XNA中的显示

 

          XNA中的显示可分为2D图片的显示和模型的显示。

1、2D图片的显示

                   XNA中2D图片是通过精灵（SpriteBatch）来显示的的。

                   （1）、在类中声明精灵对象

                            SpriteBatch spriteBatch;

         （2）、在LoadContent函数中构造精灵对象、加载2D图片信息

              spriteBatch = new SpriteBatch(GraphicsDevice);

         （3）、在Update函数中根据输入信息计算模型的屏幕坐标及旋转角度

         （4）、在Draw函数中通过spriteBatch显示myTexture信息

              spriteBatch.Draw(myTexture, spritePosition, null, Color.White,

0.5f, new Vector2(), 1.0f, SpriteEffects.None, 0.0f);

     2、字体的显示

         XNA中字体的显示与2D图片的显示一样，也是通过SpriteBatch类实现的。

          public void DrawString (

                                SpriteFont spriteFont,                         /*字体*/

                                string text,                                             /*输出字符串*/

                                Vector2 position,                                  /*显示位置*/

                               Color color,                                         /*颜色*/

                                float rotation,                                       /*旋转*/

                                Vector2 origin,                                     /*原点*/

                                Vector2 scale,                                      /*缩放*/

                                SpriteEffects effects,                            /*特效*/

                                float layerDepth                                   /*深度*/

                    ）

           显示字符串时，首先按照与2D图片显示相同的方法声明并初始化SpriteBatch对象，之后通过该对象的DrawString方法显示字符串。

spriteBatch.DrawString(spriteFont, "hello world !",

new Vector2(10, 20), Color.White);

           3、3D模型的显示

                 XNA中3D模型的显示是通过遍历并显示该模型的ModelMesh来实现的

             foreach (ModelMesh mesh in model.Meshes)

            {

                /*设置mesh的特效*/

                foreach (BasicEffect effect in mesh.Effects)

                {

                    /*投影变换*/

                    effect.World = world * boneTransforms[mesh.ParentBone.Index];

                    effect.View = camera.View;

                    effect.Projection = camera.Proj;

 

                    /*灯光效果*/

                    effect.LightingEnabled = true;

                    effect.DiffuseColor = new Vector3(1.2f);

                    effect.AmbientLightColor = new Vector3(0.5f);

 

                    /*雾化效果*/

                    effect.FogEnabled = true;

                    effect.FogStart = 6000;

                    effect.FogEnd = 10000;

                    effect.FogColor = Color.CornflowerBlue.ToVector3();

                }

                /*显示mesh*/

                mesh.Draw();

            }