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 Feature Suggestion/Request - Point of Collision

jackquake

Member
In searching the forums on how to determine the point of collision with an instance, there have been numerous work-arounds suggested, such as binary search algorithms, usage of a collision_line for estimation, etc. I'm not at all familiar with the backend of what goes on during a collision detection, but it seems that since a collision has been detected, GameMaker would be able to provide where that collision took place (x,y).

Note, this is not the x,y coordinates of the instance, but instead, the x,y coordinates of where the collision occurred with the instance.

Is this possible? Would this be beneficial to others besides myself?
 
N

NPT

Guest
it's not possible (most of the time).

When collisions occur, rarely is there a single point of contact. Instead you have multiple points of contact and overlap.
 

jackquake

Member
If multiple points are involved at the area of collision, then return the average of the x and y coordinates and return that point. At least, that would be the center of the collision (or close).

If that's too much, I'd be happy with returning the first point of collision, in the event of multiple points. In most cases that I've run into already, that would be "good enough" and prevent the implementation of some of the other techniques that are complex and CPU expensive.
 

jackquake

Member
After thinking a bit more on this, simply add a function to colision_line, which has a single point width and return the point where the line meets the edge of the colliding instance. That would be a great solution.
 
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