ref: 02d16fad3aa65b08b6e947d4c2e8745d041638c4
dir: /d_polyse.c/
#include "quakedef.h"
// 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;
uzint *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;
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, nil, 2, r_p0, r_p1, r_p2 },
{0, 2, r_p1, r_p0, r_p2, 1, r_p1, r_p2, nil},
{1, 1, r_p0, r_p2, nil, 1, r_p1, r_p2, nil},
{0, 1, r_p1, r_p0, nil, 2, r_p1, r_p2, r_p0 },
{0, 2, r_p0, r_p2, r_p1, 1, r_p0, r_p1, nil},
{0, 1, r_p2, r_p1, nil, 1, r_p2, r_p0, nil},
{0, 1, r_p2, r_p1, nil, 2, r_p2, r_p0, r_p1 },
{0, 2, r_p2, r_p1, r_p0, 1, r_p2, r_p0, nil},
{0, 1, r_p1, r_p0, nil, 1, r_p1, r_p2, nil},
{1, 1, r_p2, r_p1, nil, 1, r_p0, r_p1, nil},
{1, 1, r_p1, r_p0, nil, 1, r_p2, r_p0, nil},
{0, 1, r_p0, r_p2, nil, 1, r_p0, r_p1, nil},
};
// 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;
uzint *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_PolysetDrawSpans8 (spanpackage_t *pspanpackage, byte alpha);
void D_PolysetCalcGradients (int skinwidth);
void D_DrawSubdiv (void);
void D_DrawNonSubdiv (void);
void D_PolysetRecursiveTriangle (int *p1, int *p2, int *p3, byte alpha);
void D_PolysetSetEdgeTable (void);
void D_RasterizeAliasPolySmooth (void);
void D_PolysetScanLeftEdge (int height);
/*
================
D_PolysetDraw
================
*/
void D_PolysetDraw (void)
{
static spanpackage_t spans[DPS_MAXSPANS];
a_spans = spans;
if (r_affinetridesc.drawtype)
{
D_DrawSubdiv ();
}
else
{
D_DrawNonSubdiv ();
}
}
/*
================
D_PolysetDrawFinalVerts
================
*/
void D_PolysetDrawFinalVerts (finalvert_t *fv, int numverts, byte alpha)
{
int i, z;
uzint *zbuf;
for (i=0 ; i<numverts ; i++, fv++)
{
// valid triangle coordinates for filling can include the bottom and
// right clip edges, due to the fill rule; these shouldn't be drawn
if ((fv->v[0] < r_refdef.vrectright) &&
(fv->v[1] < r_refdef.vrectbottom))
{
z = fv->v[5]>>16;
zbuf = zspantable[fv->v[1]] + fv->v[0];
if (z >= *zbuf){
if(r_drawflags & DRAW_BLEND){
int n = d_scantable[fv->v[1]] + fv->v[0];
int pix = skintable[fv->v[3]>>16][fv->v[2]>>16];
pix = ((byte *)acolormap)[pix + (fv->v[4] & 0xFF00) ];
d_viewbuffer[n] = blendalpha(pix, d_viewbuffer[n], alpha);
}else{
int pix;
*zbuf = z;
pix = skintable[fv->v[3]>>16][fv->v[2]>>16];
pix = ((byte *)acolormap)[pix + (fv->v[4] & 0xFF00) ];
d_viewbuffer[d_scantable[fv->v[1]] + fv->v[0]] = pix;
}
}
}
}
}
/*
================
D_DrawSubdiv
================
*/
void D_DrawSubdiv (void)
{
mtriangle_t *ptri;
finalvert_t *pfv, *index0, *index1, *index2;
int i;
int lnumtriangles;
pfv = r_affinetridesc.pfinalverts;
ptri = r_affinetridesc.ptriangles;
lnumtriangles = r_affinetridesc.numtriangles;
for (i=0 ; i<lnumtriangles ; i++)
{
index0 = pfv + ptri[i].vertindex[0];
index1 = pfv + ptri[i].vertindex[1];
index2 = pfv + ptri[i].vertindex[2];
if (((index0->v[1]-index1->v[1]) *
(index0->v[0]-index2->v[0]) -
(index0->v[0]-index1->v[0]) *
(index0->v[1]-index2->v[1])) >= 0)
{
continue;
}
d_pcolormap = &((byte *)acolormap)[index0->v[4] & 0xFF00];
if (ptri[i].facesfront)
{
D_PolysetRecursiveTriangle(index0->v, index1->v, index2->v, currententity->alpha);
}
else
{
int s0, s1, s2;
