code: function recalc() {
           var edges = this.edges;
           var normals = this.normals; // Copy the original points array and apply the offset/angle
  
           var points = this.points;
  
           if (points.length !== 2) {
             throw new Error("Requires exactly 2 points");
           } // Calculate the edges/normals
  
  
           if (edges[0] === undefined) {
             edges[0] = new me.Vector2d();
           }
  
           edges[0].copy(points[1]).sub(points[0]);
  
           if (normals[0] === undefined) {
             normals[0] = new me.Vector2d();
           }
  
           normals[0].copy(edges[0]).perp().normalize();
           return this;
         }
docs: Computes the calculated collision edges and normals.
  This **must** be called if the `points` array, `angle`, or `offset` is modified manually.
  @name recalc
  @memberOf me.Line.prototype
  @function