ref: 0d66c828824abe9951af3fcfba6edc42279572bf
dir: /ref/r_polyse.c/
/*
Copyright (C) 1997-2001 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_polyset.c: routines for drawing sets of polygons sharing the same
// texture (used for Alias models)
#include <u.h>
#include <libc.h>
#include <stdio.h>
#include "../dat.h"
#include "../fns.h"
int rand1k[] = {
#include "rand1k.h"
};
#define MASK_1K 0x3FF
int rand1k_index = 0;
// TODO: put in span spilling to shrink list size
// !!! if this is changed, it must be changed in d_polysa.s too !!!
#define DPS_MAXSPANS MAXHEIGHT+1
// 1 extra for spanpackage that marks end
// !!! if this is changed, it must be changed in asm_draw.h too !!!
typedef struct {
void *pdest;
short *pz;
int count;
byte *ptex;
int sfrac, tfrac, light, zi;
} spanpackage_t;
typedef struct {
int isflattop;
int numleftedges;
int *pleftedgevert0;
int *pleftedgevert1;
int *pleftedgevert2;
int numrightedges;
int *prightedgevert0;
int *prightedgevert1;
int *prightedgevert2;
} edgetable;
aliastriangleparms_t aliastriangleparms;
int r_p0[6], r_p1[6], r_p2[6];
byte *d_pcolormap;
int d_aflatcolor;
int d_xdenom;
edgetable *pedgetable;
edgetable edgetables[12] = {
{0, 1, r_p0, r_p2, NULL, 2, r_p0, r_p1, r_p2 },
{0, 2, r_p1, r_p0, r_p2, 1, r_p1, r_p2, NULL},
{1, 1, r_p0, r_p2, NULL, 1, r_p1, r_p2, NULL},
{0, 1, r_p1, r_p0, NULL, 2, r_p1, r_p2, r_p0 },
{0, 2, r_p0, r_p2, r_p1, 1, r_p0, r_p1, NULL},
{0, 1, r_p2, r_p1, NULL, 1, r_p2, r_p0, NULL},
{0, 1, r_p2, r_p1, NULL, 2, r_p2, r_p0, r_p1 },
{0, 2, r_p2, r_p1, r_p0, 1, r_p2, r_p0, NULL},
{0, 1, r_p1, r_p0, NULL, 1, r_p1, r_p2, NULL},
{1, 1, r_p2, r_p1, NULL, 1, r_p0, r_p1, NULL},
{1, 1, r_p1, r_p0, NULL, 1, r_p2, r_p0, NULL},
{0, 1, r_p0, r_p2, NULL, 1, r_p0, r_p1, NULL},
};
// FIXME: some of these can become statics
int a_sstepxfrac, a_tstepxfrac, r_lstepx, a_ststepxwhole;
int r_sstepx, r_tstepx, r_lstepy, r_sstepy, r_tstepy;
int r_zistepx, r_zistepy;
int d_aspancount, d_countextrastep;
spanpackage_t *a_spans;
spanpackage_t *d_pedgespanpackage;
static int ystart;
byte *d_pdest, *d_ptex;
short *d_pz;
int d_sfrac, d_tfrac, d_light, d_zi;
int d_ptexextrastep, d_sfracextrastep;
int d_tfracextrastep, d_lightextrastep, d_pdestextrastep;
int d_lightbasestep, d_pdestbasestep, d_ptexbasestep;
int d_sfracbasestep, d_tfracbasestep;
int d_ziextrastep, d_zibasestep;
int d_pzextrastep, d_pzbasestep;
typedef struct {
int quotient;
int remainder;
} adivtab_t;
static adivtab_t adivtab[32*32] = {
#include "adivtab.h"
};
byte *skintable[MAX_LBM_HEIGHT];
int skinwidth;
byte *skinstart;
void (*d_pdrawspans)(spanpackage_t *pspanpackage);
void R_PolysetDrawSpans8_33 (spanpackage_t *pspanpackage);
void R_PolysetDrawSpans8_66 (spanpackage_t *pspanpackage);
void R_PolysetDrawSpans8_Opaque (spanpackage_t *pspanpackage);
void R_PolysetDrawThreshSpans8 (spanpackage_t *pspanpackage);
void R_PolysetCalcGradients (int skinwidth);
void R_DrawNonSubdiv (void);
void R_PolysetSetEdgeTable (void);
void R_RasterizeAliasPolySmooth (void);
void R_PolysetScanLeftEdge(int height);
void R_PolysetScanLeftEdge_C(int height);
// ======================
// PGM
// 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79
byte iractive = 0;
byte irtable[256] = { 79, 78, 77, 76, 75, 74, 73, 72, // black/white
71, 70, 69, 68, 67, 66, 65, 64,
64, 65, 66, 67, 68, 69, 70, 71, // dark taupe
72, 73, 74, 75, 76, 77, 78, 79,
64, 65, 66, 67, 68, 69, 70, 71, // slate grey
72, 73, 74, 75, 76, 77, 78, 79,
208, 208, 208, 208, 208, 208, 208, 208, // unused?'
