// blah
#ifdef POLYMOST

#define POLYMER_C
#include "polymer.h"

// CVARS
int             pr_occlusionculling = 50;
int             pr_fov = 426;           // appears to be the classic setting.
int             pr_billboardingmode = 1;
int             pr_verbosity = 1;       // 0: silent, 1: errors and one-times, 2: multiple-times, 3: flood
int             pr_wireframe = 0;
int             pr_mirrordepth = 1;

int             glerror;

// DATA
_prsector       *prsectors[MAXSECTORS];
_prwall         *prwalls[MAXWALLS];

GLfloat         skybox[16];

GLfloat         vertsprite[4 * 5] = {
    -0.5f, 0.0f, 0.0f,
     0.0f, 1.0f,
     0.5f, 0.0f, 0.0f,
     1.0f, 1.0f,
     0.5f, 1.0f, 0.0f,
     1.0f, 0.0f,
    -0.5f, 1.0f, 0.0f,
     0.0f, 0.0f,
};

GLfloat         horizsprite[4 * 5] = {
    -0.5f, 0.0f, -0.5f,
     0.0f, 1.0f,
     0.5f, 0.0f, -0.5f,
     1.0f, 1.0f,
     0.5f, 0.0f, 0.5f,
     1.0f, 0.0f,
    -0.5f, 0.0f, 0.5f,
     0.0f, 0.0f,
};

// CONTROL
GLdouble        spritemodelview[16];
GLdouble        rootmodelviewmatrix[16];
GLdouble        *curmodelviewmatrix;
GLdouble        projectionmatrix[16];

int             updatesectors = 1;

int             depth;
int             mirrorfrom[10]; // -3: no mirror; -2: floor; -1: ceiling; >=0: wallnum

GLUtesselator*  prtess;

short           cursky;

short           viewangle;

int             rootsectnum;

_pranimatespritesinfo asi;

// EXTERNAL FUNCTIONS
int                 polymer_init(void)
{
    int             i, j;

    if (pr_verbosity >= 1) OSD_Printf("Initalizing Polymer subsystem...\n");

    i = 0;
    while (i < MAXSECTORS)
    {
        prsectors[i] = NULL;
        i++;
    }

    i = 0;
    while (i < MAXWALLS)
    {
        prwalls[i] = NULL;
        i++;
    }

    prtess = bgluNewTess();
    if (prtess == 0)
    {
        if (pr_verbosity >= 1) OSD_Printf("PR : Tesselator initialization failed.\n");
        return (0);
    }

    polymer_loadboard();

    polymer_initskybox();

    // init the face sprite modelview to identity
    i = 0;
    while (i < 4)
    {
        j = 0;
        while (j < 4)
        {
            if (i == j)
                spritemodelview[(i * 4) + j] = 1.0;
            else
                spritemodelview[(i * 4) + j] = 0.0;
            j++;
        }
        i++;
    }

    if (pr_verbosity >= 1) OSD_Printf("PR : Initialization complete.\n");
    return (1);
}

void                polymer_glinit(void)
{
    float           a;

    bglClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    bglClearStencil(0);
    bglClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    bglViewport(0, 0, xdim, ydim);

    // texturing
    bglEnable(GL_TEXTURE_2D);
    bglTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    bglTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);

    bglEnable(GL_DEPTH_TEST);
    bglDepthFunc(GL_LEQUAL);

    if (pr_wireframe)
        bglPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    else
        bglPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

    bglMatrixMode(GL_PROJECTION);
    bglLoadIdentity();
    bgluPerspective((float)(pr_fov) / (2048.0f / 360.0f), (float)xdim / (float)ydim, 0.01f, 100.0f);

    // get the new projection matrix
    bglGetDoublev(GL_PROJECTION_MATRIX, projectionmatrix);

    bglMatrixMode(GL_MODELVIEW);
    bglLoadIdentity();

    bglEnableClientState(GL_VERTEX_ARRAY);
    bglEnableClientState(GL_TEXTURE_COORD_ARRAY);

    bglDisable(GL_FOG);

    bglFogi(GL_FOG_MODE, GL_EXP2);
    //glFogfv(GL_FOG_COLOR, fogColor);
    bglEnable(GL_FOG);

    a = (1 - ((float)(visibility) / 512.0f)) / 10.0f;
    bglFogf(GL_FOG_DENSITY, 0.1f - a);
    bglFogf(GL_FOG_START, 0.0f);
    bglFogf(GL_FOG_END, 1000000.0f);

    bglEnable(GL_CULL_FACE);
    bglCullFace(GL_BACK);
}

void                polymer_loadboard(void)
{
    int             i;

    i = 0;
    while (i < numsectors)
    {
        polymer_initsector(i);
        polymer_updatesector(i);
        i++;
    }

    i = 0;
    while (i < numwalls)
    {
        polymer_initwall(i);
        polymer_updatewall(i);
        i++;
    }

    polymer_getsky();

    if (pr_verbosity >= 1) OSD_Printf("PR : Board loaded.\n");
}

void                polymer_drawrooms(int daposx, int daposy, int daposz, short daang, int dahoriz, short dacursectnum)
{
    short           cursectnum;
    int             i;
    float           ang, horizang, tiltang;
    float           pos[3];

    if (pr_verbosity >= 3) OSD_Printf("PR : Drawing rooms...\n");

