 2 stereo sound Default 2 BitsPerSample 8 or 16 Default 16 SamplesPerSecond 10 000 to 100 000 Default 48 000 Attenuation Volume attenuation in db from 10 to 100 Default 50 Device device number as listed by cgsound devs Default 0 If you specify Device you must specify
104. e position Try the following commands gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 75 31Hz gt gt cgmouse 0 0 When you issue the cgmouse 0 0 command the mouse pointer on the screen should jump to the centre of the cogent display window Now make it jump to the top right corner gt gt cgmouse 320 240 You can use this form of the command to make the mouse pointer move to the given co ordinates The co ordinates are the local co ordinates as set up by the cgscale command Reading the mouse is also simple gt gt x y bs bp cgmouse The call above returns the mouse position x y in egscale co ordinates and the button state bs bp The bs value gives the mouse buttons that were down at the instant cgmouse was called The bp value gives the mouse buttons that had been pressed and possible subsequently released since the previous time cgmouse was called Mouse buttons are coded as the arithmetic sum of the following values 1 left mouse button 2 middle mouse button 4 right mouse button In the case of the bs value buttons down at the time of the call to cgmouse the sum can also include the following components 8 Control button also pressed 16 Shift button also pressed So if the middle and right buttons were pressed the coded value would be 2 4 6 GScnd user manual v1 29 6 November 2008 You may extract a particu
105. e the if length kp and while kd 1 statements respectively and finally the graphics are closed with the cgshut command before the function returns You should get output like this gt gt Keymap Click in the display window to activate it and then press any key to see its keycode Hit Esc to exit GPrim_ v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 60 17Hz Key 36 Key 37 Key 1 gt gt E 5 GSend user manual v1 29 6 November 2008 Screen dumps The egscrdmp command has three forms 1 cgscrdmp 2 egscrdmp Filename 3 egscrdmp Defname Defnumber The first form on its own without arguments creates a screen dump file and saves it with the current default name The default name has two parts Defname and Defnumber Defname is initially set to CGSD a pseudo acronym for CoGent Screen Dump and Defnumber is initially set to 1 The default name is then CGSDO00001 BMP Defnumber is incremented each time the default name is used so you can create a whole series of screen dump files in a simple way Such a sequence might be used to create a movie using a program such as Adobe Premier You can reset the values of Defname and Defnumber using form 3 of this command The second form with the Filename argument creates a screen dump file named Filename BMP The current values of Defname and Defnumber are not changed The third form with the Defname and Defnumber arguments does
106. ead tab You can select DualHead Multi Display and when you click on the Multi Display Settings button you get another custom dialog box which lets you configure two monitors However there is still only a single graphics controller so unfortunately all this is of little use with regard to Cogent Graphics SONY GDM 20SE2TS and Matrox Millennium G450 Dual Head Eni E lt General Adapter Monitor Troubleshooting Color M B Information GH Options DuaHead FH Monitor Settings DualHead Multi Display Settings K 6 GScnd user manual v1 29 6 November 2008 Two graphics cards one disabled Some computers are supplied with a built in graphics card on the motherboard When you add another graphics card the motherboard graphics are disabled Although it seems that the system has two graphics cards it is in fact impossible to use the motherboard graphics card When you open the Display Settings you get something like this Display Properties HE Background Screen Saver Appearance Effects Web Settings Drag the monitor icons to match the physical arrangement of your monitors Display fi SONY GDM 20SE2T5 on Matrox MGA Millennium x Colors Screen atea gt True Color 24 bit y bess More E o 1280 by 1024 pixels JV Extend my windows desktop onto this monitor Advanced Two displays are shown one ghosted out If you click on the ghosted out display you get a m
107. ed The message is of the form Driver MIRROR The message can be suppressed by using the HIDE argument cgdriver MIRROR HIDE In order to implement these workarounds in a transparent way the cgopen command has been modified It now searches the matlab path and executes a script named cginit m if such a file exists If any egdriver commands are required on your PC then simply create a script named cginit m with the appropriate commands and include it in the Cogent Graphics toolbox It is probably a good idea not to suppress the information messages which are automatically generated by cgdriver so that all users on that machine are informed of the workarounds in effect on that machine So an example cginit m script might look like this function cginit cgdriver MIRROR cgdriver TRNBLT return So how can you identify whether you need to apply any of these fixes on your platform The answer is to run the drivertest utility which is included in the sample scripts This script runs through each known driver bug and tests it interactively Any driver fixes already in force from an existing cginit m file are taken into account by this utility so it will not indicate that you need to fix something that has already been taken care of in that way Simply run the script and make a note of which fixes need to be applied and then edit the cginit m script accordingly A20 GScnd user manual v1 29 6 November 2008 ce
108. efficient but is limited in its capability to render subtle colours 24 and 32 bits per pixel gives 16 million colours on screen at one time and are suitable for photo quality images Inefficient use of memory Bits per pixel is ignored if sub window Monitor 0 is used RefRate Refresh rate in hertz Specify a rate or specify zero to select an optimal rate for your monitor This argument is ignored if sub window mode Monitor 0 is used Monitor Which monitor to use Possible values are 2 List all resolutions Do not open a screen 1 List all possible monitors Do not open a screen O Open a sub window on the main desktop 1 Take over the whole desktop on the main monitor 2 n Take over subsidiary monitors If sub window Monitor 0 is used the bits per pixel and refresh rate of the main desktop are not changed Alpha Optimize graphics for Alpha blending N B overall performance drop Opens a new graphics screen with a specified resolution on the chosen monitor A refresh rate may also be selected depending on the capabilities of your hardware Use the Alpha argument only if you have to there will be an overall performance drop cgopen 1 0 0 0 Open a new graphics screen with resolution 640 x 480 pixels as a sub window on the desktop of the main monitor cgopen 1 0 0 2 Lists available resolutions Do not open a screen cgopen 1 0 0 1 Lists available monitors Do not o
109. efine the screen width to be 30 degrees and then load Arial font with the letters 4 degrees high We then set the drawing colour to be yellow gt gt cgtext All that glisters 0 2 gt gt cgtext is not gold 0 2 gt gt cgflip Next we draw two lines of text the first is 2 degrees above the centre of the screen the second is 2 degrees below Then we make the offscreen area visible with cgflip B 18 GScnd user manual v1 29 6 November 2008 Cogent Graphics display window There are two points to note in this example both concerning the alignment of the text Firstly we selected a font that was 4 degrees high When we drew the two lines of text we drew the first 2 degrees above the midline of the screen and the second 2 degrees below the midline The vertical separation of 4 degrees the same as the font height gives a nice vertical spacing between the two lines of text Secondly the text was drawn centred vertically and horizontally on the co ordinates in the cgtext command This is the default text drawing mode but this can be changed by setting a different alignment mode with the cgalign command B 19 GScnd user manual v1 29 6 November 2008 Text alignment You can set the alignment mode with the egalign command cgalign I c r t c b This command sets the alignment mode for the horizontal and for the vertical The horizontal mode can either be I for left alignment c for c
110. eight the image will be flipped horizontally or vertically in a similar way to the cgdrawsprite command Consider the following example gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgloadbmp 1 Demo bmp gt gt cgdrawsprite 1 0 0 gt gt cgflip 0 0 0 Cogent Graphics display window lee i ae oo pape Ae ee B 39 GScnd user manual v1 29 6 November 2008 Here we have loaded a familiar image into sprite 1 and copied it onto the screen using the cgdrawsprite command Now let us use the egblitsprite command to copy just the central rectangle The Demo bmp image is 320x240 pixels so we shall set the alignment mode to horizontal and vertical centering and then blit a rectangle 160 x 120 pixels gt gt cgalign c c gt gt cgblitsprite 1 0 0 160 120 0 0 gt gt cgflip 0 0 0 Cogent Graphics display window rap We can also use the cgblitsprite command to scale the rectangle up to the full screen size of 640x480 pixels gt gt cgblitsprite 1 0 0 160 120 0 0 640 480 gt gt ceflip 0 0 0 Cogent Graphics display window B 40 GScnd user manual v1 29 6 November 2008 Once again we can select a negative value for either the source width or the destination width to flip the image horizontally Here we enter a negative value for the source width 160 gt gt cgblits
111. electronics s Intellitouch screens These have a connection to the PC serial port in addition to a VGA cable for the display If you use one of these touchscreens with Cogent Graphics you must NOT install the supplied drivers which came with the touchscreen If they have already been installed they must be uninstalled This is because the supplied drivers grab the serial port and will not allow Cogent Graphics to communicate through it There is a sample script available named Touch which is described elsewhere in this manual which gives a realtime demonstration of using a touchscreen To open communications with the touchscreen you can use the command below cgtouch open ouchID PortNum The following arguments must be supplied TouchID Currently the only supported touchscreen is EloTouch PortNum You must tell cogent where the serial connection to the touchscreen comes in This should be one of the serial ports usually COM1 or COM2 A number between 1 and 8 is expected here So typically you might use the command as shown below gt gt cgtouch open Elotouch 1 Touch screen D IntelliTouch 2500G v1 4 Serial ExtA D Z P16 Jumpers NVRAM boot Stream 9600Bd HWHndShk Binary Notice the response line which appears when you successfully open communications Touch screen ID IntelliTouch 2500G v1 4 Serial ExtA D Z P16 The 2500G indicates that the touchscreen is fitted with a model 2500G gaming controller which allows you to simul
112. enBits 8 or not In either case the drawing colour is set to maximum white Then the value of bp is set to zero The value of bp will reflect the state of the mouse buttons and the statement while bp sets up a loop which will continue until a mouse button is pressed Inside this loop we read the mouse position and button state and draw a filled ellipse to follow the mouse position We then issue the cgflip command clearing the background to black the form is slightly different depending on whether or not we are in palette mode If a mouse button has been pressed we drop out of the loop close the graphics and return When the script is run you should see the following gt gt Mouse Move the cursor into the display Hit a mouse button to exit GPrim_ v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 60 14Hz gt gt Cogent Graphics display window The white circle should follow the mouse when it is over the display window E 3 GScnd user manual v1 29 6 November 2008 Using the keyboard Currently the cgKeyMap function has not been fully integrated with the rest of Cogent In particular the use of this function may interact undesirably with the Cogent keyboard logging service Consequently use this function with caution The cgKeyMap function provides an efficient and simple way to read the keyboard The format of the command is as follows gt gt ks kp cgKeyMap The co
113. entering or r for right alignment The vertical mode can either be t for top alignment c for centering or b for bottom alignment This command has already been used to align rectangles but it is also used to align text In the following example we shall use pixel co ordinates and draw a rectangle on the screen upon which we shall draw some text gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgpencol 1 1 1 gt gt cgrect 0 0 400 80 gt gt cgfont Times 20 gt gt cgpencol 0 0 0 We have opened the graphics and drawn a 400 x 80 pixel white rectangle centred on the centre of the screen Then we loaded Times font at a height of 20 pixels and set the drawing colour to black Of course nothing appears on the display yet because it is all on the offscreen area gt gt cgalign l t gt gt cgtext There is a tide in the affairs of men 200 40 gt gt cgtext Which taken at the flood leads on to fortune 200 20 gt gt cgtext Omitted all the voyage of their life 200 0 gt gt cgtext is bound in shallows and in miseries 200 20 gt gt cgflip 0 0 0 There is a tide in the affairs of men ich taken at the flood leads on to fortune Omitted all the voyage of their life is bound in shallows and in miseries You should see that
114. equency 330 before being divided by the sampling rate 48000 Finally we take the sine of the angle to create our matrix gt gt mat sin ang Of course you could do all the above operations in a single line as follows gt gt mat sin 1 2 48000 2 pi 330 48000 This is the sort of expression that should be made into a matlab function function mat sinwav Frequency Duration SamplingRate mat sin 1 Duration SamplingRate 2 pi Frequency SamplingRate return Copy the above function and save it as a matlab file named sinwav m You can now make a matrix containing a sound of any desired frequency duration and sampling rate as follows gt gt mat sinwav 330 2 48000 You can then load up this matrix into cgsound as follows gt gt cgsound matrixSND 9 mat 48000 and play it in the usual way gt gt cgsound play 9 cgsound treats sounds from all sources identically there is effectively no difference between sounds loaded from wav files and sounds loaded from matlab workspace matrices and cgsound will be able to perform similar operations on them both regardless of how they were created E 21 GScnd user manual v1 29 6 November 2008 Let us now consider the matrixSND command in more detail cgsound matrixSND Key Matrix lt BitsPerSample gt lt SamplesPerSecond gt lt Memory gt Key Matrix BitsPerSample SamplesPerSecond Memory This value identifies the sound you want
115. er added This implements internal workarounds to fix various bugs in miscellaneous graphics drivers There is also a new utility named drivertest m which tests for each known bug in turn and informs the operator which cgdriver calls are required for the current platform 4 cgopen now automatically runs a file named cginit m if it is found in the path This allows the system manager to implement platform specific customizations such as fixes for bugs in graphics card drivers 5 cgmakesprite cgloadbmp and cgloadarray changed to accept a SYSMEM argument This creates the sprite in system rather than video memory This may be desirable in certain circumstances to prevent anti aliasing in enlarged sprite operations which can interfere with sprite transparency 6 Rasters and Sprites now have an extra flags variable When the sprite or raster is in system memory this variable takes the value 1 Otherwise it is zero This new variable is returned by the appropriate cggetdata call Changes v1 26 to v1 27 1 Function cgRotateSprite added Changes v1 25 to v1 26 1 The cgFont function has been modified to allow rotation of text The gpd structure returned by gpd cggetdata GPD now includes a FontAngle element 2 An underlying bug in CGLib was fixed so that cgLoadArray now sets colours consistently with other GScnd functions A 2 GScnd user manual v1 29 6 November 2008 Changes v1 24 to v1 25 1 A ne
116. er end This 25 way socket requires an adapter so that you can connect it to the 9 pin serial port plug on your PC The 25 wat socket also has a toggle switch which has two positions CTRL and XFER The switch must always be in the CTRL position When you have connected the PR 650 to the PC you should then switch it on by pressing the red O P button on the front of the photometer The power light should come on on the photometer You are now ready to start communications To open communications with the photometer use the command below gt gt cgphotometer open pr650 1 This command assumes that serial port COM is being used The photometer display should illuminate indicating that communication has been successful You can check the photometer identification using the command below gt gt idstr cgphotometer id idstr GScnd cgPhotometer v1 29 Compiled Nov 6 2008 PhotoResearch Spectra Colorimeter Model PR 650 SN 60954201 To make a measurement use the XYZ command gt gt xyz cgphotometer XYZ XYZ 3 7690 3 6290 1 1300 This returns the CIE 1931 XYZ values for the measurement E 9 GScnd user manual v1 29 6 November 2008 You can then also download the radiant spectrum of the measurement gt gt spc cgphotometer SPC spc 380 0000 384 0000 776 0000 780 0000 The returned matrix is an n x 2 array of values The first column gives the wavelngth of the measurement
117. er for your graphics card Some graphics cards are mainly optimized for 3D gaming applications and so the interface for 2D graphics which is used by Cogent Graphics may not be 100 standard So there are some workarounds which have been implemented in Cogent Graphics to overcome these driver problems These have not been included by default because there is an associated performance cost with them Instead a mechanism has been provided so that they can be specifically switched on when required A19 GScnd user manual v1 29 6 November 2008 The function cgdriver is used to switch these graphics driver workarounds on and off The syntax of the command is as follows cedriver Fixname lt HIDE gt or cgedriver Fixname lt HIDE gt Currently Fixname can take the following values detailed description sections follow below MIRROR Fixes a bug when blitting sprites with a mirror flip does not work TRNBLT Fixes a bug when blitting sprites with transparency SYSMEM Stops anti aliasing of enlarged blitted sprites This fix should be used with caution as it can have an adverse affect on system performance CLEAR Clears all fixes currently in force The command cgdriver MIRROR switches the workaround on cgdriver MIRROR switches it off again The default behavior is to display a message on the matlab console window when cgdriver is called to inform the user that the workaround has been invok
118. er than using the video memory built into your graphics card While this has the effect of curing many graphics driver problems it will also slow down graphics performance because system memory cannot be manipulated as quickly as video memory A better alternative is to use the SYSMEM argument which is now provided for cgmakesprite cgloadbmp and cgloadarray Just use SYSMEM in those calls for the specific sprite or sprites that need it in your code You can however use the cgdriver SYSMEM call to check whether it has the desired effect on your script without having to edit the script interactively This call fixes many driver bugs because using system memory bypasses many graphics driver function calls In particular this call is useful because it effectively disables smoothing when you enlarge a sprite When you enlarge a sprite some graphics drivers smooth the enlarged image so that the original pixels in the original sprite do not appear blocky in the enlarged sprite This can cause problems if you have set a transparent colour in the sprite and the transparent boundaries have changed colour as a result of smoothing Using SYSMEM specifically when you create those sprites with cgmakesprite cgloadbmp or cgloadarray should cure the problem A21 GScend user manual v1 29 6 November 2008 Direct colour tutorial GScnd user manual v1 29 6 November 2008 Getting started This first section checks that the instal