64, 66, 68, 70, 72, 74, 76, 78, // dark yellow
64, 65, 66, 67, 68, 69, 70, 71, // dark red
72, 73, 74, 75, 76, 77, 78, 79,
64, 65, 66, 67, 68, 69, 70, 71, // grey/tan
72, 73, 74, 75, 76, 77, 78, 79,
64, 66, 68, 70, 72, 74, 76, 78, // chocolate
68, 67, 66, 65, 64, 65, 66, 67, // mauve / teal
68, 69, 70, 71, 72, 73, 74, 75,
76, 76, 77, 77, 78, 78, 79, 79,
64, 65, 66, 67, 68, 69, 70, 71, // more mauve
72, 73, 74, 75, 76, 77, 78, 79,
64, 65, 66, 67, 68, 69, 70, 71, // olive
72, 73, 74, 75, 76, 77, 78, 79,
64, 65, 66, 67, 68, 69, 70, 71, // maroon
72, 73, 74, 75, 76, 77, 78, 79,
64, 65, 66, 67, 68, 69, 70, 71, // sky blue
72, 73, 74, 75, 76, 77, 78, 79,
64, 65, 66, 67, 68, 69, 70, 71, // olive again
72, 73, 74, 75, 76, 77, 78, 79,
64, 65, 66, 67, 68, 69, 70, 71, // nuclear green
64, 65, 66, 67, 68, 69, 70, 71, // bright yellow
64, 65, 66, 67, 68, 69, 70, 71, // fire colors
72, 73, 74, 75, 76, 77, 78, 79,
208, 208, 64, 64, 70, 71, 72, 64, // mishmash1
66, 68, 70, 64, 65, 66, 67, 68}; // mishmash2
// PGM
// ======================
/*
================
R_PolysetUpdateTables
================
*/
void R_PolysetUpdateTables (void)
{
int i;
byte *s;
if (r_affinetridesc.skinwidth != skinwidth ||
r_affinetridesc.pskin != skinstart)
{
skinwidth = r_affinetridesc.skinwidth;
skinstart = r_affinetridesc.pskin;
s = skinstart;
for (i=0 ; i<MAX_LBM_HEIGHT ; i++, s+=skinwidth)
skintable[i] = s;
}
}
/*
================
R_DrawTriangle
================
*/
void R_DrawTriangle( void )
{
spanpackage_t spans[DPS_MAXSPANS];
int dv1_ab, dv0_ac;
int dv0_ab, dv1_ac;
/*
d_xdenom = ( aliastriangleparms.a->v[1] - aliastriangleparms.b->v[1] ) * ( aliastriangleparms.a->v[0] - aliastriangleparms.c->v[0] ) -
( aliastriangleparms.a->v[0] - aliastriangleparms.b->v[0] ) * ( aliastriangleparms.a->v[1] - aliastriangleparms.c->v[1] );
*/
dv0_ab = aliastriangleparms.a->u - aliastriangleparms.b->u;
dv1_ab = aliastriangleparms.a->v - aliastriangleparms.b->v;
if ( !( dv0_ab | dv1_ab ) )
return;
dv0_ac = aliastriangleparms.a->u - aliastriangleparms.c->u;
dv1_ac = aliastriangleparms.a->v - aliastriangleparms.c->v;
if ( !( dv0_ac | dv1_ac ) )
return;
d_xdenom = ( dv0_ac * dv1_ab ) - ( dv0_ab * dv1_ac );
if ( d_xdenom < 0 )
{
a_spans = spans;
