狠狠撸

XNA Game Studio 2.0
Game Programming Made Easy(ier)
Reuben Ahmed
[February 12, 2008]

About Me
? 7 years of .NET/C#
? Minimal game programming
experience
? Avid video game player
– *Not reflected in my XBOX Live gamer score
? rahmed@bennettadelson.com

WARNING
? Disclaimer: Code shown during
this presentation is not meant to
be the “right” or “best” way of
creating a game.
? Purpose: Give you a basic
toolset to start off with XNA.

Agenda
? What is XNA?
? System Requirements
? Out of the box architecture
? Graphics/Textures
? Input
? Collision Detection
? Text Writing
? Audio
? XBOX 360 Deployment (!)
? Distribution model
? Q & A

What is XNA?
? X-Platform Next Generation Architecture
? C# Game Framework
– Windows/XBOX 360
– Reduced learning curve
– Compiles to .NET Compact Framework
– Available, Approachable, and nearly Free
? Sony Playstation 3 Dev. Kit = ~$10,500
? XNA is free on Windows.
? $49/4 months or $99/year on XBOX 360.

System Requirements
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? XBOX 360 Deployment
? Q & A

System Requirements
? Visual C# 2005 Express Edition, Standard Edition,
Professional Edition , Team Edition for Software
Architects, Team Edition for Software Developers, Team
Edition for Software Testers, Team Edition for Database
Professionals , Team Suite
? No Visual Studio 2008 support currently!
? DirectX 9.0c, Pixel Shader 1.1+
XNA Studio 2.0 and C# Express URL:
? http://creators.xna.com/Education/newtoxna.aspx

Out of the box architecture
? What is XNA?
? Graphics/Textures
? Input
? Audio
? Q & A

Out of the box architecture
? Graphics Device Manager
– Automatically sets up interaction with your
graphics card
? Optimized Game Loop
– Update, Draw methods
? Content Pipeline
– Game Assets (Graphics, Audio, etc.)
? DEMO: Our First XNA Game!
– Change background color

Graphics/Textures
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

Graphics/Textures – Drawing
1) Add Asset to your project
– Drag and drop graphic
2) Load Graphic into variable
– Texture2D class
– Content Pipeline method
? Content.Load <Texture2D> (“AssetName”);
3) Draw it
– SpriteBatch class
? SpriteBatch.Draw (Texture2D, Position, Color);

? DEMO: Adding a spaceship graphic!
? DEMO: Tint graphic with Draw
parameter.
Graphics/Textures - Demo

? Vector2 class
– Holds X and Y position
– Can represent Position, Acceleration, Velocity
Graphics – 2D Coordinates

? GraphicsDevice.Viewport
– Window size properties
? DEMO: Centering graphic with Vector2!
? Tip: Texture is drawn with upper left as
starting point…
GraphicsGraphics – Window Size

? DEMO: Scale image with Rectangles.
? Tip: Draw order matters!
GraphicsGraphics – Scale

Input
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

? Keyboard
– Static class
? Current state of keyboard
? Which keys are pressed
? Keys
– Enumerator
– Represents almost any key!
? DEMO: Read input to exit game.
Input – Read Keys

? Vector2
– (X,Y) can also represent velocity
? Vectors can be added/subtracted…
? Vector of (0,0) position + Vector of (5, 2)
velocity = new position of (5, 2).
Input – Vector2 Velocity

? DEMO: Move ship to right.
? DEMO: Use Keyboard to move ship
left/right.
Input – Vector2 Velocity

Collision Detection
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

? My ship is going off the screen!
? First level of collision detection:
– Window boundaries
– MathHelper class to the rescue…
? Clamp() method.
? DEMO: MathHelper.Clamp() to
boundaries.
Collision Detection

? Let’s add an “enemy”…remember:
– Texture2D
– Vector2 (position)
– Vector2 (velocity)
– MathHelper.Clamp (Window Boundaries)
? DEMO: Add a non-hostile Alien that
eerily resembles a Space Invader?!
Collision Detection

? Can we shoot a bullet?
– Bullet spawns from spaceship position.
– Moves vertically up (negative Y direction)
? DEMO: Kill it, KILL IT!
Collision Detection

? My bullets are too weak!
– Rectangles encompass every Texture.
– Rectangle.Intersects will help!
? DEMO: Encompass the alien and bullet
in rectangles, and figure out if they
collided…
Collision Detection

? 2D Per-Pixel Collision
– More expensive, but accurate
? Color Key Collision
– Detects collision based on color map!
Collision Detection, etc.

Text Writing
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

Text Writing
? SpriteFont asset
? SpriteBatch.DrawString()
? DEMO: Keep a bullet hit count label…

Audio
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

Audio
? Microsoft Cross Platform Audio Creation
Tool
– Creates a .XAP “Game Asset”
– .WAV files
? Classes
– audioEngine = new AudioEngine ("ContentAudioPROJECTNAME.xgs");
– waveBank = new WaveBank (audioEngine, "ContentAudioWave Bank.xwb");
– soundBank = new SoundBank (audioEngine, "ContentAudioSound Bank.xsb");
– soundBank.PlayCue (“CUENAME");
? DEMO: Background music. Loop it.

? Change volume level
? 3D Spatial audio!
Audio, etc.

XBOX 360 Deployment
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

XBOX 360 Deployment
? This costs money!
? Download XNA Creator’s License ($49 or
$99) from the Games Blade.
? Download/Launch XNA Game Studio
Connect (Free) from the Games Blade.
? Generate a key that your PC can use to
connect to your XBOX360…this only has
to be done once.

XBOX 360 Deployment
? Launch XGS Device Center on your PC.

? Your console is now connected!
XBOX 360 Deployment

? Either an XBOX 360 Project Type, OR a
Windows XNA Project Type can be
deployed!
? DEMO: Demonstrate “Copy Windows
Project to XBOX360 Project”
? Projects stay in sync.
? DEMO: Add GamePad input handling.
Add rumble!
XBOX 360 Deployment

? DEMO: …Deploy this thing.
– Incremental deployment support!
– No wireless deployment.
– Your game is now available on the Games
Blade!
? DEMO: Debugging on XBOX 360…
XBOX 360 Deployment

Distribution Model
? What is XNA?
? Out of the box functionality
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

? XBL currently a managed portfolio
? Game Developer’s Conference 2008
– Microsoft prepared to announce XBL
Community Blade for XNA.
Distribution Model

Tip of the iceberg…
? Plethora of XNA Tutorials/Starter Kits
? Network Architecture
– Client/Server, Peer to Peer, Prediction Code
– XBOX Live Profile information
? Artificial Intelligence
– State Management samples
? Speech Recognition/Synthesis
– System.Speech .NET 3.0

Tip of the iceberg…
? XNA Racing Game: YouTube
? 1 week of code (professional game
development company)
? Jitted on the fly, 1080p, 30 FPS, running
on C# (Managed code!), with 2X Anti
aliasing!
? Graphics power is equated to a $350 PC
video card. Anti aliasing…one line of
code via XNA.

References
? MSDN XNA Game Studio 2.0
– Overview of framework
? http://creators.xna.com/
– Active community site
? http://www.xnadevelopment.com/
– Beginner tutorials
? http://www.phstudios.com/
– Intro?advanced tutorials

Q & A
? What is XNA?
? Graphics/Textures
? Input
? Text Writing
? Audio
? Q & A

狠狠撸

XNAPresentation

More Related Content

Similar to XNAPresentation (20)

XNAPresentation

Editor's Notes