Wiley Professional XNA Programming : Building Games for Xbox 360 and Windows with XNA Game Studio 2.0, 2nd Edition
Contents
1. XNA Pie tor tor sprites End base Draw gameTime Draw gameTime Now you can start your project and move around with up and down This is pretty good for your first little application isn t it Notes about XNA To finish this chapter here are some additional tips and tricks about the XNA Framework and XNA Game Studio Express 1 0 and 2 0 As you saw you can just start coding and it works great but it is always good to have a couple of bookmarks for your browser you can rely on when you run into prob lems or don t know how to solve a specific issue Additionally this section discusses the advantages of NET and Cf a little and checks out the differences between XNA and Managed DirectX Important Links Here are a few links for your bookmarks A http msdn microsoft com directx xna XNA Developer Center on Microsoft s MSDN page with the XNA Game Studio Forum and the XNA Framework Forum which are the most active XNA forums you will find on the Internet You can also download the latest XNA version here read the FAO and see what s new AQ http en wikipedia org wiki Microsoft_XNA Entry on Wikipedia about XNA con stantly updated and contains many links to other topics A few useful external links are listed on the bottom of the page A www thezbuffer com One of the first Managed DirectX sites with a lot of articles links to blogs and people Andy Dunn the creator of the site always keeps it up to date sho2. formats available today Because XNA does not support the fixed function pipeline anymore as DirectX or Managed DirectX do it is important that you have a graphic card that supports at least Shader Model 1 1 or even better Shader Model 2 0 The first graphic cards with shader support were shipped back in 2001 GeForce 3 and ATI 7000 the next generation with Shader Model 2 0 GeForce 5x ATI 9x00 Series was introduced in 2003 and made popular by the many games in 2004 that made good use of shaders Far Cry Doom 3 Half Life 2 Shader Model 3 0 GeForce 6x ATI x1000 Series was the standard in 2006 and new cards with Shader Model 4 0 GeForce 8x were shipped late 2006 early 2007 The Xbox 360 uses an extended version of Shader Model 3 0 So this is what you need at a minimum before attempting to install XNA Game Studio Express Windows XP SP2 or Windows Vista 512MB RAM but better to have more 1 or 2 GB 1 GHz CPU the faster the better using the IDE and compiling your projects is faster and more fun Shader Model 1 1 graphic card Nvidia GeForce 3 or 4 ATI Radeon 7x or Shader Model 2 0 GeForce 5 FX or ATI Radeon 9x00 Oooo Installing 10 Get the latest version of XNA Game Studio Express for free at http msdn microsoft com directx xna 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 11 Chapter 1 Introducing XNA The beta versions and XNA 1 0 still required that you install Visual C Express and the latest version
3. is afraid of losing too much performance by switching to a new language and additionally they fear that they might also lose their old code base or have a lot of work converting it to a new language However game programmers quickly adopt new techniques and scripting languages and are always on the very latest hardware developments One year before Shader Model 4 cards were even available we game developers had Direct3D 10 available and many people checked this out without even having the hardware to run it I adopted NET and C pretty quickly in the beginning of 2002 after checking out the early betas at the end of 2001 I had just started a new game engine and our team had a new project we wanted to do There were absolutely no graphic engines or anything but some simple 2D games around in the early years of NET This made it very hard to use OpenGL or DirectX directly in C It required a lot of calls to unmanaged dlls and involved a lot of nasty pointer logic which is available only in the unsafe mode of C In 2003 Microsoft finally released the first beta of Managed DirectX which made it possible to pro gram new DirectX applications quite easily in NET It proved that using Managed DirectX instead of the native DirectX dlls has only a performance impact of 1 2 percent which is really not important if you think about it just the CPU has a little more work most games are GPU bound anyway However this did not mean that game developer
4. moveFactorPerSecond if gamePad DPad Down ButtonState Pressed keyboard IsKeyDown Keys Down scrollPosition moveFactorPerSecond base Update gameTime Update gameTime The first few lines are the same as before Then you calculate how many pixels you would move this frame If a frame would take 1 second moveFactorPerSecond would be 400 for 60 frames it would be 400 60 Because you use floats here instead of just integers you can have a couple of thousand frames and the movement is still 400 pixels per second if you press up or down The variable scrollPosition is changed if the user presses up or down In your draw method you can now render each tile and add the scrollPosition to the y position to move the background up and down protected override void Draw GameTime gameTime graphics GraphicsDevice Clear Color Green sprites Begin int resolutionWidth graphics GraphicsDevice Viewport Width int resolutionHeight graphics GraphicsDevice Viewport Height for int x 0 x lt resolutionWidth backgroundTexture Width x for int y 1 y lt resolutionHeight backgroundTexture Height y Vector2 position new Vector2 x backgroundTexture Width y backgroundTexture Height int scrollPosition backgroundTexture Height sprites Draw backgroundTexture position Color White 20 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 21 Chapter 1 Introducing
5. of DirectX 9 0c first maybe this will change when the final version of XNA 2 0 is shipped All of these downloads are completely free and it is really a nice thing to have all these tools available without any costs involved This enables many more people especially students hobbyists and normal players to check out the development environment and maybe get even more excited about game development than they already are Start with installing XNA Game Studio Express see Figure 1 7 There are no special options you have to select the installer will do everything for you for example adding firewall rules for Xbox 360 testing The installer also adds the XNA help the starter kits and the project templates to get you started 5 Microsoft XNA Game Studio Express Beta Setup Gold Installing Microsoft XNA Game Studio Express Beta rA Please wait while the Setup Wizard installs Microsoft XNA Game Studio Express Status Registering project templates Figure 1 7 You will not really need the DirectX SDK but I recommend that you install it You will have additional documentation available and a great repertoire of tutorials and samples in case you need more informa tion about common techniques for your graphic engine You can download DirectX from the Microsoft DirectX Developer Center page on http msdn microsoft com directx When installing it you should select to install the Redistributable in
6. or xml file But if XNA Studio detects one of the supported content file formats you will see the advanced XNA properties There are three important new settings Asset Name Content Importer and Content Processor The Asset Name is used to load the content later each content file must have a unique Asset Name For the Content Importer you can select a Texture as in this case or a Model Importer for x files or an Effect Importer for fx files The Content Processor contains more options for example you could select DXT DXT mip mapped or Sprite 32bpp for your texture here DXT is a compression format which is also used in dds files and it is very good for textures in games because they get compressed down in a 1 6 ratio or 1 4 if they contain transparent pixels This means you can have up to six times as many textures for the same space on the hard disk and graphic memory For 2D sprites it is usually better not to compress them because you see them in their full size and using 32 bpp bits per pixel guarantees the best possible sprite quality For more information about the content pipeline read the next part of this chapter Properties CityGroundSmall jpg File Properties X eed VAS El Asset Name CityGroundSmall Buld Action Content Content Importer Texture XNA Framew Content Processor Texture Sprite 32bppl Copy to Output Direc Do not copy File Name CkyGroundSmall jpg XNA Framework Cont True Asset Name The n
