Android 绘制纹理映射矩形

我试着把两个三角形一起画成一个矩形，然后在上面画出整个纹理，我想这只是1.0个坐标。我得到了一个三角形，有很多细小的褪色纹理。我对opengl非常陌生，对这些调用有点不知所措。 有没有人在我的QUAD类中看到任何明显错误的东西，比如我有错误的坐标或以错误的顺序绘制

  public class MyRenderer implements GLSurfaceView.Renderer {
        private Quad myquad;
        private Context context;
        int texture[] = new int[1];
        private int width,height;
        int x,y;
        private long startframe,timediff,sleeptime,frameskip;
        private final static int MAX_FPS = 25;
        private final static int MAX_FRAME_SKIPS = 5;
        private final static int FRAME_PERIOD = 1000/MAX_FPS;
        private static Direction move_direction=Direction.NONE;


        public MyRenderer (Context context){
          this.myquad = new Quad();
          this.context = context;
        }
        public void onSurfaceCreated(GL10 gl, EGLConfig config) {
            myquad.loadGLTexture(gl, this.context);

            //turn on alpha blending
            gl.glEnable(GL10.GL_BLEND);
            gl.glBlendFunc(gl.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);

            gl.glEnable(GL10.GL_TEXTURE_2D);
            gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
            gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
            gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
            gl.glDisable(GL10.GL_DEPTH_TEST);

            x=y=0;
        }

        public void onSurfaceChanged(GL10 gl, int w, int h) {
            width=w;
            height=h;
            gl.glViewport(0, 0, w, h);
            gl.glMatrixMode(GL10.GL_PROJECTION);    //Select The Projection Matrix          
            gl.glLoadIdentity();
            gl.glOrthof(0.0f, 320, 0.0f, 480, 1.0f, -1.0f);        
        }

        public void onDrawFrame(GL10 gl) {
            startframe=SystemClock.elapsedRealtime();
            // define the color we want to be displayed as the "clipping wall"
            gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
            // clear the color buffer to show the ClearColor we called above...
            gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
          //  gl.glLoadIdentity(); 
            switch (move_direction)
            {
            case UP:
                gl.glTranslatef(0, 1, 0);
                y=y+1;
                break;
            case DOWN:
                gl.glTranslatef(0, -1, 0);
                y= y-1;
                break;
            case LEFT:
                gl.glTranslatef(-1, 0, 0);
                x=x-1;
                break;
            case RIGHT:
                gl.glTranslatef(1, 0, 0);
                x=x+1;
                break;
            case NONE:
                //gl.glTranslatef(0, 0, 0);
                break;
            }
            myquad.Draw(gl);

class Quad {
    private FloatBuffer vertices;
    private int[] textures = new int[1];
    private ShortBuffer indexbuffer;
    //private float vertices[] = {
    //      50.0f, 50.0f,  // 0. 
    //         100.0f, 50.0f,   // 1. 
    //        100.0f,  100.0f,   // 2. 
    //         50.0f,  100.0f // 3. 
    //};

    private float texture[] = {          
             0.0f, 0.0f,   //0
             1.0f, 0.0f,    //1
             1.0f, 1.0f,     //2
             1.0f, 0.0f        //3
    };

    private short indices[] = {0,1,2,0,3,2};



              public Quad(){
                try
            {
                    float[] coords={50.0f, 50.0f,  //0
                    300.0f,50.0f, //1
                    300.0f, 300.0f,  //2
                    300.0f, 50.0f}; //3

            short[] indices = {0,1,2,0,3,2};

            ByteBuffer verticesbuffer =     ByteBuffer.allocateDirect(coords.length*4);
            verticesbuffer.order(ByteOrder.nativeOrder());
            vertices = verticesbuffer.asFloatBuffer();
            vertices.put(coords);
            //vertices.position(0);
            vertices.flip(); 

        ByteBuffer idb = ByteBuffer.allocateDirect(indices.length * 2);
        idb.order(ByteOrder.nativeOrder());
        indexbuffer = idb.asShortBuffer();
        indexbuffer.put(indices);
        //indexbuffer.position(0);
        indexbuffer.flip();
        }catch(Exception e)
         {
            Log.d("buffers","not working",e);
         }
    }

     public void loadGLTexture(GL10 gl, Context context) {
          //Get the texture from the Android resource directory
          //Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(),R.drawable.herowalkback);
         try
         {
         Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(),R.drawable.herowalkback);

          if (bitmap == null) 
          {
              Log.i ("info", "bitmap could not be decoded");
          }
          //Generate one texture pointer...
          gl.glGenTextures(1, textures, 0);
          //...and bind it to our array
          gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);

          //Create Nearest Filtered Texture
          gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
          gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_NEAREST);

          gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE, GL10.GL_REPLACE);

          //Use the Android GLUtils to specify a two-dimensional texture image from our bitmap
          GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0,bitmap, 0);

          //Clean up
          bitmap.recycle();
         }catch(Exception e)
         {
            Log.d("load texture","not working");
         }
       }

    public void Draw(GL10 gl)
    {   
        // set the color for the triangle
        gl.glColor4f(0.0f, 1.0f, 0.0f, 0.5f);

        //Enable the vertex and texture state
        vertices.position(0);
        gl.glVertexPointer(2, GL10.GL_FLOAT, 0, vertices);
        vertices.position(2);
        gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, vertices);


        // Draw the vertices as triangle strip
        gl.glDrawElements(GL10.GL_TRIANGLES, 6, GL10.GL_UNSIGNED_SHORT, indexbuffer);

    }
}


public class test extends Activity {
    private GLSurfaceView glsurface;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        glsurface = new GLSurfaceView(this);
        glsurface.setRenderer(new MyRenderer(this));
        setContentView(glsurface);
        glsurface.setOnKeyListener(watchkeys);
        glsurface.setFocusable(true);
        glsurface.setFocusableInTouchMode(true);


    }

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你没有做错什么。这称为纹理贴图，您需要习惯这种情况

例如，请记住，要水平映射三角形（x坐标），您使用了0.0和1.0。由于涉及两个三角形，您需要相应地划分坐标。所以它是0.0，0.5，1.0。Y轴也是如此

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理想情况下，您可以使用Blender之类的建模工具对对象进行纹理贴图，这样您就不用担心将1.0分割成x个三角形。

好的，谢谢。为什么它只会画一个三角形，或者它会同时画两个呢？因为纹理不对，所以我只看到一个。你的代码有很多错误，三个以上的错误。为什么不修改一个运行中的android示例来开始呢。然后返回stackoverflow寻求进一步帮助。当android开发者页面上有关于这个问题的完整代码时，修复代码将是浪费时间。希望这有帮助。