A* pathfinding for enigma

all of the A* examples on gml i found didn't work with enigma so i made this one. it generates a graph and shortest path between selected nodes

A* algorithm finds the shortest path on graph. the gml's mp_potential is based on A* algorithm, nevertheless, although the A* is intended for graphs,  to make mp_potential simple to use, it implements A* on grid (by creating a node in each cell of the grid). this is resource intensive and impractical if you want a game with thousands of npc. instead you'd have to make a node based pathfinding.
ive made a few tests and enigma kills game maker 50x with this one.