r_p0[0] = aliastriangleparms.a->u; // u
r_p0[1] = aliastriangleparms.a->v; // v
r_p0[2] = aliastriangleparms.a->s; // s
r_p0[3] = aliastriangleparms.a->t; // t
r_p0[4] = aliastriangleparms.a->l; // light
r_p0[5] = aliastriangleparms.a->zi; // iz
r_p1[0] = aliastriangleparms.b->u;
r_p1[1] = aliastriangleparms.b->v;
r_p1[2] = aliastriangleparms.b->s;
r_p1[3] = aliastriangleparms.b->t;
r_p1[4] = aliastriangleparms.b->l;
r_p1[5] = aliastriangleparms.b->zi;
r_p2[0] = aliastriangleparms.c->u;
r_p2[1] = aliastriangleparms.c->v;
r_p2[2] = aliastriangleparms.c->s;
r_p2[3] = aliastriangleparms.c->t;
r_p2[4] = aliastriangleparms.c->l;
r_p2[5] = aliastriangleparms.c->zi;
R_PolysetSetEdgeTable ();
R_RasterizeAliasPolySmooth ();
}
}
/*
===================
R_PolysetScanLeftEdge_C
====================
*/
void R_PolysetScanLeftEdge_C(int height)
{
do
{
d_pedgespanpackage->pdest = d_pdest;
d_pedgespanpackage->pz = d_pz;
d_pedgespanpackage->count = d_aspancount;
d_pedgespanpackage->ptex = d_ptex;
d_pedgespanpackage->sfrac = d_sfrac;
d_pedgespanpackage->tfrac = d_tfrac;
// FIXME: need to clamp l, s, t, at both ends?
d_pedgespanpackage->light = d_light;
d_pedgespanpackage->zi = d_zi;
d_pedgespanpackage++;
errorterm += erroradjustup;
if (errorterm >= 0)
{
d_pdest += d_pdestextrastep;
d_pz += d_pzextrastep;
d_aspancount += d_countextrastep;
d_ptex += d_ptexextrastep;
d_sfrac += d_sfracextrastep;
d_ptex += d_sfrac >> 16;
d_sfrac &= 0xFFFF;
d_tfrac += d_tfracextrastep;
if (d_tfrac & 0x10000)
{
d_ptex += r_affinetridesc.skinwidth;
d_tfrac &= 0xFFFF;
}
d_light += d_lightextrastep;
d_zi += d_ziextrastep;
errorterm -= erroradjustdown;
}
else
{
d_pdest += d_pdestbasestep;
d_pz += d_pzbasestep;
d_aspancount += ubasestep;
d_ptex += d_ptexbasestep;
d_sfrac += d_sfracbasestep;
d_ptex += d_sfrac >> 16;
d_sfrac &= 0xFFFF;
d_tfrac += d_tfracbasestep;
if (d_tfrac & 0x10000)
{
d_ptex += r_affinetridesc.skinwidth;
d_tfrac &= 0xFFFF;
}
d_light += d_lightbasestep;
d_zi += d_zibasestep;
}
} while (--height);
}
/*
===================
FloorDivMod
Returns mathematically correct (floor-based) quotient and remainder for
numer and denom, both of which should contain no fractional part. The
quotient must fit in 32 bits.