    ang = (float)(daang) / (2048.0f / 360.0f);
    horizang = (float)(100 - dahoriz) / (512.0f / 180.0f);
    tiltang = (gtang * 90.0f);

    pos[0] = daposy;
    pos[1] = -(float)(daposz) / 16.0f;
    pos[2] = -daposx;

    bglMatrixMode(GL_MODELVIEW);
    bglLoadIdentity();

    bglRotatef(tiltang, 0.0f, 0.0f, -1.0f);
    bglRotatef(horizang, 1.0f, 0.0f, 0.0f);
    bglRotatef(ang, 0.0f, 1.0f, 0.0f);

    bglDisable(GL_DEPTH_TEST);
    bglColor4f(1.0f, 1.0f, 1.0f, 1.0f);
    polymer_drawartsky(cursky);
    bglEnable(GL_DEPTH_TEST);

    bglScalef(1.0f / 1000.0f, 1.0f / 1000.0f, 1.0f / 1000.0f);
    bglTranslatef(-pos[0], -pos[1], -pos[2]);

    bglGetDoublev(GL_MODELVIEW_MATRIX, rootmodelviewmatrix);

    cursectnum = dacursectnum;
    updatesector(daposx, daposy, &cursectnum);

    if ((cursectnum >= 0) && (cursectnum < numsectors))
        dacursectnum = cursectnum;

    // external view (editor)
    if ((dacursectnum < 0) || (dacursectnum >= numsectors))
    {
        i = 0;
        while (i < numsectors)
        {
            polymer_updatesector(i);
            polymer_drawsector(i);
            polymer_scansprites(i, tsprite, &spritesortcnt);
            i++;
        }

        i = 0;
        while (i < numwalls)
        {
            polymer_updatewall(i);
            polymer_drawwall(sectorofwall(i), i);
            i++;
        }
        viewangle = daang;
        return;
    }

    rootsectnum = dacursectnum;

    // unflag all sectors
    i = 0;
    while (i < numsectors)
    {
        prsectors[i]->controlstate = 0;
        prsectors[i]->wallsproffset = 0.0f;
        prsectors[i]->floorsproffset = 0.0f;
        i++;
    }
    i = 0;
    while (i < numwalls)
    {
        prwalls[i]->controlstate = 0;
        i++;
    }

    // GO!
    depth = 0;
    mirrorfrom[0] = -3; // no mirror
    polymer_displayrooms(dacursectnum);

    viewangle = daang;
    curmodelviewmatrix = rootmodelviewmatrix;
    cosglobalang = sintable[(viewangle+512)&2047];
    singlobalang = sintable[viewangle&2047];
    cosviewingrangeglobalang = mulscale16(cosglobalang,viewingrange);
    sinviewingrangeglobalang = mulscale16(singlobalang,viewingrange);

    if (pr_verbosity >= 3) OSD_Printf("PR : Rooms drawn.\n");
}

void                polymer_drawmasks(void)
{
    bglEnable(GL_ALPHA_TEST);
    bglEnable(GL_BLEND);
    bglEnable(GL_POLYGON_OFFSET_FILL);

    while (spritesortcnt)
    {
        spritesortcnt--;
        tspriteptr[spritesortcnt] = &tsprite[spritesortcnt];
        polymer_drawsprite(spritesortcnt);
    }

    bglDisable(GL_POLYGON_OFFSET_FILL);
    bglDisable(GL_BLEND);
    bglDisable(GL_ALPHA_TEST);
}

void                polymer_rotatesprite(int sx, int sy, int z, short a, short picnum, signed char dashade, char dapalnum, char dastat, int cx1, int cy1, int cx2, int cy2)
{
    UNREFERENCED_PARAMETER(sx);
    UNREFERENCED_PARAMETER(sy);
    UNREFERENCED_PARAMETER(z);
    UNREFERENCED_PARAMETER(a);
    UNREFERENCED_PARAMETER(picnum);
    UNREFERENCED_PARAMETER(dashade);
    UNREFERENCED_PARAMETER(dapalnum);
    UNREFERENCED_PARAMETER(dastat);
    UNREFERENCED_PARAMETER(cx1);
    UNREFERENCED_PARAMETER(cy1);
    UNREFERENCED_PARAMETER(cx2);
    UNREFERENCED_PARAMETER(cy2);
}

void                polymer_drawmaskwall(int damaskwallcnt)
{
    _prwall         *w;

    if (pr_verbosity >= 3) OSD_Printf("PR : Masked wall %i...\n", damaskwallcnt);

    w = prwalls[maskwall[damaskwallcnt]];

    polymer_drawplane(-1, -3, w->maskglpic, w->maskcolor, w->portal, NULL, 0, NULL);
}

void                polymer_drawsprite(int snum)
{
    int             curpicnum, glpic, xsize, ysize, tilexoff, tileyoff, xoff, yoff;
    spritetype      *tspr;
    pthtyp*         pth;
    float           color[4], xratio, yratio, ang, *curspritedata;
    float           spos[3];

    if (pr_verbosity >= 3) OSD_Printf("PR : Sprite %i...\n", snum);

    tspr = tspriteptr[snum];

    curpicnum = tspr->picnum;
    if (picanm[curpicnum]&192) curpicnum += animateoffs(curpicnum,tspr->owner+32768);

    if (!waloff[curpicnum])
        loadtile(curpicnum);

