| Re: [AD] polygon_cull_criterion() |
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Von: Shawn Hargreaves <shawn@xxxxxxxxxx>
>ex3d is perfectly correct, as it culls after the projection. The depth
>sort is only required to sort one cube against another. For an example of
>culling before projection, see the 3d bit in test.c, which uses the dot
>product method.
I had a talk with Jason Wilkins about that same topic. Now I know that
polygon_z_normal() is supposed to be used in homogenous coordinates (=after
projection, remember I mentioned this as special case), but I would say the
documentation for polygon_z_normal() could at least need an update to be
more clear about this.
I wrote polygon_cull_criterion() as alternative in the mood of the other
math 3d routines. Of course it is not as effective as if you do it by hand.