7. see each other You can test ping ing the Xbox 360 IP from your PC or connecting to your PC as a media center from the Xbox 360 Q If the Xbox 360 XNA Framework could not be installed search for more help on the Internet to see if your Xbox 360 meets the minimum requirements you need a hard disk for example Q When you create an encryption key in Settings of the XNA Game Launcher and it is not accepted by your PC because you maybe mistyped it or it contained 0 the number zero and O letters which almost look the same just try it again you can always create a new encryption key See the section Configuring Your Xbox 360 earlier in this chapter for details Q Ifthe XNA Game Launcher does not start or all buttons are grayed out or if you receive some error like Oxffffffff it means that your profile is not connected to Xbox Live or it has some wrong settings If you had an older version of the XNA Framework installed before uninstall it delete your profile and create a new profile and reinstall the XNA Framework again 27 fp 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 28 Part XNA Framework Basics Chapter 2 provides more detailed coverage of the steps required to get a game running on the Xbox 360 but the sample in this chapter also works on the console out of the box Just start the project switch to the Xbox 360 output and press F5 If you have set up everything correctly you can see the same output on the Xbox
8. the 32 bit mode of Windows XP x64 or Windows Vista x64 Why do I even bring this up if you can run 32 bit and 64 bit applications on 64 bit operating systems Well you cannot use 64 bit assemblies dlls from 32 bit applications or vice versa The reason for that is that a Windows process has to be run either in 64 bit or 32 bit emulating 32 bit from 64 bit would be too slow and is not even supported Now how do you get XNA working in 64 bit mode You don t it is just not supported Instead you have to make sure that the NET Framework and your application run in 32 bit mode then Windows will start the whole process in 32 bit mode and you can load the XNA dlls just fine If you don t do that your game cannot even be started on any x64 bit platform In Visual Studio 2005 you can just select x86 platform instead of All CPUs in the Project Properties Build screen In XNA Game Studio Express there is no such option and if you want the same setting you have to add a line to your csproj file in each PropertyGroup section lt PlatformTarget gt x86 lt PlatformTarget gt I also wrote a little tool that converts XNA Game Studio Express projects to Visual Studio 2005 projects and back and it handles the x64 bit issue The newest version of the tool also supports Visual Studio 2008 You can download it from my blog at http exdream no ip info blog 2007 07 19 XnaProjectChangerToolWithvS2008Support aspx Configuring Your Xbox 360 To connect you
9. the custom setup step too You will need it if you want to install your game on other computers When DirectX is installed you can check out the newest features by taking a look at the samples with the DirectX Sample Browser If you haven t worked much with Managed DirectX before and are interested check out the documentation and tutorials If you want to use an Xbox 360 controller on your Windows machine which works just fine thanks to the fact that the controller uses USB you can just plug it into your PC and it should work fine on Windows XP and Vista after it automatically installs all required drivers If that does not work automatically you can 11 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 12 Part XNA Framework Basics also download the drivers yourself and follow the instructions from the official hardware site of Microsoft products at www microsoft com hardware gaming download mspx Last but not least you will do a lot of unit testing in this book and for that I usually recommend NUnit and TestDriven NET and later even xUnit a newer unit testing framework released in late 2007 NUnit is an external dll and TestDriven NET is not supported in the Visual Studio Express Editions anymore It does not matter for this book because all source code will use its own kind of unit testing with a special class later on If you use Visual Studio 2005 I suggest using TestDriven NET and if you are using Visual Studio 2005 Team
10. very active and willing to share but it might not have much to do with the application model Check out the links later in this chapter for more information Content Pipeline The content pipeline is used to import compile and load game assets such as textures 3D models shaders and sound files to your game project see Figure 1 6 It greatly reduces the amount of custom code you have to do to get graphics 3D data and shaders into your game For example if you drop a model file into your project and it uses two textures and a specific shader the content pipeline will process your model file and automatically find and add the required textures and shaders You don t have to do this for yourself the content importer compiles the data into a binary format and in the process it picks up everything you need Say the shader you added through the model you dropped into your project contains an error In the past you would have to start your game project and then get an exception telling you that the shader could not be compiled and the game would crash Now the shader is compiled in the build process and you don t have to start your game to see that it does not work yet You can quickly fix the error through the line and error message from the build output in XNA Game Studio Express and then rebuild The content pipeline does not just consist of one dll there are five different dlls Q Microsoft Xna Framework Content Pipeline dll conta
11. 2006 DirectX developers saw only the XNA logo in the upper right corner of the DirectX SDK documentation from 2004 to 2006 see Figure 1 1 XNA just means XNAs Not Acronymed a Microsoft 5 DE Directx and KIA Figure 1 4 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 4 Part XNA Framework Basics This means Microsoft was working on the XNA Framework for quite a while but the developers did not really know what to expect It could be a successor to the DirectX Framework they thought but when Direct3D 10 Beta for Windows Vista was released in the end of 2005 it seemed that DirectX was still the preferred graphics framework even for this new operating system Then early in 2006 at the GDC the Microsoft XNA Build March 2006 CTP was released XNA Build is a tool that allows you to manage com plex build processes similar to Ms build and tools like Ants but more complex and powerful Because Microsoft s MechCommander 2 was also released as a Shared Source Release a lot of people down loaded it and tried to rebuild the MechCommander 2 game But after a while not much happened and small to mid sized teams in particular don t really need a complex build management tool Then it was quiet for a while and only Microsoft personnel and DirectX MVPs I am lucky to be one received information about the upcoming XNA Framework and XNA Game Studio releases The rest of the world found out about that at the Gamefest conference in Au
12. 360 Congratulations you just started your first Xbox 360 game Last but not least if you run into compiler errors from the code in this chapter here are some final tips A Make sure you have all required variables defined graphics content backgroundTexture sprites and scrollingPosition A Read the compiler error message and change the code accordingly Maybe you are trying to use an obsolete method either replace it with the new method or just comment it out to see how the rest of the code behaves A If the compiling works but the program crashes or throws an exception it is most likely that you have some content file missing the CityGroundsmal1 jpg texture in this project or that your graphic hardware does not support at least Shader Model 1 1 Summary This chapter covered a lot about the background of XNA and how to get XNA Game Studio Express working on your PC and even how to install XNA on your Xbox 360 if available You also wrote your first little project I wouldn t really call it a game but it has a texture the Xbox 360 controller input and keyboard input is handled and you have a response on the screen by scrolling the background texture up and down The following chapters focus more on programming cool little games Here s a recap of what you have learned so far Background of the XNA Framework Installing XNA Game Studio Express Tips and tricks on how to get XNA running on Visual Studio 2005 Additio
