i have a strange bug in my program and i don’t know whose fault it is. in short: when the ‘IM’ bit of the FPU’s ControlWord (bit 0 of the FPU ControlWord) is 0 and i call for example glRasterPosXX or glDrawPixels i get an EInvaliOP exception. This is the case when i use hardware accelerated rendering with my nvidia geforce 4 mx440 with the latest driver from nvidia (56.72 dated 03/24/2004), windows xp home. When i use the microsoft OpenGL driver (no hardware acceleration) everything works fine. When i use another graphics board (for example ATI radeon 9200 with a current driver) also everything works fine.
But when i wirte a one into the FPU’s controlword ‘IM’ bit (e.g. asm fldcw 0x1333, or using the fpu to calculate something … ) the program runs on my nvidia card without problems… has anybody else experienced such a problem, or does anybody know what i can do against it ???
This bug doesn’t occur with the 53.03 driver from nvidia… does that have to mean something ???
any help would be greatly appreciated.