| /*
|
| Copyright (C) 1996-1997 Id Software, Inc.
|
|
|
| This program is free software; you can redistribute it and/or
|
| modify it under the terms of the GNU General Public License
|
| as published by the Free Software Foundation; either version 2
|
| of the License, or (at your option) any later version.
|
|
|
| This program is distributed in the hope that it will be useful,
|
| but WITHOUT ANY WARRANTY; without even the implied warranty of
|
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
|
| See the GNU General Public License for more details.
|
|
|
| You should have received a copy of the GNU General Public License
|
| along with this program; if not, write to the Free Software
|
| Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
|
| */
|
| // |
| // 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" |
| |
| #if 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 |
| |