code: function getIndices(x, y) {
           if (this.indices.length === 0) {
             var points = this.points;
             var data = []; // flatten the points vector array
  
             for (var i = 0; i < points.length; i++) {
               // XXX Optimize me
               data.push(points[i].x);
               data.push(points[i].y);
             }
  
             this.indices = earcut_1(data);
           }
  
           return this.indices;
         }
docs: returns a list of indices for all triangles defined in this polygon
  @name getIndices
  @memberOf me.Polygon.prototype
  @function
  @param {Vector2d[]} a list of vector
  @return {me.Polygon} this Polygon