Screen Arrows

by Kaiochao
Draw an arrow on-screen for tracking things.
See this post for the origin of this library.

This library contains just one proc.

mob.PointArrow(obj/Arrow, atom/Target, MinDistance, ArrowDistance)

Arrow: an obj in src's client's screen to be updated.

Target: the atom that the arrow is tracking.

MinDistance: the minimum pixel distance between src and Target before the arrow is made visible.

ArrowDistance: the pixel distance between the center of the screen and the arrow in the screen.