    pth = gltexcache(curpicnum, tspr->pal, 0);

    color[0] = color[1] = color[2] = ((float)(numpalookups-min(max(tspr->shade,0),numpalookups)))/((float)numpalookups);

    if (pth && (pth->flags & 2) && (pth->palnum != tspr->pal))
    {
        color[0] *= (float)hictinting[tspr->pal].r / 255.0;
        color[1] *= (float)hictinting[tspr->pal].g / 255.0;
        color[2] *= (float)hictinting[tspr->pal].b / 255.0;
    }

    if (tspr->cstat & 2)
    {
        if (tspr->cstat & 512)
            color[3] = 0.33f;
        else
            color[3] = 0.66f;
    }
    else
        color[3] = 1.0f;

    glpic = (pth) ? pth->glpic : 0;

    if (((tspr->cstat>>4) & 3) == 0)
        xratio = (float)(tspr->xrepeat) * 32.0f / 160.0f;
    else
        xratio = (float)(tspr->xrepeat) / 4.0f;

    yratio = (float)(tspr->yrepeat) / 4.0f;

    xsize = tilesizx[curpicnum] * xratio;
    ysize = tilesizy[curpicnum] * yratio;

    tilexoff = (int)tspr->xoffset;
    tileyoff = (int)tspr->yoffset;
    tilexoff += (signed char)((usehightile&&h_xsize[curpicnum])?(h_xoffs[curpicnum]):((picanm[curpicnum]>>8)&255));
    tileyoff += (signed char)((usehightile&&h_xsize[curpicnum])?(h_yoffs[curpicnum]):((picanm[curpicnum]>>16)&255));

    xoff = tilexoff * xratio;
    yoff = tileyoff * yratio;

    if (tspr->cstat & 128)
        yoff -= ysize / 2;

    spos[0] = tspr->y;
    spos[1] = -(float)(tspr->z) / 16.0f;
    spos[2] = -tspr->x;

    curspritedata = vertsprite;

    if (pr_billboardingmode && !((tspr->cstat>>4) & 3))
    {
        // do surgery on the face tspr to make it look like a wall sprite
        tspr->cstat |= 16;
        tspr->ang = (viewangle + 1024) & 2047;
    }

    switch ((tspr->cstat>>4) & 3)
    {
        case 0:
            bglMatrixMode(GL_MODELVIEW);
            bglPushMatrix();

            spritemodelview[12] =   curmodelviewmatrix[0] * spos[0] +
                                    curmodelviewmatrix[4] * spos[1] +
                                    curmodelviewmatrix[8] * spos[2] +
                                    curmodelviewmatrix[12];
            spritemodelview[13] =   curmodelviewmatrix[1] * spos[0] +
                                    curmodelviewmatrix[5] * spos[1] +
                                    curmodelviewmatrix[9] * spos[2] +
                                    curmodelviewmatrix[13];
            spritemodelview[14] =   curmodelviewmatrix[2]  * spos[0] +
                                    curmodelviewmatrix[6]  * spos[1] +
                                    curmodelviewmatrix[10] * spos[2] +
                                    curmodelviewmatrix[14];

            bglLoadMatrixd(spritemodelview);
            bglRotatef((gtang * 90.0f), 0.0f, 0.0f, -1.0f);
            bglTranslatef((float)(-xoff)/1000.0f, (float)(yoff)/1000.0f, 0.0f);
            bglScalef((float)(xsize) / 1000.0f, (float)(ysize) / 1000.0f, 1.0f / 1000.0f);

            bglPolygonOffset(0.0f, 0.0f);
            break;
        case 1:
            bglMatrixMode(GL_MODELVIEW);
            bglPushMatrix();

            ang = (float)((tspr->ang + 1024) & 2047) / (2048.0f / 360.0f);

            bglTranslatef(spos[0], spos[1], spos[2]);
            bglRotatef(-ang, 0.0f, 1.0f, 0.0f);
            bglTranslatef((float)(-xoff), (float)(yoff), 0.0f);
            bglScalef((float)(xsize), (float)(ysize), 1.0f);

            prsectors[tspr->sectnum]->wallsproffset += 0.5f;
            bglPolygonOffset(-prsectors[tspr->sectnum]->wallsproffset,
                             -prsectors[tspr->sectnum]->wallsproffset);
            break;
        case 2:
            bglMatrixMode(GL_MODELVIEW);
            bglPushMatrix();

            ang = (float)((tspr->ang + 1024) & 2047) / (2048.0f / 360.0f);

            bglTranslatef(spos[0], spos[1], spos[2]);
            bglRotatef(-ang, 0.0f, 1.0f, 0.0f);
            bglTranslatef((float)(-xoff), 1.0f, (float)(yoff));
            bglScalef((float)(xsize), 1.0f, (float)(ysize));

            curspritedata = horizsprite;

            prsectors[tspr->sectnum]->floorsproffset += 0.5f;
            bglPolygonOffset(-prsectors[tspr->sectnum]->floorsproffset,
                             -prsectors[tspr->sectnum]->floorsproffset);
            break;
    }

    bglMatrixMode(GL_TEXTURE);
    bglLoadIdentity();

    if ((tspr->cstat & 4) || (((tspr->cstat>>4) & 3) == 2))
        bglScalef(-1.0f, 1.0f, 1.0f);