FIXME: GET RID OF THIS! (FloorDivMod)
====================
*/
void FloorDivMod (float numer, float denom, int *quotient,
int *rem)
{
int q, r;
float x;
if (numer >= 0.0)
{
x = floor(numer / denom);
q = (int)x;
r = (int)floor(numer - (x * denom));
}
else
{
//
// perform operations with positive values, and fix mod to make floor-based
//
x = floor(-numer / denom);
q = -(int)x;
r = (int)floor(-numer - (x * denom));
if (r != 0)
{
q--;
r = (int)denom - r;
}
}
*quotient = q;
*rem = r;
}
/*
===================
R_PolysetSetUpForLineScan
====================
*/
void R_PolysetSetUpForLineScan(fixed8_t startvertu, fixed8_t startvertv,
fixed8_t endvertu, fixed8_t endvertv)
{
float dm, dn;
int tm, tn;
adivtab_t *ptemp;
// TODO: implement x86 version
errorterm = -1;
tm = endvertu - startvertu;
tn = endvertv - startvertv;
if (((tm <= 16) && (tm >= -15)) &&
((tn <= 16) && (tn >= -15)))
{
ptemp = &adivtab[((tm+15) << 5) + (tn+15)];
ubasestep = ptemp->quotient;
erroradjustup = ptemp->remainder;
erroradjustdown = tn;
}
else
{
dm = tm;
dn = tn;
FloorDivMod (dm, dn, &ubasestep, &erroradjustup);
erroradjustdown = dn;
}
}
/*
================
R_PolysetCalcGradients
================
*/
void R_PolysetCalcGradients (int skinwidth)
{
float xstepdenominv, ystepdenominv, t0, t1;
float p01_minus_p21, p11_minus_p21, p00_minus_p20, p10_minus_p20;
p00_minus_p20 = r_p0[0] - r_p2[0];
p01_minus_p21 = r_p0[1] - r_p2[1];
p10_minus_p20 = r_p1[0] - r_p2[0];
p11_minus_p21 = r_p1[1] - r_p2[1];
xstepdenominv = 1.0 / (float)d_xdenom;
ystepdenominv = -xstepdenominv;
// ceil () for light so positive steps are exaggerated, negative steps
// diminished, pushing us away from underflow toward overflow. Underflow is
// very visible, overflow is very unlikely, because of ambient lighting
t0 = r_p0[4] - r_p2[4];
t1 = r_p1[4] - r_p2[4];
r_lstepx = (int)
ceil((t1 * p01_minus_p21 - t0 * p11_minus_p21) * xstepdenominv);
r_lstepy = (int)
ceil((t1 * p00_minus_p20 - t0 * p10_minus_p20) * ystepdenominv);
t0 = r_p0[2] - r_p2[2];
t1 = r_p1[2] - r_p2[2];
r_sstepx = (int)((t1 * p01_minus_p21 - t0 * p11_minus_p21) *
xstepdenominv);
r_sstepy = (int)((t1 * p00_minus_p20 - t0* p10_minus_p20) *
ystepdenominv);
t0 = r_p0[3] - r_p2[3];
t1 = r_p1[3] - r_p2[3];
r_tstepx = (int)((t1 * p01_minus_p21 - t0 * p11_minus_p21) *
xstepdenominv);
r_tstepy = (int)((t1 * p00_minus_p20 - t0 * p10_minus_p20) *
ystepdenominv);
t0 = r_p0[5] - r_p2[5];
t1 = r_p1[5] - r_p2[5];
r_zistepx = (int)((t1 * p01_minus_p21 - t0 * p11_minus_p21) *
xstepdenominv);
r_zistepy = (int)((t1 * p00_minus_p20 - t0 * p10_minus_p20) *
ystepdenominv);
a_sstepxfrac = r_sstepx & 0xFFFF;
a_tstepxfrac = r_tstepx & 0xFFFF;
a_ststepxwhole = skinwidth * (r_tstepx >> 16) + (r_sstepx >> 16);
}
/*
================
R_PolysetDrawThreshSpans8
Random fizzle fade rasterizer
================
*/
void R_PolysetDrawThreshSpans8 (spanpackage_t *pspanpackage)
{
int lcount;
byte *lpdest;
byte *lptex;
int lsfrac, ltfrac;
int llight;
int lzi;
short *lpz;
do
{
lcount = d_aspancount - pspanpackage->count;
errorterm += erroradjustup;
if (errorterm >= 0)
{
d_aspancount += d_countextrastep;
errorterm -= erroradjustdown;
}
else
{
d_aspancount += ubasestep;
}
if (lcount)
{
