ref: 06eb848b99587ef882c121a5a65d2082e3b88aeb
dir: qk1/d_scana.s
// // d_scana.s // x86 assembly-language turbulent texture mapping code // #include "asm_i386.h" #include "quakeasm.h" #include "asm_draw.h" #include "d_ifacea.h" #ifdef id386 .data .text //---------------------------------------------------------------------- // turbulent texture mapping code //---------------------------------------------------------------------- .align 4 .globl C(D_DrawTurbulent8Span) C(D_DrawTurbulent8Span): pushl %ebp // preserve caller's stack frame pointer pushl %esi // preserve register variables pushl %edi pushl %ebx movl C(r_turb_s),%esi movl C(r_turb_t),%ecx movl C(r_turb_pdest),%edi movl C(r_turb_spancount),%ebx Llp: movl %ecx,%eax movl %esi,%edx sarl $16,%eax movl C(r_turb_turb),%ebp sarl $16,%edx andl $(CYCLE-1),%eax andl $(CYCLE-1),%edx movl (%ebp,%eax,4),%eax movl (%ebp,%edx,4),%edx addl %esi,%eax sarl $16,%eax addl %ecx,%edx sarl $16,%edx andl $(TURB_TEX_SIZE-1),%eax andl $(TURB_TEX_SIZE-1),%edx shll $6,%edx movl C(r_turb_pbase),%ebp addl %eax,%edx incl %edi addl C(r_turb_sstep),%esi addl C(r_turb_tstep),%ecx movb (%ebp,%edx,1),%dl decl %ebx movb %dl,-1(%edi) jnz Llp movl %edi,C(r_turb_pdest) popl %ebx // restore register variables popl %edi popl %esi popl %ebp // restore caller's stack frame pointer ret #endif // id386