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View Full Version : Will fragment shaders work with glDrawPixels



jas511
06-10-2011, 06:33 AM
Are fragment shaders supposed to run when using glDrawPixels? It seems to work on my nvidia card, but I've had mixed results on some ATI cards. It doesn't seem to work on my HD Radeon 3450, but I don't know if that's a bug or by design.

Alfonse Reinheart
06-10-2011, 12:41 PM
Fragment shaders should be executed by glDrawPixels (though I have no idea what the fragment shader inputs would be), so this is a driver bug. However, I wouldn't hold my breath on it getting fixed anytime soon. This is a pretty low-priority case; most people using shaders simply don't use glDrawPixels. If they need to do that, they upload to a texture and then render a quad with that texture on it.

jas511
06-10-2011, 01:05 PM
Alfonse,

That's what I was afraid of. I'll see if I can switch to using texture mapping with the quads instead of glDrawPixels.

Thanks,
Jeff