lpdest = pspanpackage->pdest;
lptex = pspanpackage->ptex;
lpz = pspanpackage->pz;
lsfrac = pspanpackage->sfrac;
ltfrac = pspanpackage->tfrac;
llight = pspanpackage->light;
lzi = pspanpackage->zi;
do
{
if ((lzi >> 16) >= *lpz)
{
rand1k_index = (rand1k_index + 1) & MASK_1K;
if (rand1k[rand1k_index] <= r_affinetridesc.vis_thresh)
{
*lpdest = ((byte *)vid.colormap)[*lptex + (llight & 0xFF00)];
*lpz = lzi >> 16;
}
}
lpdest++;
lzi += r_zistepx;
lpz++;
llight += r_lstepx;
lptex += a_ststepxwhole;
lsfrac += a_sstepxfrac;
lptex += lsfrac >> 16;
lsfrac &= 0xFFFF;
ltfrac += a_tstepxfrac;
if (ltfrac & 0x10000)
{
lptex += r_affinetridesc.skinwidth;
ltfrac &= 0xFFFF;
}
} while (--lcount);
}
pspanpackage++;
} while (pspanpackage->count != -999999);
}
/*
================
R_PolysetDrawSpans8
================
*/
void R_PolysetDrawSpans8_33( spanpackage_t *pspanpackage)
{
int lcount;
byte *lpdest;
byte *lptex;
int lsfrac, ltfrac;
int llight;
int lzi;
short *lpz;
do
{
lcount = d_aspancount - pspanpackage->count;
errorterm += erroradjustup;
if (errorterm >= 0)
{
d_aspancount += d_countextrastep;
errorterm -= erroradjustdown;
}
else
{
d_aspancount += ubasestep;
}
if (lcount)
{
lpdest = pspanpackage->pdest;
lptex = pspanpackage->ptex;
lpz = pspanpackage->pz;
lsfrac = pspanpackage->sfrac;
ltfrac = pspanpackage->tfrac;
llight = pspanpackage->light;
lzi = pspanpackage->zi;
do
{
if ((lzi >> 16) >= *lpz)
{
int temp = vid.colormap[*lptex + ( llight & 0xFF00 )];
*lpdest = vid.alphamap[temp+ *lpdest*256];
}
lpdest++;
lzi += r_zistepx;
lpz++;
llight += r_lstepx;
lptex += a_ststepxwhole;
lsfrac += a_sstepxfrac;
lptex += lsfrac >> 16;
lsfrac &= 0xFFFF;
ltfrac += a_tstepxfrac;
if (ltfrac & 0x10000)
{
lptex += r_affinetridesc.skinwidth;
ltfrac &= 0xFFFF;
}
} while (--lcount);
}
pspanpackage++;
} while (pspanpackage->count != -999999);
}
void R_PolysetDrawSpansConstant8_33( spanpackage_t *pspanpackage)
{
int lcount;
byte *lpdest;
int lzi;
short *lpz;
do
{
lcount = d_aspancount - pspanpackage->count;
errorterm += erroradjustup;
if (errorterm >= 0)
{
d_aspancount += d_countextrastep;
errorterm -= erroradjustdown;
}
else
{
d_aspancount += ubasestep;
}
if (lcount)
{
lpdest = pspanpackage->pdest;
lpz = pspanpackage->pz;
lzi = pspanpackage->zi;
do
{
if ((lzi >> 16) >= *lpz)
{
*lpdest = vid.alphamap[r_aliasblendcolor + *lpdest*256];
}
lpdest++;
lzi += r_zistepx;
lpz++;
} while (--lcount);
}
pspanpackage++;
} while (pspanpackage->count != -999999);
}
void R_PolysetDrawSpans8_66(spanpackage_t *pspanpackage)
{
int lcount;
byte *lpdest;
byte *lptex;
int lsfrac, ltfrac;
int llight;
int lzi;
short *lpz;
do
{
lcount = d_aspancount - pspanpackage->count;
errorterm += erroradjustup;
if (errorterm >= 0)
{
d_aspancount += d_countextrastep;
errorterm -= erroradjustdown;
}
else
{
d_aspancount += ubasestep;
}
if (lcount)
{
lpdest = pspanpackage->pdest;
lptex = pspanpackage->ptex;
lpz = pspanpackage->pz;
lsfrac = pspanpackage->sfrac;
ltfrac = pspanpackage->tfrac;
llight = pspanpackage->light;
lzi = pspanpackage->zi;
do
{
if ((lzi >> 16) >= *lpz)
{
int temp = vid.colormap[*lptex + ( llight & 0xFF00 )];
*lpdest = vid.alphamap[temp*256 + *lpdest];
*lpz = lzi >> 16;
}
lpdest++;
lzi += r_zistepx;
lpz++;
llight += r_lstepx;