119. error message such as ERR GPrim gDrwD IB StretchDIBits Failed under Win95 98 ME sprite too big This happens because these versions of Windows cannot zoom an image beyond certain limits B 38 GScnd user manual v1 29 6 November 2008 Blitting sprites You can copy a complete sprite using the cgdrawsprite command described earlier However you may want to copy just a rectangular section from one sprite to another This process is called blitting Blit is an abbreviation for BLock Image Transfer which simply means copying a rectangular block from one image to another You can use the cgblitsprite command to copy an arbitrary rectangle from a sprite to the current destination cgblitsprite Key srcx srcy srew srch dstx dsty lt dstw dsth gt lt Alpha gt Key The identification number for the source sprite srcx srcy The source position for the rectangle This is modified by the current alignment mode as set by cgalign srew srch The width and height of the rectangle to copy dstx dsty The destination position for the rectangle Again this is modified by the current alignment mode as set by cgalign dstw dsth You may optionally set the destination width and height if it is different from the source width and height In this way you can scale the rectangle Alpha This optional value controls translucency and is described in the Alpha blending section of this manual If you select a negative value for a width or a h
120. es is to hold images which will be described in a later section The command to make a sprite is rather lengthy cgmakesprite Key Width Height lt R G B or RGB gt lt SYSMEM gt The RGB and SYSMEM arguments are optional Key Width Height R G B or RGB SYSMEM Your identification number for this sprite This can be any number from 1 to 10 000 You use this Key to identify this sprite If a sprite with this identification number already exists then this new sprite will replace it This is in whatever units you are currently using either pixels or degrees of visual angle as set by the cgscale command If you want to initialise the rectangular area to a flat colour you can specify the colour here Lets you specify that system rather than video memory should be used See the Graphics Drivers section for further details The command to delete a sprite is quite succinct cgefreesprite Key Key The identification number of the sprite you want to delete The command to draw a sprite is also straightforward cgdrawsprite Key x y lt w h gt lt Alpha gt Key XY w h Alpha Defines the sprite you want to draw Where you want to draw it The current alignment mode as set by cgalign is used to position the sprite relative to these co ordinates You may optionally choose to scale the sprite to a new size on the destination These values specify the width and height of the copied
121. essage similar to this Monitor 2 Ez i The monitor you have selected is currently disabled If you enable this monitor then it will be used as part of your Windows desktop you can move your mouse to it place icons on it and show program windows on it Some applications may have problems with more than one monitor enabled Do you want to enable this monitor a No If you click on Yes the display seems to be enabled but when you click on Apply on the Display settings box the display becomes ghosted again to indicate that it cannot be enabled When you use cgopen to list the available displays you get something like this gt gt cgloadlib gt gt cgopen 1 0 0 1 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Available devices 1 Display1 Matrox MGA Millenium Only the enabled display is listed K 7 GScnd user manual v1 29 6 November 2008 Two graphics cards If your system has two graphics cards it should be set up so that both displays are enabled You may get better performance if you use display number for Cogent Graphics and switch the windows to display 2 or it may not make any difference You will have to experiment to see what configuration is best Typically your Display Properties settings will look like Display Properties 24x Background Screen Saver Appearance Web Effects Settings Drag the monitor icons to match the physical arrangement
122. eversing black and white chessboard on the display F 2 GScnd user manual v1 29 6 November 2008 Stars This script starsrgb starspal draws an animated starfield with the colour of the objects changing from yellow in the centre to magenta at the edges vN NN P NORMAL Tim 00 00 05 Frm 199 Av 75 Dartboard Another sample script named Dartboard uses palette animation to draw three spinning animated dartboards on the screen Tennis This script tennisrgb tennispal plays a simple tennis game controlled by the mouse vN NN P NORMAL Tim 00 00 05 Frm 199 Av 75 F 3 GScnd user manual v1 29 6 November 2008 SoundAdj This script SoundAdj m shows an animation with interactive sound Use the mouse to alter the sound horizontal movement alters the stereo balance vertical movement alters the pitch and the mouse buttons R L alter the volume up down Alpha The script Alpha m demonstrates alpha blending Two different images fade in and out Alpha v1 25 P NORMAL Tim 00 00 04 Frm 12 F 4 GScnd user manual v1 29 6 November 2008 Equipment examples This next script demonstrates the use of the eyetracker Tracker This scripts gives a real time demonstration of the eyetracker for calibrate or R The screen shows the setup values for the eyetracker cl c2 c3 c4 PortNum Mode and BaudRate at the top Next comes the latest eye data from the eyetracker EyePos Pupil Timesta
123. f this waveform is shown This wave has been sampled along the x axis at a sample rate of 11 025 Hz 11 025 samples per second The vertical axis shows the numerical value of the waveform at each sampling point and you can see that the values vary from 1 to 1 So this waveform can be represented by a matlab data array with 1x11 025 values 1 row by 11 025 columns with each value being a number between 1 and 1 A single waveform like this can be referred to as a single channel of data corresponding to mono or monaural sound You can also have two channel or stereo sound where there is a different sound for left and right speakers and this can similarly be represented by a 2xn two rows by n columns matlab data array The matlab data array contains values that vary between 1 and 1 but the computer s underlying sound system converts this to a smaller less accurate value either an 8 bit or a 16 bit value The 16 bit values are most accurate but take up twice the memory capacity of the 8 bit values You may quite reasonably point out that all this seems unneccesarily complicated when all you want to do is just play a sound but unfortunately this is the way digital sound is processed on the computer and so it is necessary to understand these underlying principles GScnd user manual v1 29 6 November 2008 Sample format and playing format When you open the sound device you specify a playing format You specify how many channels to us
124. ff the transparent colour for the sprite and copy sprite 1 again above Then we display what we have drawn with the cgflip command Cogent Graphics display window B 31 GScnd user manual v1 29 6 November 2008 Image files You may load up an image file into a sprite using the cgloadbmp command The image file must be in uncompressed BMP format cgloadbmp Key Filename lt Width Height gt lt S YSMEM gt The Width and Height arguments are optional Key Filename Width Height SYSMEM is your ID number for the sprite which will be created is the full filename of the BMP file to load are the dimensions of the sprite you want to create The image will be scaled to fit these dimensions exactly By choosing different dimensions to the image you can achieve some special effects such as squeezing or stretching the image You can also enlarge the image However if you try to make the image smaller the result can be very poor You may set either Width or Height to be zero If you do this the aspect ratio of the image is used to calculate the width or height from the other supplied dimension Lets you specify that system rather than video memory should be used See the Graphics Drivers section for further details You may download sample BMP files named Demo bmp and Demo2 bmp from the website for use in the following examples You should copy them into the same directory that you run matlab from gt
125. ffer really is clear at this point Then draw sprite 79 into the offscreen area and display it gt gt cgsetsprite 0 gt gt cgflip 0 0 0 gt gt cgdrawsprite 79 0 0 gt gt cgflip 0 0 0 Cogent Graphics display window Finally we can also scale the sprite if we want gt gt cgsetsprite 0 gt gt cgdrawsprite 78 0 0 640 480 gt gt cgflip Cogent Graphics display window B 28 GScnd user manual v1 29 6 November 2008 Furthermore we can flip the sprite horizontally by entering a negative value for the width gt gt cgdrawsprite 78 0 0 640 480 gt gt cgflip A negative value for the height flips the sprite vertically gt gt cgdrawsprite 78 0 0 640 480 gt gt cgflip Negative values for both width and height result in a 180 rotation gt gt cgdrawsprite 78 0 0 640 480 gt gt cgflip B 29 GSend user manual v1 29 6 November 2008 Transparency Transparency allows us to create a sprite with an irregular outline In order to do this we associate a transparent colour with the sprite You may choose the transparent colour from the following black red green yellow blue magenta cyan white The cgtrncol command selects the transparent colour cgtrncol Key TCol Key The identification number of the sprite whose transparent colour you want to set TCol Transparent colour to use for this sprite If you omit the TCol value transparency is s
126. from this manual There are some examples from this manual which have been included with the samples These demonstrate aspects of graphics which use loops and are not suitable for interactive command line usage Mouse This script puts up a black display screen with a white circle that follows the mouse position Hit a mouse button to exit gt gt Mouse Move the cursor into the display Hit a mouse button to exit GPrim_ v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 60 14Hz gt gt Cogent Graphics display window F 7 GScnd user manual v1 29 6 November 2008 KeyMap This script puts up a black display screen Click on the screen with the mouse to select it and then use the keyboard The key number of each button you press will be printed on the matlab console screen Hit the Esc key to exit gt gt Keymap Click in the display window to activate it and then press any key to see its keycode Hit Esc to exit GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 60 17Hz Key 36 Key 37 Key 1 gt gt Cogent Graphics display window F 8 GScnd user manual v1 29 6 November 2008 Utilities Some useful utility scripts are also included with the samples PerfTest Perftest runs a Cogent Graphics performance test displays the results on screen and also saves them to a file named perfdata txt Drawing of dots li
127. g oo AA o amp g Xp B20 of P80 gt Q o o 68 O BO 9 gt w O o0 DOS 6 80 o F 029 5 B g gt S o oop o 09 do o S o Sew A o 2 ar o oo O o 0 amp oF oo 0 9 e Sog ag M9 oo SS oe GH 09 00 o 0 amp os 5 amp 000 PO B8So o d 3 x P 5 8 o RECN o ob 6 Co oo Sa E P Beo 0 8 Oop 8 go o Of course we do not need to have the dimensions all the same Let us set the widths and heights to random values between 1 and 20 pixels and draw filled ellipses instead gt gt w 1 1000 1 rand 1 1000 19 gt gt h 1 1000 1 rand 1 1000 19 gt gt cgflip 1 1 1 gt gt cgpencol 0 0 0 gt gt cgellipse x y w h f gt gt cgflip 1 1 0 Cogent Graphics display window B 46 GScnd user manual v1 29 6 November 2008 We can do a similar thing with the egare command this time with larger ellipses gt gt w 1 1000 1 rand 1 1000 49 gt gt h 1 1000 1 rand 1 1000 49 gt gt a1 1 1000 rand 1 1000 360 gt gt a2 1 1000 rand 1 1000 360 gt gt cgpencol 0 0 0 gt gt cgpenwid 1 gt gt cgarc x y w h al a2 gt gt ceflip 1 1 1 Cogent Graphics display windo BENT NEEM a SAS AP pa St if Ot Or with filled sectors gt gt cgarc x y w h al a2 S gt gt ceflip 1 1 1 Cogent Graphics display window f i 1 PR y B 47 GScnd user manual v1 29 6 November 2008 It is also possible to specify a different colour for each item T
128. g gprim library and should not be required by most users of the GScnd suite Key The identification number to use for this sprite aw ah The width and height of the image array PixVal This array defines the pixel value for the image for each pixel in turn starting at the top left of the image and then moving across rightwards and then downwards An rgb image is defined by an nx3 array with values ranging from 0 to 1 A palette image requires a 1xn array containing palette indices from 0 to 255 in which case the PalRGB argument is also required PalRGB This mx3 array m 1 256 defines the palette colours for the array The red green and blue components of each palette entry take values from 0 to 1 StartIndex When the display is in palette mode the array must be of palette type and also this variable must be included to indicate where in the display palette the array indices should start sw sh Optional The width and height of the sprite to create If omitted the sprite will be created so that its pixel size is the same as the supplied image array Otherwise you may optionally set the sprite width and height using these values SYSMEM Lets you specify that system rather than video memory should be used See the Graphics Drivers section for further details This function loads up a sprite with identification number Key with an image from the matlab workspace You supply the image using the aw ah an
129. get point 9 3 c4 You can check what the co ordinates are for points 1 and 9 by using the Check Target Points item from the Calibration menu of the eyepos program Check Target Points Oe x se c Current point 1 m SceneXx 46 Y 55 Set Target Points Done Here you can see that the co ordinates for point 1 are 46 55 i e cl 46 and c2 55 You can get the values for c3 and c4 in a similar way from the co ordinates for point 9 Check Target Points Bil x Da co Current point 19 mi Scenex 219 Y 214 Show All Set Target Points Done Here we get c3 219 and c4 214 So the open command we would use in this case would be gt gt cgtracker open ASL5000 1 1 57600 46 55 219 214 GScnd user manual v1 29 6 November 2008 Calibrating each subject You only really need to Set Target Points once the values you set up should be fine for all subsequent cogent experiments However you also need to carry out an individual calibration for each subject or before each experiment You may even feel that you want to recalibrate during an experiment This should not be a problem because this calibration can usually be carried out in less than a minute To do this part of the calibration you must have your subject looking at the cogent display exactly as if he were doing your experiment You may find it useful to use some kind of head support or chin rest although this is not absolu
130. gnals The cgsignal command takes the form cgsignal PortNum Signal PortNum Serial port number 1 to 8 Signal Signal code 0 1 2 3 The PortNum argument specifies which serial port you want to use You specify a number from 1 to 8 Most PCs have only one or two serial ports and if you request a non existent serial port you will get a message similar to that shown below gt gt cgsignal 3 1 ERR cgSignal Signal CreateFile Failed OSErr 2 The system cannot find the file specified The Signal argument specifies the signal pattern that should appear Remember that we have two outputs from each serial port Outputl and Output2 You switch Outputl on with the number and you switch Output2 on with the number 2 You switch both outputs on with the number 3 3 1 2 and the number zero switches both outputs off The off state is represented by 12V and the on state is represented by 12V The table below shows the values for both outputs for each value of Signal Signal Outputl Output2 0 12V 12V 1 12V 12V 2 12V 12V 3 12V 12V Really you only need to refer to the table above if you want to manipulate both outputs otherwise if you only need to control Output1 then just use Signal 0 and Signal 1 to switch it off 12V and on 12V respectively and similarly use Signal 0 and Signal 2 to switch Output2 off 12V and on 12V Finally when you are finished with the serial
131. ha blending operation can be coped with satisfactorily but there is a bottleneck It takes a comparitively long time for the processor to access the video memory on the graphics card This has to happen three times per pixel once to read the source pixel once to read the destination pixel and once to write the destination pixel To alleviate this bottleneck I have introduced cgopen Alpha which opens all surfaces in system rather than video memory This can be accessed much more quickly by the processor and so results in better performance However it does mean that there is much less hardware accelleration from the graphics card and that the processor is doing a lot more work Synchronisation of the cgflip command is also problematical and has to be handled in a different way from the standard graphics mode so users should check synchronisation if it is important for their stimulus D 4 GScnd user manual v1 29 6 November 2008 Further Tutorials GScnd user manual v1 29 6 November 2008 Using the mouse Currently the egmouse function has not been fully integrated with the rest of Cogent In particular the use of this function may interact undesirably with the Cogent mouse event logging service Consequently use this function with caution The cgmouse function provides an efficient and simple way to read and set the mouse pointer position Because of the nature of this function it is simplest to begin by describing how to set the mous
132. ha gt cgrotatesprite Key srcx srcy srcw srch dstx dsty lt dstw dsth gt Rotation lt Alpha gt Key srcx srcy srcw srch dstx dsty dstw dsth Rotation Alpha The identification number for the source sprite The source position for the rectangle This is modified by the current alignment mode as set by cgalign The width and height of the rectangle to copy The destination position for the rectangle Again this is modified by the current alignment mode as set by cgalign You may optionally set the destination width and height if it is different from the source width and height In this way you can scale the rectangle Specify a rotation angle in degrees The sprite will be rotated anticlockwise by this amount Performs a translucent copy Alpha takes values from 0 completely transparent to 1 completely opaque When omitted the default value is 1 completely opaque A negative width or height flips the image horizontally or vertically Consider the following example gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgloadbmp 1 Demo bmp gt gt cgrotatesprite 1 0 0 20 gt gt cgflip 0 0 0 B25 GScnd user manual v1 29 6 November 2008 Here you can see that the familiar image has been rotated anticlockwise by 20 degrees as requested Note here that the rotated image is cent
133. his is now synchronized properly with the display In previous versions the display lagged behind this command by a period of one frame The bug has been fixed in the underlying gprim library The command has also had another change made which makes it much more reliable with regard to dropped frames See the new section in this manual on Display timing 2 New instructions in the manual explain how you can use the cgopen command to select high refresh rates up to 160Hz It is possible to select refresh rate directly through the cgopen command providing your graphics card supports it See the revised section on Direct X and Refresh Rate and the Opening and closing graphics item in the Direct colour tutorial section 3 A recording function has been added to the eyetracker commands you can now use start and stop to retrieve a sequence of values You can also set the background and foreground colours of the calibration screen 4 The sample scripts have been reworked and are now useful tools for testing timing I recommend that you download the new samples when you download the toolbox 5 There was a bug in the cgEllipse and cgArc functions a memory leak used up the system brush resources after a long period This has now been fixed 6 Three bug fixes In the cgopen command the Windows desktop would sometimes appear in the initial cogent display The display is now correctly cleared to black In sub window mode while playing m
