COCOS 2D屏幕截图在Android中是黑色的

我正在使用以下代码.图像被保存,但它是黑色的.
请看我的代码,告诉我我做错了什么.
我在菜单中使用这个代码.

case R.id.id_menu_Save:

            Bitmap bmp = SavePixels(0, 0, 800, 400, CCDirector.sharedDirector().gl);

            File file = new File("/sdcard/test.jpg");
            try
            {
                file.createNewFile();
                FileOutputStream fos = new FileOutputStream(file);
                bmp.compress(CompressFormat.JPEG, 100, fos);

                Toast.makeText(getApplicationContext(), "Image Saved", 0).show();
                Log.i("Menu Save Button", "Image saved as JPEG");
            }

            catch (Exception e)
            {
                e.printStackTrace();
            }

            break;

这是我的保存图像功能.

public static Bitmap SavePixels(int x, int y, int w, int h, GL10 gl)
{  
     int b[]=new int[w*(y+h)];
     int bt[]=new int[w*h];
     IntBuffer ib=IntBuffer.wrap(b);
     ib.position(0);
     gl.glReadPixels(x, 0, w, y+h, GL10.GL_RGBA, GL10.GL_UNSIGNED_BYTE, ib);

     for(int i=0, k=0; i<h; i++, k++)
     {//remember, that OpenGL bitmap is incompatible with Android bitmap
      //and so, some correction need.        
          for(int j=0; j<w; j++)
          {
               int pix=b[i*w+j];
               int pb=(pix>>16)&0xff;
               int pr=(pix<<16)&0x00ff0000;
               int pix1=(pix&0xff00ff00) | pr | pb;
               bt[(h-k-1)*w+j]=pix1;
          }
     }

    Bitmap sb = Bitmap.createBitmap(bt, w, h, Bitmap.Config.ARGB_8888); 
    return sb;
}

除此之外,我想要的是指出我的方向正确.喜欢如果我得到屏幕的像素,我应该探索什么类/实体？

只需将SavePixelx方法更改为：

public static Bitmap SavePixels(int x, int y, int w, int h, GL10 gl)
{  
     int b[]=new int[w*(y+h)];
     int bt[]=new int[w*h];
     IntBuffer ib=IntBuffer.wrap(b);
     ib.position(0);
     gl.glReadPixels(x, 0, w, y+h, GL10.GL_RGBA, GL10.GL_UNSIGNED_BYTE, ib);

     for(int i=0, k=0; i<h; i++, k++)
     {
          //remember, that OpenGL bitmap is incompatible with Android bitmap
          //and so, some correction need.        
          for(int j=0; j<w; j++)
          {
               int pix=b[i*w+j];
               int pb=(pix>>16)&0xff;
               int pr=(pix<<16)&0xffff0000;
               int pix1=(pix&0xff00ff00) | pr | pb;
               bt[(h-k-1)*w+j]=pix1;
          }
     }

    Bitmap sb = Bitmap.createBitmap(bt, w, h, Bitmap.Config.ARGB_8888); 
    return sb;
}