lptex += a_ststepxwhole;
lsfrac += a_sstepxfrac;
lptex += lsfrac >> 16;
lsfrac &= 0xFFFF;
ltfrac += a_tstepxfrac;
if (ltfrac & 0x10000)
{
lptex += r_affinetridesc.skinwidth;
ltfrac &= 0xFFFF;
}
} while (--lcount);
}
pspanpackage++;
} while (pspanpackage->count != -999999);
}
void R_PolysetDrawSpansConstant8_66( spanpackage_t *pspanpackage)
{
int lcount;
byte *lpdest;
int lzi;
short *lpz;
do
{
lcount = d_aspancount - pspanpackage->count;
errorterm += erroradjustup;
if (errorterm >= 0)
{
d_aspancount += d_countextrastep;
errorterm -= erroradjustdown;
}
else
{
d_aspancount += ubasestep;
}
if (lcount)
{
lpdest = pspanpackage->pdest;
lpz = pspanpackage->pz;
lzi = pspanpackage->zi;
do
{
if ((lzi >> 16) >= *lpz)
{
*lpdest = vid.alphamap[r_aliasblendcolor*256 + *lpdest];
}
lpdest++;
lzi += r_zistepx;
lpz++;
} while (--lcount);
}
pspanpackage++;
} while (pspanpackage->count != -999999);
}
void R_PolysetDrawSpans8_Opaque (spanpackage_t *pspanpackage)
{
int lcount;
do
{
lcount = d_aspancount - pspanpackage->count;
errorterm += erroradjustup;
if (errorterm >= 0)
{
d_aspancount += d_countextrastep;
errorterm -= erroradjustdown;
}
else
{
d_aspancount += ubasestep;
}
if (lcount)
{
int lsfrac, ltfrac;
byte *lpdest;
byte *lptex;
int llight;
int lzi;
short *lpz;
lpdest = pspanpackage->pdest;
lptex = pspanpackage->ptex;
lpz = pspanpackage->pz;
lsfrac = pspanpackage->sfrac;
ltfrac = pspanpackage->tfrac;
llight = pspanpackage->light;
lzi = pspanpackage->zi;
do
{
if ((lzi >> 16) >= *lpz)
{
//PGM
if(r_newrefdef.rdflags & RDF_IRGOGGLES && currententity->flags & RF_IR_VISIBLE)
*lpdest = ((byte *)vid.colormap)[irtable[*lptex]];
else
*lpdest = ((byte *)vid.colormap)[*lptex + (llight & 0xFF00)];
//PGM
*lpz = lzi >> 16;
}
lpdest++;
lzi += r_zistepx;
lpz++;
llight += r_lstepx;
lptex += a_ststepxwhole;
lsfrac += a_sstepxfrac;
lptex += lsfrac >> 16;
lsfrac &= 0xFFFF;
ltfrac += a_tstepxfrac;
if (ltfrac & 0x10000)
{
lptex += r_affinetridesc.skinwidth;
ltfrac &= 0xFFFF;
}
} while (--lcount);
}
pspanpackage++;
} while (pspanpackage->count != -999999);
}
/*
================
R_PolysetFillSpans8
================
*/
void R_PolysetFillSpans8 (spanpackage_t *pspanpackage)
{
int color;
// FIXME: do z buffering
color = d_aflatcolor++;
while (1)
{
int lcount;
byte *lpdest;
lcount = pspanpackage->count;
if (lcount == -1)
return;
if (lcount)
{
lpdest = pspanpackage->pdest;
do
{
*lpdest++ = color;
} while (--lcount);
}
pspanpackage++;
}
}
/*
================
R_RasterizeAliasPolySmooth
================
*/
void R_RasterizeAliasPolySmooth (void)
{
int initialleftheight, initialrightheight;
int *plefttop, *prighttop, *pleftbottom, *prightbottom;
int working_lstepx, originalcount;
plefttop = pedgetable->pleftedgevert0;
prighttop = pedgetable->prightedgevert0;
pleftbottom = pedgetable->pleftedgevert1;
prightbottom = pedgetable->prightedgevert1;
initialleftheight = pleftbottom[1] - plefttop[1];
initialrightheight = prightbottom[1] - prighttop[1];
//
// set the s, t, and light gradients, which are consistent across the triangle
// because being a triangle, things are affine
//
R_PolysetCalcGradients (r_affinetridesc.skinwidth);
//
// rasterize the polygon
//
//