134. ics card may not support immediate mode for cgflip If that is the case you will receive an error message when you issue the command If that happens your only alternative is to run cgnewpal in immediate mode instead S cgflip cgnewpal I This is generally undesirable because the cgflip command will take some time to execute and so when the cgnewpal command is issued you may get some flicker at the top of the screen The previous configuration is much better because the cgnewpal command executes quickly in comparison to cgflip If you still have problems with flicker you must redesign your code C 4 GScnd user manual v1 29 6 November 2008 Drawing commands You have just seen how the cgflip command takes a palette index rather than an RGB triplet when in palette mode Similarly the cgpencol command also takes a palette index when in palette mode gt gt rgb 000 100 010 110 0015 101 011 111 gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 85 03Hz gt gt cgcoltab 10 rgb gt gt cgnewpal Here we have set up the following palette index colours 10 black 12 green 14 blue 16 cyan 11 red 13 yellow 15 magenta 17 white Now let us issue some drawing commands gt gt cgpencol 17 gt gt cgrect gt gt cgpencol 11 gt gt cgellipse 0 0 300 200 f gt gt cgpenwid 8 gt gt cgpencol 12 gt gt cgdraw 1
135. ies cgarc 0 0 20 10 45 90 Draws a hollow arc of an ellipse centred on 0 0 with width 20 and height 10 The start and finish angles of the arc are 45 and 90 degrees respectively cgarc 0 0 10 10 90 135 S Draws a filled sector of an ellipse of radius 10 centred on 0 0 The start and finish angles of the sector are 90 and 135 degrees respectively cgarc 100 100 100 100 100 50 50 100 50 70 100 200 1 0 0 0 0 1 S Draws two filled sectors in direct colour mode One is drawn for an ellipse with centre 100 100 with width 100 and height 50 in colour 1 0 0 red The other is drawn for an ellipse with centre 100 100 with width 50 and height 100 in colour 0 0 1 blue Start and finish angles for the two sectors are 50 100 and 70 200 respectively cgarc 100 100 100 100 100 50 50 100 50 70 100 200 1 2 Draws two hollow arcs in palette mode One is drawn for an ellipse with centre 100 100 with width 100 and height 50 in palette index 1 The other is drawn for an ellipse with centre 100 100 with width 50 and height 100 in palette index 2 Start and finish angles for the two arcs are 50 100 and 70 200 respectively G 2 GScnd user manual v1 29 6 November 2008 cgblitsprite Key srcx srcy srcw srch dstx dsty lt dstw dsth gt lt Alpha gt Key Identification number of the sprite to draw srcx srcy Co ordinates defining the position of the rectangle on the source spri
136. ill be optimized for Cogent Graphics Of course other configurations are also possible you can deselect display 2 in the control panel and just use display 1 Or you could keep display 1 as your windows screen and open your Cogent Graphics to run without hardware acceleration in display 2 by using 2 as the device number in the cgopen command K 5 GScnd user manual v1 29 6 November 2008 Single display dual monitor Some graphics cards such as the Matrox Millenium G450 Dual Head allow you to create an extra large windows desktop which spreads over two monitors Unfortunately this facility is of little use for Cogent Graphics as there is only one display controller and so effectively this is just a single display system The display properties box looks like this Display Properties 2 x Background Screen Saver Appearance Web Effects Settings Display SONY GDM 20SE2TS5 on Matrox Millennium G450 Dual Head English Colors Screen area fT Color 32 bit 7 bess More i olor 32 bit at a ma 1280 by 1024 pixels Troubleshoot OK Cancel Apply When you use cgopen to list the available displays you get the following gt gt cgloadlib gt gt cgopen 1 0 0 1 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Available devices 1 display Primary Display Driver When you click on the Advanced button you get a custom G450 dialog box which has a DualH
137. ill find in the same folder as the e5Win exe program The file you run depends on the operating system of the eyetracker PC If you are using Windows 95 or Windows 98 you should run load bat If you are using Windows 2000 you should run load_nt bat A console window will appear on the desktop and two files should upload to the ASL model 5000 M3 Finished Load UPLOAD Version 2 02 Program pattern upload program for ASL ETE ing e5121 ytes left BRT lt 21814 bytes gt 6 e5322 LRR lt 192858 bytes gt 6 s left iC WINDOWS Desktop eS5win gt C WINDOWS Desktop e5win gt If there is a problem with uploading switch the ASL model 5000 off wait 15 seconds switch it on and start again Once you have uploaded the software you can run the controller program e5Win exe m Control Program Fie Configure Calibrate Eyehead Pan Tilt MHT Misc Help Ble am ol1 2 alalsljel7 als Online COM Power J Illuminator Camera Discrimination Pupil ef B CR m a Illumination m E POG Indicator Style XHair C Cursor Color C Black White Pan Tilt Tracking Manual C Auto Time 17 47 23 Elapsed 00 00 07 Units Cm Eye Recognition e Pupil Scene POG h fo xo Pupil Diameter LOSS XDAT Data File lt NOT OPEN gt Scene POG cr Disk 346752 K bytes free Comment 2 GScnd user manual v1 29 6 November 2008 You sho
138. ines are drawn into the destination currently selected by cgsetsprite If you include the Col argument each point or line will be drawn in the requested colour otherwise the current drawing colour as set by cgpencol will be used All arrays x y x2 y2 and Col must have the same number of entries When in direct mode where Col is an n x 3 array n gives the number of entries cgdraw 0 0 Draws a point at co ordinates 0 0 cgdraw 0 0 10 10 Draws a line from 0 0 to 10 10 cgdraw 100 100 100 100 1 2 Draws two points in palette mode The first point is drawn at 100 100 in palette index and the second point is drawn at 100 100 in palette index 2 cgdraw 50 100 100 50 150 100 100 150 1 0 0 0 0 1 Draws two lines in direct colour mode The first line is drawn from 50 100 to 150 100 in colour 1 0 0 red The second line is drawn from 100 50 to 100 150 in colour 0 0 1 blue G 4 GScnd user manual v1 29 6 November 2008 cgdrawsprite Key x y lt w h gt lt Alpha gt Key Identification number of the sprite to draw X Y Co ordinates defining the target position for the sprite w h You may optionally define a width and height for the destination if you want to scale the sprite If you specify a negative value for w the image will be flipped horizontally and a negative value for h flips the image vertically Negative values for both w a
139. initializited Bytes 0 Click on the On Demand button check that the COM port setting is correct and that Baud rate is set to 57600 and then click on the Connect button The circle next to it should go green to indicate the connection is working correctly Then click on the Continuous button and you should see a steady stream of numbers in the window If this does not happen then ask a member of your computer support staff for assistance L 4 GScnd user manual v1 29 6 November 2008 The probable cause is that a setting in the e5000 cfg in the eyepos folder on the controller PC is incorrectly set The line should read serial_data_output_format 1 This sets the ASL model 5000 to send eye data only when requested If you see the following line serial_data_output_format 129 then the ASL model 5000 will send eye data continuously Although the cogent interface can deal with this this mode is undesirable because there is currently a bug with the ASL software when you perform the subject eye calibration the data mode switches back to On Demand mode This causes the data stream to stop and you have to restart it by going into the System item of the Configuration menu and clicking on OK It is a lot more convenient to operate entirely in On Demand mode right from the start L 5
140. is sprite to the offscreen area Then we set the transparent palette index for our sprite to be 11 and copy the sprite again underneath The upper sprite is drawn with the red background but the lower sprite appears without a red background as the red background was palette index 11 which we made transparent C 7 GScnd user manual v1 29 6 November 2008 Image files Images are now supported in palette mode However the image must be palette based and an extra argument StartIndex is required for the cgloadbmp command shown here in its full form RASKey RGBPal cgloadbmp Key Filename StartIndex lt Width Height gt lt SYSMEM gt The new variables are RASKey This is the key for the underlying raster for the sprite to be created This variable is only of use if you want to use some of the lower level graphics commands RGBPal This contains the palette for the image in an array of size nx3 where there are n rows one for each palette entry in the image and 3 columns red green and blue palette entry values respectively StartIndex You can choose where the image colours will be in your display palette this value 0 to 255 defines the starting palette entry for the image colours SYSMEM Lets you specify that system rather than video memory should be used See the Graphics Drivers section for further details Now for an example You can download sample BMP file Demo3 bmp from the website
141. is to be feared for always I am Caesar B 22 GScnd user manual v1 29 6 November 2008 Text rotation If you want to rotate text you must specify the orientation you want using the cgfont Fontname Fontsize FontAngle command The FontAngle argument specifies the orientation of the text in angles measured anticlockwise from horizontal left to right The alignment of text is in accordance to the orientation you select So to draw text at an angle of 20 degrees you can use the following commands gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgfont Arial 40 20 gt gt cgpencol 1 0 0 gt gt cgflip 0 0 0 gt gt cgalign c c gt gt cgtext for always I am Caesar 0 0 gt gt ceflip 0 0 0 B 23 GScnd user manual v1 29 6 November 2008 Sprites A sprite is a rectangular graphics area that you can create draw into and then manipulate If you have a complicated piece of graphics that you want to use again and again you can create a sprite for it and then use the sprite each time rather than reconstructing the graphics over and over again One example of this might be a background for a scene that you want to present a stimulus on If the background is complicated then create it once in a sprite and then draw it each time you need to redraw your graphics Another use for sprit
142. l angle as the co ordinate system for subsequent drawing operations ScrWidmm ObsDstmm Optional Specifies the width of the screen and the observer distance in millimetres Selects degrees of visual angle as the co ordinate system for subsequent drawing operations Sets the screen scaling and co ordinate system for subsequent drawing commands including cgdraw cgdrawsprite cgellipse cgloadarray cgmakesprite cgpenwid cgpolygon cgrect cgtext cgscale Set pixel co ordinates cgscale 25 4 Set the screen width to be 25 4 degrees of visual angle and select visual angle as the co ordinate system to use cgscale 400 650 Set the screen width to be 400mm and the observer distance to be 650mm and select visual angle as the co ordinate system to use G 22 GScnd user manual v1 29 6 November 2008 cgscrdmp or cgscrdmp Filename or cgscrdmp Defname Defnumber When called without arguments this command creates a screen dump of the current display and saves it in a file with the current default name The default name is of the form DefRootNNNNN BMP where DefRoot is a text prefix and NNNNN is a five digit number The initial value of DefRoot is CGSD pseudo acronym for CoGent ScreenDump and the initial value of NNNNN is 00001 The value of NNNNN is incremented each time such a file is requested So the first file is named CGSD00001 BMP the second is named CGSD00002 BMP and so on When called
143. l only work if you have a second monitor otherwise you will get an error message If you want to know what your available device options are try the command below gt gt cgopen 1 0 0 1 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Available devices 1 display Primary Display Driver If you want to list the available resolutions try the command below gt gt cgopen 1 0 0 2 Available display resolutions 1 640 x 480 2 800 x 600 3 1024 x 768 4 1152 x 864 5 1280 x 1024 6 1600 x 1200 Alternatively if you want to specify your own specific resolution and that resolution is supported by your graphics card you can use the following form of the command gt gt cgopen 1792 1344 0 0 2 The example above opens a screen 1 792 pixels wide by 1 344 pixels high You may also explicitly request a specific refresh rate such as 120 Hz by using the command cgopen 1 0 120 1 You can only request refresh rates that are supported by your graphics card See the section Direct X and Refresh rate to discover how to find out which refresh rates are supported The cgopen command was extended in v1 28 onwards to automatically search for and run a script named cginit m This was principally intended for use by system manager to implement platform specific customizations such as fixes for bugs in graphics card drivers See the Graphics Drivers section for further details Colours Co
144. lar button value using the matlab bitand function bitand bp 1 will be non zero if the left button has been pressed bitand bp 2 will be non zero if the middle button has been pressed bitand bp 4 will be non zero if the right button has been pressed You do not have to read all four variables each time the following are all valid alternatives gt gt cgmouse gt gt x cgmouse gt gt x y cgmouse gt gt x y bs cgmouse gt gt x y bs bp cgmouse This function is best demonstrated in a loop and so an example script named Mouse m has been included with the samples which you can download from the website Here is a listing of Mouse m function Mouse o9 ae Move the cursor into the display o9 le Hit a mouse button to exit o9 fprintf nMove the cursor into the display n n fprintf Hit a mouse button to exit n n cgloadlib cgopen 1 0 0 0 gsd cgGetData GSD if gsd ScreenBits cgcoltab 1 1 1 1 cgnewpal cgpencol 1 else cgpencol 1 1 1 end bp 0 while bp x y bs bp cgmouse cgellipse x y 100 100 f if gsd ScreenBits cgflip 0 else cgflip 0 0 0 end end cgshut return Ba GScnd user manual v1 29 6 November 2008 The script starts off with some help information which is also printed out as a matter of course when the script is run Then a window is opened and we use the cgGetData command to find out whether we are in palette mode gsd Scre
145. lation has gone correctly and that all the components of the program are compatible From the Matlab console type the following gt gt cgloadlib If you type the command in correctly and get an error message gt gt cgloadlib Undefined function or variable cgloadlib 1t means that there is something wrong with your installation Use the File menu Set Path item to invoke the MATLAB Path dialog box Double check that the Cogent Graphics toolbox folder is one of the listed paths and that it does contain a file named cgloadlib You may want to repeat the Cogent Graphics toolbox installation at this point The cgloadlib command prepares all the program components for execution You must start each Cogent Graphics session with this command The command also checks that all the necessary components are present If something is missing you will get an error message such as gt gt cgloadlib Undefined function cgellipse Error in gt E matlabR12 toolbox CogGphTB cgLoadLib The message above means that a file named cgellipse is missing from the Cogent Graphics toolbox If this happens you must exit matlab and re install Cogent Graphics from the web distribution The cgloadlib command also has another form cgloadlib U which unloads all the graphics library files You should not need to use this form of the command under normal circumstances B 1 GScnd user manual v1 29 6 November 20
146. lay resolution 640x480 pixels NnBWNR 9 In these lines a while loop is executed On line 8 the keyboard state is read into an array named kd When the escape key is pressed the value of kd 1 will change from zero to one and the loop will be broken Line 6 simply initializes kd 1 to zero 10 11 The full screen display is closed 12 The function has ended and control returns to the Matlab console The above example is all very well but it is somewhat lacking in excitement We can now proceed to add an animated element GScnd user manual v1 29 6 November 2008 function Example cgloadlib cgopen 1 0 0 1 siz 0 cgpenwid 10 kd 1 0 while kd 1 kd cgkeymap cgellipse 0 0 siz siz 1 1 1 cgflip 0 0 0 siz siz 2 if siz gt 640 siz 0 end OMDAIADUBPBPWNHNFPOWO WMATA UIBWNE 21 end 23 cgshut 24 return This time when you run the script you should see a simple animation You can press the escape key as before to quit the demonstration The extra lines that have been added accomplish the following 6 Sets the initial value of siz to zero 7 Sets the drawing pen width to ten units 13 Draws a circle of size siz in the centre of the screen in full white in the back buffer 14 Flips the display to make the latest circle visible and clears the back buffer to black 16 Makes siz greater by 2 17 19 If siz is greater than 640 the screen size reset it to zero We now h
147. lays the new scene Cogent Graphics display window B 17 GSend user manual v1 29 6 November 2008 Fonts A font defines the typeface in which your text will appear A particular font defines the size of the text as well as the exact shape of the letters You can also specify the text orientation which is described below under the heading Text rotation To view fonts on your computer 2 Click Start point to Settings click Control Panel and then double click Fonts 2 To look at a sample of a font click the icon for the font You can select a particular font using the egfont command cgfont Fontname FontHeight lt FontAngle gt This command selects the font called Fontname at a size specified by FontHeight and in an orientation specified by FontAngle for subsequent text drawing operations Text You can draw text using the cgtext command cgtext Text x y This command draws the given text at the point x y using the currently selected font as set by cgfont in the current drawing colour as set by cgpen The current alignment mode is used to position the text with respect to x y The following example illustrates the use of the cgtext command gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgscale 30 gt gt cgfont Arial 4 gt gt cgpencol 1 1 0 We open the graphics d
148. lette mode Alpha blending Alpha blending is not currently supported in palette mode C 17 GScnd user manual v1 29 6 November 2008 Alpha blending GScnd user manual v1 29 6 November 2008 Transparency versus alpha blending We have covered transparency in previous tutorials but let us recap with an example You should have downloaded the sample image files Demo bmp and Demo4 bmp from the website with this manual and you will use them in this exercise You can also take a look at the sample script Alpha m First of all open graphics and load the image files scaling the first to full screen 640 x 480 draw them one over the other and display the result gt gt cgloadlib gt gt cgopen 1 0 0 0 gt gt cgloadbmp 1 Demo bmp 640 480 gt gt cgloadbmp 2 Demo4 bmp gt gt cgdrawsprite 1 0 0 gt gt cgdrawsprite 2 0 0 gt gt cgflip Cogent Graphics display window You can see the superimposed figure appears with a black surround We can make this transparent using cgtrncol and repeat the process gt gt cgtrncol 2 n gt gt cgdrawsprite 1 0 0 gt gt cgdrawsprite 2 0 0 gt gt cgflip Cogent Graphics display window D 1 GScnd user manual v1 29 6 November 2008 However we can also introduce a further subtle translucency called Alpha blending Let us now blend the figure onto the background with a 50 50 blend gt gt cgdrawsprite 1 0 0 gt gt cgdrawsprite 2 0 0 0 5 gt
