anchor.diff:    int viewPortW = 0;
     int viewPortH = 0;
   
  -  RenderPhase(String name, this._cgl, [this._framebuffer = null])
  -      : super(name) {
  +  RenderPhase(String name, this._cgl, [this._framebuffer]) : super(name) {
       if (_framebuffer == null) _framebuffer = new Framebuffer.Screen(_cgl);
     }
   
  
positive.code:   /// @param name
    /// @param this.program
    /// @param unis
    Scene(String name, this.program, [List<UniformGroup> unis = null])
        : uniforms = unis == null ? <UniformGroup>[] : unis,
          super(name);
  
    void add(Node n) {
      assert( n != null);
      nodes.add(n);
    }
  
     void remove(Node n) {
      nodes.remove(n);
    }
  
     void removeAll() {
      nodes.clear();
     }
  }
  
  void drawRecursively(RenderProgram prog, Node node, final VM.Matrix4 parent,
  
negative.code:   }
  
    void add(Scene s) {
      assert(s != null);
      _scenes.add(s);
    }
  
    void Draw([List<DrawStats> stats]) {
      _framebuffer.Activate(
          _clear_mode, viewPortX, viewPortY, viewPortW, viewPortH);
  
  