13. 61286c01 qxd WroxPro 1 21 08 3 43 PM Page 1 Part I XNA Framework Basics Chapter 1 Introducing XNA Chapter 2 Creating Your First Game Pong Chapter 3 Helper Classes Chapter 4 Game Components 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 2 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 3 F Introducing XNA Welcome to the world of XNA As a game programmer you probably know about DirectX and maybe even the basics of the XNA Framework This chapter explains how to install XNA Game Studio Express and how to use it in a productive way It also contains quite a lot of tips that might even be useful for anyone who already knows the basics In the next few chapters you start developing some cool smaller games Part I contains the basic foundation and information about the helper classes you will use later in this book to develop a full blown graphics engine for more advanced game projects To keep things simple you start with 2D programming in Part I and then advance to 3D in Part IL Let s get started Introduction to the XNA Framework XNA developed by Microsoft was started a few years ago but kept very secret At the GDC the biggest annual Game Developers Conference in 2004 Microsoft announced XNA for the first time XNA is not just a framework like DirectX it also contains a lot of tools and even a custom IDE derived from Visual Studio to make the game programmer s life easier Because no tools or bits were released until
14. 8 follow the tricks I describe later in this chapter on how to work with VS and XNA productively Microsoft released another beta of XNA 1 0 a few months later in November 2006 before the final release of XNA Game Studio Express in December 2006 The final version included the content pipeline and many new features you will learn about in Chapters 2 and 3 XNA is completely free and for the first time allows developers to create games for both the Windows platform and for the Xbox 360 platform simultaneously But if you want to run your XNA game on the Xbox 360 console you have to join the Creators Club for an annual fee of 99 XNA Game Studio Express Figure 1 2 shows you XNA Game Studio Express The information provided here is for XNA Game Studio Express 1 0 but installing version 2 0 should be identical The screen does not just look similar to Visual C 2005 Express it actually is Visual C 2005 There are only some minor changes to your project settings if you create an XNA project Also an extra option in Tools gt Options allows you to select your Xbox 360 device and enter the encryption key Additionally there are some new features inside the IDE for example the content pipeline that allows you to import textures models and shaders very quickly into your project More about all that in a little bit fp 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 5 Chapter 1 Introducing XNA 2 Start Page Microsoft
15. DIDRS_LIGHTING FALSE Turn y_pazabes arn c Y_pd3dDevice gt SetRenderState D3DRS_ZEWABLZ TRUE Ine 1 to create a texture fron a file based ixnge if FAILED D3DXCreateTextureFroxFile g_pd3dDevice banane tay sg_pTexture If texture is not in current folder try parent folder at FAILED DIDXCreateTextureFronfile g_pd3dDevice banana bup eg pTexture MessageBox NULL Could not find banana bnp Textuzes exe Figure 1 15 Getting Used to the Content Pipeline As you saw earlier with your first XNA project it is quite easy to just drag and drop a texture into your game project inside XNA Studio Although it is nice to have all your game content in one place and side by side with the code there are a couple of things you have to remember Most of the projects I have seen throughout my career have not put the textures models or shaders directly in the Visual Studio project The reason for that is that it is much easier to just copy a few files over and then let the game load them directly By default Visual Studio will also not copy any content files to your output directory you have to change the Build Action from None to Content and set the Copy to Output Directory setting to Copy if newer This is quite a hassle and XNA makes it a little easier 23 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 24 Part l XNA Framework Basics You might even ask why you should
16. System you can also use the Unit Testing features implemented directly in VS there Alternatively there are also other Unit Testing Frameworks around for example MbUnit csUnit and so on Most of the samples in this book keep things simple and use only very basic features of unit testing and make it look like many little test programs You can certainly do all your work inside the XNA Game Studio Express IDE and Microsoft encourages you to do so All samples in this book work fine with the Express editions and I did not use any external dlls which was also one of the requirements for the XNA Starter Kits However some people already have Visual Studio 2005 and may feel more comfortable doing their coding over there Read on for a couple of tricks on how to get XNA working with Visual Studio 2005 Professional What About Visual Studio 2005 Professional 12 XNA Game Studio Express 1 0 is fine and a nice environment to work in However if you are used to tools like SourceSafe or any other CMS Content Management System or plug ins like CodeRush TestDriven NET and other productivity tools you will run into a bunch of problems As I said earlier it is not even possible to open your XNA 1 0 projects from Visual Studio 2005 If you are using XNA 2 0 where Visual Studio 2005 is supported out of the box or do not care about Visual Studio 2005 or Visual Studio 2008 you can skip this section The XNA Framework uses the NET 2 0 Framework and Di
17. Visual C 2005 E iew Tool Window Community Help carModel Microsoft Visual C 2005 Express Edition Recent Projects MSDN Visual C 2005 Express Edition Learn how to use Settings in C la Tue 3 Oct 2006 20 18 06 GMT So VB has the My namespace in C we can access user and application settings through the Properties namespace Learn how How To Item Template Customization Tue 3 Oct 2006 20 18 05 GMT Ever wanted to know how to create custom class templates for your projects Anson Horton shows us how Check out his blog which contains some great C tips and tricks XNA Game Studio Express Bringing Game Development to the Masses Mon 21 Aug 2006 20 20 18 GMT For the first time hobbyists students and indie developers will have access to professional grade tools amp technologies for PC amp Xbox console game development Make your dream game a realty and download the Beta today Get the New Robotics Studio CTP Tue 25 Jul 2006 21 26 58 GMT The Microsoft Robotics Studio customer technical m m What s nenin Gezos preview CTP is now available to download and try out It offers an end to end Create Your First Application robotics development environment using YB C C or even browser JavaScript ee Use a r Ki 2 Toolbox AYSolution Explorer dal That s Totally Disco Cot With the vane Tue 25 Jul 2006 21 26 58 GMT Clint Rutkas describes h
18. al release most of the initial game component code was removed as well as the graphical designer component in XNA Game Studio This happened because Microsoft was not able to find a way to implement the designer and game components idea in a useful way for the Xbox 360 console It had only worked on the Windows platform before See Chapter 4 for more details about game components While it can be a hassle to implement the Ul and menu logic yourself it makes game menus more unique Almost every game implements its own UI But if you think about it a standard menu system as Windows uses for every app is boring it is always nice to see the ways in which menus are presented in new games You can still extract code very easily and create your own game components if you want to create a new game and then you can just reuse the code for example the SkyCubeMapping class Some game components such as the camera and screenshot capturer classes from Chapter 4 are good examples for components that can be reused in many other games but almost everything else in the games from this book is implemented without using game components One of Microsoft s goals with this application model is for the community of game developers to create and share their game components quite easily and improve the community aspect of XNA As you can see from the many XNA game development sites and the projects on open source sites such as www codeplex com the community is
19. ame that will be used to reference this content at runtime Figure 1 13 If you press F5 or build the project F6 the content is processed and a new file CityGroundSma11 xnb will be created in your output directory The build output window also shows the following new line Building CityGroundSmall jpg gt bin x86 Debug CityGroundSmall xnb The final thing you have to do is load the imported texture You do that in the Initialize method and use a new variable backgroundTexture in your class To load the texture you use the asset name you specified earlier it was actually generated automatically from the filename of the file you dragged into your project To render the texture on the screen you need a SpriteBatch which is discussed in the next chapter Basically it sets up the alpha blending then draws textures into the sprite and finally draws everything on the screen Texture2D backgroundTexture SpriteBatch sprites 18 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 19 Chapter 1 Introducing XNA protected override void Initialize backgroundTexture content Load lt Texture2D gt CityGroundSmall sprites new SpriteBatch graphics GraphicsDevice base Initialize Initialize To display the background texture you have to start the sprite batch and render the texture to your sprites in the Draw method protected override void Draw GameTime gameTime graphics GraphicsDevice Clear Color Gre
