title: Rotate GLSurfaceView
body: <p>I am showing 2D Image on GLSurfaceView and Want to rotate it with specific degree (ie. 180 ,75,360...)</p>
  
  <p>I written following code in touch event.( Here GPUImageView extends GLSurfaceView ) and I am getting value in variable rotationDegree from my Rotate Gesture Detector class which process two finger rotation gestures. Below code rotate the GLSufaceview but content / iamge shown in GLSurfaceView remain same (not rotating inside it). android have examples but they are for 3D and not rotation with degree.</p>
  
  <pre><code>    @Override
      public boolean onTouchEvent(MotionEvent event)
      {
          rotationDetector.onTouchEvent(event);
          /* Rotate View Here */
          GPUImageView.this.setRotation(rotationDegree);
          requestRender();
          return true;
      }
  </code></pre>
  
  <p>I have my custom rotation detector class which dispatches events related to two finger rotation </p>
  
  <pre><code>    private class RotateListener extends RotateGestureDetector.SimpleOnRotateGestureListener
      {
          @Override
          public boolean onRotate(RotateGestureDetector detector)
          {
              rotationDegree -= detector.getRotationDegreesDelta();
              return true;
          }
      }
  </code></pre>