text: function View2dCanvasLayer(dom, opt) {
      CS(this, dom, opt);
  
      this.viewObjects = {};
  }
  CE(View2dCanvasLayer, View2dCanvasBase);
  
  Object.assign(View2dCanvasLayer.prototype, {
      init: function () {
          CS(this, "init");
  
          var o = this.context.circle(0, 0, 10).attr({
              fill: "red"//仅仅用来测试，没有实际意义
          })
      },
      toJSON: function () {
          return Object.keys(this.viewObjects).map(function (viewObjectId) {
              var vo = this.viewObjects[viewObjectId];
              return vo.toJSON();
          }, this)
      },
      clear: function () {
          CS(this, "clear");
          this.viewObjects = {};
      },
  
      update: function (scene) {
      }
  });
  
  
  
  //# sourceURL=file://js/view2d/canvaslayer.js