    if (tspr->cstat & 8)
        bglScalef(1.0f, -1.0f, 1.0f);

    if ((tspr->cstat & 64) && (((tspr->cstat>>4) & 3) == 1))
        bglEnable(GL_CULL_FACE);

    polymer_drawplane(-1, -3, glpic, color, curspritedata, NULL, 0, NULL);

    if ((tspr->cstat & 64) && (((tspr->cstat>>4) & 3) == 1))
        bglDisable(GL_CULL_FACE);

    bglLoadIdentity();
    bglMatrixMode(GL_MODELVIEW);
    bglPopMatrix();
}

void                polymer_setanimatesprites(animatespritesptr animatesprites, int x, int y, int a, int smoothratio)
{
    asi.animatesprites = animatesprites;
    asi.x = x;
    asi.y = y;
    asi.a = a;
    asi.smoothratio = smoothratio;
}

// CORE
static void         polymer_displayrooms(short dacursectnum)
{
    sectortype      *sec, *nextsec;
    walltype        *wal, *nextwal;
    _prwall         *w;
    int             i, j;
    GLint           result;
    int             front;
    int             back;
    int             firstback;
    short           sectorqueue[MAXSECTORS];
    short           querydelay[MAXSECTORS];
    GLuint          queryid[MAXSECTORS];
    short           drawingstate[MAXSECTORS];
    GLdouble        localmodelviewmatrix[16];
    float           frustum[5 * 4];
    int             localspritesortcnt;
    spritetype      localtsprite[MAXSPRITESONSCREEN];
    short           localmaskwall[MAXWALLSB], localmaskwallcnt;

    if (depth)
    {
        curmodelviewmatrix = localmodelviewmatrix;
        bglGetDoublev(GL_MODELVIEW_MATRIX, localmodelviewmatrix);
    }
    else
        curmodelviewmatrix = rootmodelviewmatrix;

    polymer_extractfrustum(curmodelviewmatrix, projectionmatrix, frustum);

    memset(querydelay, 0, sizeof(short) * MAXSECTORS);
    memset(queryid, 0, sizeof(GLuint) * MAXSECTORS);
    memset(drawingstate, 0, sizeof(short) * MAXSECTORS);

    front = 0;
    back = 0;
    localspritesortcnt = localmaskwallcnt = 0;

    polymer_pokesector(dacursectnum);
    polymer_drawsector(dacursectnum);
    polymer_scansprites(dacursectnum, localtsprite, &localspritesortcnt);
    drawingstate[dacursectnum] = 1;

    sec = &sector[dacursectnum];
    wal = &wall[sec->wallptr];

    i = 0;
    while (i < sec->wallnum)
    {
        if (((wallvisible(sec->wallptr + i))) &&
            (polymer_portalinfrustum(sec->wallptr + i, frustum)))
        {
            if (mirrorfrom[depth] != (sec->wallptr + i))
                polymer_drawwall(dacursectnum, sec->wallptr + i);
            // mask
            if ((wal->cstat&48) == 16) localmaskwall[localmaskwallcnt++] = sec->wallptr + i;

            if ((wal->nextsector != -1) &&
                 (drawingstate[wal->nextsector] == 0))
            {
                sectorqueue[back++] = wal->nextsector;
                drawingstate[wal->nextsector] = 1;
            }
        }
        i++;
        wal = &wall[sec->wallptr + i];
    }

    mirrorfrom[depth] = -3;

    firstback = back;

    while (front != back)
    {
        if ((front >= firstback) && (pr_occlusionculling))
        {
            if (querydelay[sectorqueue[front]] == 0)
            {
                bglGetQueryObjectivARB(queryid[sectorqueue[front]],
                                    GL_QUERY_RESULT_ARB,
                                    &result);
                bglDeleteQueriesARB(1, &queryid[sectorqueue[front]]);
                if (!result)
                {
                    front++;
                    continue;
                }
                else
                    querydelay[sectorqueue[front]] = pr_occlusionculling-1;
            }
            else if (querydelay[sectorqueue[front]] == -1)
                querydelay[sectorqueue[front]] = pr_occlusionculling-1;
            else if (querydelay[sectorqueue[front]])
                querydelay[sectorqueue[front]]--;
        }

        polymer_pokesector(sectorqueue[front]);
        polymer_drawsector(sectorqueue[front]);
        polymer_scansprites(sectorqueue[front], localtsprite, &localspritesortcnt);

        // scan sectors
        sec = &sector[sectorqueue[front]];
        wal = &wall[sec->wallptr];

        i = 0;
        while (i < sec->wallnum)
        {
            if ((wallvisible(sec->wallptr + i)) &&
                (polymer_portalinfrustum(sec->wallptr + i, frustum)))
            {
                polymer_drawwall(sectorqueue[front], sec->wallptr + i);
                // mask
                if ((wal->cstat&48) == 16) localmaskwall[localmaskwallcnt++] = sec->wallptr + i;

                if ((wal->nextsector != -1) &&
                     (drawingstate[wal->nextsector] == 0))
                {
                    polymer_pokesector(wal->nextsector);
                    sectorqueue[back++] = wal->nextsector;
                    drawingstate[wal->nextsector] = 1;

                    if (pr_occlusionculling && !querydelay[wal->nextsector])
                    {
                        nextsec = &sector[wal->nextsector];
                        nextwal = &wall[nextsec->wallptr];

