Collision with Grid and Hitbox is off by a pixel when the Hitbox's entity has non-integer x and y values. about haxepunk HOT 1 OPEN

This was also the case in another engine I used to use, but the solution wasn't to fix their engine it was actually to just ceil or floor the positions you're using in the collision function.

The problem is somewhat in your control as well . . . this may be more of a feature request rather than a bug. . .

The second problem is that both instances can have decimal locations, so that causes more precision problems to work with. In most cases you'll know how you want the interactions to happen and understand what instances move in non-integer increments, so you should try to work with that in mind. It would be much harder for us to generalize the common precision problem in programming since its not a problem for every game.

I recommend something like this:

if( collide("level", x, y) == null ){
	this.y ++;
}

// offset gaurd  
y = Math.round( y );
if( collide("level", x, y ) != null ){
	this.y --;
}

from haxepunk.