negative color with glBlendFunc() ?

Posted by Newbie on Stack Overflow See other posts from Stack Overflow or by Newbie
Published on 2009-12-09T14:00:42Z Indexed on 2010/06/08 17:22 UTC
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c++

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opengl

i want my lines to be drawn with negative color (taken from the screen under the line), i just didnt understand how the blending works, looked at docs etc, tested 50 combinations and so on. started to think its not possible at all...

could someone just give the two values, im tired of thinking how it works.

thanks,

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