/*
 * 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_polyset.c: routines for drawing sets of polygons sharing the same
// texture (used for Alias models)

#include "quakedef.h"
#include "r_local.h"
#include "d_local.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;
    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;

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_PolysetDrawSpans8 (spanpackage_t * pspanpackage);
void          D_PolysetCalcGradients (int skinwidth);
void          D_DrawSubdiv (void);
void          D_DrawNonSubdiv (void);
void          D_PolysetRecursiveTriangle (int *p1, int *p2, int *p3);
void          D_PolysetSetEdgeTable (void);
void          D_RasterizeAliasPolySmooth (void);
void          D_PolysetScanLeftEdge (int height);

#if !id386

/*
 * D_PolysetDraw
 */
void D_PolysetDraw (void) {
    spanpackage_t spans[DPS_MAXSPANS + 1 + ((CACHE_SIZE - 1) / sizeof (spanpackage_t)) + 1];
    // one extra because of cache line pretouching

    a_spans = (spanpackage_t *) (((long) &spans[0] + CACHE_SIZE - 1) & ~(CACHE_SIZE - 1));

    if (r_affinetridesc.drawtype) {
        D_DrawSubdiv ();
    } else {
        D_DrawNonSubdiv ();
    }
}

/*
 * D_PolysetDrawFinalVerts
 */
void D_PolysetDrawFinalVerts (finalvert_t * fv, int numverts) {
    int           i, z;
    short        *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) {
                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);
        } 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);

            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) {
    int          *temp;
    int           d;
    int           new[6];
    int           z;
    short        *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) {
        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);
    D_PolysetRecursiveTriangle (lp3, new, lp2);
}

#endif                                 // !id386

/*
 * 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;
    }
}

#if !id386

/*
 * 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);
}

#endif                                 // !id386

/*
 * 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;
    }
}

#if !id386

/*
 * 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);

#  if id386
    a_sstepxfrac = r_sstepx << 16;
    a_tstepxfrac = r_tstepx << 16;
#  else
    a_sstepxfrac = r_sstepx & 0xFFFF;
    a_tstepxfrac = r_tstepx & 0xFFFF;
#  endif

    a_ststepxwhole = skinwidth * (r_tstepx >> 16) + (r_sstepx >> 16);
}

#endif                                 // !id386

// joe: enabled
byte          gelmap[256];
void InitGel (byte * palette) {
    int           i;
    int           r;

    for (i = 0; i < 256; i++) {
        // r = (palette[i*3]>>4);
        r = (palette[i * 3] + palette[i * 3 + 1] + palette[i * 3 + 2]) / (16 * 3);
        gelmap[i] = /* 64 */ 0 + r;
    }
}

#if !id386

/*
 * D_PolysetDrawSpans8
 */
void D_PolysetDrawSpans8 (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) {
                    *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 != -999999);
}
#endif                                 // !id386

/*
 * 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, working_lstepx, originalcount;
    int          *plefttop, *prighttop, *pleftbottom, *prightbottom;

    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_PolysetSetUpForLineScan (plefttop[0], plefttop[1], pleftbottom[0], pleftbottom[1]);

    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;
#if id386
    d_sfrac = (plefttop[2] & 0xFFFF) << 16;
    d_tfrac = (plefttop[3] & 0xFFFF) << 16;
    d_pzbasestep = (d_zwidth + ubasestep) << 1;
    d_pzextrastep = d_pzbasestep + 2;
#else
    d_sfrac = plefttop[2] & 0xFFFF;
    d_tfrac = plefttop[3] & 0xFFFF;
    d_pzbasestep = d_zwidth + ubasestep;
    d_pzextrastep = d_pzbasestep + 1;
#endif
    d_light = plefttop[4];
    d_zi = plefttop[5];

    d_pdestbasestep = screenwidth + ubasestep;
    d_pdestextrastep = d_pdestbasestep + 1;
    d_pdest = (byte *) d_viewbuffer + ystart * screenwidth + plefttop[0];
    d_pz = d_pzbuffer + ystart * d_zwidth + plefttop[0];

