I am trying to draw an arrowhead in my DynamicDraw method of a custom CRhinoGetPoint. The code below isn’t drawing an arrowhead so I must be doing something silly. What is the proper way to accomplish this? Also, I am assuming the vector magnitude controls the arrow size - is this a correct assumption (or how do you size the arrow)?
//partial code from dynamic draw method
ON_2dVector a_dir(elbow2d.x - target2d.x, elbow2d.y - target2d.y);
a_dir *= _leader_scale;