alt Hacker NewsAgreed on other counts except for FPU.
Quake performs one FPU divide per pixel for texture mapping perspective correction.
ARM7TDMI does not have any kind of divide, so perspective correction is tricky, even if it's just 120 px horizontally.
Agreed on other counts except for FPU.
Quake performs one FPU divide per pixel for texture mapping perspective correction.
ARM7TDMI does not have any kind of divide, so perspective correction is tricky, even if it's just 120 px horizontally.
Afaik, Quake does not do one divide per pixel, it is in steps of 8 pixels (see dscan.c in winquake). Yes, there is non divide but instead of taking hundreds of cycles, tables and other approximations could be used. Of course, div/vdiv which take only 14 cycles or less are a strong boost on CM4/33.