經過前幾節內容的學習，我們已經讓物體具有了平移、縮放、旋轉的三大運動能力，通過組合使用，可以形成復雜的物體運動模型。 接下來，我們要給物體增加些顏色了，改變灰濛濛的世界。 還記得我們之前定義的三角形數據嗎？當初定義的時候是這樣的： ~~~ ??????????triangle = new VertexPositionColor[]{ ??????????????new VertexPositionColor(new Vector3(0, 1, 0), Color.Red), ??????????????new VertexPositionColor(new Vector3(1, -1, 0), Color.Green), ??????????????new VertexPositionColor(new Vector3(-1,-1, 0), Color.Blue) ????? ?????}; ~~~ 我們使用了VertexPositionColor對象數組，該類型使用坐標和顏色值來表示一個頂點，但在此之前，該顏色值一直沒起到作用，我們看到的都是白色的三角形，其實想讓顏色生效非常簡單，只要在Draw()方法添加下句即可： basicEffect.VertexColorEnabled= true; 運行一下，絢麗的三角形就出來了。  不過，僅用顏色顯然不能制作更逼真的物體，比如說木頭的三角形，用顏色就不能準確表達了。這時，我們需要的是使用紋理，即使用木紋的圖片貼到三角形上，最終看上去成為想要的效果。 在Windows Phone中，紋理是使用Texture2D類來表示的，最常用的就是代表資源中的一張圖片。具體的實現是在Content工程中添加一張圖片，比如在HelloContent中添加一張wood.jpg圖片，然后在LoadContent()方法中就可以使用如下語句將圖片表示為Texture2D對象了。 texture =Content.Load<Texture2D>(@"wood"); 有了紋理，還要有正確的貼圖坐標，這里我們稱為UV坐標，一個紋理圖片的UV坐標規定為：  這樣我們就可以指定不同頂點的貼圖位置了。比如我們的三角形最上邊的點的UV坐標就是(0.5,0)，左下角點是(0,1)，右下角點是(1,1)。對于需要使用紋理坐標的三角形，前文用到的VertexPositionColor類型已經不夠了，我們需要使用VertexPositionTexture類型，即每個頂點使用坐標和紋理坐標來描述，而不再是坐標和顏色來描述了。對應的三角形數據如下： ~~~ ?????????? triangle = newVertexPositionTexture[]{ ?????????????? new VertexPositionTexture(newVector3(0, 1, 0), new Vector2(0.5f,0)), ?????????????? new VertexPositionTexture(newVector3(1, -1, 0), new Vector2(1,1)), ?????????????? new VertexPositionTexture(newVector3(-1,-1, 0), new Vector2(0,1)) ?????????? }; ~~~ 最后，要想得到渲染結果，修改Draw()方法，調整basicEffect的紋理屬性為： ~~~ ?????????? basicEffect.TextureEnabled = true; ?????????? basicEffect.Texture = texture; ~~~ 運行程序，可以得到帶木紋的三角形了。  附本節Game1類的完整源碼： ~~~ public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; Camera camera; Matrix world = Matrix.Identity; BasicEffect basicEffect; VertexPositionTexture[] triangle; Matrix translateMatrix=Matrix.Identity; Matrix scaleMatrix = Matrix.CreateScale(0.5f); Matrix rotateMatrix = Matrix.Identity; Texture2D texture; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; // Frame rate is 30 fps by default for Windows Phone. TargetElapsedTime = TimeSpan.FromTicks(333333); // Extend battery life under lock. InactiveSleepTime = TimeSpan.FromSeconds(1); graphics.IsFullScreen = true; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here base.Initialize(); } /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { camera = new Camera(this, new Vector3(0, 0, 5), Vector3.Zero, Vector3.Up, MathHelper.PiOver4, GraphicsDevice.Viewport.AspectRatio, 1.0f, 50.0f); Components.Add(camera); basicEffect = new BasicEffect(GraphicsDevice); triangle = new VertexPositionTexture[]{ new VertexPositionTexture(new Vector3(0, 1, 0), new Vector2(0.5f,0)), new VertexPositionTexture(new Vector3(1, -1, 0), new Vector2(1,1)), new VertexPositionTexture(new Vector3(-1,-1, 0), new Vector2(0,1)) }; texture = Content.Load<Texture2D>(@"wood"); } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { // TODO: Unload any non ContentManager content here } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); TouchPanel.EnabledGestures = GestureType.Tap; if (TouchPanel.IsGestureAvailable) { GestureSample gestureSample = TouchPanel.ReadGesture(); if (gestureSample.GestureType == GestureType.Tap) { translateMatrix *= Matrix.CreateTranslation(0.3f, 0, 0); //scaleMatrix = Matrix.CreateScale(0.9f); rotateMatrix *= Matrix.CreateRotationY(MathHelper.ToRadians(10)); } } base.Update(gameTime); } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); RasterizerState rasterizerState = new RasterizerState(); rasterizerState.CullMode = CullMode.None; GraphicsDevice.RasterizerState = rasterizerState; basicEffect.World = scaleMatrix * translateMatrix * rotateMatrix; basicEffect.View = camera.view; basicEffect.Projection = camera.projection; basicEffect.TextureEnabled = true; basicEffect.Texture = texture; GraphicsDevice.SamplerStates[0] = SamplerState.PointClamp; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawUserPrimitives<VertexPositionTexture>(PrimitiveType.TriangleStrip, triangle, 0, 1); } base.Draw(gameTime); } } ~~~ ——歡迎轉載，請注明出處 [http://blog.csdn.net/caowenbin](http://blog.csdn.net/caowenbin) ——