code: function (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(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