ref: 83d4cf3fd1a257df21468f5bb3b4329e5cf8a40f
dir: /r_aliasa.s/
//
// r_aliasa.s
// x86 assembly-language Alias model transform and project code.
//
#include "asm_i386.h"
#include "quakeasm.h"
#include "asm_draw.h"
#include "d_ifacea.h"
#ifdef id386
.data
Lfloat_1: .single 1.0
Ltemp: .long 0
Lcoords: .long 0, 0, 0
.text
#define fv 12+4
#define pstverts 12+8
.globl C(R_AliasTransformAndProjectFinalVerts)
C(R_AliasTransformAndProjectFinalVerts):
pushl %ebp // preserve caller's stack frame
pushl %edi
pushl %esi // preserve register variables
// int i, temp;
// float lightcos, *plightnormal, zi;
// trivertx_t *pverts;
// pverts = r_apverts;
movl C(r_apverts),%esi
// for (i=0 ; i<r_anumverts ; i++, fv++, pverts++, pstverts++)
// {
movl pstverts(%esp),%ebp
movl fv(%esp),%edi
movl C(r_anumverts),%ecx
subl %edx,%edx
Lloop:
// // transform and project
// zi = 1.0 / (DotProduct(pverts->v, aliastransform[2]) +
// aliastransform[2][3]);
movb (%esi),%dl
movb %dl,Lcoords
fildl Lcoords // v[0]
movb 1(%esi),%dl
movb %dl,Lcoords+4
fildl Lcoords+4 // v[1] | v[0]
movb 2(%esi),%dl
movb %dl,Lcoords+8
fildl Lcoords+8 // v[2] | v[1] | v[0]
fld %st(2) // v[0] | v[2] | v[1] | v[0]
fmuls C(aliastransform)+32 // accum | v[2] | v[1] | v[0]
fld %st(2) // v[1] | accum | v[2] | v[1] | v[0]
fmuls C(aliastransform)+36 // accum2 | accum | v[2] | v[1] | v[0]
fxch %st(1) // accum | accum2 | v[2] | v[1] | v[0]
fadds C(aliastransform)+44 // accum | accum2 | v[2] | v[1] | v[0]
fld %st(2) // v[2] | accum | accum2 | v[2] | v[1] | v[0]
fmuls C(aliastransform)+40 // accum3 | accum | accum2 | v[2] | v[1] |
// v[0]
fxch %st(1) // accum | accum3 | accum2 | v[2] | v[1] | v[0]
faddp %st(0),%st(2) // accum3 | accum | v[2] | v[1] | v[0]
movb tv_lightnormalindex(%esi),%dl
movl stv_s(%ebp),%eax
movl %eax,fv_v+8(%edi)
faddp %st(0),%st(1) // z | v[2] | v[1] | v[0]
movl stv_t(%ebp),%eax
movl %eax,fv_v+12(%edi)
// // lighting
// plightnormal = r_avertexnormals[pverts->lightnormalindex];
fdivrs Lfloat_1 // zi | v[2] | v[1] | v[0]
// fv->v[2] = pstverts->s;
// fv->v[3] = pstverts->t;
// fv->flags = pstverts->onseam;
movl stv_onseam(%ebp),%eax
movl %eax,fv_flags(%edi)
movl fv_size(%edi),%eax
movl stv_size(%ebp),%eax
movl 4(%esi),%eax
leal (%edx,%edx,2),%eax // index*3
fxch %st(3) // v[0] | v[2] | v[1] | zi
// lightcos = DotProduct (plightnormal, r_plightvec);
flds C(r_avertexnormals)(,%eax,4)
fmuls C(r_plightvec)
flds C(r_avertexnormals)+4(,%eax,4)
fmuls C(r_plightvec)+4
flds C(r_avertexnormals)+8(,%eax,4)
fmuls C(r_plightvec)+8
fxch %st(1)
faddp %st(0),%st(2)
fld %st(2) // v[0] | laccum | laccum2 | v[0] | v[2] |
// v[1] | zi
fmuls C(aliastransform)+0 // xaccum | laccum | laccum2 | v[0] | v[2] |
// v[1] | zi
fxch %st(2) // laccum2 | laccum | xaccum | v[0] | v[2] |
// v[1] | zi
faddp %st(0),%st(1) // laccum | xaccum | v[0] | v[2] | v[1] | zi
// temp = r_ambientlight;
// if (lightcos < 0)
// {
fsts Ltemp
movl C(r_ambientlight),%eax
movb Ltemp+3,%dl
testb $0x80,%dl
jz Lsavelight // no need to clamp if only ambient lit, because
// r_ambientlight is preclamped
// temp += (int)(r_shadelight * lightcos);
fmuls C(r_shadelight)
// FIXME: fast float->int conversion?
