Difference between revisions of "Game Programming Class12"

 1 /// <summary>
 2         /// Constructs a new quadrilateral drawing worker.
 3         /// </summary>
 4         public QuadDrawer(GraphicsDevice device)
 5         {
 6             graphicsDevice = device;
 7 
 8             effect = new AlphaTestEffect(device);
 9 
10             effect.AlphaFunction = CompareFunction.Greater;
11             effect.ReferenceAlpha = 128;
12 
13             // Preallocate an array of four vertices.
14             vertices = new VertexPositionTexture[4];
15 
16             vertices[0].Position = new Vector3(2, 2, 0);
17             vertices[1].Position = new Vector3(-2, 2, 0);
18             vertices[2].Position = new Vector3(2, -2, 0);
19             vertices[3].Position = new Vector3(-2, -2, 0);
20         }
21 
22 
23         /// <summary>
24         /// Draws a quadrilateral as part of the 3D world.
25         /// </summary>
26         public void DrawQuad(Texture2D texture, float textureRepeats,
27                              Matrix world, Matrix view, Matrix projection)
28         {
29             // Set our effect to use the specified texture and camera matrices.
30             effect.Texture = texture;
31 
32             effect.World = world;
33             effect.View = view;
34             effect.Projection = projection;
35 
36             // Update our vertex array to use the specified number of texture repeats.
37             vertices[0].TextureCoordinate = new Vector2(0, 0);
38             vertices[1].TextureCoordinate = new Vector2(textureRepeats, 0);
39             vertices[2].TextureCoordinate = new Vector2(0, textureRepeats);
40             vertices[3].TextureCoordinate = new Vector2(textureRepeats, textureRepeats);
41 
42             // Draw the quad.
43             effect.CurrentTechnique.Passes[0].Apply();
44 
45             graphicsDevice.DrawUserPrimitives(PrimitiveType.TriangleStrip, vertices, 0, 2);
46         }