# Point/click pixel-based collision with transparent pngs

**URL:** https://forum.kirupa.com/t/point-click-pixel-based-collision-with-transparent-pngs/228776
**Category:** programming
**Created:** [June 11, 2007, 2:29pm UTC](https://forum.kirupa.com/t/point-click-pixel-based-collision-with-transparent-pngs/228776 "2007-06-11T14:29:10Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![NickZA](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/nickza/32/3452_2.png) [@NickZA](https://forum.kirupa.com/u/NickZA)
#### Post date: [June 11, 2007, 2:29pm UTC](https://forum.kirupa.com/t/point-click-pixel-based-collision-with-transparent-pngs/228776/1 "2007-06-11T14:29:10Z")

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Hi

I’m making a simple boardgame type thing. I need to know if there is a simple way (using hitTest) to get Flash to recognize my transparent png’s “alpha=0” pixels as being empty (therefore, not registering a collision with these).

NOTE, I don’t need to know anything about sprite-to-sprite collision detection. This is literally pixel-to-sprite only, i.e. I need to detect a single-point mouseclick on an irregular bitmap.

PS Do I HAVE TO use shapeFlag? If so, how.

Thanks very much in advance.

EDIT: Problem solved [here](http://www.kirupa.com/forum/showpost.php?p=1922772&postcount=4)as pointed out by Odysseus elsewhere.

-NickZA