Course 3D_XNA: 3D-Computer Graphics with XNA Chapter C2: Light and Texture Copyright © by V. Miszalok, last update: 25-09-2010
Let me know what you think	Project light1   Game1, Initialize, Update, Draw   Experiments   Texture   Help

Project light1

It requires no DirectX SDK but:
1. Visual C# 2010 Express or Visual Studio 2010 Professional
2. XNA Game Studio 4.0
3. DirectX End User Runtimes, which is a subset of DirectX SDK.

Main Menu after starting VS 2010: File → New Project... → Project types: XNA GameStudio 4.0 → Templates: Windows Game (4.0) → Name: light1 → Location: C:\temp → Create directory for solution: switch it off → OK.
Solution Explorer - light1: Delete the file Program.cs and the default content of Game1.cs.

Game1, Initialize, Update, Draw

Write the following code into the empty code window of Game1.cs:

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Content;

static class Program
{ static void Main() { Game1 game = new Game1(); game.Run(); }

public class Game1 : Microsoft.Xna.Framework.Game
{ private GraphicsDeviceManager g;
  private VertexBuffer vbuffer;  
  private BasicEffect  effect;
  private EffectPass   pass;
  private float rotAngle = 0f;
  private const int xsteps = 100;
  
  public Game1()
  { Window.Title = "Light1";
    Window.AllowUserResizing = true;
    g = new GraphicsDeviceManager( this );
    g.IsFullScreen = false;
    g.PreferredBackBufferWidth  = 600;
    g.PreferredBackBufferHeight = 600;
  }
  protected override void Initialize()
  { VertexPositionNormalTexture[] v = new VertexPositionNormalTexture[xsteps];
    float  amplitude = 0.2f;
    double frequency = 4.0 * MathHelper.TwoPi;
    for ( int i = 0; i < xsteps; i++ )
    { float x = (float)i / xsteps;
      v[i].Position.X          = -0.5f + x;
      v[i].TextureCoordinate.X =         x;
      if ( i%2 == 0 ) { v[i].Position.Y =  0.5f; v[i].TextureCoordinate.Y = 0f; }
      else            { v[i].Position.Y = -0.5f; v[i].TextureCoordinate.Y = 1f; }
      v[i].Position.Z = amplitude * (float)System.Math.Sin( x*frequency );
    }
    for ( int i = 0; i < xsteps-2; i++ )
    { Vector3 a = v[i+1].Position - v[i].Position;
      Vector3 b = v[i+2].Position - v[i].Position;
      Vector3 c = Vector3.Cross( a, b );
      c.Normalize();
      if ( c.Z > 0f ) v[i].Normal = c;
      else            v[i].Normal = Vector3.Negate( c );
    }
    vbuffer = new VertexBuffer( g.GraphicsDevice, typeof(VertexPositionNormalTexture), xsteps, BufferUsage.WriteOnly );
    vbuffer.SetData< VertexPositionNormalTexture >( v );
    effect = new BasicEffect( g.GraphicsDevice, null );
    effect.View = Matrix.CreateLookAt( new Vector3(0, 0, 4), Vector3.Zero, Vector3.Up );
    effect.Projection = Matrix.CreatePerspectiveFieldOfView( MathHelper.Pi/8, 1f, 1f, 10f );
    effect.LightingEnabled = true;
    //effect.Texture = new ContentManager(Services).Load< Texture2D >("Content\\Foto");
    //effect.TextureEnabled = true;
    pass = effect.CurrentTechnique.Passes[0];
    BasicDirectionalLight light = effect.DirectionalLight0;
    light.Direction = new Vector3( 0f, 0f, -1f ); 
    light.Direction.Normalize();
    light.DiffuseColor  = Color.White.ToVector3();
    light.SpecularColor = Color.CornflowerBlue.ToVector3();
    light.Enabled = true;
  }
  protected override void Update( GameTime gameTime )
  { g.GraphicsDevice.Vertices[0].SetSource( vbuffer, 0, VertexPositionNormalTexture.SizeInBytes );
    g.GraphicsDevice.VertexDeclaration = new VertexDeclaration( g.GraphicsDevice, VertexPositionNormalTexture.VertexElements );
    g.GraphicsDevice.RenderState.CullMode = CullMode.None;
    //g.GraphicsDevice.RenderState.FillMode = FillMode.WireFrame;
    g.GraphicsDevice.RenderState.DepthBufferEnable      = false;
    g.GraphicsDevice.RenderState.DepthBufferWriteEnable = false;
  }
  protected override void Draw( GameTime gameTime )
  { g.GraphicsDevice.Clear( Color.DarkBlue );
    //effect.World = Matrix.CreateRotationZ( rotAngle += 0.01f );
    //effect.World = Matrix.CreateRotationY( rotAngle += 0.01f );
    //effect.World = Matrix.CreateRotationX( rotAngle += 0.01f );
    effect.Begin();
      pass.Begin();
        try { g.GraphicsDevice.DrawPrimitives( PrimitiveType.TriangleStrip, 0, xsteps-2 ); } catch {}
      pass.End();
    effect.End();
    base.Draw(gameTime);
  }
} // end of class Game1
} // end of class Program

Click Debug → Start Without Debugging Ctrl F5. Drag the window borders.

Experiments

Texture

1. Remove all experimental changes and restore the original code from Game1, Initialize, Update, Draw above.

2. Right click this link: Foto.jpg and store the image into the project directory C:\temp\light1.
Now You have to add the texture image to project light1:
Right click light1 → Content → Add → Existing Item... → Files of type: All Files (*.*).
Select Foto.jpg, quit by clicking the Add-button and check whether it arrived underneath project light1 → Content.

3. Remove the comment slashes // in front of //effect.Texture = new ContentManager(Services).Load< Texture2D >("Content\\Foto"); and //effect.TextureEnabled = true;

4. Click Debug → Start Without Debugging Ctrl F5.

Experiments:

if ( i%2 == 0 ) { v[i].Position.Y =  0.5f; v[i].TextureCoordinate.Y = 0f; }
else            { v[i].Position.Y = -0.5f; v[i].TextureCoordinate.Y = 1f; }
→
if ( i%2 == 0 ) { v[i].Position.Y =  0.5f; v[i].TextureCoordinate.Y = 1f; }
else            { v[i].Position.Y = -0.5f; v[i].TextureCoordinate.Y = 0f; }

Help

1. I recommend the following german booklet: KONEROW Jens: XNA Framework. schnell + kompakt, entwickler.press, ISBN: 978-3-939084-53-2,  € 7,90 (130 pages) and the code of Konerow's samples from the link "Quellcode" or everything as e-book, € 6,70.

2. You find extensive information about XNA here: http://msdn2.microsoft.com/en-us/library/bb200104.aspx.
Click trough the tree on the left side:
1: XNA Game Studio x.0 → Getting Started with XNA Game Studio → Your First Game: Microsoft XNA Game Studio in 2D
2: XNA Game Studio x.0 → Programming Guide
3: XNA Game Studio x.0 → XNA Framework Class Library Reference

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