                        if ((nextsec->ceilingstat & 1) &&
                            (nextsec->floorz == nextsec->ceilingz))
                        {
                            querydelay[wal->nextsector] = -1;
                            i++;
                            wal = &wall[sec->wallptr + i];
                            continue;
                        }

                        bglDisable(GL_TEXTURE_2D);
                        bglDisable(GL_FOG);
                        bglColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
                        bglDepthMask(GL_FALSE);

                        bglGenQueriesARB(1, &queryid[wal->nextsector]);
                        bglBeginQueryARB(GL_SAMPLES_PASSED_ARB, queryid[wal->nextsector]);

                        j = 0;
                        while (j < nextsec->wallnum)
                        {
                            if ((nextwal->nextwall == (sec->wallptr + i)) ||
                                ((nextwal->nextwall != -1) &&
                                 (wallvisible(nextwal->nextwall)) &&
                                 (polymer_portalinfrustum(nextwal->nextwall, frustum))))
                            {
                                w = prwalls[nextwal->nextwall];
                                bglVertexPointer(3, GL_FLOAT, 5 * sizeof(GLfloat), w->portal);
                                bglDrawArrays(GL_QUADS, 0, 4);
                                if ((w->underover & 1) && (w->underover & 4))
                                {
                                    bglVertexPointer(3, GL_FLOAT, 5 * sizeof(GLfloat), w->wallbuffer);
                                    bglDrawArrays(GL_QUADS, 0, 4);
                                }
                                if ((w->underover & 2) && (w->underover & 8))
                                {
                                    bglVertexPointer(3, GL_FLOAT, 5 * sizeof(GLfloat), w->overbuffer);
                                    bglDrawArrays(GL_QUADS, 0, 4);
                                }
                            }

                            j++;
                            nextwal = &wall[nextsec->wallptr + j];
                        }
                        bglEndQueryARB(GL_SAMPLES_PASSED_ARB);

                        bglDepthMask(GL_TRUE);
                        bglColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

                        bglEnable(GL_FOG);
                        bglEnable(GL_TEXTURE_2D);
                    }
                }
            }
            i++;
            wal = &wall[sec->wallptr + i];
        }
        front++;
    }

    spritesortcnt = localspritesortcnt;
    memcpy(tsprite, localtsprite, sizeof(spritetype) * MAXSPRITESONSCREEN);
    maskwallcnt = localmaskwallcnt;
    memcpy(maskwall, localmaskwall, sizeof(short) * MAXWALLSB);

    if (depth)
    {
        cosglobalang = sintable[(viewangle+512)&2047];
        singlobalang = sintable[viewangle&2047];
        cosviewingrangeglobalang = mulscale16(cosglobalang,viewingrange);
        sinviewingrangeglobalang = mulscale16(singlobalang,viewingrange);

        display_mirror = 1;
        polymer_animatesprites();
        display_mirror = 0;

        bglDisable(GL_CULL_FACE);
        drawmasks();
        bglEnable(GL_CULL_FACE);
        bglEnable(GL_BLEND);
    }
}


#define OMGDRAWSHIT                                                             \
    bglVertexPointer(3, GL_FLOAT, 5 * sizeof(GLfloat), buffer);                 \
    bglTexCoordPointer(2, GL_FLOAT, 5 * sizeof(GLfloat), &buffer[3]);           \
    if (!indices)                                                               \
        bglDrawArrays(GL_QUADS, 0, 4);                                          \
    else                                                                        \
        bglDrawElements(GL_TRIANGLES, indicecount, GL_UNSIGNED_SHORT, indices)

static void         polymer_drawplane(short sectnum, short wallnum, GLuint glpic, GLfloat* color, GLfloat* buffer, GLushort* indices, int indicecount, GLdouble* plane)
{

    if ((depth < 1) && (plane != NULL) &&
        (wallnum >= 0) && (wall[wallnum].overpicnum == 560)) // insert mirror condition here
    {
        int             gx, gy, gz, px, py, pz;
        float           coeff;

        // set the stencil to 1 and clear the area to black where the sector floor is
        bglDisable(GL_TEXTURE_2D);
        bglDisable(GL_FOG);
        bglColor4f(0.0f, 1.0f, 0.0f, 1.0f);
        bglDepthMask(GL_FALSE);

        bglEnable(GL_STENCIL_TEST);
        bglStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
        bglStencilFunc(GL_EQUAL, 0, 0xffffffff);

        OMGDRAWSHIT;
        bglDepthMask(GL_TRUE);

        // set the depth to 1 where we put the stencil by drawing a screen aligned quad
        bglStencilFunc(GL_EQUAL, 1, 0xffffffff);
        bglStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
        bglDepthFunc(GL_ALWAYS);
        bglMatrixMode(GL_PROJECTION);
        bglPushMatrix();
        bglLoadIdentity();
        bglMatrixMode(GL_MODELVIEW);
        bglPushMatrix();
        bglLoadIdentity();

        bglColor4f(0.0f, 0.0f, 0.0f, 1.0f);
        bglBegin(GL_QUADS);
        bglVertex3f(-1.0f, -1.0f, 1.0f);
        bglVertex3f(1.0f, -1.0f, 1.0f);
        bglVertex3f(1.0f, 1.0f, 1.0f);
        bglVertex3f(-1.0f, 1.0f, 1.0f);
        bglEnd();

