title: How to rotate on Android (java) and OpenGL ES 2.0
body: <p>Actually Im doing this into the draw method of my renderer class:</p>
  
  <pre><code>    Matrix.setIdentityM(mMMatrix, 0);
  //      Rotate view
  
  long time = SystemClock.uptimeMillis()*4000L;
  float angle = .09F*(int)time;
  Matrix.setRotateM(mMMatrix, 0, angle, 1, 0, 0);
  Matrix.rotateM(mMMatrix, 0, -2f, 1, 0, 0);
  //Matrix.scaleM(mMMatrix, 0, 0.01f, 0.01f, 0.01f);
  
  // Calculate the projection and view transformation
  Matrix.multiplyMM(mMVPMatrix, 0, mVMatrix, 0, mMMatrix, 0);
  Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mMVPMatrix, 0);
  
  // Draw Shapes      
  obj.draw(mMVPMatrix);
  </code></pre>
  
  <p>But it doesn't work... i'v tried some other but no luck, the objects stays the same, no rotation.</p>
  
  <p>Update: I change the code to this and no luck.</p>
  
  <pre><code>        // Clear Screen
          GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
  
  
          Matrix.setIdentityM(mMMatrix, 0);
  
          // Rotate view
          Matrix.setRotateM(mMMatrix, 0, angle, 1, 0, 0);
          //Matrix.scaleM(mMMatrix, 0, 0.01f, 0.01f, 0.01f);
  
          // Calculate the projection and view transformation
          Matrix.multiplyMM(mMVMatrix, 0, mVMatrix, 0, mMMatrix, 0);
          Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mMVMatrix, 0);
  
          // Draw Shapes      
          obj.draw(mMVPMatrix);
  </code></pre>