149. lette mode This bug has been fixed by changing CGLib_DD7 SetMode although I do not see why the original version caused a problem It may be that this bug crops up again on different systems 2 Bug fix cgMouse was not working properly on dual monitor systems This has been fixed by adding a couple of variables to CGLib m_Data MouseOffsetX amp MouseOffsetY and by modifying CGLib Mouse CGLib_DD7 MouseProc and CGLib_DD7 SetMode Changes from v1 13 to v1 14 1 Bug fix cgRect had some problems since v1 10 now fixed Changes from v1 12 to v1 13 1 New function cgScrDmp added to allow screen dumps of the display screen Changes from v1 11 to v1 12 1 Bug fix 16 bit graphics had some colour problems which have been sorted out now A 6 GSend user manual v1 29 6 November 2008 Changes from v1 10 to v1 11 1 Cogent Graphics now supports the playing of movies Changes from v1 09 to v1 10 1 The cgRect function now follows the alignment regime set up by cgAlign 2 The cgDrawSprite function can now take a width and a height so that sprites can be scaled when drawn 3 The cgMouse function now detects when the control and shift buttons are down with a mouse button 4 A new function has been added cgKeyMap which allows the user to quickly and easily scan the keyboard for keys pressed At the moment this function has not been fully integrated with the rest of cogent and there may be some problems
150. libration parameters array of 1 x 4 elements SetPars Use the cgTouch Calibrate command to perform an accurate calibration of the screen You will have to touch five reference points The command can optionally return an array of 1x4 elements as SetPars You may then use the form cgTouch Calibrate SetPars if you wish to set the same calibration parameters without going through the calibration sequence Communication with touchscreen You must first open communications with the Open command and finish by closing communications with the Shut command The Calibrate commands displays the standard calibration screen the touch command returns up to two simultaneous touch point co ordinates cgtouch Open Elotouch 1 Opens communications with the touchscreen on serial port 1 COM1 cgtouch Shut Closes touchscreen communications ID cgtouch ID Returns ID information struing about the current touchscreen xyz cgtouch touch Returns current screen touch data cgtouch Calibrate Calibrates the touchscreen NewPars cgtouch Calibrate Calibrates the touchscreen and returns the calibration parameters in NewPars cgtouch Calibrate SetPars Sets the calibration parameters to SetPars G 25 GSend user manual v1 29 6 November 2008 cgtracker Open TrackerID PortNum Mode
151. lors settings as you will be using display 2 for your windows screen You may find that you are limited in what you can choose for display 2 and you may for example have to settle for 256 colours on your Windows screen At this point you can also move the icon for display 2 your Windows screen to a different position relative to display 1 by dragging it with the mouse Display Properties 2 xi Background Screen Saver Appearance Web Effects Settings Drag the monitor icons to match the physical arrangement of your monitors 1 Display 2 Plug and Play Monitor on Matrox Graphics Millennium G200 r Colors 256 Colors 7 Screen area Less More E 1280 by 1024 pixels IV Use this device as the primary monitor WM Extend my Windows desktop onto this monitor Identify Troubleshoot Advanced Cancel Apply Then click the OK button You may need to confirm the new settings within a certain time period if you change the display dimensions You must then drag the windows taskbar onto your 2 display using the mouse and reboot your system You must have a monitor connected to your 2 video output to complete this stage If you set up your multi display system in this way you can open your Cogent Graphics screen on device so that it will run with full graphics speed by selecting 1 as the device number in the cgopen command If you set up your system in this way then it w
152. lours are represented as a mixture of red green and blue intensities The intensities can take values from zero off to one maximum intensity Thus 0 0 0 represents black 1 0 0 represents maximum red 0 1 0 represents maximum green 0 0 1 represents maximum blue Other colours can be expressed as mixtures of red green and blue 1 1 0 represents maximum yellow 1 0 1 represents maximum magenta B 5 GScnd user manual v1 29 6 November 2008 0 1 1 represents maximum cyan 1 1 represents maximum white eee 1 1 B 6 GScnd user manual v1 29 6 November 2008 Varying intensities can be expressed using decimal fractions 0 2 0 2 0 2 represents dark grey 0 5 0 5 0 5 represents mid grey 0 8 0 8 0 8 represents light grey Page flipping When you execute a drawing command there is no change visible on the screen This is because all drawing commands are executed on an offscreen area of graphics memory This offscreen area may be visualised as a rectangle exactly the same size as the screen floating somewhere invisibly in space The act of copying this invisible offscreen area to the visible monitor screen is called page flipping When you execute the cgflip command the offscreen area 1s copied to the display You can also clear the offscreen area to a flat colour at the same time gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz
153. lue should be either 8 or 16 If you do not specify this argument then 16 is used SamplesPerSecond The playing rate of the sound If you do not specify this argument then 48 000 is used Attenuation A negative attenuation in decibels db for the volume control cgsound Vol If unspecified the default value is 50db The value specified here gives the volume attenuation across the scale 0 to 1 which is passed to cgsound Vol However 0 always means silence and always means full volume If accurate values are required here it is necessary to calibrate your system independently Specify a value from 10 to 100 Device Use the device numbers returned by cgsound Devs If you do not specify this argument then 0 the default sound device is used Open the sound device You may use default values or you can specify values for Channels BitsPerSample SamplesPerSecond and Attenuation If you want to specify which sound device to use you must specify all arguments and Device must be the last one Remember to call egsound Shut when you have finished with sound cgsound open Open the sound device with the default settings Channels 2 BitsPerSample 16 SamplesPerSecond 48000 Attenuation 50db Device 0 default sound device cgsound open 1 8 22050 30 3 Open the sound device with these specific settings Channels 1 BitsPerSample 8 SamplesPerSecond 22050 Attenuation 30db Device
154. m 0 200 to 0 200 Then we set the drawing colour to maximum green and the line width to 1 pixel and draw a horizontal line from 200 0 to 200 0 To see what it all looks like we must execute the page flipping command gt gt cgflip You should see something similar to the window shown below Cogent Graphics display window You should also read Drawing multiple items later on in this section so you know how to draw many points or lines efficiently with a single command B 10 GSend user manual v1 29 6 November 2008 Rectangles scaling and alignment You can use the cgrect command to draw filled rectangles The rectangle is filled with the current drawing colour as set by cgpen The command has two forms cgrect The command on its own fills the whole destination with the current drawing colour cgrect x y w h This command fills a rectangle with the current drawing colour The centre of the rectangle is at co ordinate x y and the rectangle width and height are defined by w and h In this example we will use cgscale to use a visual angle co ordinate system We open the graphics and then set the screen width to 30 degrees We set the drawing colour to maximum red and then draw a rectangle centred on the middle of the screen with width 20 degrees and height 20 degrees a square Nothing appears on the display yet as it is all being drawn on the offscreen area gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim_ v
155. m the website in compressed format in a file named CogGphvNNN x exe where NNN represents the version number of the release When you double click this file the following dialog box will appear WinZip Self Extractor CogGphv124 exe To unzip all files in CogGphv1 24 exe to the Unzi specified folder press the Unzip button Run WinZip Unzip to folder E Browse Close M Overwrite files without prompting Freer Help When you click on the Unzip button the toolbox will be uncompressed into the location in the Unzip to folder box A new folder will be created named CogGph This in turn contains three folders CogGphTB which contains the matlab toolbox files for Cogent Graphics Doc which contains documentation and Samples which contains example Matlab scripts You should then copy the CogGphTB folder and its contents into your Matlab Toolbox folder The toolbox has been changed for v1 28 and later versions There are now mex and mexw32 files for each library These replace the previous dll files This allows for compatibility with various releases of Matlab Make sure that previous versions of Cogent Graphics are removed when you install the latest version Otherwise you may get a matlab error of the form Warning In the directory AAAA BBBB mexw32 now shadows BBBB dIl If this happens you should delete BBBB dll A12 GScnd user manual v1 29 6 November 2008 Finally you have to instruct
156. mmand returns two arrays ks and kp Both array contain 95 elements which represent the keys on the keyboard If a particular key say key n is currently pressed then ks n will equal 1 otherwise it will equal 0 The kp arrays indicate those keys that have been pressed and possibly released since the previous call to cgKeyMap The key numbers for the keys on the keyboard are given below Key No Key No Key No Key No ESC 1 26 N 49 SCROLL 70 1 2 27 M 50 HOME 71 2 3 ENTER 28 lt 51 HOME 71 3 4 ENTER 28 gt 52 UP 12 4 5 LCTRL 29 53 UP 12 5 6 RCTRLE 29 GREY 53 PGUP 73 6 7 A 30 R SHIFT 54 PGUP 73 71 amp 8 S 31 PRT SCR 55 GREY 74 8 9 D 32 L ALT 56 LEFT 75 9 10 F 33 R ALTE 56 LEFT 75 0 11 G 34 SPACE 57 CENTRE 76 _ 12 H 35 CAPS 58 RIGHT 77 13 J 36 Fl 59 RIGHTE 77 BK SP 14 K 37 F2 60 GREY 78 TAB 15 L 38 F3 61 END 79 Q 16 39 F4 62 END 79 W 17 40 F5 63 DOWN 80 E 18 41 F6 64 DOWNE 80 R 19 L SHIFT 42 E7 65 PGDN 81 T 20 I 43 F8 66 PGDN 81 Y 21 Z 44 F9 67 INS 82 U 22 X 45 F10 68 INS 82 I 23 C 46 F11 87 DEL 83 O 24 V 47 F12 88 DEL 83 P 25 B 48 NUM 69 Keys marked with a following symbol are only available on extended keyboards E 4 GScnd user manual v1 29 6 November 2008 This func
157. mp and Status Underneath that comes a count of the number of blinks detected If there is valid eyedata Pupil gt 0 crosshairs and a spot in red indicate the point of gaze on the screen Otherwise No Eye Data appears in red under the blink count You can press the R key to reset the blinks count and timestamp values to zero or the C key to display the eyetracker calibration screen The Esc key exits the script The script takes the following arguments Tracker c1 c2 c3 c4 PortNum Mode BaudRate c1 c2 c3 c4 Calibration co ordinates c3 gt cl c4 gt c2 Default values are 40 40 220 200 PortNum Serial port COM port number 1 to 8 Default value is 1 Mode Eyetracker mode 1 On Demand 0 Continuous Default is 1 On Demand BaudRate Serial port baud rate 9600 19200 38400 57600 Default value is 57600 You may use any of the forms of the command shown below Missing values assume the default setting Tracker Tracker cl c2 c3 c4 Tracker cl c2 c3 c4 PortNum Tracker cl c2 c3 c4 PortNum Mode Tracker c1 c2 c3 c4 PortNum Mode BaudRate F 5 GScnd user manual v1 29 6 November 2008 Touch The script Touch m demonstrates the touchscreen First the calibration sequence is performed and then any touches are displayed on screen by white circles with diameters proportional to the pressure of the touch Touch v1 25 P HIGH Tim 00 00 22 Frn F 6 GSend user manual v1 29 6 November 2008 Examples
158. mpling rate channels and sample size E 18 Opening and closing the sound device E 19 Playing a sound file E 20 Creating a sound in the matlab workspace E 21 Creating a stereo sound matrix E 23 Modifying sounds as they play E 24 Getting information about the sound sub system E 26 Optimising sound performance E 27 Troubleshooting sound E 28 Online help for sound E 31 Using a touchscreen E 32 Touchscreen calibration E 33 Calibration graphics co ordination E 36 Making a signal cable E 37 Generating signals E 39 Matlab scripts F Sample scripts F 1 Animation examples F 1 Balls F 2 Scroll F 2 Chess F 2 Stars F 3 Dartboard F 3 Tennis F 3 ii GScnd user manual v1 29 6 November 2008 Matlab scripts contd SoundAdj F 4 Alpha F 4 Equipment examples Tracker F 5 Touch F 6 Examples from this manual Mouse F 7 KeyMap F 8 Utilities PerfTest F 9 Equil F 10 DriverTest F 11 Function specifications G cgalign G 1 cgarc G 2 cgblitsprite G 3 cgcoltab G 4 cgdraw G 4 cgdrawsprite G 5 cgdriver G 6 cgellipse G 7 cgflip G 8 cgfont G 9 cgfreesprite G 9 cggetdata G 9 cgkeymap G 11 cgloadarray G 12 cgloadbmp G 13 cgloadlib G 14 cgmakesprite G 14 cgmouse G 15 cgnewpal G 15 cgopen G 16 cgopenmovie G 17 cgpencol G 17 cgpenwid G 17 cgphotometer G 18 cgplaymovie G 18 cgpolygon G 19 cgrect G 20 cgrotatesprite G 21 cgscale G 22 cgscrdmp G 23 cgsetsprite G 23 cgshut G 23 cgshutmovie G 24 cgsignal G 24 cgsound G 24 cgte
159. n The file to download is currently named eyps121 exe It is a self expanding archive file which will create a folder containing the program files when you run it The controller program for the eyetracker is named e5Win exe Controlling the eyetracker You need a separate PC to control the eyetracker This PC should be connected to the ASL model 5000 control unit using the PC serial port usually a male 9 pin D type connector on the back of the PC This connects to a similar male 9 pin D type connector on the back of the ASL model 5000 control unit labeled Controller 4 The cable wiring between these connectors should be as follows Pin Pin 2 2 3 3 5 The wiring should be exactly as shown above with pins 2 3 and 5 connected to corresponding pins on both connectors i e no reversal of pins 2 and 3 L 1 Port DC In Camera GScnd user manual v1 29 6 November 2008 Typically the following ports on the back of the ASL model 5000 should also be connected Eye Out Scene Out Remote Scene OR Svid In You should then switch on the ASL model 5000 and the eye camera Connected to Power adaptor Eye camera CRT monitor CRT monitor Camera or computer display via VGA convertor Then you should upload some software to the ASL model 5000 from the eyetracker PC You have to do this each time you switch on the ASL model 5000 You do this by running a batch file which you w
160. n fully integrated with the rest of cogent In particular there may be undesirable interactions between this function and cogent logging of mouse events Use this function with caution 3 Multiple displays have not yet been tested with the rest of Cogent It is possible that there could be some problems 4 The playing of movies is not supported in palette mode 5 When running a tight animation loop on a dual display system Ctrl C does not always terminate the script If this happens it is necessary to invoke the task manager with Ctl Alt Del to clear the hang 6 Alpha blending is not supported in palette mode 7 The cgloadarray command can fail under Windows 95 98 ME if the source image is much smaller than the destination sprite 8 Arcs drawn with thick lines have rounded ends under Windows 95 98 ME This can also happen occasionally with Windows 2000 A l GSend user manual v1 29 6 November 2008 Update history Changes v1 28 to v1 29 1 Function cgloadarray now correctly accepts the SYSMEM argument 2 cgtracker can now store more eye data when using the start and stop commands Changes v1 27 to v1 28 1 dll files renamed to mex and mexw32 and mexw 64 files added for each mex file This allows compatibility with Matlab r2007b and 64 bit Windows 2 cgflipQ cgpencol and cgmakesprite all now accept an 1x3 RGB array as well as the previous individual R G and B values 3 New function cgdriv
161. n to understand why this happens and how to avoid it cgsound Play 7 Play SND number 7 once only cgsound Play 8 1 Play SND number 8 continuously in a loop cgsound Shut This command closes down the sound system Call this command after cgsound Open when you have finished with sound to free up any resources you have used cgsound Shut Closes the sound system after a previous call to cgsound Open and frees any resources you have used cgsound Stop Key Key The ID number of the SND buffer to stop This command stops a SND buffer which is playing after a previous call to cgsound Play cgsound Stop 7 Stop SND number 7 after a previous call to cgsound Play H 4 GScnd user manual v1 29 6 November 2008 cgsound Vol Key Volume Key The ID number of the SND buffer to modify Volume Set a value between 0 silence and 1 maximum volume The volume scale is nominally logarithmic and you can set the full scale 0 to 1 attenuation in the cgsound Open command the default is 50db If sound volume is important to you you must calibrate your equipment using independent methods This command sets the playing volume of a SND buffer cgsound Vol 9 0 Set the volume for SND 9 to be zero silent cgsound Vol 9 1 Set the volume for SND 9 to be 1 maximum volume cgsound Vol 9 0 5 Set the volume for
162. nd h rotate the image by 180 Alpha Performs a translucent copy Alpha takes values from 0 completely transparent to 1 completely opaque When omitted the default value is 1 completely opaque This function draws the selected sprite at the co ordinates x y on the current destination as set by cgsetsprite The destination may be scaled to the specified width and height if required and flipped horizontally and vertically The sprite placement with respect to x y depends on the current alignment mode as set by cgalign If Alpha is defined a translucent copy is made cgdrawsprite 1 0 0 Draws sprite number 1 at co ordinates 0 0 on the current destination cgdrawsprite 2 0 0 10 10 Draws sprite number 2 at co ordinates 0 0 on the current destination and scales it to fit in a box 10 units square cgdrawsprite 3 0 0 20 20 Draws sprite number 3 at co ordinates 0 0 on the current destination and scales it to fit in a box 20 units square The image is flipped horizontally cgdrawsprite 1 0 0 0 25 Draws sprite number 1 at co ordinates 0 0 on the current destination A translucent copy is performed with the result being 75 of the current destination and 25 of the source sprite number 1 G 5 GScnd user manual v1 29 6 November 2008 cgdriver Fixname lt HIDE gt Fixname Which driver fix to apply MIRROR problems enlarging sprites with mirror flipping
163. ndcard on the motherboard I do not get proper separation between left and right channels for stereo sounds This can happen when you are using surround sound either knowingly or unknowingly You will typically find that you cannot completely shut off the left or right speaker using the cgsound pan command and also that you do not get pure tones from each speaker when you try the Creating a stereo sound matrix exercise The solution is to switch off surround sound This switch can be difficult to find and it seems to differ slightly depending on which soundcard you are using The first step is to run the Sounds and Multimedia item from the Control Panel J Control Panel ioj x Eile Edit View Favorites Tools Help Back gt QDSearch 4 Folders CB Uae Tae X DE Address a Control Panel z Go l Links mr n amn Ll s m r Accessibilty Add Remove Add Remove Administrative Adobe Gamma Automatic Control Panel Options Hardware Programs ools 1g A E Use the settings in Control Panel to Va 3 amp EA GT personalize your computer P AvantGo Date Time Direc Disc Detector Display Folder Options Select an item to view its description Connect Updates Windows Update E 4 pees le S fill as Windows 2000 Support a4 Z l gt Fonts Gaming Internet Keyboard Mail Mouse Options Options ra a s 4 Network and Phone and Power Options Printers QuickTime Regional Dial
