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[MekanikDestructiwKommando]

Anyone have experience with pixel precise hitboxes? I'm imagining using the mask of an image, and comparing two masks (eg the mask of an explosion or weapon) with the masks of all characters/hittable objects. This way hit detection would be literally pixel-perfect  . Has anyone done this? Or know how to do this? In any language?

[jjs]

Check out this thread: http://forums.tigsource.com/index.php?topic=1097.msg25675#msg25675

The most important optimization is to use bounding circles or boxes to see if there even could be a collision, before resorting to the expensive pixel-perfect check.

[Zaphos]

If you're using allegro, PPCol seems pretty good for this purpose.  For SDL, there is SDL_Collide.

If you google pixel perfect collision detection, you'll find it's a fairly well discussed thing, so you can probably find a bunch more implementations and some tutorials if you look.

[Farbs]

As a side note, I usually find it better to just use circles or rects since they can be tweaked to give the player a helping hand. Shmups sometimes do this by only colliding enemy bullets with the player's middle pixel.

[Robotacon]

The most important optimization is to use bounding circles or boxes to see if there even could be a collision, before resorting to the expensive pixel-perfect check.

Testing the bounding box before testing individual pixels isn't optimization, it's just straight thinking. How else do you know where the test is taking place? Moving the mask into map coordinates would be just silly, who would do that?

What I think everyone is trying to say is that you should only test overlapping rectangular areas, that way you automatically won't test pixels that don't matter.