// scan out the top (and possibly only) part of the left edge
//
d_pedgespanpackage = a_spans;
ystart = plefttop[1];
d_aspancount = plefttop[0] - prighttop[0];
d_ptex = (byte *)r_affinetridesc.pskin + (plefttop[2] >> 16) +
(plefttop[3] >> 16) * r_affinetridesc.skinwidth;
d_sfrac = plefttop[2] & 0xFFFF;
d_tfrac = plefttop[3] & 0xFFFF;
d_light = plefttop[4];
d_zi = plefttop[5];
d_pdest = (byte *)d_viewbuffer +
ystart * r_screenwidth + plefttop[0];
d_pz = d_pzbuffer + ystart * d_zwidth + plefttop[0];
if (initialleftheight == 1)
{
d_pedgespanpackage->pdest = d_pdest;
d_pedgespanpackage->pz = d_pz;
d_pedgespanpackage->count = d_aspancount;
d_pedgespanpackage->ptex = d_ptex;
d_pedgespanpackage->sfrac = d_sfrac;
d_pedgespanpackage->tfrac = d_tfrac;
// FIXME: need to clamp l, s, t, at both ends?
d_pedgespanpackage->light = d_light;
d_pedgespanpackage->zi = d_zi;
d_pedgespanpackage++;
}
else
{
R_PolysetSetUpForLineScan(plefttop[0], plefttop[1],
pleftbottom[0], pleftbottom[1]);
d_pzbasestep = d_zwidth + ubasestep;
d_pzextrastep = d_pzbasestep + 1;
d_pdestbasestep = r_screenwidth + ubasestep;
d_pdestextrastep = d_pdestbasestep + 1;
// TODO: can reuse partial expressions here
// for negative steps in x along left edge, bias toward overflow rather than
// underflow (sort of turning the floor () we did in the gradient calcs into
// ceil (), but plus a little bit)
if (ubasestep < 0)
working_lstepx = r_lstepx - 1;
else
working_lstepx = r_lstepx;
d_countextrastep = ubasestep + 1;
d_ptexbasestep = ((r_sstepy + r_sstepx * ubasestep) >> 16) +
((r_tstepy + r_tstepx * ubasestep) >> 16) *
r_affinetridesc.skinwidth;
d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) & 0xFFFF;
d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) & 0xFFFF;
d_lightbasestep = r_lstepy + working_lstepx * ubasestep;
d_zibasestep = r_zistepy + r_zistepx * ubasestep;
d_ptexextrastep = ((r_sstepy + r_sstepx * d_countextrastep) >> 16) +
((r_tstepy + r_tstepx * d_countextrastep) >> 16) *
r_affinetridesc.skinwidth;
d_sfracextrastep = (r_sstepy + r_sstepx*d_countextrastep) & 0xFFFF;
d_tfracextrastep = (r_tstepy + r_tstepx*d_countextrastep) & 0xFFFF;
d_lightextrastep = d_lightbasestep + working_lstepx;
d_ziextrastep = d_zibasestep + r_zistepx;
R_PolysetScanLeftEdge_C(initialleftheight);
}
//
// scan out the bottom part of the left edge, if it exists
//
if (pedgetable->numleftedges == 2)
{
int height;
plefttop = pleftbottom;
pleftbottom = pedgetable->pleftedgevert2;
height = pleftbottom[1] - plefttop[1];
// TODO: make this a function; modularize this function in general
ystart = plefttop[1];
d_aspancount = plefttop[0] - prighttop[0];
d_ptex = (byte *)r_affinetridesc.pskin + (plefttop[2] >> 16) +
(plefttop[3] >> 16) * r_affinetridesc.skinwidth;
d_sfrac = 0;
d_tfrac = 0;
d_light = plefttop[4];
d_zi = plefttop[5];
d_pdest = (byte *)d_viewbuffer + ystart * r_screenwidth + plefttop[0];
d_pz = d_pzbuffer + ystart * d_zwidth + plefttop[0];
if (height == 1)
{
d_pedgespanpackage->pdest = d_pdest;
d_pedgespanpackage->pz = d_pz;
d_pedgespanpackage->count = d_aspancount;
d_pedgespanpackage->ptex = d_ptex;
d_pedgespanpackage->sfrac = d_sfrac;
d_pedgespanpackage->tfrac = d_tfrac;
// FIXME: need to clamp l, s, t, at both ends?
