Class #3: July 14, 2010 Create New Project Open Visual C#: Start - PowerPoint PPT Presentation

Class #3: July 14, 2010

Create New Project  Open Visual C#:  Start Menu  Microsoft XNA Game Studio 3.1  Visual C# Express Edition  Create New Project:  File  New Project  Type: XNA Game Studio 3.1  Template: Windows Game 3.1

Classes  Classes:  Program class in Program.cs  Game1 class in Game1.cs  Namespace AwesomeGame  Like a package in Java, is just a grouping for your classes.

Program class  Has a main method that is called at runtime  Initializes a new Game1 object game.  Calls game.Run()  If you check Game1.cs you will not find this method, because it is in the Microsoft.XNA.Framework.Game class.  Game1 inherits from this class.  Run() begins the game loop.

Game Loop running = true; while (running) { update(); draw(); }  As the programmer, it’s up to you to make sure everything gets updated in the update() function and displayed in the draw() function.

Game1 class  Update()  Get player input  Move everything on screen  Check for collisions  Make decisions based on all the above. (is the player dead? Is the game over?)  Draw(), display objects to screen.

Game1 class  GraphicsDeviceManager graphics;  Handles the management of the graphics device, or what is output to the screen. Defaults to a game window of 800x600.  SpriteBatch spriteBatch;  Allows us to draw our sprites to the screen.  Initialize()  Where we initialize our variables.  LoadContent()  Where we load our content – images, audio, models, etc.

Other Data Types  Just like the Java API provides classes like String, the XNA framework is an API and we will be using many of its classes.  Today we will be using Vector2 and Texture2D

Vector2  Vector2 is a container for 2 values,  an X coordinate and a Y coordinate, both floats. Useful for storing positions.  For example if we wanted to store the position of the background texture we would create a Vector2 : Vector2 backgroundPosition = new Vector2(0.0f, 0.0f);  To get or set the X coordinate, we do that like this: backgroundPosition.X = backgroundPosition.X +10; backgroundPosition = backgroundPosition +10;

Texture2D class  Is a container for an image.  After you have added an image to your Content folder:  Declare under global variables: Texture2D backgroundTexture;  Load the texture under LoadContent(): backgroundTexture = Content.Load <Texture2D>(“Sprites \\ background”);

Draw()  Have to use the following syntax to draw your texture in Draw(): spriteBatch.Begin(SpriteBlendMode.AlphaBlend); spriteBatch.Draw(texture, texturePosition,Color.White); spriteBatch.End();

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