s0 = index0->v[2];
s1 = index1->v[2];
s2 = index2->v[2];
if (index0->flags & ALIAS_ONSEAM)
index0->v[2] += r_affinetridesc.seamfixupX16;
if (index1->flags & ALIAS_ONSEAM)
index1->v[2] += r_affinetridesc.seamfixupX16;
if (index2->flags & ALIAS_ONSEAM)
index2->v[2] += r_affinetridesc.seamfixupX16;
D_PolysetRecursiveTriangle(index0->v, index1->v, index2->v, currententity->alpha);
index0->v[2] = s0;
index1->v[2] = s1;
index2->v[2] = s2;
}
}
}
/*
================
D_DrawNonSubdiv
================
*/
void D_DrawNonSubdiv (void)
{
mtriangle_t *ptri;
finalvert_t *pfv, *index0, *index1, *index2;
int i;
int lnumtriangles;
pfv = r_affinetridesc.pfinalverts;
ptri = r_affinetridesc.ptriangles;
lnumtriangles = r_affinetridesc.numtriangles;
for (i=0 ; i<lnumtriangles ; i++, ptri++)
{
index0 = pfv + ptri->vertindex[0];
index1 = pfv + ptri->vertindex[1];
index2 = pfv + ptri->vertindex[2];
d_xdenom = (index0->v[1]-index1->v[1]) *
(index0->v[0]-index2->v[0]) -
(index0->v[0]-index1->v[0])*(index0->v[1]-index2->v[1]);
if (d_xdenom >= 0)
{
continue;
}
r_p0[0] = index0->v[0]; // u
r_p0[1] = index0->v[1]; // v
r_p0[2] = index0->v[2]; // s
r_p0[3] = index0->v[3]; // t
r_p0[4] = index0->v[4]; // light
r_p0[5] = index0->v[5]; // iz
r_p1[0] = index1->v[0];
r_p1[1] = index1->v[1];
r_p1[2] = index1->v[2];
r_p1[3] = index1->v[3];
r_p1[4] = index1->v[4];
r_p1[5] = index1->v[5];
r_p2[0] = index2->v[0];
r_p2[1] = index2->v[1];
r_p2[2] = index2->v[2];
r_p2[3] = index2->v[3];
r_p2[4] = index2->v[4];
r_p2[5] = index2->v[5];
if (!ptri->facesfront)
{
if (index0->flags & ALIAS_ONSEAM)
r_p0[2] += r_affinetridesc.seamfixupX16;
if (index1->flags & ALIAS_ONSEAM)
r_p1[2] += r_affinetridesc.seamfixupX16;
if (index2->flags & ALIAS_ONSEAM)
r_p2[2] += r_affinetridesc.seamfixupX16;
}
D_PolysetSetEdgeTable ();
D_RasterizeAliasPolySmooth ();
}
}
/*
================
D_PolysetRecursiveTriangle
================
*/
void D_PolysetRecursiveTriangle (int *lp1, int *lp2, int *lp3, byte alpha)
{
int *temp;
int d;
int new[6];
int z;
uzint *zbuf;
d = lp2[0] - lp1[0];
if (d < -1 || d > 1)
goto split;
d = lp2[1] - lp1[1];
if (d < -1 || d > 1)
goto split;
d = lp3[0] - lp2[0];
if (d < -1 || d > 1)
goto split2;
d = lp3[1] - lp2[1];
if (d < -1 || d > 1)
goto split2;
d = lp1[0] - lp3[0];
if (d < -1 || d > 1)
goto split3;
d = lp1[1] - lp3[1];
if (d < -1 || d > 1)
{
split3:
temp = lp1;
lp1 = lp3;
lp3 = lp2;
lp2 = temp;
goto split;
}
return; // entire tri is filled
split2:
temp = lp1;
lp1 = lp2;
lp2 = lp3;
lp3 = temp;
split:
// split this edge
new[0] = (lp1[0] + lp2[0]) >> 1;
new[1] = (lp1[1] + lp2[1]) >> 1;
new[2] = (lp1[2] + lp2[2]) >> 1;
new[3] = (lp1[3] + lp2[3]) >> 1;
new[5] = (lp1[5] + lp2[5]) >> 1;
// draw the point if splitting a leading edge
if (lp2[1] > lp1[1])
goto nodraw;
if ((lp2[1] == lp1[1]) && (lp2[0] < lp1[0]))
goto nodraw;
z = new[5]>>16;
zbuf = zspantable[new[1]] + new[0];
if (z >= *zbuf){
if(r_drawflags & DRAW_BLEND){
int n = d_scantable[new[1]] + new[0];
int pix = d_pcolormap[skintable[new[3]>>16][new[2]>>16]];
d_viewbuffer[n] = blendalpha(pix, d_viewbuffer[n], alpha);
}else{
int pix;
*zbuf = z;
pix = d_pcolormap[skintable[new[3]>>16][new[2]>>16]];