164. ndom values from 320 to 320 and the y array contains random values from 240 to 240 We then open a 640x480 pixel screen clear the background to white 1 1 1 and set the drawing colour to black 0 0 0 We then use the cgdraw command to draw our array of 1000 randomly positioned pixels with a single call We can use the same method to draw lines Let us now set up two further arrays x2 and y2 which form short lines extending the single pixels into short diagonal lines 30 pixels long gt gt x2 x 30 gt gt y2 y 30 B 44 GScnd user manual v1 29 6 November 2008 We can now draw these 1000 lines in a very simple way gt gt cgflip 1 1 1 gt gt cgpencol 0 0 0 gt gt cgdraw x y x2 y2 gt gt cgflip Vj ff Gy Lis Jy ddd bi In a similar way we can draw rectangles Let us draw 1000 squares of width 10 pixels gt gt w 1 1000 10 gt gt h 1 1000 10 gt gt cgflip 1 1 1 gt gt cgpencol 0 0 0 gt gt cgrect x y w h gt gt cgflip B 45 GScnd user manual v1 29 6 November 2008 Or we can draw hollow circles instead of squares using the cgellipse command gt gt cgflip 1 1 1 gt gt cgpencol 0 0 0 gt gt cgellipse x y w h gt gt cgflip Cogent Graphics display window e v zS o oo 2 gt amp oS Bee Ero oy S ss a ae g o OB o 3 end o g 09 PD QO 4 0g Pa Lo o B00 amp 20 gB Be B o2 amp Kea 2 2
165. nes rectangles and ellipses are tested for 8 16 24 and 32 bit graphics The test should take less than five minutes During testing some messages may appear on screen as graphics screens are opened You may also see the line Number of array elements exceeds 16384 which is produced while testing whether Student Matlab is being used These messages can be ignored The first proper lines of output give the time of the test and identify the test program and machine ID of the PC as shown below perftest v1 01 10 Sep 2001 Machine mustard00 128 40 206 2 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480 85 40Hz Then for each of the graphics modes 8 16 24 and 32 bit you get lines as follows Cogent Graphics perfomance test 32 bit graphics Dots per second 126448 StdErr 87 Lines per second 32447 StdkErr 31 Rects per second 60442 StdErr 999 Ellipses per second 9941 StdErr 3 This gives the number of graphics objects drawn per second for dots lines rectangles and ellipses as well as a measure of the standard error in each measurement The variation in these measurements is due to disk activity virtual memory operations and task swapping which are part of the normal running of the operating system F 9 GScnd user manual v1 29 6 November 2008 Equil The scripts equilPAL m equilRGB m can be used to determine equiluminance points for different colours using a flicker method
166. ness of the scene they are observing You can specify different colours for the calibration screen in the following way gt gt cgtracker calibrate 1 0 0 0 0 1 Here we specify that the background of the calibration screen should be red 1 0 0 and the figures should be blue 0 0 1 Remember to shut down the eyetracker when you are finished gt gt cgtracker shut GScnd user manual v1 29 6 November 2008 Setting the Target Points As mentioned previously there are two parts to the calibration procedure The first part is to tell the ASL software where the calibration points are Generally this only needs to be done once so that the ASL software knows the general configuration of the target points on the cogent calibration screen You should not be monitoring a subject when you do this To do this part of the calibration you must run the eyepos software on the eyetracker controller PC and then select Set Target Points from the Calibration menu a SE Bjel a ajia 2 nasere ssc bof 2 es Online Scene POG Power Illuminator Camera Discrimination _ Pupil is CR ce T Illuminati m ari s Set Target Points Of x a Specify position for 1 T POG Indicator Scene Xx 46 Y 55 Style XHair C Cursor Recogniti Save Target Points and Quit oe 3 ale ede lene ee C Black White ave an eck Target Points Quit without Saving Target
167. ng up before exit G 23 GScnd user manual v1 29 6 November 2008 cgshutmovie Key Key Identification number of the movie to be closed Close a movie freeing up the memory it uses cgshutmovie 23 Closes up movie number 24 cgsignal PortNum Signal or cgsignal Shut PortNum Specifies which serial port to use 1 to 8 Signal Specifies what signal state should appear 0 to 3 Signal Outputl Output2 0 12V 12V 1 12V 12V 2 12V 12V 3 12V 12V Output1 appears on the DTR pin 4 and Output2 appears on the RTS pin 7 of a standard PC 9 pin serial port If you just need Outputl then just use Signal 0 1 to switch it off on and if you just need Output2 then just use Signal 0 2 to switch it off on Generates a signal on a serial port cgsignal 2 2 Sets the following signal state on serial port number 2 COM2 Outputl 12V Output2 12V cgsignal Shut Closes all serial ports which have been used for signals cgsound various arguments There are various commands available with this function which manipulates sound Timing resolution and synchronisation is of the order of 100mS The commands available with this function are described in a separate section cgsound functions cgtext Text x y Text The text to draw X Y Where to draw the text Draws the specified text on the current destination as selected by cg
168. ny doubt as to which to choose please consult a member of the computer support staff You should then follow the installation procedure described on the website for that component DirectX and refresh rate You may request a specific refresh rate in the cgopen command providing it is supported by your graphics card If you want a refresh rate of 100Hz you may use cgopen 1 0 100 1 You may select refresh rates in this way that are not normally available using the Direct X control panel or even under Windows This is only possible if the Forced Refresh Rate is set to Default on the DirectX control panel described below To find out which refresh rates are supported by your graphics card open the Display control panel and then click on the Advanced button A 9 GScnd user manual v1 29 6 November 2008 Display Properties 1 SONY CPD G520 on Rage Fury Pro Xpert 2000 Pro True Color 326i j Mae Click on the Adapter tab and then click the List all modes button You should see a list showing which refresh rates are supported at different display resolutions List All Modes 640 by 480 256 Colors 60 Hertz 640 by 480 256 Colors 72 Hertz 640 by 480 256 Colors 75 Hertz 640 by 480 256 Colors 85 Hertz A10 GScnd user manual v1 29 6 November 2008 If you do not see your required refresh rate then there are still a couple of things you can do First step is to go to the website
169. o do this we must define a colour array with the same number of entries as there are items to be drawn When we are in direct colour mode a colour is defined as an RGB triplet 1 0 0 represents red for example So to define an array of n colours we must define an nx3 matrix n rows and 3 columns 100 001 010 111 The above matrix defines four colours 1 0 0 red O O 1 blue O 1 O green and 1 1 1 white We can define an rgb array with 1000 values where r g and b are individually either 0 or 1 using the following lines gt gt rgb 1 1000 1 fix rand 1000 1 5 gt gt rgb 1 1000 2 fix rand 1000 1 5 gt gt rgb 1 1000 3 fix rand 1000 1 5 Now let us draw those filled sectors again this time in different colours and on a grey background gt gt cgflip 5 5 5 gt gt cgarc x y w h rgb S gt gt cgflip 5 5 5 Cogent Graphics display window gc ee B 48 GScnd user manual v1 29 6 November 2008 We can use this method to draw all the other figures in different colours too For example hollow arcs gt gt cgarc x y w h rgb gt gt cgflip 5 5 5 Cogent Graphics display window ry l Filled ellipses resetting the ellipse size to small again gt gt w 1 1000 1 rand 1 1000 19 gt gt h 1 1000 1 rand 1 1000 19 gt gt cgellipse x y w h f gt gt cgflip 5 5 5 Cogent Graphics display window t B 49
170. ode where colours are defined in red green and blue colour components However for some applications you may elect to use palette or 8 bit mode In this mode you have a fixed number of palette indices usually 256 and once you have drawn something in a particular palette index you can then set that palette index to any colour you want This mode allows you to achieve some particular animation effects very efficiently You can for example set all colours to black to blank the whole screen You can cycle colours to achieve movement You can also achieve effects of changing illumination Another reason for using 8 bit mode is increased speed Any drawing operation including clearing the screen will be up to four times faster in palette mode than in direct mode This is because each pixel on the screen is represented by a single byte in palette mode whereas it may occupy up to four bytes in direct mode Similarly palette mode conserves memory sprites will be up to four times smaller in this mode than in direct colour mode However using palette mode means that you have to manage the palette yourself and there are only 256 palette entries to play with so this can be a difficult task For this reason you should only use palette mode if you are forced to because of one of the reasons mentioned above The first tutorial section describes direct colour mode and then there is a separate tutorial on palette mode
171. of greater than 0 1 seconds or if you are synchronising your display to external control or measuring equipment Display complexity If you are running an animation at a certain frame rate say 60Hz you will have a fixed length of time available to draw each frame in this case 1 60 second or 16 7 mS If your stimulus is too complicated to draw in this time period you will find that your display will no longer run at 60Hz but will run at a slower frame rate If this is unacceptable you should first try to optimize your script so that it runs more efficiently Try to replace any for loops with matlab matrix operations try to draw multiple objects use palette animation if applicable and try drawing some complex elements of the stimulus beforehand if possible You could even consider preparing all your frames beforehand in off screen sprites Dropped frames The following sample scripts can be used to test the timing accuracy of Cogent Graphics on your PC BallsRGB BallsPAL ChessRGB ChessPAL Dartboard ScrolIRGB ScrolIPAL StarsRGB StarsPAL TennisRGB TennisPAL SoundAdj Alpha These sample scipts are described briefly in a later section of this manual Each one provides the following timing information ProgName vN NN P NORMAL Tim 00 00 05 Frm 199 Av 75 12Hz Drp 0 The components are as follows ProgName vN NN Program name and version number P NORMAL Current priority class explained below Tim 00 00 05 Time elapsed in hours minutes and
172. of the CogStd library multiplied by 100 Thus if the version number is 1 29 the value of Version will be 129 CogStdString A character string identifying the CogStd library version and compilation date J 2 GScnd user manual v1 29 6 November 2008 GPrimData structure Version The version number of the gprim library multiplied by 100 Thus if the version number is 1 29 Version will be 129 GPrimString A string identifying the GPrim library version and compilation date GLibString A string identifying the underlying graphics library version and compilation date Pix Width The width of the display screen in pixels PixHeight The height of the display screen in pixels BitDepth The number of bits for each pixel RefRate100 The display refresh rate in Hertz multiplied by 100 Thus if the refresh rate is 75 34 Hz the value of RefRate100 will be 7534 TranCOL COL structure see below containing the current transparent colour DrawCOL COL structure see below containing the current drawing colour Fontname The name of the currently selected font PointSize The pointsize for text drawing FontAngle The current text orientation Line Width The current line width CurrentRASKey The number of the currently selected raster CurrentDIBKey The number of the currently selected DIB AlignX Horizontal alignment mode 0 left justified 1 centre
173. of the manufacturer of your graphics card and install the most up to date driver for it Then reboot your machine and look again I have also found that with some graphics cards such as the Matrox G450 you can set up custom refresh rates which then become available In this way you can push the G450 up to 160Hz even though initially it appears to only go up to 85Hz You will perhaps have to tinker with these display settings to get the most out of the graphics card you have on your system However I have found that this method does not work on some operating systems If this is the case you have another way to select your refresh rate use the Direct X control panel DirectX cpl This may be downloaded from the Microsoft website as part of the DirectX SDK Software developer s kit and it should be copied into your WINNT System32 folder Windows 2000 or Windows System folder Windows 98 Once it has been installed in this way it will appear with all your other control panels Start Menu Settings Control panel Directs When you run the control panel you should select the DirectDraw tab and then set the Forced Refresh Rate to the value you require DirectX Properties 21x DirectMusic DirectPlay DirectSound DirectX Direct3D DirectDraw DirectInput Version 4 07 00 0700d i i Advanced Settings Performance Display Properties M Use Hardware Acceleration T Use Mode for 320 by x Installed D
174. open command You must have opened a cogent graphics screen before you perform a touchscreen calibration The full form of the calibration command is lt NewPars gt cgtouch Calibrate lt SetPars gt NewPars Optional If you do not want to go through the full calibration sequence every time in your script you can save the returned calibration parameters NewPars Then you can change your script so that it uses the SetPars form of the command in future Use a different calibration for each display resolution and refresh rate You may also decide to recalibrate for different touchscreen users SetPars Optional If you supply some previously acquired calibration parameters here you do not need to perform the calibration Let us now look at the calibration sequence using the simplest form of the command First open a cogent graphics window Then open communication with the touchscreen and then issue the Calibrate command gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 75 24Hz gt gt cgtouch open elotouch 1 Touch screen ID IntelliTouch 2500G v1 4 Serial ExtA D Z P16 Jumpers NVRAM boot Stream 9600Bd HWHndShk Binary Mode IniTouch Stream UnTouch Bit1 3 Z Track gt gt cgtouch calibrate If you issue a calibration command but you do not have any cogent graphics screen open you get an error message
175. oscope and photodiode circuit can then be used to check the synchronization directly You should ask a member of the computer support staff to assist you if you want to do this You should also be aware that using different graphics cards and different displays may disrupt synchronization In particular the use of LCD screens and projectors may introduce a constant timelag of one frame between issuing a cgflip or cgnewpal command and the results appearing on the display If this would affect your experiment you should consult the computer support staff who will advise you how to proceed further System Tuning On a typical PC 1 4GHz Pentium IV 256Mb RAM running Windows 2000 Matlab v6 1 and Cogent Graphics v1 29 running in the high priority class the sample scripts should exhibit a dropped frame rate of about one in a million If you find that you are getting significantly more dropped frames than this you should take steps to improve the situation The system configuration described above is the currently recommended minimum configuration Cogent Graphics will work on a machine with lower specifications but the performance may be so poor on a slower machine as to render the program unusable Problems with dropped frames are due to two possible reasons hardware conflicts and software conflicts Hardware conflicts may occur when a card in your PC is causing an interrupt which interferes with Cogent Graphics The most likely suspect here is y
176. ound device must have first been opened using the cgsound open command The first form of the command lists the capabilities of the currently opened sound device The second form lists the playback settings and the third form lists information about a chosen SND buffer cgsound Info List information about the currently opened sound device cgsound Info 0 List the playback settings for the currently opened sound device cgsound Info 3 List information about SND buffer number 3 cgsound MatrixSND Key Matrix lt BitsPerSample gt lt SamplesPerSecond gt lt Memory gt Key The ID number of the SND buffer to create Matrix Matlab matrix containing the sound sample Mono sounds are 1xn stereo sounds are 2xn Individual values are 1 to 1 BitsPerSample Optional The sound is stored internally as either 8 bit or 16 bit values Specify either 8 or 16 If you do not specify this argument then the value used for cgsound Open is used SamplesPerSecond Optional The sampling rate of the sound If the sound is sampled at 22 050 samples per second use 22 050 here If you do not specify this argument then the value used for cgsound Open is used Memory Optional If your soundcard has its own memory area you can specify 1 to force the sound to be stored there Otherwise specify 2 to use PC memory If you do not specify a value here the sound will be stored in the so
177. our network card Try unplugging your PC from the network This may well cure the dropped frames If this is the case then you should remember to unplug your PC from the network whenever you run a time critical experiment You may also be able to cure the problem by changing the process priority as described below for dealing with software conflicts or by using a different driver for your network card Software conflicts may occur between Cogent Graphics and other software that has been installed on the system Usually these conflicts can be resolved by increasing the priority class to high either by using the CogProcess command as employed in start_cogent and stop_cogent or by using the CogStd spriority high command If this fails you could try increasing the priority class to realtime using the CogStd spriority realtime command This may solve the problem but it may have undesirable consequences regarding system performance It is an option which should be tried as a simple quick fix but checks should also be made to make sure that other system processes such as keyboard mouse and serial communications and disk operations are not affected In particular a possible side effect may be that timestamps for communications events become tied to the vertical blanking interrupt of the screen If increasing the priority class to realtime does not work the next step is to try to ascertain which process is causing the conflict You should do
178. ouse position and button state Mouse position at the time of the call to cgmouse is given by x y in local co ordinates as set by cgscale The button state is given by bd bp where bd gives the mouse buttons down when cgmouse was called and bp gives the buttons that had been pressed and possibly released since the previous time cgmouse was called Buttons are given as the arithmetic sum of the following values 1 left button 2 middle button 4 right button This function reads and optionally sets the mouse When you are reading you may request as many of x y bd bp as you require This function is not yet fully integrated with the rest of cogent In particular there may be undesirable interactions between this function and the cogent logging service for mouse events Use this function with caution cgmouse 0 0 Sets the mouse position to 0 0 x y cgmouse Reads the current position of the mouse x y bd cgmouse Reads the current position and button state of the mouse lt S gt cgnewpal lt ImFlag I or i gt Palette mode ImFlag Optional If present the colour table will be made visible immediately rather than waiting for the next vertical blanking period This is appropriate when the flip immediately follows a cgflip command which automatically synchronises with the VBL anyway S Optional Timestamp in seconds for displaying the new palette
