ref: 8723be0d01ab4150ed6ca63649a6ec1ddcc06efb
dir: /snd_mixa.s/
/*
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.
*/
//
// snd_mixa.s
// x86 assembly-language sound code
//
#include "asm_i386.h"
#include "quakeasm.h"
#if id386
.text
//----------------------------------------------------------------------
// 8-bit sound-mixing code
//----------------------------------------------------------------------
#define ch 4+16
#define sc 8+16
#define count 12+16
.globl C(SND_PaintChannelFrom8)
C(SND_PaintChannelFrom8):
pushl %esi // preserve register variables
pushl %edi
pushl %ebx
pushl %ebp
// int data;
// short *lscale, *rscale;
// unsigned char *sfx;
// int i;
movl ch(%esp),%ebx
movl sc(%esp),%esi
// if (ch->leftvol > 255)
// ch->leftvol = 255;
// if (ch->rightvol > 255)
// ch->rightvol = 255;
movl ch_leftvol(%ebx),%eax
movl ch_rightvol(%ebx),%edx
cmpl $255,%eax
jna LLeftSet
movl $255,%eax
LLeftSet:
cmpl $255,%edx
jna LRightSet
movl $255,%edx
LRightSet:
// lscale = snd_scaletable[ch->leftvol >> 3];
// rscale = snd_scaletable[ch->rightvol >> 3];
// sfx = (signed char *)sc->data + ch->pos;
// ch->pos += count;
andl $0xF8,%eax
addl $(sfxc_data),%esi
andl $0xF8,%edx
movl ch_pos(%ebx),%edi
movl count(%esp),%ecx
addl %edi,%esi
shll $7,%eax
addl %ecx,%edi
shll $7,%edx
movl %edi,ch_pos(%ebx)
addl $(C(snd_scaletable)),%eax
addl $(C(snd_scaletable)),%edx
subl %ebx,%ebx
movb -1(%esi,%ecx,1),%bl
testl $1,%ecx
jz LMix8Loop
movl (%eax,%ebx,4),%edi
movl (%edx,%ebx,4),%ebp
addl C(paintbuffer)+psp_left-psp_size(,%ecx,psp_size),%edi
addl C(paintbuffer)+psp_right-psp_size(,%ecx,psp_size),%ebp
movl %edi,C(paintbuffer)+psp_left-psp_size(,%ecx,psp_size)
movl %ebp,C(paintbuffer)+psp_right-psp_size(,%ecx,psp_size)
movb -2(%esi,%ecx,1),%bl
decl %ecx
jz LDone
// for (i=0 ; i<count ; i++)
// {
LMix8Loop:
// data = sfx[i];
// paintbuffer[i].left += lscale[data];
// paintbuffer[i].right += rscale[data];
movl (%eax,%ebx,4),%edi
movl (%edx,%ebx,4),%ebp
addl C(paintbuffer)+psp_left-psp_size(,%ecx,psp_size),%edi
addl C(paintbuffer)+psp_right-psp_size(,%ecx,psp_size),%ebp
movb -2(%esi,%ecx,1),%bl
movl %edi,C(paintbuffer)+psp_left-psp_size(,%ecx,psp_size)
movl %ebp,C(paintbuffer)+psp_right-psp_size(,%ecx,psp_size)
movl (%eax,%ebx,4),%edi
movl (%edx,%ebx,4),%ebp
movb -3(%esi,%ecx,1),%bl
addl C(paintbuffer)+psp_left-psp_size*2(,%ecx,psp_size),%edi
addl C(paintbuffer)+psp_right-psp_size*2(,%ecx,psp_size),%ebp
movl %edi,C(paintbuffer)+psp_left-psp_size*2(,%ecx,psp_size)
movl %ebp,C(paintbuffer)+psp_right-psp_size*2(,%ecx,psp_size)
// }
subl $2,%ecx
jnz LMix8Loop
LDone:
popl %ebp
popl %ebx
popl %edi
popl %esi
ret
//----------------------------------------------------------------------
// Transfer of stereo buffer to 16-bit DMA buffer code
//----------------------------------------------------------------------
.globl C(Snd_WriteLinearBlastStereo16)
C(Snd_WriteLinearBlastStereo16):
pushl %esi // preserve register variables
pushl %edi
pushl %ebx
// int i;
// int val;
movl C(snd_linear_count),%ecx
movl C(snd_p),%ebx
movl C(snd_vol),%esi
movl C(snd_out),%edi
// for (i=0 ; i<snd_linear_count ; i+=2)
// {
LWLBLoopTop:
// val = (snd_p[i]*snd_vol)>>8;
// if (val > 0x7fff)
// snd_out[i] = 0x7fff;
// else if (val < (short)0x8000)
// snd_out[i] = (short)0x8000;
// else
// snd_out[i] = val;
movl -8(%ebx,%ecx,4),%eax
imull %esi,%eax
sarl $8,%eax
cmpl $0x7FFF,%eax
jg LClampHigh
cmpl $0xFFFF8000,%eax
jnl LClampDone
movl $0xFFFF8000,%eax
jmp LClampDone
LClampHigh:
movl $0x7FFF,%eax
LClampDone:
// val = (snd_p[i+1]*snd_vol)>>8;
// if (val > 0x7fff)
// snd_out[i+1] = 0x7fff;
// else if (val < (short)0x8000)
// snd_out[i+1] = (short)0x8000;
// else
// snd_out[i+1] = val;
movl -4(%ebx,%ecx,4),%edx
imull %esi,%edx
sarl $8,%edx
cmpl $0x7FFF,%edx
jg LClampHigh2
cmpl $0xFFFF8000,%edx
jnl LClampDone2
movl $0xFFFF8000,%edx
jmp LClampDone2
LClampHigh2:
movl $0x7FFF,%edx
LClampDone2:
shll $16,%edx
andl $0xFFFF,%eax
orl %eax,%edx
movl %edx,-4(%edi,%ecx,2)
// }
subl $2,%ecx
jnz LWLBLoopTop
// snd_p += snd_linear_count;
popl %ebx
popl %edi
popl %esi
ret
#endif // id386