        bglMatrixMode(GL_PROJECTION);
        bglPopMatrix();
        bglMatrixMode(GL_MODELVIEW);
        bglPopMatrix();
        bglDepthFunc(GL_LEQUAL);
        bglEnable(GL_TEXTURE_2D);
        bglEnable(GL_FOG);
        // finally draw the shit
        bglPushMatrix();
        bglClipPlane(GL_CLIP_PLANE0, plane);
        polymer_inb4mirror(buffer, plane);
        bglCullFace(GL_FRONT);
        bglEnable(GL_CLIP_PLANE0);

        if (wallnum >= 0)
            preparemirror(globalposx, globalposy, 0, globalang,
                          0, wallnum, 0, &gx, &gy, &viewangle);

        gx = globalposx;
        gy = globalposy;
        gz = globalposz;

        // map the player pos from build to polymer
        px = globalposy;
        py = -globalposz / 16;
        pz = -globalposx;

        // calculate new player position on the other side of the mirror
        // this way the basic build visibility shit can be used (wallvisible)
        coeff = -plane[0] * px +
                -plane[1] * py +
                -plane[2] * pz +
                -plane[3];

        coeff /= (float)(plane[0] * plane[0] +
                         plane[1] * plane[1] +
                         plane[2] * plane[2]);

        px = coeff*plane[0]*2 + px;
        py = coeff*plane[1]*2 + py;
        pz = coeff*plane[2]*2 + pz;

        // map back from polymer to build
        globalposx = -pz;
        globalposy = px;
        globalposz = -py * 16;

        depth++;
        mirrorfrom[depth] = wallnum;
        polymer_displayrooms(sectnum);
        depth--;

        globalposx = gx;
        globalposy = gy;
        globalposz = gz;

        bglDisable(GL_CLIP_PLANE0);
        bglCullFace(GL_BACK);
        bglMatrixMode(GL_MODELVIEW);
        bglPopMatrix();

        bglColor4f(color[0], color[1], color[2], 0.0f);
    }
    else
        bglColor4f(color[0], color[1], color[2], color[3]);

    bglBindTexture(GL_TEXTURE_2D, glpic);
    OMGDRAWSHIT;

    if ((depth < 1) && (plane != NULL) &&
         (wallnum >= 0) && (wall[wallnum].overpicnum == 560)) // insert mirror condition here
    {
        bglDisable(GL_STENCIL_TEST);
        bglClear(GL_STENCIL_BUFFER_BIT);
    }
}

static void         polymer_inb4mirror(GLfloat* buffer, GLdouble* plane)
{
    float           pv;
    float           reflectionmatrix[16];

    pv = buffer[0] * plane[0] +
         buffer[1] * plane[1] +
         buffer[2] * plane[2];

    reflectionmatrix[0] = 1 - (2 * plane[0] * plane[0]);
    reflectionmatrix[1] = -2 * plane[0] * plane[1];
    reflectionmatrix[2] = -2 * plane[0] * plane[2];
    reflectionmatrix[3] = 0;

    reflectionmatrix[4] = -2 * plane[0] * plane[1];
    reflectionmatrix[5] = 1 - (2 * plane[1] * plane[1]);
    reflectionmatrix[6] = -2 * plane[1] * plane[2];
    reflectionmatrix[7] = 0;

    reflectionmatrix[8] = -2 * plane[0] * plane[2];
    reflectionmatrix[9] = -2 * plane[1] * plane[2];
    reflectionmatrix[10] = 1 - (2 * plane[2] * plane[2]);
    reflectionmatrix[11] = 0;

    reflectionmatrix[12] = 2 * pv * plane[0];
    reflectionmatrix[13] = 2 * pv * plane[1];
    reflectionmatrix[14] = 2 * pv * plane[2];
    reflectionmatrix[15] = 1;

    bglMultMatrixf(reflectionmatrix);
}

static void         polymer_animatesprites(void)
{
    asi.animatesprites(globalposx, globalposy, viewangle, asi.smoothratio);
}

// SECTORS
static int          polymer_initsector(short sectnum)
{
    sectortype      *sec;
    _prsector*      s;

    if (pr_verbosity >= 2) OSD_Printf("PR : Initalizing sector %i...\n", sectnum);

    sec = &sector[sectnum];
    s = calloc(1, sizeof(_prsector));
    if (s == NULL)
    {
        if (pr_verbosity >= 1) OSD_Printf("PR : Cannot initialize sector %i : malloc failed.\n", sectnum);
        return (0);
    }

    s->verts = calloc(sec->wallnum, sizeof(GLdouble) * 3);
    s->floorbuffer = calloc(sec->wallnum, sizeof(GLfloat) * 5);
    s->ceilbuffer = calloc(sec->wallnum, sizeof(GLfloat) * 5);
    if ((s->verts == NULL) || (s->floorbuffer == NULL) || (s->ceilbuffer == NULL))
    {
        if (pr_verbosity >= 1) OSD_Printf("PR : Cannot initialize geometry of sector %i : malloc failed.\n", sectnum);
        return (0);
    }

    s->controlstate = 2; // let updatesector know that everything needs to go

    prsectors[sectnum] = s;

    if (pr_verbosity >= 2) OSD_Printf("PR : Initalized sector %i.\n", sectnum);