179. ovies the movie is properly fixed in the display and a memory leak has been fixed in the movie playing functions 7 The cgloadbmp function now accepts BMP files formatted to 1 and 4 bits per pixel 8 Audio and visual synchronisation problems fixed for playing of some movies Changes v1 22 to v1 23 1 A new function has been added cgTracker communicates with the ASL Model 5000 eyetracker control unit You can now read eye position in cogent screen co ordinates in real time 2 A bug has been fixed in the serial interface code for the photometer interface The cgPhotometer function should now function properly on all systems 3 A bug has been fixed in sub window mode graphics The cgFlip command now swaps background and foreground buffers in sub window mode A 4 GScnd user manual v1 29 6 November 2008 Changes v1 21 to v1 22 1 The cgopen function now accepts a bits per pixel bpp value of zero When this is passed the display is opened in 32 bpp mode If this is unavailable the display is opened in 24 bpp mode and if this is also unavailable the display is opened in 16 bpp mode This gives a mechanism of opening a display when we are not sure what bpp values are available 2 The rgb sample scripts have been modified to utilise bpp 0 They first check that we are using v1 22 or later 3 The cgloadlib unload function crashed with Matlab v12 1 it of course unloaded itself cgloadlib dll and then failed to return The unload f
180. pen a screen cgopen 2 24 0 1 Take over the whole desktop of the main monitor Set resolution 800x600 pixels 24 bit pixels Use an optimal refresh rate cgopen 3 16 60 1 Take over the whole desktop on the main monitor for graphics Make the graphics screen 1024 pixels wide by 768 pixels high and use 16 bits per pixel Set the refresh rate to 60 Hz egopen 1 0 0 0 Alpha Optimize for Alpha blending Use with caution G 16 GSend user manual v1 29 6 November 2008 cgopenmovie Key Filename Key The identification number to use for this movie Filename The name of the movie file to load This command loads a movie file for later use cgopenmovie 7 movie avi Open the movie file movie avi and associate it with ID number 7 cgpencol R G B or cgpencol RGB Direct colour mode or cgpencol PI Palette mode R G B or Drawing colour to use in subsequent drawing operations commands RGB cgdraw cgellipse cgpolygon cgrect cgtext R G and B set the red green and blue components of the colour respectively They can take values between zero and one The RGB form is a 1x3 array of R G and B values This argument is only valid in direct colour mode PI Palette index to use in subsequent drawing operations commands cgdraw cgellipse cgpolygon cgrect cgtext PI sets the palette index to use 0 to 255 This argument is only valid in palette mode Set the dra
181. present the offscreen buffer will be cleared to this palette index PI represents the palette index and takes values from 0 to 255 This argument is only valid in palette mode ImFlag Optional If present the pageflip will occur immediately rather than waiting for the next vertical blanking period This is appropriate when the flip immediately follows a cgnewpal command which automatically synchronises with the VBL anyway This argument is only valid in palette mode This argument can only be 1 or T If your hardware does not support immediate flip mode the command will return an error This command can be used to copy the offscreen buffer to the screen making it visible However the VBLFlag mode does not update the screen but simply waits until the next display frame You may optionally receive a timestamp indicating the precise time that the offscreen buffer became visible using the S variable This timestamp gives you a time in seconds since you made your initialising call to cgopen Currently the precision of the timestamp is 0 001S ImS The returned S value is always 1 in immediate mode A value of 2 indicates that an error has occurred Prior to v1 17 this function returned a timestamp in microseconds but there was a bug with this value which became negative after 35 minutes This bug has now been fixed and the function returns its timestamp in units of seconds If you supply the optional R G B
182. prite 1 0 0 160 120 0 0 640 480 gt gt ceflip 0 0 0 Cogent Graphics display window A negative value for either the source height or the destination height flips the image vertically Here we enter a negative value for the destination height 480 gt gt cgblitsprite 1 0 0 160 120 0 0 640 480 gt gt ceflip 0 0 0 Cogent Graphics display window If you enter negative values for both source and destination widths then they both cancel each other out which also happens if both heights are negative A combined horizontal and vertical flip results in a 180 rotation B41 GScnd user manual v1 29 6 November 2008 The cgblitsprite command obeys the cgalign setting The previous examples demonstrate how the command operates when alignment is set to horizontal and vertical centering However we can also demonstrate other alignment modes Here we shall set the alignment mode to left top alignment and then blit the lower right corner of the image into the lower right corner of the screen scaling the rectangle by a factor of 2 from 160x120 pixels to 320x240 pixels gt gt cgalign l t gt gt cgblitsprite 1 0 0 160 120 0 0 320 240 gt gt ceflip 0 0 0 Cogent Graphics display window Next we can set the alignment mode to right bottom and copy the upper left corner using exactly the same cgblitsprite settings once we have reset the alignment mode gt gt cgalign r b gt gt cgblitsprite 1 0 0 160 120 0
183. r for your graphics card The best source for this is usually the graphics card manufacturer rather than Microsoft 2 Ensure that you have installed the latest driver for your display device If the device appears as Plug and Play Monitor in the displays control panel then you must download and install the specific driver for your display instead Doing this often resolves problems with display timing jerky motion etc 3 Get to know the advanced control panel settings for your graphics card These differ from card to card so it is not possible to give specific advice here But if you find for example that the cgflip command is not working properly then you might find that adjusting something to do with vertical blanking resolves the problem 4 Another step which can solve many problems is simply to reboot your PC If you are developing a new display and have gone through many cgopen cgshut cycles then a reboot of the PC can sometimes resolve your problem This often seems to be relevant in dual display mode 5 Click on the Settings tab of the Display control panel and then click the Advanced button A new dialog window opens When you select the Troubleshoot tab of this dialog you should see a slider control called Hardware acceleration Sometimes you can reduce the value of this setting to cure a problem you have with the graphics If the five steps above are no use then there is a problem with the driv
184. r sets the priority level for your experiment I 1 GSend user manual v1 29 6 November 2008 n cogstd sDXVer Arguments This function takes no arguments Return values n The function returns the version number of the currently installed version of DirectX multiplied by 100 Description Use this function to get the version number of the currently installed version of DirectX multiplied by 100 For example if you have installed DirectX v9 0 gt gt n cogstd sDXVer n cogstd sGetTime t Arguments t If you supply zero or a positive value the master timer is set to that value in seconds If you supply a negative value the command will return the time elapsed since the last call to cgopen Return values n The function returns the master time in seconds This is either the time elapsed since the last call to cgopen or a timebase you have set explicitly by setting t to a specific non negative value Description This function returns the elapsed time in seconds since the last call to cgopen This function is also used internally by the Cogent Graphics functions for their returned timestamps but you can use it anywhere in your script to obtain the current time e g gt gt n cogstd sGetTime 1 Notice the value for t here 1 A negative value for t simply returns the current time If you supply zero or a positive value for t then the function resets the master time to th
185. ray has dimension n x 3 n rows and three columns The three columns represent the red green and blue components of each pixel respectively and take values from 0 to 1 In the case of a palette based image this array has just n values Each value represents an index into the palette 0 to 255 which is defined by PalRGB Matlab array defining the palette of a palette based image The appropriate type of PixVal argument must be supplied This array has dimension m x 3 m rows and three columns There may be up to 256 rows in the array The three columns represent the red green and blue components respectively of each palette entry Width and height of the sprite The image will be stretched in the x and y dimensions to exactly fit the sprite If you are using Windows 95 98 ME then the cgloadarray command can fail if the source image is much smaller than the destination sprite Lets you specify that system rather than video memory should be used See the Graphics Drivers section for further details If the image is w pixels wide and h pixels high there will be w x h pixels in the image and so there must be w x h elements in each of the R G and B arrays For example if you want to create an image that is 80 pixels wide by 70 pixels high there must be 80 x 70 5600 pixel values in the PixVal array The first value in PixVal corresponds to the top left pixel in the image and as you go on through the array elements you move horizon
186. red on the central point of the screen 0 0 because the default alignment mode is cgalign c c Now try the following example gt gt cgalign l t gt gt cgrotatesprite 1 0 0 320 240 30 gt gt ceflip 0 0 0 This time the top left corner of the sprite is aligned with 0 0 of the display because we selected cgalign I t Also note further that the image has been flipped horizontally because we specified the width of the destination as 320 Note also that we can use the egblitsprite form of the command to copy a sub rectangle of the image gt gt cgrotatesprite 1 0 120 160 120 0 0 160 120 30 gt gt ceflip 0 0 0 Cogent Graphics display window B 56 GScnd user manual v1 29 6 November 2008 You may also use transparency with rotated sprites We are going to use the demonstration image Demo2 bmp for this example Demo2 bmp is a greyscale portrait on a red background In this example we first set the alignment mode to horizontal and vertical centering and then draw the landscape image sprite 1 centred on the display gt gt cgalign c c gt gt cgdrawsprite 1 0 0 Then we load the portrait image Demo2 bmp into sprite 2 and set the transparent colour for sprite 2 to be red gt gt cgloadbmp 2 Demo2 bmp gt gt cgtrncol 2 r Then when we use the cgrotate 2 0 0 45 command the red parts of sprite 2 are not copied and we just get the
187. rivers E Bankswitched m Supported Modes Video Memory Approximate Installed 8192 0k Total Available toDDraw 3070 0k Total Free 3070 0k 12801024424 1600 1200 24 Forced Refresh Rate eo Hz 1600120016 565 al Capabilities Bit Overlays BLT BLTQUEUE BLTFOURCC BLTSTRETCH BLTCOLORFILL Advanced Cancel Apply You may find that your requested refresh rate is not supplied For example you may select 90Hz and only receive 85Hz This means that DirectX cannot supply that refresh rate and has instead given the fastest refresh rate it can for your hardware All GScnd user manual v1 29 6 November 2008 Matlab Installation The PC should have Matlab installed Either the full version of Matlab can be used or if you want to use your own personal computer you may prefer to purchase the student version of Matlab which is available at a discounted price Please refer to the Matlab documentation for installation instructions Cogent Graphics Installation The Cogent Graphics website is to be found at the following URL http www vislab ucl ac uk CogentGraphics html From that site you may download the Cogent Graphics package This is downloaded in compressed form to your PC and must be first decompressed and then copied into the Matlab toolbox directory Finally Matlab must be set up to search for commands in the new toolbox Cogent Graphics is downloaded fro
188. rogName vN NN P NORMAL Tim 00 00 05 Frm 199 Av 75 12Hz Drp 0 The components are as follows ProgName vN NN Program name and version number P NORMAL Current priority class Tim 00 00 05 Time elapsed in hours minutes and seconds since script was started Frm 199 Number of frames since script was started Av 75 12Hz Average frame rate in Hertz Drp 0 The number of frames dropped since script was started The sample scripts time each frame and calculates the average frame rate in hertz This gives an average frame time Each frame time is compared to the average and if it differs by more than 2 mS 0 002 seconds it is counted as a Dropped Frame You should read the section on Display Timing in this manual if you are concerned about timing for your experiment The following examples can be viewed in the matlab editor to see how the script achieves the animations Itis also possible to pass arguments to each of the example scripts to control display parameters but a detailed description of these examples will not be presented here Hit the escape key to terminate most of these scripts F 1 GScnd user manual v1 29 6 November 2008 Balls The first example ballsrgb ballspal draws seven moving coloured circles on the display Scroll The second example scrollrgb scrollpal draws a smoothly scrolling random grid on the display Chess The third example chessrgb chesspal draws a r
189. rol panel and then repeat the cgopen 1 8 0 1 command above You may find that your requested refresh rate has not been delivered For example you may select 90Hz and only receive 85Hz If this happens it means that DirectX has done the best it can and set the fastest refresh rate for you C 1 GSend user manual v1 29 6 November 2008 The colour table In palette mode there are 256 palette entries which can be set to whatever colour you require When you first open a screen it is filled with palette entry number 0 Initially all the colour entries are set to black gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x8 85 03Hz You can set the colour for palette entry number 0 using the cgcoltab command Here we use it to set palette entry O to colour 1 0 1 magenta gt gt cgcoltab 0 1 0 1 However the screen does not change until we issue the command to make the current colour table visible cgnewpal gt gt cgnewpal Preparing the colour table with cgcoltab and displaying it with cgnewpal is analogous to preparing graphics with the drawing commands and then displaying them with cgflip You can obtain a timestamp for displaying the new palette in the following way gt gt S cgnewpal The cgcoltab command can also accept an array to define the r g and b values gt gt rgb 11 1 gt gt cgcoltab 0 rgb Is equivalent to gt gt cgcolta
190. rom the Cogent Graphics libraries in the form of a matlab structure The structure elements are described in the Data Values chapter of this manual csd cggetdata CSD Obtains the CogStdData structure gpd cggetdata GPD Obtains the GPrimData structure ras cggetdata RAS 3 Obtains the RAS structure for raster number 3 dib cggetdata DIB 7 Obtains the DIB structure for DIB number 7 gsd cggetdata GSD Obtains the GScndData structure spr cggetdata SPR 2 Obtains the Sprite structure for sprite number 2 myd cggetdata MVD 8 Obtains the MOVData structure for MOV number 8 mve cggetdata MVE 9 Obtains the Movie structue for movie number 9 G 10 GScnd user manual v1 29 6 November 2008 lt ks lt kp gt gt cgKeyMap ks Returned array of 95 elements representing the current state of keys on the keyboard Each element can be 1 indicating the key is pressed or 0 indicating it is not pressed kp Returned array of 95 elements showing the keys that have been pressed can be 1 indicating the key has been pressed or 0 indicating it has not pres This function reads the keyboard state cgKeyMap This call on its own simply clears the state of the key pressed kp data All keys are reset to not having been pressed ks cgKeyMap Return the state of keyboard keys in the array ks ks kp cgKeyMap Return
191. rotated irregular shape of the head of the portrait gt gt cgrotatesprite 2 0 0 45 gt gt ceflip 0 0 0 B 57 GScnd user manual v1 29 6 November 2008 You can also rotate a sprite using translucency gt gt cgdrawsprite 1 0 0 gt gt cgrotatesprite 2 0 0 45 0 5 gt gt ceflip 0 0 0 If you want to rotate a sprite with translucency but without transparency the operation is much faster if you nevertheless define a transparent colour which is not in the image In this example we specify a blue transparent colour gt gt cgdrawsprite 1 0 0 gt gt cgtrncol 2 b gt gt cgrotatesprite 2 0 0 45 0 5 gt gt ceflip 0 0 0 You should bear in mind that sprite rotation takes much longer than an unrotated cgdrawsprite or cgblitsprite function call and depending on the speed of your PC and the complexity of your image you may be unable to draw a complete frame of your display within a single refresh period in a realtime animation B 58 GScnd user manual v1 29 6 November 2008 Palette mode tutorial GScnd user manual v1 29 6 November 2008 Opening and closing graphics This tutorial is for palette mode graphics You should set your Windows desktop to 256 colour mode using the display control panel see the Palette mode section in the introduction Assuming you have correctly set up your Windows desktop in 256 colour mode you should open Cogent Graphics as before gt gt cgopen 1 0 0 0
192. ry multiplied by 100 Thus if the version number is 1 29 the value of Version will be 129 GScndString A character string identifying the GScnd library version and compilation date CurrentRAS The currently selected Raster ID number Flags This contains binary flag values Currently the only flag used is 1 This flag is set to indicate that the GScnd library has opened successfully AlignX Horizontal alignment mode 0 left justified 1 centred 2 right justified AlignY Vertical alignment mode 0 top 1 centre 2 bottom Screen Width The width of the display screen in pixels ScreenHeight The height of the display screen in pixels ScreenBits The number of bits for each pixel PixScale This conversion factor is used to multiply GScnd co ordinates to convert them into gprim co ordinates PixOffsetX PixOffsetY These offsets are added to GScnd co ordinates to convert them into gprim co ordinates J 7 GScnd user manual v1 29 6 November 2008 Sprite structure The Sprite structure also comes from the GScnd library It describes a Sprite and contains the following members RASKey The identification number of the underlying gprim Raster TCol A COL structure described below containing the transparent colour for the sprite Width The width of the sprite in pixels Height The height of the sprite in pixels Flags A value of 1 indicates this sprite uses system memory The COL
193. s and prints out an error message Alright now let us try centering gt gt cgpencol 1 1 1 gt gt cgalign c c gt gt cgrect 0 0 400 80 gt gt cgpencol 0 0 0 gt gt cgalign c t gt gt cgtext Let me have men about me that are fat 0 40 gt gt cgtext Sleek headed men and such as sleep a nights 0 20 gt gt cgtext Yond Cassius has a lean and hungry look 0 0 gt gt cgtext He thinks too much such men are dangerous 0 20 gt gt cgflip 0 0 0 Let me have men about me that are fat Sleek headed men and such as sleep a nights Yond Cassius has a lean and hungry look He thinks too much such men are dangerous B 21 GScnd user manual v1 29 6 November 2008 The next example shows vertical alignment Three horizontal lines are drawn and then three lines of text The top of the first text is aligned with the first line the centre of the second text with the second and the bottom of the third text with the third gt gt cgpencol 1 1 1 gt gt cgdraw 320 100 320 100 gt gt cgdraw 320 0 320 0 gt gt cgdraw 320 100 320 100 gt gt cgalign c t gt gt cgtext I rather tell thee what is to be feared 0 100 gt gt cgalign c c gt gt cgtext than what I fear 0 0 gt gt cgalign c b gt gt cgtext for always I am Caesar 0 100 gt gt cgflip 0 0 0 I rather tell thee what