20. change the way you loaded textures before If you just want your game to run on the Windows platform you can certainly load textures and shaders dynamically and without importing them first into your project as XNA content files This has the advantage that you can change textures or shaders while the game is running a feature that is not supported by the XNA con tent pipeline However for model files this will not work because there are no load methods other than from the ContentManager class which only loads compiled xnb content files On the Xbox 360 you can load content files only there is no support to load textures or shaders directly If you use direct texture or shader loading make sure you exclude that code from the Xbox 360 platform the dlls for the Xbox will not support loading anything but the content files For more details about important model files read the chapters in Part II of this book Handling 3D models is not as easy as just using textures for 2D games For that reason this part of the book sticks with sprites and 2D textures and keeps things simple For simple 2D games it is nice and easy but to write a serious game you will need 3D models and many cool shader effects I also suggest that you get an artist to do the textures and 3D models for you Itis a quite complex topic and you might waste a lot of time doing all this yourself Other people might also be more talented doing textures and 3D models take advantage of y
21. cuses more on XNA 2 0 and the added networking capabilities But all changes required to make the older code run on XNA 2 0 were implemented and additions were made to the chapters where something new happened in XNA 2 0 Please note that if you just want to develop on the Windows platform you can already write network games in XNA 1 0 with help of the System Net namespace This section states the changes that are coming in XNA 2 0 and known at the time of this writing Most information about XNA 2 0 was first announced on the Gamefest in August 2007 First and foremost XNA 2 0 supports Visual Studio 2005 out of the box both the standard editions and the professional editions including the Team System version In XNA 1 0 you could only use Visual C Express and while C is still the only officially supported language for XNA you can use other lan guages such as Visual Basic IronPython F or even C which will work on Windows but might not work on the Xbox 360 because of some restrictions Only the Compact NET 2 0 Framework runs on the Xbox 360 and some languages such as IronPython make use of language features such as Reflect Emit which are just not available on the Xbox 360 at this time Aside from other improvements to the project management and framework the most important addi tion to XNA is the new networking API which allows you to write multiplayer games and using Xbox Live on the Xbox 360 and Windows System Link on Windows XP an
22. d Vista All the new networking capabilities will be discussed in Part V of this book These are the key points about XNA networking in XNA 2 0 A Enables you to write networked multiplayer games on the Xbox 360 and Windows Q Matchmaking system via Xbox LIVE on the Xbox 360 and System Link on Windows A Noneedtocreateor host your own servers which really makes creating multiplayer games a lot easier than it used to be All the server management will be hosted for you on the Xbox Live and Windows for Games Live services A Easy to create game sessions and search for them Q Game flow management Host Migration and an integrated messaging system keeps you focused on developing the game not the networking APIs required As described in more detail in Chapter 14 all data in the XNA 2 0 networking APIs is transmitted through UDP which is normally unreliable but the XNA team has built a reliable framework on top of it similar to DirectPlay You basically just use the SendData and ReceiveData methods to send and receive network messages You can implement client server style games as first person shooters usually 25 fp 61286c01 Pa 26 qxd WroxPro 1 21 08 3 44 PM Page 26 rt l XNA Framework Basics use or peer to peer games as role playing or strategy games usually use It is totally up to you you could even use a hybrid approach Because XNA makes great use of the Xbox Live system you get all the features in there f
23. d by the author just for hosting XNA games like the ones in this book It is a completely open website for everyone to use upload games and to add your own links to but there are no articles or tutorials on this site just the games with installers source code screenshots and videos Is C Good for Game Development There are constantly forum threads on sites like www GameDev net discussing the differences between C and C Usually after a few posts they all end in a senseless language war Back in the early days of NET 2002 I discussed quite a lot in those threads but it was way too depressing when 99 9 percent of the programmers were on the C side and there was no way to convince anyone because they didn t even take you seriously The language war does not really have anything to do with C as a language but the constant language battles gave newer languages like Java or C a bad start For example Java failed as a game programming platform except for cell phone games But if you think about it the same kind of wars happened in the days when C replaced Assembler and C replaced C Even to this day more than 20 years after C was developed by Bjarne Stroustrup some game programmers still use C and do not really take full advantage of C If you take a look at the source code for popular game engines such as Quake or Half Life it looks more like C than C This is something really strange in the game programming world everyone
24. d keyboard states in extra variables to have easier access If you press F5 again you can quit the game with Escape now Next you are going to jump a little bit ahead and load a graphic into your game More details about sprites are discussed in Chapter 2 The idea is to display a small background texture and tile it over the whole screen Then you implement some simple keyboard and gamepad controls to move the back ground as in a top down racing game or a tile engine which is often used in 2D role playing games For a more complex tile engine you would need more textures like stones grass water mud and so on and then even transition textures you can put between grass and water for example This requires more tex tures and custom code but overall this is not a very hard topic You can also find a lot of information about this topic on the Internet if you are really interested in tile engines For your simple first project you just add the texture shown in Figure 1 12 17 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 18 Part l XNA Framework Basics To load this texture CityGroundSmal1 jpg into your game just drag it into your project on the Solution Explorer Then click the file in the project and select Properties You should now see the screen shown in Figure 1 13 Normally you would just see the build action and some options for copying the content file to the output directory e g if you want to include a dll
25. de can be half the size of unmanaged code For XNA the code would even be shorter and it gets much easier to load textures and show them on the screen but the comparison to MDX gets harder because the concepts are different public class Textures Fora c LPDIRECTIDS g_pbap NULL LPDIRES ICES Q_pasaevice NULL LPDIRECT TEXBUFFERI g_pre gt NULL LPDIRECT TUPE9 qpTextuce NULL Our Lex Texture texture mull ertices public void InivializeGrephics jet up the structure used to create ch ising omplex y Y DIDPRESENT_PARAMETERS d3dpp Zecoffeno sd3dpp sizeof d3dpp didpp Vindowed TRUE d3dpp SwopEttect DIDSUAPEYFECT_DISCARD d3dpp BackButterFo D3DFHT_UNEMOUN didpp EnableAutoDe ancil TRUE didpp AuteDepthStencilPormat DIDFNT Turn off culling 0 we see the front end back of the triangle device RenderState CullMode Cull None Turn oft ghi Gevice Render5tate Lighting Talse Turn or re RencerState ZEufCerEnable true create the D3DDevic iC FAILED g_pD3D gt CreateDevice DIDADAPTIR_DEFAULT devic DEYTYPE_HAL hind ir te DIDCREATE_SOFTUARE PROCESSING texture ireLoader FronFi le device ad3dpp lt g_pd3dDev 1 Application StartupPath banana bmp 4 InitselizeGraphics return E_FAIL Turn off culline g_pd3dbevic tRenderState DIORS_CULLMODE DIDCULL NONE gheing tRenderstate
