So I have implemented some slope movement that first moves you horizontally by 1 pixel, then checks if there is a collision one pixel above and moves you up (to go up slopes). For some weird reason when one collision object stops and the next begins the collision_point check fails, even though the collision mask should be a perfect diagonal of uninterrupted pixels. I am using precise collisions, so only the pixels have collision here. The point checked is x, bbox_bottom -1. In the video I draw a pixel at x, bbox_bottom and the last pixel of the object/start of the next object are displayed in blue. Has anyone else encountered this? Is this a Game Maker bug?
TL;DR collision_point is returning inconsistent results at the edges of objects.