194. seconds since script was started Frm 199 Number of frames since script was started Av 75 12Hz Average frame rate in Hertz Drp 0 The number of frames dropped since script was started The sample scripts time each frame and calculate the average frame rate in hertz This gives an average frame time Each frame time is compared to the average and if it differs by more than 2 mS 0 002 seconds it is counted as a Dropped Frame An exception to this is the SoundAdj script Using the sound system can put some extra instability into the frame rate and so for this script each frame is allowed to differ by up to 4mS 0 004 seconds before it is counted as a Dropped Frame There are two checks that you should make on these timing statistics The first is to test the elapsed time counter against a stopwatch This will check that the PC s inbuilt millisecond timer is accurate It should be accurate to at least one second per hour The second is to monitor the frequency of dropped frames You should aim for a rate of one dropped frame per one million frames You must run the sample for several hours to check the statistics to this level of accuracy A16 GScnd user manual v1 29 6 November 2008 When a frame is dropped your cogent animation will appear to hesitate momentarily and the dropped frames counter will increase by one You will especially notice this if you do not use the full cogent distribution commands start_cogent and stop_cogent
195. sed This will still work although the performance may be compromised Now let us try an example using transparency gt gt cgloadbmp 2 Demo2 bmp gt gt cgdrawsprite 1 0 0 gt gt cgdrawsprite 2 0 0 gt gt cgflip 0 0 0 Cogent Graphics display window We have loaded a new image file Demo2 bmp into a new sprite number 2 and then drawn sprite 1 and then sprite 2 You can see that the new image is of a face on a red background Now let us try that again setting the transparent colour to red gt gt cgtrncol 2 r gt gt cgdrawsprite 1 0 0 gt gt cgdrawsprite 2 0 0 gt gt cgflip 0 0 0 Cogent Graphics display window B 34 GSend user manual v1 29 6 November 2008 Loading an image from the matlab workspace You can also create and display an image using the matlab workspace The image may be defined as a direct mode rgb image or as a palette defined image cgloadarray Key ImgWid ImgH t PixVal lt PalRGB gt lt SprWid SprHgt gt lt SYSMEM gt The PalRGB argument is required for a palette based image The SprWid and SprHgt arguments are optional Key ImgWid ImgHgt PixVal PalRGB SprWid SprHet SYSMEM is your ID number for the sprite which will be created are the width and height of the image in matlab Matlab array that defines the colour of each pixel in the matlab workspace image There are n ImgWid x ImgHgt pixels In the case of an RGB image this ar
196. setsprite in the current font as selected by cgfont in the current colour as selected by cgpencol at the point x y using the current alignment mode as selected by cgalign cgtext abcdef 0 0 Draws the text abcdef at the point 0 0 G 24 GScnd user manual v1 29 6 November 2008 cgtouch Open TouchID PortNum or cgtouch Shut or xyz cgtouch Touch or IDString cgtouch ID or lt NewPars gt cgtouch Calibrate lt SetPars gt TouchID Currently the only touchscreen supported is EloTouch EloTouch Intellitouch family PortNum_ Serial port to which the touchscreen is connected 1 to 8 XYZ Returned n x 3 array where n 0 if the screen is not being touched and n l or n 2 if there are one or two touches respectively The xyz elements are respectively xyz 1 x position in cogent graphics screen co ordinates xyZ 2 y position in cogent graphics screen co ordinates xyZ 3 pressure applied to screen 0 to 1 If there is no cogent graphics screen open the x and y positions are returned in the range 0 to 4095 with 0 0 as the bottom left of the screen IDString Returned 2 x n character array containing an ID string of the form cgTouch ID vn nn Compiled MMM DD YYYY IntelliTouch 2500G v1 4 Serial ExtA D Z P16 Or if communications have not yet been opened cgTouch ID vn nn Compiled MMM DD YYYY Not Initialized NewPars Ca
197. stallation A 12 gprim and cogstd A 14 Palette mode A 14 Display timing A 16 Display complexity A 16 Dropped Frames A 16 Synchronisation A 17 System Tuning A 17 Graphics Drivers A 19 Direct colour tutorial B Getting started B 1 Opening and closing graphics B 4 Colours B 5 Page flipping B 6 Co ordinate system B 7 Drawing pen B 8 Points and lines B 8 Rectangles scaling and alignment B 10 Ellipses and circles B 12 Arcs and sectors B 13 Polygons B 15 Fonts B 17 Text B 17 Text alignment B 19 Text rotation B 21 Sprites B 23 Drawing into sprites B 25 Transparency B 28 Image files B 30 Loading an image from the matlab workspace B 33 Blitting sprites B 38 Drawing multiple items B 43 Movies B 51 Sprite rotation B 54 GSend user manual v1 29 6 November 2008 Palette mode tutorial C Opening and closing graphics C l The colour table C2 cgnewpal and cgflip synchronisation C 4 Drawing commands C5 Sprites and transparency C 7 Image files C 8 Loading an image from the matlab workspace C 10 Drawing multiple items C 1l Movies C 16 Alpha blending C 16 Alpha blending D Transparency versus alpha blending D 1 Alpha performance issues D 3 Alpha blending programmer s notes D4 Further tutorials E Using the mouse E 1 Using the keyboard E 4 Screen dumps E 6 Animations E 7 Using the photometer ES Using the eyetracker E 11 Eyetracker calibration screen E 12 Setting the Target Points E 13 Calibrating each subject E 15 Using sound E 18 Sa
198. subject s point of gaze If the calibration co ordinates were supplied in the cgtracker open call then the co ordinates will be in cogent screen co ordinates otherwise they will be in arbitrary units This gives the exact time when the eyedata was received The eyetracker system calculates a new position for each frame taken by the eye camera and so if the camera is operating at 50Hz there will be a new eye position every 20mS This is the pupil diameter as calculated by the eyetracker A value of zero means that the pupil was not discriminated i e the subject had turned away or blinked This value is returned by the eyetracker A value of zero means normal operation Other values may be used to indicate special conditions Consult the ASL manual for details Timing and synchronization may be critical in studies involving eyeposition and so an internal check is made than 50mS old then a w on the timestamp for each eyedat structure If the eye data is more arning message will be generated as shown below gt gt cgtracker open ASL5000 1 50 57600 46 55 214 219 gt gt eyedat cgtracker eyedat WRN cgTracker EyeDat Eyetracker data is 0 065 seconds old gt gt cgtracker shut If no serial data has been received you will get an error message gt gt cgtracker open ASL5000 1 50 57600 46 55 214 219 gt gt eyedat cgtracker eyedat ERR cgTracker EyeDat No serial connection gt gt cgtracker shut
199. t Graphics display window should open on your desktop showing a black screen and a two line message should appear on the matlab console The first line gives the version number of the underlying gprim library that is being used and the second line tells you some information about the display that has been opened 640x480x32 denotes a display that is 640 pixels wide by 480 pixels high with pixels that are 32 bits big and 75 24Hz tells you the refresh rate of the screen in this case 75 24 hertz You can close the graphics screen with the cgshut command gt gt cgshut The window that you opened above was a sub window on the desktop This is useful for developing and debugging your experiment but when the time comes to run your experiment in earnest you will want the display to take over the whole screen This is because the program runs very slowly in sub window mode You can do this using a slightly different command gt gt cgopen 1 0 0 1 This time the whole display goes black At this point you can minimise the black full screen window by holding down the Alt key and pressing the tab key The minimised window is now represented by a rectangle on the system toolbar You can restore it by clicking on the rectangle B 4 GScnd user manual v1 29 6 November 2008 Furthermore if you have a PC with two monitors you can open the window on the second monitor using the following command gt gt cgopen 1 0 0 2 The command above wil
200. tally right along each row of pixels When you get to the right hand side of a row you then move to the leftmost pixel of the next row down in the image and then continue horizontally to the right The diagram below shows how array elements to 9 represent pixels in a three by three pixel image 1 2 3 4 5 6 71849 B 35 GScnd user manual v1 29 6 November 2008 Now for an example gt gt PixVal 000 100 010 110 001 101 011 111 000 Here we have created our 9x3 element RGB arrays which we will use to define a three by three pixel image So the 9 elements in turn have RGB components and colours as follows Array R G B_ Colour Element 1 O O O Black 2 1 0 O Red 3 O 1 O Green 4 1 1 0 Yellow 5 O O 1 Blue 6 1 0 1 Magenta 7 O 1 1 Cyan 8 1 1 1 White 9 O O O Black Translating back to pixels in an image we get Black Red Green Yellow Blue Magenta Cyan White Black So let us now create this image gt gt PixVal 00 0 100 010 110 001 101 011 111 000 gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim_ v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgloadarray 1 3 3 PixVal 240 240 gt gt cgdrawsprite 1 0 0 gt gt ceflip 0 0 0 The arrays we created were for a 3 by 3 pixel image which is rather tiny so we
201. taneously track two screen touches The Z indicates that the touchscreen will return Z data which is a number from zero to one indicating how much pressure is being applied to the screen at that point You may obtain the ID string for the currently opened touchscreen at any time using the cgtouch id command gt gt s cgtouch id Ss cgTouch ID v1 29 Compiled Nov 6 2008 IntelliTouch 2500G v1 4 Serial ExtA D Z P16 When you have finished using the touchscreen it is important that you close the connection using the command below gt gt cgtouch shut E 32 GScnd user manual v1 29 6 November 2008 Touchscreen calibration Cogent assumes by default that the display on the touchscreen corresponds exactly to the co ordinates it receives This is fine as a rough and ready approximation but if you require more accurate co ordinates then you will need to carry out a calibration This is a fairly simple operation during which five points are displayed on screen in turn and the operator is asked to touch each point as it appears At the end of the calibration an array of four calibration values is returned Once this has been done for a screen of a particular resolution and refresh rate you can use those four calibration values again without having to go through the full calibration process If you want to use the more accurate calibrated points then a calibration command must be executed directly after every cgtouch
202. te srcw srch The width and height of the rectangle on the source sprite If you specify a negative value for srcw the image will be flipped horizontally and a negative value for srch flips the image vertically Negative values for both srcw and srch rotate the image by 180 However if you choose negative values for both srcw and dstw or srch and dsth they cancel each other out dstx dsty Co ordinates defining the position of the rectangle on the destination dstw dsth You may optionally define the width and height of the rectangle on the destination if it differs from the source sprite dimensions If you specify a negative value for dstw the image will be flipped horizontally and a negative value for dsth flips the image vertically Negative values for both dstw and dsth rotate the image by 180 However if you choose negative values for both srcw and dstw or srch and dsth they cancel each other out Alpha Performs a translucent copy Alpha takes values from 0 completely transparent to 1 completely opaque When omitted the default value is 1 completely opaque This function copies an arbitrary rectangle from a sprite to the current destination as set by cgsetsprite The destination may be scaled to the specified width and height if required and flipped horizontally and vertically The sprite placement with respect to x y depends on the current alignment mode as set by cg
203. tely necessary You must run the ASL eyetracker software and adjust it correctly for your subject so that the pupil and corneal reflection is being correctly discriminated Then display the cogent calibration screen kg ES sjej m olrjejaja sjelzlajo e 4 Online COMI g Bis Power Illuminator Camera Discrimination Pupil Ld E 4 CR mf ot Illumination T POG Indicator Style g Se Eye Calibration x Color Get Calibration Data C Black White Tell subject to look at point E si T Custom Calibration Ok Cancel Pan Tilt Tracking Data File lt NOT OPEN gt Disk 359488 K bytes free Manual Auto Comment Time 12 54 39 Elapsed 01 03 55 Units Cm You should then ask your subject to look at each of the points in turn on the cogent display and when they look at each one click on the Store Data for Current Point so that all nine points are stored That completes the calibration GSend user manual v1 29 6 November 2008 Eyetracker eye data You can obtain eye data from the eyetracker using the eyedat command gt gt cgtracker open ASL5000 1 1 57600 46 55 219 214 gt gt eyedat cgtracker eyedat eyedat X 280 Y 176 Timestamp 17 6532 Pupils 7 Status 0 gt gt cgtracker shut The eyedat structure contains the following elements X Y Timestamp Pupil Status The X and Y co ordinates of the
204. tem is being used cgpencol 1 0 0 Sets the current drawing colour to maximum red You can also use the form cgpencol 1 0 0 Points and lines You can use the egdraw command to draw points and lines The command can take two forms cgdraw x y Draws a point at co ordinate x y The point is drawn in the current drawing colour cgdraw x1 y1 x2 y2 Draws a line between co ordinates x1 y1 and x2 y2 The line is drawn in the current drawing colour The width of the line may be set with the cgpen command Try the following exercise gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgpencol 1 1 1 So far we have opened the graphics and then set the current drawing colour to maximum white Now let us draw some points gt gt cgdraw 100 100 gt gt cgdraw 100 100 gt gt cgdraw 100 100 gt gt cgdraw 100 100 Of course nothing appears on screen yet because it is all being drawn on the offscreen area Anyway for the moment trust that the points have been drawn Now let us add some lines gt gt cgpencol 0 0 1 gt gt cgpenwid 5 gt gt cgdraw 0 200 0 200 gt gt cgpencol 0 1 0 gt gt cgpenwid 1 gt gt cgdraw 200 0 200 0 B 9 GScnd user manual v1 29 6 November 2008 First we set the drawing colour to maximum blue and the line width to 5 pixels Next we draw a vertical line fro
205. the Close button Advanced Controls for Playback Control x Ej These settings can be used to make fine adjustments to your audio r Tone Controls These settings control how the tone of your audio sounds Treble r Other Controls These settings make other changes to how your audio sounds See your hardware documentation for details T 1 Spatial 4 I get dropped frames when I use sound Using sound can introduce some variability into the Cogent Graphics frame rate You may find that individual frames are off by up to 4mS rather than the usual 2mS value Allow a greater margin for detecting dropped frames if you notice this happening but beware if the variability starts to get close to the actual frame rate that does mean frames are being dropped E 30 GSend user manual v1 29 6 November 2008 Online help for sound To list all available commands type the following gt gt cgsound ERR GScnd cgSound Usage ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR cgSound Devs cgSound Free Key cgSound Frq Key Factor Matrix lt SamplesPerSecond lt BitsPerSample gt gt cgSound GetSND Key cgSound Info GScnd cgSound cgSound MatrixSND Key Matrix lt BitsPerSample gt lt SamplesPerSecond gt lt Memory gt ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound ERR GScnd cgSound
206. the eyetracker it is important that you close the connection using the command below gt gt cgtracker shut GScnd user manual v1 29 6 November 2008 Eyetracker calibration screen In order to use the eyetracker correctly you must calibrate it for your subject There are two steps to this first you must let the ASL software know where your calibration points are and secondly you must ask your subject to look at each calibration point in turn and tell the ASL software when they are doing so There is a command to let you do the calibration Try the lines below gt gt cgtracker open ASL5000 1 1 57600 gt gt cgtracker calibrate GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 59 96Hz The screen should appear as shown below Eye tracker calibration screen This screen can be used to perform both parts of the calibration procedure and it will stay on the display until you press the Esc key You may use it at any point even during a Cogent Graphics experiment and it will appear in the current display and when you exit the display should be restored to its original condition You may use this feature to recalibrate during an experiment at any time You may want to use different colours for the calibration screen which more closely resemble the colours of your stimulus This is because your subject s pupil diameter will change according to the overall bright
207. the state of keyboard keys in the array ks and a record of all keys that have been pressed since the previous call to cgKeyMap in array kp Key codes are as follows Key No Key No Key No Key No ESC 1 26 N 49 SCROLL 70 1 2 i 27 M 50 HOME 71 py 3 ENTER 28 lt 51 HOME 71 3 4 ENTERE 28 gt 52 UP 12 4 5 LCTRL 29 53 UPE 72 5 6 RCTRLE 29 GREY 53 PGUP 73 6 7 A 30 R SHIFT 54 PGUP 13 T amp 8 S 31 PRT SCR 55 GREY 74 Se 9 D 32 L ALT 56 LEFT 75 9 10 F 33 R ALTE 56 LEFT 75 0 11 G 34 SPACE 57 CENTRE 76 _ 12 H 35 CAPS 58 RIGHT 11 13 J 36 F1 59 RIGHT 77 BK SP 14 K 37 F2 60 GREY 78 TAB 15 L 38 F3 61 END 79 Q 16 a 39 F4 62 END 79 W 17 40 F5 63 DOWN 80 E 18 41 F6 64 DOWNE 80 R 19 L SHIFT 42 F7 65 PGDN 81 T 20 l 43 F8 66 PGDNE 81 Y 21 Z 44 F9 67 INS 82 U 22 X 45 F10 68 INS 82 I 23 C 46 F11 87 DEL 83 O 24 V 47 F12 88 DEL 83 P 25 B 48 NUM 69 Keys marked with a following symbol are only available on extended keyboards GSend user manual v1 29 6 November 2008 lt RASKey gt cgloadarray Key aw ah Pix Val lt PalRGB lt StartIndex gt lt sw sh gt lt SYSMEM gt RASKey Optional This gives the ID number of the raster that has been created for this sprite The raster is created by the underlyin
208. tion is best demonstrated in a loop and so an example script named KeyMap m has been included with the samples which you can download from the website Here is a listing of KeyMap m function KeyMap oP ole Click in the display window to activate it and then press any key to see its keycode oP ol Hit Esc to exit ole ol fprintf nClick in the display window to activate it n fprintf and then press any key to see its keycode n n fprintf Hit Esc to exit n n cgloadlib cgopen 1 0 0 0 kd 1 0 while kd 1 kd kp cgkeymap kp find kp if length kp fprintf Key d n kp end end cgshut return The script starts off with some help information which is also printed out as a matter of course when the script is run Then a window is opened and the value of kd 1 is set to zero The value of kd 1 will reflect the state of the escape key on the keyboard and the statement while kd 1 sets up a loop which will continue until the escape key is pressed Inside this loop we obtain the state of the keyboard with the command kd kp cgkeymap and then we find all the keys that have been pressed since the last call using the command kp find kp which selects all non zero values in the kp array If there are any keys that have been pressed then the statement if length kp will be true and we print out the number of the key with the fprintf Key d n kp command The two end statements clos
209. ue to the nex This utility tests each known driver bug in turn on your system and informs the operator which cgdriver command should correct the problem Any cgdriver commands already in force from entries in cginit m will be used and so the operator will not be told to apply them again For a full overview of topics surrounding the drivertest utility please read the section on Graphics Drivers F 11 GSend user manual v1 29 6 November 2008 Function specifications GSend user manual v1 29 6 November 2008 cgalign XAlign Y Align XAlign T c or r for left centre or right alignment respectively YAlign t c or b for top centre or bottom alignment respectively This function sets the alignment mode for the cgtext cgrect and cgdrawsprite commands If left alignment is chosen the text rectangle or sprite will have its left edge aligned with the x co ordinate If centre alignment is chosen the text rectangle or sprite will be centred horizontally on the x co ordinate If right alignment is chosen the text rectangle or sprite will have its right edge aligned with the x c ordinate In a similar way the YAlign argument controls the vertical placement of the sprite with respect to the y co ordinate cgalign l t Selects left and top alignment for cgtext cgrect and cgdrawsprite commands G 1 GScnd user manual v1 29 6 November 2008 cgarc cx