26. e on the screen If your game is GPU limited it can very well happen that Update is called more often than Draw but your update code should run independent of the drawing code anyway None of the samples in this book will need special care for the number of times Update and Draw are called And finally Draw is called each frame to draw everything to the screen The separation of Update and Draw might not always be important and can almost always be ignored for unit tests but for the final game it is important to make sure the game logic runs independent of the draw code For example on the Windows platform the user could press Alt and Tab or minimize the game in which case Draw does not need to be called anymore Even with Draw not called anymore you may still want the game to continue to run in the background via the Update method This is especially important for network games to make sure the player is still synchronized Additionally you can add GameComponent classes to your game class which again have an Update and a Draw method Both of these methods are automatically called from your game Update and Draw meth ods The initialization can happen directly in the constructor there Initially Microsoft wanted the devel opers to create and add game components with the designer of Visual Studio which can be seen in the first beta of XNA Game Studio Express released August 30 2006 The designer feature was later removed because it did not work w
27. e class which contains all the impor tant game components the graphics device the window settings and the content manager You can also add the input and sound handling here Basically everything that your game does on a very high level somehow roots in the game class or at least is in some component that can be accessed from the game class 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 7 Chapter 1 Introducing XNA The following are the three most important methods in the game class see Figure 1 5 For the final release Microsoft also added the LoadGraphicsContent and UnloadGraphicsContent helper meth ods by default to the Game1 cs class which is created automatically for you when you create a new XNA project but in most samples of this book these methods are not used because it is much simpler to have all initialization and loading code at one place in the Initialize function a Initialize A Update GameTime time a Draw GameTime time YourGame Class E Methods 6 Initialize Update Y Draw Figure 1 5 You can probably already guess what all these do Initialize loads all your game content sets all your startup settings and initializes everything you need If you want to follow the design patterns Microsoft provides for XNA you would do all the loading in the LoadGraphicsContent method Update is called before each frame is drawn to update your game time input sound and everything else that is not visibl
28. eating an XNA Framework 1 0 game application for Windows Name WindowsGamet Location CiCodelkNAa im Browse Solution Name create directory for solution Ca Figure 1 10 15 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 16 F Part l XNA Framework Basics The Game1 class contains the Initialize Update and Draw methods mentioned a little bit earlier Initialize does nothing for now and Update just checks if the Back button on the first connected gamepad was pressed For now you are just interested in the Draw method which basically just executes the following line to clear the background to a specific color graphics GraphicsDevice Clear Color CornflowerBlue F5 and Go If you press F5 the project starts same as Debug Start Debugging and you see the screen shown in Figure 1 11 which shows the blue color on a blank boring window that is specified in the Draw method To feel like you are actually doing something change the Color to Color Green and press F5 again The window now has a green background The Clear method of the graphics device has other over loads that can be used to clear the depth and stencil buffers which will be done automatically if you just set the color For example later in this book you will just need to clear the depth buffer but not the color of the background To do that you just write the following line graphics GraphicsDevice Clear ClearOptions DepthBuffer Color Green 1 0 B
29. ecent version of the source codes for the samples in this book go to the official book site or XnaProjects net Troubleshooting You have now read everything you need to know to get started with your first XNA project If you just read through this chapter I highly recommend that you at least open up the project for this chapter download it from www wrox com WileyCDA WroxTitle productCd 0470126779 htm1 and run it If you run into problems installing DirectX NET 2 0 or XNA try to search for help on the XNA Forums athttp forums xna com If the tips in this book do not help you with a particular problem you should always do a Google search and check out the XNA Forums This way you can get more current help about some problems For NET 2 0 it is important that you have the most recent service pack for your operating system For DirectX make sure you have the most recent graphics driver and a decent graphics card to even work on 3D graphics Finally for XNA make sure you have everything correctly installed before starting the XNA setup Getting XNA to work on Windows isn t very hard On the Xbox 360 a lot of things can go wrong Here are a couple of tips to make sure you meet the requirements for running XNA games on your 360 Q You need an Xbox 360 Live Account on your Xbox 360 which must be connected at all times when you develop and test your XNA games Make sure your PC and the Xbox 360 are on the same network and that they can
30. ell was not supported for the Xbox 360 platform and because not many devel opers used it anyway The idea with the game components is to reuse parts of your code and make it very easy to just plug them into your games Examples of game components include a frame counter or maybe a sky cube mapping renderer for the 3D background In my opinion there are two major drawbacks No standard game components are shipped with XNA and it is not really hard to code such an application model yourself and even extend it I do not use many GameComponent classes in this book but feel free to plug them in on your own Read Chapter 4 for more details of the GameComponent class and learn about its advantages and disadvantages Because the game class has a Components property it is very easy to add more components fp 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 8 Part XNA Framework Basics Don t get me wrong the basic idea of game components is really great There was a small webcast from Mitch Walker the Program Manager of the XNA Framework at Microsoft at the time the first XNA beta was released about the game components and how to combine them At first I was not very sure what to think of the content pipeline and the game components idea it looked cool in the webcasts but when I started coding my first game projects in XNA I did not find it very useful to work with the designer that was presented in the first beta In the second beta and the fin
31. en sprites Begin sprites Draw backgroundTexture Vector2 Zero Color White sprites End base Draw gameTime Draw gameTime This renders the background texture at the location 0 0 on top of your green background With the color parameter you can also recolor a sprite but for now this is not important If you press F5 you will now see the result shown in Figure 1 14 Figure 1 14 19 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 20 Part XNA Framework Basics One final thing you are going to add for this first project is the capability to scroll the background with the cursor keys or a gamepad and then you render the scrollable tiles to the whole background To cap ture the gamepad and keyboard input you modify the Update method a little float scrollPosition 0 protected override void Update GameTime gameTime Get current gamepad and keyboard states GamePadState gamePad GamePad GetState PlayerIndex One KeyboardState keyboard Keyboard GetState Back or Escape exits our game on Xbox 360 and Windows if gamePad Buttons Back ButtonState Pressed keyboard IsKeyDown Keys Escape this Exit Move 400 pixels each second float moveFactorPerSecond 400 float gameTime ElapsedRealTime TotalMilliseconds 1000 0f Move up and down if we press the cursor or gamepad keys if gamePad DPad Up ButtonState Pressed keyboard IsKeyDown Keys Up scrollPosition