d_viewbuffer[d_scantable[new[1]] + new[0]] = pix;
}
}
nodraw:
// recursively continue
D_PolysetRecursiveTriangle (lp3, lp1, new, alpha);
D_PolysetRecursiveTriangle (lp3, new, lp2, alpha);
}
/*
================
D_PolysetUpdateTables
================
*/
void D_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;
}
}
/*
===================
D_PolysetScanLeftEdge
====================
*/
void D_PolysetScanLeftEdge (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);
}
/*
===================
D_PolysetSetUpForLineScan
====================
*/
void D_PolysetSetUpForLineScan(fixed8_t startvertu, fixed8_t startvertv,
fixed8_t endvertu, fixed8_t endvertv)
{
double 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 = (double)tm;
dn = (double)tn;
FloorDivMod (dm, dn, &ubasestep, &erroradjustup);
erroradjustdown = dn;
}
}
/*
================
D_PolysetCalcGradients
================
*/
void D_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);
}
/*
================
D_PolysetDrawSpans8
================
*/
void D_PolysetDrawSpans8 (spanpackage_t *pspanpackage, byte alpha)
{
int lcount;
byte *lpdest;
byte *lptex;
int lsfrac, ltfrac;
int llight;
int lzi;
uzint *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){
if(r_drawflags & DRAW_BLEND){
*lpdest = blendalpha(
((byte *)acolormap)[*lptex + (llight & 0xFF00)],
*lpdest,
alpha
);
}else{
*lpdest = ((byte *)acolormap)[*lptex + (llight & 0xFF00)];
// gel mapping *lpdest = gelmap[*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 != Q_MININT);
}
/*
================
D_PolysetFillSpans8
================
*/
void D_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++;
}
}
/*
================
D_RasterizeAliasPolySmooth
================
*/
void D_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
D_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 * 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
{
D_PolysetSetUpForLineScan(plefttop[0], plefttop[1],
pleftbottom[0], pleftbottom[1]);
d_pzbasestep = d_zwidth + ubasestep;
d_pzextrastep = d_pzbasestep + 1;
d_pdestbasestep = 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;
D_PolysetScanLeftEdge (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 * 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
{
D_PolysetSetUpForLineScan(plefttop[0], plefttop[1],
pleftbottom[0], pleftbottom[1]);
d_pdestbasestep = 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;
D_PolysetScanLeftEdge (height);
}
}
// scan out the top (and possibly only) part of the right edge, updating the
// count field
d_pedgespanpackage = a_spans;
D_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 = Q_MININT; // mark end of the spanpackages
D_PolysetDrawSpans8 (a_spans, currententity->alpha);
// 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];
D_PolysetSetUpForLineScan(prighttop[0], prighttop[1],
prightbottom[0], prightbottom[1]);
d_countextrastep = ubasestep + 1;
a_spans[initialrightheight + height].count = Q_MININT;
// mark end of the spanpackages
D_PolysetDrawSpans8 (pstart, currententity->alpha);
}
}
/*
================
D_PolysetSetEdgeTable
================
*/
void D_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];
}