anchor.diff:      _camera = new Camera();
   
       if (addDefaultRenderingPhase) {
  -      _renderPhases.add(new RenderingPhase(gl, null, true));
  +      addRenderPhase(new RenderingPhase(gl, null, true));
       }
       setUpEventCapture(_canvas);
     }
  
positive.code:     _canvas.width = perspar.width;
      _canvas.height = perspar.height;
      //_aspect = _canvas.clientWidth / _canvas.clientHeight;
      gl = _canvas.getContext("experimental-webgl");
      if (gl == null) {
        throw new Exception(
            'calling canvas.getContext("experimental-webgl") failed, make sure you run on a computer that supports WebGL, test here: http://get.webgl.org/');
  
negative.code:       List<ShaderObject> fxShader,
        near: 0.1,
        far: 1000.0,
        bool preserveDrawingBuffer: false,
        bool addDefaultRenderingPhase: true,
        bool useElementIndexUint: false}) {
      if (canvasOrID is HTML.CanvasElement) {
  