32. gust a new game developer conference by Microsoft where Microsoft announced the XNA Game Studio Express beta 1 release on August 30 2006 The first beta contained only one starter kit Space Wars and XNA did not include much 3D functionality Many developers and hobbyists tried out XNA and wrote many small 2D games with the help of the Sprite classes in XNA Although you could quickly create your Pong clone or some simple shoot em up game it was very hard to write your own 3D model importer and render code XNA Game Studio Express was initially targeted at beginners hobbyists and students to allow them to quickly develop their own games for the Windows and Xbox 360 platform But this does not mean pro fessional game studios cannot use XNA A special XNA Game Studio Professional version targeted to professional game studios was planned to be released in 2007 but plans have changed quite a lot Instead of having two separate versions one for professional game developers and one for hobbyists Microsoft s XNA team decided that it made more sense to have only one version namely XNA 2 0 that can do everything To publish a game on the Xbox 360 even if using the Xbox Live Arcade system you need a publishing deal anyway and have to submit your game to Xbox Live New with XNA 2 0 comes the support of Visual Studio 2005 Professional but if you want to develop with XNA 1 0 first four parts of the book and want to use Visual Studio 2005 or 200
33. has a great replay value and allows users to create new worlds easily Other new features of XNA 2 0 include simplified model rendering such as helping you to render models quickly via the new EnableDefaultLighting method in the BasicEffect class There were also improvements made to the game components classes not only are more game components available but you can also nest game components now You can learn more about game components in Chapter 4 Most of the XNA 2 0 Framework has not changed and is still compatible with XNA 1 0 code Even in parts where performance improvements were made the calling code is still the same You will just enjoy the new capabilities and you can extend your game easier or add one of the new features in the render ing engine For example occlusion querying and multiple render targets are now supported Another improvement is the project templates for content importers and processors to help you writing content processors which was very hard to do previously Working on your own content processors is still hard work but at least there is some help to get you started now I also want to mention the many samples that are available on the XNA Creators Club When the first edition of this book was written the website was non existent but now only 9 months later many more community sites are available and you can find many very active XNA forums On XNA Creators Club athttp creators xna com you can find a lot of
34. ins the basic functions for the content pipeline A Microsoft Xna Framework Content Pipeline EffectImporter d l is used to compile and import shaders 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 9 Chapter 1 Introducing XNA OQ Microsoft Xna Framework Content Pipeline FBXImporter dll is the biggest of all dlls and con tains a lot of code to import fbx 3D model files and supports many features for example skinning and bones A Microsoft Xna Framework Content Pipeline Texturelmporter dll is used to import texture files to your game These files can be dds files already in the DirectX format which is the best format for textures and supports hardware compression but png jpg bmp and tga files are also supported 2D sprites are just textures too and usually use the uncompressed 32 bit format A Microsoft Xna Framework Content Pipeline XImporter dll allows you to import x 3D model files a format that was used by many DirectX applications and samples 3D Models Textures XNA Content Pipeline Shaders Figure 1 6 Your game itself will never require any of these dlls they are just used to build and compile the content into xnb XNA Binary files in your build process This makes the distribution easier because you don t have to worry about the game content files anymore it is easier to make sure all the content files are there when you start your game Don t modify the xnb files they are
35. ion key don t close this window On your PC open XNA Game Studio Express and go to ToolsOptions and scroll down You will see the new XNA Game Studio option Here you can add your Xbox 360 and enter your encryption key then just click Add see Figure 1 9 13 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 14 Part XNA Framework Basics Figure 1 8 Options JE Environment Available xbox 360 consoles to deploy to Projects and Solutions TITO _qg G Text Editor a _ _ A _ zAA lt 4 gt 4 Database Tools Enter Xbox 360 Name and Connection Key Debugging Windows Forms Designer Xbox 360 Name Active XNA Game Studio YourXbox Xbox 360 Connection Key ENTER KEYEE RE on Eston tine Figure 1 9 After you have successfully entered the encryption key you can click OK on both the PC and the console If this fails or you reinstall XNA Game Studio you can always get a new encryption key and enter it again here 14 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 15 Chapter 1 Introducing XNA From now on you can create Xbox 360 projects and deploy them to your console which can be done in the XNA Studio build menu If you start to debug a project with F5 it will get deployed too and you can directly debug it on your console which is pretty cool because you can step through code on your PC and immediately see the results on your Xbox 360 kind of multi monitor developing for free Read
36. ique base Techniques BasicEffect this basicTextureParam base Parameters BasicTexture this fogEnabled aram base Parameters FogEnable this fogStartParam base Parameters FogStart this fogEndParam base Parameters FogEnd this fogColorParam base Parameters FogColor this worldParam base Parameters World this viewParam base Parameters View this projectionParam base Parameters Projection this diffuseColorParam base Parameters DiffuseColor this specularColorParam base Parameters SpecularColor this emissiveColorParam base Parameters EmissiveColor this specularPowerParam base Parameters SpecularPower this alphaParam base Parameters Alpha this lightingEnableParam base Parameters LightingEnable this ambientLightColorParam base Parameters AmbientLightColor this eyePositionParam base Parameters EyePostion this shaderIndexParam base Parameters ShaderIndex this lightO new BasicDirectionalLight base Parameters DirLight0Enable this light new BasicDirectionalLight base Parameters DirLight 1Enable this light2 new BasicDirectionalLight base Parameters DirLight2Enable le private void CacheEffectParams Declaring Type Microsoft Xna Framework Graphics BasicEffect Assembly Microsoft Xna Framework Version 1 0 0 0 Figure 1 4 Take a look at the Application Model Each XNA project uses a Gam
37. is months long quest to Download Additional t create a party dance floor for him and his friends to enjoy by combining his sl Error List AX alt Description Fie Line Column Project e Error List E Output Ready Figure 1 2 XNA Game Studio Express is currently the only available IDE for developing games with the XNA Framework but once Microsoft ships XNA Game Studio 2 0 end of 2007 you can also develop with Visual Studio 2005 Standard or Professional If you have Visual Studio 2005 but try to use XNA 1 0 with it to create an XNA project there will be no templates in it Even worse If you try to open a csproj file you created with XNA Game Studio Express Visual Studio cannot open the project It is not supported in XNA 1 0 Read on for a few tips on how to get XNA 1 0 working with Visual Studio 2005 in the section What About Visual Studio 2005 Professional If you start with XNA 2 0 you don t have to worry about this Visual Studio 2005 will be supported out of the box Application Model The XNA Framework is divided into three essential parts see Figure 1 3 Q XNA Graphic Engine in the Microsoft Xna Framework dll OQ XNA Game Application Model in the Microsoft Xna Framework Game dll Q XNA Content Pipeline in the Microsoft Xna Framework Content Pipeline dll 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 6 Part XNA Framework Basics Application Model in XNA Graphic Engine Mic
38. just the output format such as exe and should not be modified directly You also can t convert the data back to textures models or shaders well it might be possible but it is hard to find working tools for that The xnb files are also very different on the Windows platform and the Xbox 360 platform whereas the game source code and the content files might be exactly the same Additionally you can create your own custom content processors which allow you to compile any other game asset you have for example another model format into xnb files You explore that in Part II when you have to make sure all your 3D models have tangent data for the normal mapping shaders Okay that s all the basics you need for now It is time to get going and code your first game Get the Free XNA Game Studio Express To start coding right away you have to make sure that you have the correct tools installed the IDE is an especially important tool to get started quickly If you already have XNA Game Studio Express installed and configured you can skip this chapter This part was written just in case anyone needs additional tips 9 p 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 10 Part XNA Framework Basics and tricks such as how to get XNA running in Visual Studio 2005 Professional which is not supported out of the box but quite useful if you use Visual Studio plug ins or tools such as SourceSafe or Team Foundation to work bet