    return (1);
}

static int          polymer_updatesector(short sectnum)
{
    _prsector*      s;
    sectortype      *sec;
    walltype        *wal;
    int             i, j;
    int             ceilz, florz;
    int             tex, tey;
    float           secangcos, secangsin, scalecoef;
    int             ang, needfloor, wallinvalidate;
    short           curstat, curpicnum, floorpicnum, ceilingpicnum;
    char            curxpanning, curypanning;
    GLfloat*        curbuffer;
    GLuint          *curglpic, *curfbglpic;
    pthtyp*         pth;

    s = prsectors[sectnum];
    sec = &sector[sectnum];

    secangcos = secangsin = 2;

    if (s == NULL)
    {
        if (pr_verbosity >= 1) OSD_Printf("PR : Can't update uninitialized sector %i.\n", sectnum);
        return (-1);
    }

    needfloor = wallinvalidate = 0;

    // geometry
    wal = &wall[sec->wallptr];
    i = 0;
    while (i < sec->wallnum)
    {
        if ((-wal->x != s->verts[(i*3)+2]))
        {
            s->verts[(i*3)+2] = s->floorbuffer[(i*5)+2] = s->ceilbuffer[(i*5)+2] = -wal->x;
            needfloor = wallinvalidate = 1;
        }
        if ((wal->y != s->verts[i*3]))
        {
            s->verts[i*3] = s->floorbuffer[i*5] = s->ceilbuffer[i*5] = wal->y;
            needfloor = wallinvalidate = 1;
        }

        i++;
        wal = &wall[sec->wallptr + i];
    }

    if ((s->controlstate == 2) ||
        (sec->floorz != s->floorz) ||
        (sec->ceilingz != s->ceilingz) ||
        (sec->floorheinum != s->floorheinum) ||
        (sec->ceilingheinum != s->ceilingheinum))
    {
        wallinvalidate = 1;

        wal = &wall[sec->wallptr];
        i = 0;
        while (i < sec->wallnum)
        {
            getzsofslope(sectnum, wal->x, wal->y, &ceilz, &florz);
            s->floorbuffer[(i*5)+1] = -(float)(florz) / 16.0f;
            s->ceilbuffer[(i*5)+1] = -(float)(ceilz) / 16.0f;

            i++;
            wal = &wall[sec->wallptr + i];
        }

        s->floorz = sec->floorz;
        s->ceilingz = sec->ceilingz;
        s->floorheinum = sec->floorheinum;
        s->ceilingheinum = sec->ceilingheinum;
    }

    floorpicnum = sec->floorpicnum;
    if (picanm[floorpicnum]&192) floorpicnum += animateoffs(floorpicnum,sectnum);
    ceilingpicnum = sec->ceilingpicnum;
    if (picanm[ceilingpicnum]&192) ceilingpicnum += animateoffs(ceilingpicnum,sectnum);

    if ((s->controlstate != 2) && (!needfloor) &&
        (sec->floorstat == s->floorstat) &&
        (sec->ceilingstat == s->ceilingstat) &&
        (floorpicnum == s->floorpicnum) &&
        (ceilingpicnum == s->ceilingpicnum) &&
        (sec->floorxpanning == s->floorxpanning) &&
        (sec->ceilingxpanning == s->ceilingxpanning) &&
        (sec->floorypanning == s->floorypanning) &&
        (sec->ceilingypanning == s->ceilingypanning))
        goto attributes;

    wal = &wall[sec->wallptr];
    i = 0;
    while (i < sec->wallnum)
    {
        j = 2;
        curstat = sec->floorstat;
        curbuffer = s->floorbuffer;
        curpicnum = floorpicnum;
        curxpanning = sec->floorxpanning;
        curypanning = sec->floorypanning;

        while (j)
        {
            if (j == 1)
            {
                curstat = sec->ceilingstat;
                curbuffer = s->ceilbuffer;
                curpicnum = ceilingpicnum;
                curxpanning = sec->ceilingxpanning;
                curypanning = sec->ceilingypanning;
            }

            if (!waloff[curpicnum])
                loadtile(curpicnum);

            if (((sec->floorstat & 64) || (sec->ceilingstat & 64)) &&
                ((secangcos == 2) && (secangsin == 2)))
            {
                ang = (getangle(wall[wal->point2].x - wal->x, wall[wal->point2].y - wal->y) + 512) & 2047;
                secangcos = (float)(sintable[(ang+512)&2047]) / 16383.0f;
                secangsin = (float)(sintable[ang&2047]) / 16383.0f;
            }


            tex = (curstat & 64) ? ((wal->x - wall[sec->wallptr].x) * secangsin) + ((-wal->y - -wall[sec->wallptr].y) * secangcos) : wal->x;
            tey = (curstat & 64) ? ((wal->x - wall[sec->wallptr].x) * secangcos) - ((wall[sec->wallptr].y - wal->y) * secangsin) : -wal->y;

            if (curstat & 4)
                swaplong(&tex, &tey);

            if (curstat & 16) tex = -tex;
            if (curstat & 32) tey = -tey;

            scalecoef = (curstat & 8) ? 8.0f : 16.0f;

            curbuffer[(i*5)+3] = ((float)(tex) / (scalecoef * tilesizx[curpicnum])) + ((float)(curxpanning) / 256.0f);
            curbuffer[(i*5)+4] = ((float)(tey) / (scalecoef * tilesizy[curpicnum])) + ((float)(curypanning) / 256.0f);

