Reducing number of divisions for polygon mappers – part 2 March 24, 2008
Posted by winden in coding, demoscene.trackback
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The software rendering world
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The software rendering world 
So this mean you can back-face-cull _before_ projection… Nice. Ah, 1/(zzz*zzz) is always positive so it will not change the sign of “area” (so only need to do the division when the back face test actually passes)
Yes, not doing any divide if it is back-facing is nice :)
Interesting, though using the original 3d coordinates for back face culling instead of the projected ones produces little problems like polygons disappearing before their time, but those problems are mostly happening if you try to render a glenz cube and have different color for back and front, not for solid objects.