fistpl Ltemp
addl Ltemp,%eax
// // clamp; because we limited the minimum ambient and shading light, we
// // don't have to clamp low light, just bright
// if (temp < 0)
// temp = 0;
jns Lp1
subl %eax,%eax
// }
Lp1:
// fv->v[4] = temp;
//
// // x, y, and z are scaled down by 1/2**31 in the transform, so 1/z is
// // scaled up by 1/2**31, and the scaling cancels out for x and y in the
// // projection
// fv->v[0] = ((DotProduct(pverts->v, aliastransform[0]) +
// aliastransform[0][3]) * zi) + aliasxcenter;
// fv->v[1] = ((DotProduct(pverts->v, aliastransform[1]) +
// aliastransform[1][3]) * zi) + aliasycenter;
// fv->v[5] = zi;
fxch %st(1) // v[0] | xaccum | v[2] | v[1] | zi
fmuls C(aliastransform)+16 // yaccum | xaccum | v[2] | v[1] | zi
fxch %st(3) // v[1] | xaccum | v[2] | yaccum | zi
fld %st(0) // v[1] | v[1] | xaccum | v[2] | yaccum | zi
fmuls C(aliastransform)+4 // xaccum2 | v[1] | xaccum | v[2] | yaccum |zi
fxch %st(1) // v[1] | xaccum2 | xaccum | v[2] | yaccum |zi
movl %eax,fv_v+16(%edi)
fmuls C(aliastransform)+20 // yaccum2 | xaccum2 | xaccum | v[2] | yaccum|
// zi
fxch %st(2) // xaccum | xaccum2 | yaccum2 | v[2] | yaccum|
// zi
fadds C(aliastransform)+12 // xaccum | xaccum2 | yaccum2 | v[2] | yaccum|
// zi
fxch %st(4) // yaccum | xaccum2 | yaccum2 | v[2] | xaccum|
// zi
fadds C(aliastransform)+28 // yaccum | xaccum2 | yaccum2 | v[2] | xaccum|
// zi
fxch %st(3) // v[2] | xaccum2 | yaccum2 | yaccum | xaccum|
// zi
fld %st(0) // v[2] | v[2] | xaccum2 | yaccum2 | yaccum |
// xaccum | zi
fmuls C(aliastransform)+8 // xaccum3 | v[2] | xaccum2 | yaccum2 |yaccum|
// xaccum | zi
fxch %st(1) // v[2] | xaccum3 | xaccum2 | yaccum2 |yaccum|
// xaccum | zi
fmuls C(aliastransform)+24 // yaccum3 | xaccum3 | xaccum2 | yaccum2 |
// yaccum | xaccum | zi
fxch %st(5) // xaccum | xaccum3 | xaccum2 | yaccum2 |
// yaccum | yaccum3 | zi
faddp %st(0),%st(2) // xaccum3 | xaccum | yaccum2 | yaccum |
// yaccum3 | zi
fxch %st(3) // yaccum | xaccum | yaccum2 | xaccum3 |
// yaccum3 | zi
faddp %st(0),%st(2) // xaccum | yaccum | xaccum3 | yaccum3 | zi
addl $(tv_size),%esi
faddp %st(0),%st(2) // yaccum | x | yaccum3 | zi
faddp %st(0),%st(2) // x | y | zi
addl $(stv_size),%ebp
fmul %st(2),%st(0) // x/z | y | zi
fxch %st(1) // y | x/z | zi
fmul %st(2),%st(0) // y/z | x/z | zi
fxch %st(1) // x/z | y/z | zi
fadds C(aliasxcenter) // u | y/z | zi
fxch %st(1) // y/z | u | zi
fadds C(aliasycenter) // v | u | zi
fxch %st(2) // zi | u | v
// FIXME: fast float->int conversion?
fistpl fv_v+20(%edi) // u | v
fistpl fv_v+0(%edi) // v
fistpl fv_v+4(%edi)
// }
addl $(fv_size),%edi
decl %ecx
jnz Lloop
popl %esi // restore register variables
popl %edi
popl %ebp // restore the caller's stack frame
ret
Lsavelight:
fstp %st(0)
jmp Lp1
#endif // id386