we use samsung SC series target, in this target, there is one samsung vendor’s 3D chipset and library. in this target, the depth test and stencil test is very expensive, in the programming guideline, it is recommened to avoid the usage of depth test and stencil test.
but currently ,we have one clipping feathure need to be reimplemended , the current solution is based on stencil buffer , so the polygon clipping is supported. in powervr , the performance is good, in SC chipset, it is very slow, unaccepatable, so this feathure is to be reimplemented in other way.
i review several way, there are many way to do clipping:
1) clip plane.
2) stencil buffer test clipping
3) Obluique frustum clipping
4) depth buffer test clipping
5) texture based clipping
but we know, in our new target, 2,4 option is exculeded.
and we also need to support ploygon clipping, so 1,3 seems also not acceptable,
so i prefer to use option 5 , can anyone give me some suggestion?
we want to use hardware-accelated clipping, to speedup the clipping performance, meanwhile , to suffice our ploygon clipping