d_pedgespanpackage->light = d_light;
d_pedgespanpackage->zi = d_zi;
}
else
{
R_PolysetSetUpForLineScan(plefttop[0], plefttop[1],
pleftbottom[0], pleftbottom[1]);
d_pdestbasestep = r_screenwidth + ubasestep;
d_pdestextrastep = d_pdestbasestep + 1;
d_pzbasestep = d_zwidth + ubasestep;
d_pzextrastep = d_pzbasestep + 1;
if (ubasestep < 0)
working_lstepx = r_lstepx - 1;
else
working_lstepx = r_lstepx;
d_countextrastep = ubasestep + 1;
d_ptexbasestep = ((r_sstepy + r_sstepx * ubasestep) >> 16) +
((r_tstepy + r_tstepx * ubasestep) >> 16) *
r_affinetridesc.skinwidth;
d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) & 0xFFFF;
d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) & 0xFFFF;
d_lightbasestep = r_lstepy + working_lstepx * ubasestep;
d_zibasestep = r_zistepy + r_zistepx * ubasestep;
d_ptexextrastep = ((r_sstepy + r_sstepx * d_countextrastep) >> 16) +
((r_tstepy + r_tstepx * d_countextrastep) >> 16) *
r_affinetridesc.skinwidth;
d_sfracextrastep = (r_sstepy+r_sstepx*d_countextrastep) & 0xFFFF;
d_tfracextrastep = (r_tstepy+r_tstepx*d_countextrastep) & 0xFFFF;
d_lightextrastep = d_lightbasestep + working_lstepx;
d_ziextrastep = d_zibasestep + r_zistepx;
R_PolysetScanLeftEdge_C(height);
}
}
// scan out the top (and possibly only) part of the right edge, updating the
// count field
d_pedgespanpackage = a_spans;
R_PolysetSetUpForLineScan(prighttop[0], prighttop[1],
prightbottom[0], prightbottom[1]);
d_aspancount = 0;
d_countextrastep = ubasestep + 1;
originalcount = a_spans[initialrightheight].count;
a_spans[initialrightheight].count = -999999; // mark end of the spanpackages
(*d_pdrawspans) (a_spans);
// scan out the bottom part of the right edge, if it exists
if (pedgetable->numrightedges == 2)
{
int height;
spanpackage_t *pstart;
pstart = a_spans + initialrightheight;
pstart->count = originalcount;
d_aspancount = prightbottom[0] - prighttop[0];
prighttop = prightbottom;
prightbottom = pedgetable->prightedgevert2;
height = prightbottom[1] - prighttop[1];
R_PolysetSetUpForLineScan(prighttop[0], prighttop[1],
prightbottom[0], prightbottom[1]);
d_countextrastep = ubasestep + 1;
a_spans[initialrightheight + height].count = -999999;
// mark end of the spanpackages
(*d_pdrawspans) (pstart);
}
}
/*
================
R_PolysetSetEdgeTable
================
*/
void R_PolysetSetEdgeTable (void)
{
int edgetableindex;
edgetableindex = 0; // assume the vertices are already in
// top to bottom order
//
// determine which edges are right & left, and the order in which
// to rasterize them
//
if (r_p0[1] >= r_p1[1])
{
if (r_p0[1] == r_p1[1])
{
if (r_p0[1] < r_p2[1])
pedgetable = &edgetables[2];
else
pedgetable = &edgetables[5];
return;
}
else
{
edgetableindex = 1;
}
}
if (r_p0[1] == r_p2[1])
{
if (edgetableindex)
pedgetable = &edgetables[8];
else
pedgetable = &edgetables[9];
return;
}
else if (r_p1[1] == r_p2[1])
{
if (edgetableindex)
pedgetable = &edgetables[10];
else
pedgetable = &edgetables[11];
return;
}
if (r_p0[1] > r_p2[1])
edgetableindex += 2;
if (r_p1[1] > r_p2[1])
edgetableindex += 4;
pedgetable = &edgetables[edgetableindex];
}