210. ues will be in cogent screen co ordinates Otherwise they will be in arbitrary units A pupil radius of zero means that the pupil was not discriminated The subject was either looking away or had closed their eye Communication with eyetracker You must first open communications with the Open command and finish by closing communications with the Shut command The Calibrate commands displays the standard calibration screen the eyedat command returns the current eye position The Start and Stop commands are used to retrieve a sequence of positions cgtracker Open ASL5000 1 1 57600 46 55 219 214 Opens communications with the ASL5000 eyetracker on serial port 1 COM1 in On Demand mode at 57600 baud with calibration co ordinates 46 55 219 214 cgtracker shut Closes communications with the eyetracker cgtracker calibrate 1 0 0 0 0 1 Displays the eyetracker calibration screen with a red 100 background and blue 0 O 1 characters eyedat cgtracker eyedat Obtains the latest eyedata from the eyetracker cgtracker start Starts recording eye data eyearray cgtracker stop Stops recording eyedata and returns an array of eyedat structures G 26 GScnd user manual v1 29 6 November 2008 cgtrncol Key lt TCol gt Direct colour mode or cgtrncol Key lt PI gt Palette mode Key The ID number of the sprit
211. uld check that the Online button is green which indicates that the link has been established If it is red then there is a problem Check the cables into the ASL model 5000 again and check that you have uploaded the software correctly Check also that you are using the correct serial port on the controller PC You should be using the serial port for COMI If you need to use another serial port you should select System Settings from the Configure menu and set the Interface port appropriately as shown below E System Settings ME E System Type Head mounted optics Pan Tilt optics Pan Tilt optics with MHT option Eye Camera Speed 50 z Number of Eye Position Fields to Average a T Dark Pupil Direct Scene Camera IV Use Metric System centimeters T Auto Record T Auto File Open T 17 Point Eye Calibration Scene Video Source C Au C Camera and Remoe Scene connectors Interface Port COM2 coe You should also check with your computer support staff that the other settings are correct for the apparatus you are using In particular you should set the Eye Camera Speed to the correct value for the camera that you are using and you should select the appropriate System Type for your equipment If that still does not work then ask a member of your computer support staff for assistance You should now be able to control your eyetracker as described in the appropriate manu
212. unction does NOT now unload cgloadlib 4 A small bug has been fixed in gprim gRectFill When called with no arguments it now functions correctly 5 A message processing loop in gprim gFlip has been added so that graphic animations work better with Matlab v12 1 Specifically Alt Tab can now be used to flip to the matlab console and some occasional flashes of white after a few seconds of running scripts that don t poll the keyboard or mouse no longer occur Changes v1 20 to v1 21 1 The cgloadlib function which was previously implemented as a matlab script m or p file has now been implemented as a library dll file This is because older versions of Matlab would not run the pcode file The function can now also unload the libraries if requested There should not be any conflict with previous undeleted copies of cgloadlib m and cgloadlib p because the dll file takes precedence Changes v1 19 to v1 20 1 A new function cgBlitSprite has been added which can copy arbitrary rectangles from one sprite to another 2 A bug has been fixed in the underlying gprim libraries so that cgFlip now operates correctly in immediate mode Changes v1 18 to v1 19 1 A new function cgArc has been added which can draw hollow arcs or filled sectors 2 Minor bug fix back buffer is cleared to black or palette index 0 when graphics are opened A 5 GSend user manual v1 29 6 November 2008 Changes v1 17 to v1 18 1 Bug fix
213. undcard s memory unless there is none available in when it will use PC memory Load up a sound from a matlab workspace matrix Create the matrix to be 1xn for mono sound or 2xn for stereo sound The individual values should range from 1 to 1 You can optionally specify BitsPerSample and SamplesPerSecond otherwise the values used in cgsound Open are assumed Specify Memory 1 if you want the sound to be loaded into the memory area of your soundcard if it has one cgsound MatrixSND 17 m 8 11025 1 Create a new SND buffer number 17 with the sound sample in matrix m The sound will be 8 bits per sample 11 025 samples per second and it will be stored on the soundcard s dedicated memory area cgsound MatrixSND 19 m2 22050 Create a new SND buffer number 19 with the sound sample in matrix m2 The sound is sampled at 22 050 samples per second Use the value from cgsound Open for sample size H 2 GScnd user manual v1 29 6 November 2008 cgsound Open Channels BitsPerSample SamplesPerSecond Attenuation All arguments are optional or cgsound Open Channels BitsPerSample SamplesPerSecond Attenuation Device All arguments are compulsory and Device must be the last one Channels Specify 1 for mono sound 2 for stereo sound If you do not specify this argument then 2 stereo is used BitsPerSample The sound is stored internally as either 8 bit or 16 bit values This va
214. used the SprWid and SprHgt arguments of the cgloadarray command to blow the image up to a 240 by 240 pixel sprite The results should be as we predicted Cogent Graphics display window B 36 GScnd user manual v1 29 6 November 2008 To demonstrate transparency we can create another smaller sprite from our array but we shall make the central blue square transparent We can then draw it over the image above to illustrate the transparency of the central square gt gt cgloadarray 2 3 3 PixVal 80 80 gt gt cgtrncol 2 b gt gt cgdrawsprite 1 0 0 gt gt cgdrawsprite 2 120 120 gt gt cgflip 0 0 0 Cogent Graphics display window It is also possible to define the same image using a palette based system gt gt PixVal 01234567 8 gt gt PalRGB 00 0 100 010 110 001 101 011 111 000 gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgloadarray 1 3 3 Pix Val PalRGB 240 240 gt gt cgdrawsprite 1 0 0 gt gt ceflip 0 0 0 Here we have defined our pixel values as palette indices 0 to 8 and we have also defined a palette which contains the 9 colours defined previously The result should be the same Cogent Graphics display window B 37 GScnd user manual v1 29 6 November 2008 If you are using Windows 95 98 ME the command can sometimes fail and you may get an
215. value Alternatively you may specify 2 to load the sound into software memory Software memory is located in the PC s RAM memory space rather than on the soundcard If no memory type is specified the sound will be loaded into hardware memory if it is available or software memory if not cgsound play Key lt LoopFlag gt Key This value identifies the sound you want to play LoopFlag optional If you set this value to 1 the sound will repeat itself over and over again You may set the sound to play forever by setting LoopFlag to 1 gt gt cgsound play 6 1 You can stop the sound playing by using the stop command gt gt cgsound stop 6 And when you have finished using the sound you should free the resources it uses gt gt cgsound free 6 GScnd user manual v1 29 6 November 2008 Creating a sound in the matlab workspace You can also create a sound as a matlab matrix Let us make a sound which is a sine wave of a frequency of 330Hz lasting 2 seconds at a sampling rate of 48 000Hz The sound will have 2 x 48 000 96 000 samples and so the matrix will have 96 000 values Let us set up an intermediate matrix im simply containing the numbers 1 to 96 000 gt gt im 1 96000 Now create another matrix ang which converts im into an angle corresponding to a frequency of 330Hz gt gt ang im 2 pi 330 48000 Angles in radians are used here and so im is multiplied by 2 x pi and then by the desired fr
216. values the offscreen area will be cleared after the pageflip to that colour If you are in palette mode you can use the PI value to clear the offscreen area to that palette index after the pageflip In palette mode you can also specify the immediate mode for the flip if it immediately follows a cgnewpal cgflip Makes the offscreen buffer visible S cgflip Makes the offscreen buffer visible and records the time it became visible in S S cgflip V Waits for the next display frame and records the time in S ceflip T Makes the offscreen buffer visible immediately without waiting for the vertical blanking interval This form is only available in palette mode S ceflip 5 5 5 Makes the offscreen buffer visible records the time it became visible in S and then clears the offscreen buffer to colour RGB 0 5 0 5 0 5 mid grey This form is only available in direct colour mode S ceflip 10 Makes the offscreen buffer visible records the time it became visible in S and then clears the offscreen buffer to palette index 10 This form is only available in palette mode G 8 GSend user manual v1 29 6 November 2008 cgfont Fontname Fontheight lt Fontangle gt Fontname The name of the font you want to use Fontheight The height of the font you want to use Fontangle Orientation of text in degrees measured anticlockwise from left to right This function loads the specified font It
217. w ellipse with the same dimensions as the first ellipse Finally we display what we have drawn gt gt cgpencol 0 0 1 gt gt cgellipse 0 0 10 10 f gt gt cgpencol 0 0 0 gt gt cgellipse 0 0 2 2 f gt gt cgpencol 1 0 0 gt gt cgpenwid 1 gt gt cgellipse 0 0 20 10 gt gt cgflip Cogent Graphics display window You should also read Drawing multiple items later on in this section so you know how to draw many ellipses efficiently with a single command B 13 GScnd user manual v1 29 6 November 2008 Arcs and sectors You can use the cgarc command to draw hollow arcs and filled sectors cgarc cx cy w h al a2 Typ This command draws an arc using the current drawing colour and the current line width as set by cgpen The arc is drawn around the circumference of an ellipse with centre at co ordinate cx cy and the ellipse width and height are defined by w andh The starting and ending angles of the arc are defined by al and a2 see below The Typ argument can take the value A the default to draw hollow arcs or S to draw filled sectors The al and a2 arguments define the start and end angles of the arc These are specified in degrees with zero degrees being a horizontal direction to the right Angles increase anti clockwise so that 90 is a vertical upward direction 180 is horizontally to the left and 270 is vertically down The figure below shows an arc defined by al 10 a2 90 N
218. w function has been added cgSound This function allows you to create and manipulate sounds There is also a new sample script SoundAdj 2 A new function has been added cgSignal This function allows you to create digital signals on the serial port which can be used in combination with an oscilloscope for accurate synchronisation of sound and visual effects 3 The cgopen command now displays the version of DirectX that is installed on the PC 4 cgDrawSprite and cgBlitSprite now support horizontal and vertical flipping 5 cgOpen cgDrawSprite and cgBlitSprite now support Alpha blending translucency and there is a new sample script Alpha m 6 The manual contains a new section describing a selection of the cogstd commands 7 Bug fixes cgmakesprite command sprites wider than the screen could not be made on some graphics cards System memory now used for these sprites rather than video memory Another fix cgscrdmp works properly in palette mode Finally palette mode has been stabilized on W2000 system colours are now restored properly by cgShut 8 A new function has been added cgTouch This function allows you to receive input from a touch screen There is also a new sample script Touch 9 cgOpen can now specify the resolution as individual X and Y pixel dimensions A 3 GScnd user manual v1 29 6 November 2008 Changes v1 23 to v1 24 1 A bug has been fixed in the cgFlip function T
219. w is 300Hz duration 1 second sampling rate 48 000Hz Open the sound device and load the matrix into sound buffer number 1 gt gt mat sinwav 300 1 48000 gt gt cgloadlib gt gt cgsound open cgSound v1 29 Compiled Nov 6 2008 Sound library DirectSound v9 DX9 0 Compiled Nov 6 2008 Primary Sound Buffer 2x16x48000 Vol Att 50 0 gt gt cgsound matrixSND 1 mat 48000 Now set it playing continuously gt gt cgsound play 1 1 You can now modify the loudness of the sound as follows gt gt cgsound vol 1 0 9 Now reset the volume to the original level gt gt cgsound vol 1 1 You specify the volume on a scale of 0 to 1 0 9 is used above Zero always means silent and 1 always means maximum volume The underlying DirectSound interface uses a nominal attenuation of 100db for silence and Odb for maximum volume but I have found that this compresses the useful volume range into just half the available scale attenuations of less than 50db are barely audible on my system even with the amplifier gain set to maximum With this in mind I have remapped the volume scale to use 50db attenuation as the default If you want to change the volume scale you can do so in the egsound open command by seting your desired value for the Attenuation argument Remember though that the volume attenuation is nominal and will depend on your amplifier and speaker system so if sound intensity is important to you you will have to c
220. wing colour for use in subsequent drawing operations cgpencol 1 0 0 Set the drawing colour to be 1 0 0 maximum red cgpencol 22 Set the drawing palette index to 22 cgpenwid Width Width Line width to use in subsequent drawing operations commands cgdraw and cgellipse Units depend on the current co ordinate system as selected by cgscale A value of zero always sets the line width to a single pixel Set the line width for use in subsequent drawing operations cgpenwid 5 Set the line width to be 5 units G 17 GScnd user manual v1 29 6 November 2008 cgphotometer Open PhotometerID PortNum or cgphotometer Shut or str cgphotometer ID or xyz cgphotometer X YZ or spc cgphotometer SPC PhotometerID Currently the only photometer supported is PR650 PhotoResearch PR 650 Spectra Colorimeter PortNum Serial port to which the photometer is connected Takes values from 1 to 8 str Array of two strings The first string identifies the version number of cgphotometer The second string identifies the photometer XYZ Array with three elements containing the CIE 1931 X Y and Z values from the last measurement spc n x 2 array containing the radiant spectrum from the last measurement spc 1 contains the wavelength in nanometres for each measurement spc 2 contains the spectral radiance in Wm sr nm
221. witched off for the sprite You may choose from the following values n selects black 0 0 0 r selects maximum red 1 0 0 g selects maximum green 0 1 0 y selects maximum yellow 1 1 0 b selects maximum blue 0 0 1 m selects maximum magenta 1 0 1 ce selects maximum cyan 0 1 1 w selects maximum white 1 1 1 Consider the following example gt gt cgloadlib gt gt cgopen 1 0 0 0 GPrim v1 29 Compiled Nov 6 2008 GLib DirectDraw v7 DX9 0 Compiled Nov 6 2008 Display 640x480x32 72 85Hz gt gt cgpencol 0 0 1 gt gt cgrect gt gt cgpencol 1 1 0 gt gt cefont Arial 240 gt gt cgtext SPQR 0 0 gt gt cefont Arial 40 gt gt cgpencol 1 0 0 We open the graphics clear the offscreen area to blue and then draw some yellow text on the screen We then select a smaller font and set the pen to red gt gt cgmakesprite 1 600 40 0 1 0 gt gt cgsetsprite 1 gt gt cgtext Senatus Populusque Romanus 0 0 gt gt cgtrncol 1 g gt gt cgsetsprite 0 gt gt cgdrawsprite 1 0 50 gt gt cgtrncol 1 gt gt cgdrawsprite 1 0 50 gt gt cgflip B 30 GScnd user manual v1 29 6 November 2008 Here we make sprite 1 This sprite is initialised to a green background and we draw some red text into it Then we set the transparent colour for the sprite to green We then copy it into the offscreen buffer Then we switch o
222. with just the Filename argument this command creates a screen dump of the current display and saves it in a file named Filename BMP When called with both the Defname and Defnumber arguments no screen dump is created but the default filename DefRoot and NNNNN values as described above are set to Filename and Filenumber respectively Cgscrdmp Save the current display as an image file The first file created will be called by default CGSD00001 BMP the second CGSD00002 BMP and so on cgscrdmp jpr Save the current display as an image file named jpr BMP cgscrdmp Picts aa 10 Do not create an image file but set the default filenaming to be Picts aa00010 BMP Picts aa00011 BMP etc This puts all the screendump files in a sub folder named Picts You must create the Picts subfolder beforehand cgsetsprite Key Key The ID number of the sprite to use for subsequent drawing operations Allowable values are 1 to 10000 or if you specify zero the offscreen area will be used Sets the destination for subsequent drawing commands cgdrawsprite cgellipse cgpolygon cgrect cgtext cgsetsprite 17 From now on draw into sprite number 17 cgsetsprite 0 From now on draw into the offscreen area including cgdraw cgshut Close down graphics closing the screen freeing all memory and cleaning up before exit cgshut Closing the screen and cleani
223. xt G 24 cgtouch G 25 cgtracker G 26 cgtrncol G 27 cgvers G 27 iii GScnd user manual v1 29 6 November 2008 cgsound functions cgsound Devs cgsound Free cgsound Frq cgsound GetSND cgsound Info cgsound MatrixSND cgsound Open cgsound Pan cgsound Play cgsound Shut cgsound Stop cgsound Vol cgsound WavFilSND cogstd helper functions Introduction Identification functions System functions s cogstd sDXVer n cogstd sGetTime t s cogstd sMachineID s cogstd sOSID s cogstd sPriority Lev s cogstd sUserID Data Values Introduction CogStdData structure GPrimData structure RAS structure DIB structure MOVData structure GScndData structure Sprite structure Multiple Displays Introduction Recommendations Single Monitor Display Single graphics card dual display Single display dual monitor Two graphics cards one disabled Two graphics cards Eyetracker setup Eyetracker introduction Eyetracker software Controlling the eyetracker Connecting to your cogent PC iv GScnd user manual v1 29 6 November 2008 Introduction GScnd user manual v1 29 6 November 2008 Known bugs and limitations 1 When using more than two monitors try to use the rightmost and bottommost screen for the cogent display Otherwise the cgMouse function may behave strangely 2 The cgMouse function has not yet bee
224. y up to 4mS when using sound E 27 1 GScnd user manual v1 29 6 November 2008 Troubleshooting sound I get periodic clicks when I play my sound continuously If you make a sound which you want to play continuously using the cgsound play Key 1 command you must ensure that the last point of the soundwave marries correctly with the first point and forms a seamless wave as it loops through Consider the wave shown below This wave is not an integer number of wavelengths long and so when it repeats there will be a discontinuity shown in red below which will cause a click in the sound output Now consider the waveform below It is exactly two wavelengths long When it repeats the join shown in red marries perfectly and so there is no click in the sound output 2 3 GScnd user manual v1 29 6 November 2008 When I put two soundcards in my PC neither one works properly I tried installing two Creative brand PCI soundcards in my PC and I found that neither worked properly they both emitted a weird whirring noise instead of producing the sounds they were supposed to When I contacted the manufacturers they told me that multiple soundcards are not supported and that there was nothing I could do I tried changing various settings and ended up concluding the same thing so be aware of this problem In the end I successfully installed the extra PCI soundcard on a different PC that had an integral sou

GScnd v1.29 User Manual

Contents

Download Pdf Manuals

Related Search

Related Contents