39. more about running your first game in Chapter 2 Getting Started You have everything set up now and it is time to finally do some coding and get your hands dirty In this chapter you will just create a simple project with the help of the XNA Studio templates Then you will change the code a little and add a little functionality to the update and Draw methods In the next chap ter you create your first game after you learn about the SpriteBatch class Your First Project Create a new XNA project in XNA Studio by clicking File gt New Project Now select Windows Game and enter a name for your first project for example Hello World or just leave it as WindowsGamel see Figure 1 10 As you can see you can also create games based on the starter kits quite easily from here too You can see now that a new project was created and it contains two source files Game1 cs and Program cs The Program file basically just contains the following three lines of code using Gamel game new Gamel game Run using New Project z z z ax mira Templates E E Visual Studio installed templates a 7 A z E a asas Windows Class Library Console Empty Project Screen Saver Movie Windows Windows Application Application Starter Kit Collecti Game Game Library ad A A Xbox 360 xbox 360 Spacewar Spacewar Game Game Library Windo Xbox 3 My Templates i ld A project for cr
40. nal tools that might be useful such as TestDriven NET SourceSafe and Ants Profiler Writing your first XNA project Clearing the background Drawing a texture with help of a sprite batch Handling gamepad and keyboard input Drawing a tiled background based on your input a a a a a A Concept of the Application Model and the Initialize Update and Draw methods a a a O a Changes in XNA 2 0 28
41. or NET development is the Ants Profiler Unlike all other tools and programs I mentioned so far it is not free but there are alter natives available on the Internet which might help you as well The Ants Profiler can be used to directly see how much time every single line of your project takes In my opinion this is much more useful than using some high level application performance tool such as NvPerf from Nvidia PIX from the DirectX SDK or the Performance Counters of Windows You can quickly figure out why parts of your render code get slow and you can detect bugs that call slow methods way too often By using a profiler tool and by investigating you and others source code you not only get a lot of interesting information but you also 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 25 Chapter 1 Introducing XNA learn more about the structure of an application and why some things work so well and others take so much time For more links on the Internet check out the great collection of XNA links at http xnadevelopment com links shtml There are many more sites about XNA and it seems every day you see a couple of new community sites and more resources Do a Google search to find out which site is the most popular Changes in XNA 2 0 This book was originally written with XNA Game Studio Express 1 0 in mind While Parts I through IV were originally written when only XNA 1 0 was available Part V Writing Multiplayer Games fo
42. or free which includes your gamer card friend management and chat system you can even show the keyboard and messages boxes on the Xbox 360 now You can even enable voice support for your games There are also nice tools to support the development of multiplayer games on the Xbox 360 and the built in latency and packet loss simulation tools help you prepare for problems that can occur when playing your game over the Internet This all sounds similar to DirectPlay of the DirectX Framework which was not very successful and was depreciated a few years ago because game developers would not use it Instead most games would just use Windows sockets directly or use another networking API But in XNA it will be the only way to write network games at least on the Xbox 360 which gives me hope that XNA networking will be a lot more successful than DirectPlay was It is very easy to enable multiplayer support in XNA with just one single line of code Components Add new GamerServicesComponent this But writing network games themselves is not that easy It is great to have all that built in support and as you will see in Chapter 14 it gets you up and running quickly but to write a full blown network game and to understand all multiplayer components you have a long road ahead For this reason the networking APIs are discussed at the end of this book with the most complex game Dungeon Quest which is a full blown multiplayer role playing game that
43. our coding skills and let other people do the painting If you don t have any artists avail able try to use some of the models and textures from this book and the XNA starter kits Differences with MDX If you are coming from MDX Managed DirectX and want to migrate your game to the XNA Framework there is a great guide on the official XNA pages at http msdn2 microsoft com en us directx Aa937797 aspx You can find the same help in the XNA documentation I won t repeat all that here but basically you have to remember that XNA uses right handed matrices and MDX was left handed by default Also there are some new classes and structures to make sure you don t need the Windows Forms namespace anymore Because there is no fixed function pipeline support the old way of working with Windows Forms and handles and thinking of supporting older PC configurations is no longer necessary Graphics and shaders are discussed in Part II of this book Additional Tools and Tips 24 Additionally you should take a look at the Getting Started help topics in the XNA documentation which can be accessed from XNA Studio Help Contents XNA Game Studio Express You can find more infor mation about connecting to your Xbox 360 writing your first project and using all the starter kits As I mentioned before TestDriven NET is a nice tool for Visual Studio and test driven development is a very important methodology in this book see Chapter 3 Another great tool f
44. r Xbox 360 to your PC you have to install the XNA Framework on your Xbox 360 first via the Xbox Live Service Unlike the Windows platform the download of the XNA Framework for the Xbox 360 is not free You will have to join the Creator s Club subscription on the Xbox 360 through the Xbox Live Marketplace for 99 a year or 49 for four months Microsoft does this to have a little control over the developers Console development is usually very closed off and there is no open source thinking as in the Windows or Linux world We can all just hope this is going to change First of all make sure your PC and the Xbox 360 are connected to the same network You don t have to connect the Xbox 360 directly to your PC just plug it into the same network router or modem It is important that you always have access to the Internet from the console and not just to your PC because XNA requires an Xbox Live connection on your console Once you have installed the XNA Framework on the Xbox 360 which also includes a custom version of the NET 2 0 Compact Framework to make it run on the console you can start the XNA Game Launcher see Figure 1 8 In the XNA Game Launcher you can now start your game projects or copy over XNA games from your friends or the Internet and start them on your console Before you can connect to the PC you will have to make an encryption key first by clicking Settings and then Create Encryption Key You will now see the encrypt
45. rectX 9 0c To run games on any Windows PC it needs the NET 2 0 Framework DirectX 9 0c and the XNA dlls If you are a game developer you will have the latest DirectX SDK anyway and if you have Visual Studio 2005 you will have the NET 2 0 Framework too so the only thing you need for running and even compiling XNA applications are the two XNA dlls QA Microsoft Xna Framework dll Q Microsoft Xna Framework Game dll These dlls are referenced in all XNA projects so if you just add them to a project in Visual Studio 2005 you can directly start coding To get started just copy over the Game1 cs and Program cs files from an empty XNA project you created with XNA Game Studio Express Another problem could arise if you work on a 64 bit operating system such as Windows XP x64 or Windows Vista x64 Although DirectX 9 0c has had 64 bit dlls for some time now and the NET Framework runs fine on 64 bit too the problem lies in the XNA Framework which is available only in a 32 bit version 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 13 Chapter 1 Introducing XNA called x86 by the way People using the 64 bit operating systems of Windows had the same problem in the past with Managed DirectX which is available only for 32 bit too Using a 64 bit operating system does not mean you cannot use 32 bit applications anymore quite the contrary Almost all applications that exist today are written for 32 bit operating systems but they run fine in