    // 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;
#if id386
    d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) << 16;
    d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) << 16;
#else
    d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) & 0xFFFF;
    d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) & 0xFFFF;
#endif
    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;
#if id386
    d_sfracextrastep = (r_sstepy + r_sstepx * d_countextrastep) << 16;
    d_tfracextrastep = (r_tstepy + r_tstepx * d_countextrastep) << 16;
#else
    d_sfracextrastep = (r_sstepy + r_sstepx * d_countextrastep) & 0xFFFF;
    d_tfracextrastep = (r_tstepy + r_tstepx * d_countextrastep) & 0xFFFF;
#endif
    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;

        D_PolysetSetUpForLineScan (plefttop[0], plefttop[1], pleftbottom[0], pleftbottom[1]);

        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_pdestbasestep = screenwidth + ubasestep;
        d_pdestextrastep = d_pdestbasestep + 1;
        d_pdest = (byte *) d_viewbuffer + ystart * screenwidth + plefttop[0];
#if id386
        d_pzbasestep = (d_zwidth + ubasestep) << 1;
        d_pzextrastep = d_pzbasestep + 2;
#else
        d_pzbasestep = d_zwidth + ubasestep;
        d_pzextrastep = d_pzbasestep + 1;
#endif
        d_pz = d_pzbuffer + ystart * d_zwidth + plefttop[0];

        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;
#if id386
        d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) << 16;
        d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) << 16;
#else
        d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) & 0xFFFF;
        d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) & 0xFFFF;
#endif
        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;
#if id386
        d_sfracextrastep = ((r_sstepy + r_sstepx * d_countextrastep) & 0xFFFF) << 16;
        d_tfracextrastep = ((r_tstepy + r_tstepx * d_countextrastep) & 0xFFFF) << 16;
#else
        d_sfracextrastep = (r_sstepy + r_sstepx * d_countextrastep) & 0xFFFF;
        d_tfracextrastep = (r_tstepy + r_tstepx * d_countextrastep) & 0xFFFF;
#endif
        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 = -999999;        // mark end of the
    // spanpackages
    D_PolysetDrawSpans8 (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];

        D_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_PolysetDrawSpans8 (pstart);
    }
}

/*
 * 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];
}

#if 0

void D_PolysetRecursiveDrawLine (int *lp1, int *lp2) {
    int           d;
    int           new[6];
    int           ofs;

    d = lp2[0] - lp1[0];
    if (d < -1 || d > 1)
        goto split;
    d = lp2[1] - lp1[1];
    if (d < -1 || d > 1)
        goto split;

    return;                            // line is completed

  split:
    // split this edge
    new[0] = (lp1[0] + lp2[0]) >> 1;
    new[1] = (lp1[1] + lp2[1]) >> 1;
    new[5] = (lp1[5] + lp2[5]) >> 1;
    new[2] = (lp1[2] + lp2[2]) >> 1;
    new[3] = (lp1[3] + lp2[3]) >> 1;
    new[4] = (lp1[4] + lp2[4]) >> 1;

    // draw the point
    ofs = d_scantable[new[1]] + new[0];
    if (new[5] > d_pzbuffer[ofs]) {
        int           pix;

        d_pzbuffer[ofs] = new[5];
        pix = skintable[new[3] >> 16][new[2] >> 16];
        // pix = ((byte *)acolormap)[pix + (new[4] & 0xFF00)];
        d_viewbuffer[ofs] = pix;
    }
    // recursively continue
    D_PolysetRecursiveDrawLine (lp1, new);
    D_PolysetRecursiveDrawLine (new, lp2);
}

void D_PolysetRecursiveTriangle2 (int *lp1, int *lp2, int *lp3) {
    int           d;
    int           new[4];

    d = lp2[0] - lp1[0];
    if (d < -1 || d > 1)
        goto split;
    d = lp2[1] - lp1[1];
    if (d < -1 || d > 1)
        goto split;
    return;

  split:
    // split this edge
    new[0] = (lp1[0] + lp2[0]) >> 1;
    new[1] = (lp1[1] + lp2[1]) >> 1;
    new[5] = (lp1[5] + lp2[5]) >> 1;
    new[2] = (lp1[2] + lp2[2]) >> 1;
    new[3] = (lp1[3] + lp2[3]) >> 1;
    new[4] = (lp1[4] + lp2[4]) >> 1;

    D_PolysetRecursiveDrawLine (new, lp3);

    // recursively continue
    D_PolysetRecursiveTriangle (lp1, new, lp3);
    D_PolysetRecursiveTriangle (new, lp2, lp3);
}

#endif
