title: When frame buffer in used on android, scene does not render
body: <p>I am trying to switch my application over to using framebuffer/renderbuffer objects (looking to render to texture later) but whenever I use the framebuffer/renderbuffer, nothing renders. When the default framebuffer is left on, as is the default, it renders fine; All colour, depth and stencil related features work exactly as expected.</p>
  
  <p>Initialisation code:</p>
  
  <pre><code>if(frameBuffer == 0 || !GLES20.glIsFramebuffer(frameBuffer)){
      int[] retVal = new int[1];
      GLES20.glGenFramebuffers(1, retVal, 0);
      frameBuffer = retVal[0];
      retVal[0] = 0;
  
      if(renderBufferColour != 0 || !GLES20.glIsRenderbuffer(renderBufferColour)){
          GLES20.glGenRenderbuffers(1, retVal, 0);
          renderBufferColour = retVal[0];
      }
  
      if(renderBufferDepth != 0 || !GLES20.glIsRenderbuffer(renderBufferDepth)){
          GLES20.glGenRenderbuffers(1, retVal, 0);
          renderBufferDepth = retVal[0];
      }
  
      if(renderBufferStencil != 0 || !GLES20.glIsRenderbuffer(renderBufferStencil)){
          GLES20.glGenRenderbuffers(1, retVal, 0);
          renderBufferStencil = retVal[0];
      }
  }
  </code></pre>
  
  <p>Framebuffer enabling code (commenting this out allows rendering using the default buffer):</p>
  
  <pre><code>GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, frameBuffer);
  
  GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, renderBufferColour);
  GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_RGBA4, width, height);
  GLES20.glFramebufferRenderbuffer(
          GLES20.GL_FRAMEBUFFER,
          GLES20.GL_COLOR_ATTACHMENT0,
          GLES20.GL_RENDERBUFFER,
          renderBufferColour);
  
  GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, renderBufferDepth);
  GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_DEPTH_COMPONENT16, width, height);
  GLES20.glFramebufferRenderbuffer(
          GLES20.GL_FRAMEBUFFER,
          GLES20.GL_DEPTH_ATTACHMENT,
          GLES20.GL_RENDERBUFFER,
          renderBufferDepth);
  
  GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, renderBufferStencil);
  GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_STENCIL_INDEX8, width, height);
  GLES20.glFramebufferRenderbuffer(
          GLES20.GL_FRAMEBUFFER,
          GLES20.GL_STENCIL_ATTACHMENT,
          GLES20.GL_RENDERBUFFER,
          renderBufferStencil);
  
  if (GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER) != GLES20.GL_FRAMEBUFFER_COMPLETE)
      throw new RuntimeException(String.format("Failed to make complete framebuffer object %x", GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER)));
  </code></pre>
  
  <p>The exception at the end is not thrown and when checking <code>glGetError()</code> after each step, no error is returned. Am I missing something here?</p>