46. rosoft Xna Framework Pipeline dil Game Application Model Microsoft Xna Framework Pipeline dll Content Pipeline Microsoft Xna Framework Pipeline dll Figure 1 3 All of these dlls are written in C and are completely managed This means you can open them up with a tool like Reflector available from www aisto com roeder dotnet and see directly how they work see Figure 1 4 Most internal functionality just calls to the DirectX dlls and simplifies things a little bit The content pipeline is discussed shortly Lutz Roeder s NET Reflector guay File View Tools Help Oole ald p Ajo xl e Microsoft xXna Framework E IM Microsoft Xna Fremework dll Sj References O lt CppImplementationDetails gt lt CrtImplementationDetails gt Microsoft Xna Microsoft Xna Framework Mcrosoft Xna Framework Audio Microsoft Xna Framework Content Microsoft Xna Framework Design Microsoft Xna Framework Graphics BasicDirectionalLight Ay BasicEffect B M Base Types Derived Types 3 ctor GraphicsDevice BasicEffect Y ctor GraphicsDevice EffectPool 9 CacheEffectParams Void Clone GraphicsDevice Effect EnableDefaukLighting Void SY IntializeEffectPara oid 0 UpdateshaderIndex Void S amp F Alpha Single S ST AmbientLightColor Vector3 Sf DiffuseColor Vector3 DOS Disassembler ler private void CacheEffectParams this basicShader Techn
47. s were jumping on C everyone was still very skeptical and even after I released the first commercial NET game ever Arena Wars in 2004 it took another year until more and more developers finally gave NET another chance Students and beginners especially really appreciate the simplicity of C and more and more people started to develop games in NET C versus C discussions still exist and the discussion points are still the same but the result is more balanced right now I stopped looking at any topic that has vs in the name a long time ago it is just a waste of time reading the same arguments over and over again Always remember this when you run into someone who tells you that C is superior and that C is only for newbies The same thing happened with Assembler and C a few years ago In the future there will be new languages that make our life easier and there will still be people hesitant to adopt them right 22 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 23 Chapter 1 Introducing XNA away Most big game studios also can t just adopt every new technology right away The studio might be in the middle of a big project and also might have a very big code base which is not easy to port In the long run however code will get converted and we will move up the ladder of high level languages Figure 1 15 is an old picture I did to show the differences between DirectX with C and Managed DirectX in C As you can see MDX co
48. ter in a team for example Requirements XNA Game Studio Express targets Windows XP SP2 SP means Service Pack and Windows Vista SP2 is important because of the requirements of the NET 2 0 Framework Other platforms such as Windows 2003 or older Windows platforms that support NET 2 0 are not officially supported but run fine too XNA is also tested only on 32 bit platforms but it works fine on Windows XP x64 and Windows Vista too even as a development platform Because XNA Game Studio Express is based on Visual C Express it has the same basic requirements You basically need a computer nothing fancy But for game development you have much higher basic requirements anyway which I discuss shortly Visual C Express runs on Windows 2000 SP4 Windows XP SP2 Windows 2003 SP1 Windows XP x64 and Windows Vista As you can see the older the operating system the more service packs you need And finally you also need the most current DirectX runtimes and if you are serious about game devel opment better get the full DirectX SDK The DirectX SDK is not required by XNA Game Studio Express because the dlls just call the underlying DirectX dlls but it is always useful to have some more docu mentation on your system and DirectX contains many samples and tutorials which are useful if you run into trouble For example the DirectX SDK contains tools to help you generate DDS texture files which are optimized for the best graphic card texture
49. useful samples beyond the scope of this book such as Generated Geometry Aiming 3d Audio 3D Picking Billboards and 3D particles Distortion Effects Normal Mapping Non Photorealistic rendering Bloom post process and other samples Several mini games and the very popular XNA Starter kits can also be found on the XNA Creators club including Space Wars Asteroids clone Marblets puzzle game Ship Game Descent style game and the Racing Game see Part IV of this book 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 27 Chapter 1 Introducing XNA Another notable feature in XNA 2 0 is the ability to use XNA inside a window control which is useful for level editors such as the Dungeon Quest Editor discussed at the very end of this book The Input classes in XNA now support more devices like the Chatpad the Big button pad guitars drums or flight sticks See Chapter 10 for more information Last but not least there are improvements to the Audio framework too which are discussed in Chapter 9 XNA 2 0 features better cue management and a new and easier XACT editor which is important to create and manage sound effect files in XNA Other changes to the XNA Framework will be mentioned when they are relevant to the discussion in the book such as the Content Pipeline which is a little bit simpler to use in XNA 2 0 You can more easily load and unload assets and you no longer have to handle device loss or device reset events To get the most r
50. ws you the newest XNA projects and knows a lot about Managed DirectX and XNA Q www ziggyware com An XNA community website founded by Michael Ziggy Morton It has grown a lot in the last years and contains hundreds of articles and news posts and has a very active community behind it Make sure to check out the active discussion forum the site also features XNA Image of the day polls and other cool stuff A www riemers net A very old and solid DirectX site with tons of information about DirectX Recently switched to XNA and has great information on that too There is also an active forum on this site A http xnadevelopment com One of the first XNA sites with many links tutorials and tips to get you started in the XNA world Not many updates here however Q http xnaresources com Another site that had a lot of news and some really useful tuto rials on tile engines for XNA 1 0 but not much updates recently either A http abi exdream com Official website of the author You can find more games I made here as well as Rocket Commander XNA the XNA Shooter or the Racing Game from this book and all the documentation and video tutorials I made for them Additionally I suggest checking out the Rocket Commander Video Tutorials which were pretty popular on Coding4Fun 21 fp 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 22 Part XNA Framework Basics AQ http XnaProjects net Another website create
51. y default the ClearOptions are set to ClearOptions Target ClearOptions DepthBuffer which means both the background color and the depth buffer are cleared By the way if you don t know it already the operator between the ClearOptions flags will combine both settings Figure 1 11 16 61286c01 qxd WroxPro 1 21 08 3 44 PM Page 17 Chapter 1 Introducing XNA Changing the Code Instead of giving up here think about some ways you can modify the code in a useful manner First of all you should be able to quit your program by pressing Esc By default XNA just adds the following lines to the update method which quits the program when the Xbox 360 controller s Back button is being pressed Allows the default game to exit on Xbox 360 and Windows if GamePad GetState PlayerIndex One Buttons Back ButtonState Pressed illes Jae 0 To learn more about the Input classes see Chapter 3 Helper Classes For now you will just use a quick and dirty way to access the keyboard If you modify the code in the following way you can also press Escape now to quit the application Get current gamepad and keyboard states GamePadState gamePad GamePad GetState PlayerIndex One KeyboardState keyboard Keyboard GetState Back or Escape exits our game on Xbox 360 and Windows if gamePad Buttons Back ButtonState Pressed keyboard IsKeyDown Keys Escape ais motel As you can see you put the gamepad an
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