            j--;
        }
        i++;
        wal = &wall[sec->wallptr + i];
    }

    s->floorstat = sec->floorstat;
    s->ceilingstat = sec->ceilingstat;
    s->floorxpanning = sec->floorxpanning;
    s->ceilingxpanning = sec->ceilingxpanning;
    s->floorypanning = sec->floorypanning;
    s->ceilingypanning = sec->ceilingypanning;

attributes:

    if ((s->controlstate != 2) &&
        (sec->floorshade == s->floorshade) &&
        (sec->floorpal == s->floorpal) &&
        (floorpicnum == s->floorpicnum) &&
        (ceilingpicnum == s->ceilingpicnum))
        goto finish;

    i = 0;
    while (i < sec->wallnum)
    {
        //attributes
        j = 2;
        curbuffer = s->floorcolor;
        curstat = sec->floorshade;
        curxpanning = sec->floorpal;
        curpicnum = floorpicnum;
        curglpic = &s->floorglpic;
        curfbglpic = &s->floorfbglpic;

        while (j > 0)
        {
            if (j == 1)
            {
                curbuffer = s->ceilcolor;
                curstat = sec->ceilingshade;
                curxpanning = sec->ceilingpal;
                curpicnum = ceilingpicnum;
                curglpic = &s->ceilglpic;
                curfbglpic = &s->ceilfbglpic;
            }

            if (!waloff[curpicnum])
                loadtile(curpicnum);

            curbuffer[0] = curbuffer[1] = curbuffer[2] = ((float)(numpalookups-min(max(curstat,0),numpalookups)))/((float)numpalookups);
            curbuffer[3] = 1.0f;

            pth = gltexcache(curpicnum,curxpanning,0);

            if (pth && (pth->flags & 2) && (pth->palnum != curxpanning))
            {
                curbuffer[0] *= (float)hictinting[curxpanning].r / 255.0;
                curbuffer[1] *= (float)hictinting[curxpanning].g / 255.0;
                curbuffer[2] *= (float)hictinting[curxpanning].b / 255.0;
            }

            *curglpic = (pth) ? pth->glpic : 0;

            if (pth && (pth->flags & 16))
                *curfbglpic = pth->ofb->glpic;
            else
                *curfbglpic = 0;

            j--;
        }

        i++;
    }

    s->floorshade = sec->floorshade;
    s->floorpal = sec->floorpal;
    s->floorpicnum = floorpicnum;
    s->ceilingpicnum = ceilingpicnum;

finish:

    if (needfloor)
        polymer_buildfloor(sectnum);

    if (wallinvalidate)
    {
        s->invalidid++;
        polymer_buffertoplane(s->floorbuffer, s->floorindices, s->indicescount, s->floorplane);
        polymer_buffertoplane(s->ceilbuffer, s->ceilindices, s->indicescount, s->ceilplane);
    }

    s->controlstate = 1;

    if (pr_verbosity >= 3) OSD_Printf("PR : Updated sector %i.\n", sectnum);

    return (0);
}

void PR_CALLBACK    polymer_tesserror(GLenum error)
{
    // This callback is called by the tesselator whenever it raises an error.
    if (pr_verbosity >= 1) OSD_Printf("PR : Tesselation error number %i reported : %s.\n", error, bgluErrorString(errno));
}

void PR_CALLBACK    polymer_tessedgeflag(GLenum error)
{
    // Passing an edgeflag callback forces the tesselator to output a triangle list
    UNREFERENCED_PARAMETER(error);
    return;
}

void PR_CALLBACK    polymer_tessvertex(void* vertex, void* sector)
{
    _prsector*      s;

    s = (_prsector*)sector;

    if (s->curindice >= s->indicescount)
    {
        if (pr_verbosity >= 2) OSD_Printf("PR : Indice overflow, extending the indices list... !\n");
        s->indicescount++;
        s->floorindices = realloc(s->floorindices, s->indicescount * sizeof(GLushort));
        s->ceilindices = realloc(s->ceilindices, s->indicescount * sizeof(GLushort));
    }
    s->ceilindices[s->curindice] = (int)vertex;
    s->curindice++;
}

static int          polymer_buildfloor(short sectnum)
{
    // This function tesselates the floor/ceiling of a sector and stores the triangles in a display list.
    _prsector*      s;
    sectortype      *sec;
    int             i;

    if (pr_verbosity >= 2) OSD_Printf("PR : Tesselating floor of sector %i...\n", sectnum);

    s = prsectors[sectnum];
    sec = &sector[sectnum];

    if (s == NULL)
        return (-1);

    if (s->floorindices == NULL)
    {
        s->indicescount = (sec->wallnum - 2) * 3;
        s->floorindices = calloc(s->indicescount, sizeof(GLushort));
        s->ceilindices = calloc(s->indicescount, sizeof(GLushort));
    }

    s->curindice = 0;

    bgluTessCallback(prtess, GLU_TESS_VERTEX_DATA, polymer_tessvertex);
    bgluTessCallback(prtess, GLU_TESS_EDGE_FLAG, polymer_tessedgeflag);
    bgluTessCallback(prtess, GLU_TESS_ERROR, polymer_tesserror);

    bgluTessProperty(prtess, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_POSITIVE);

    bgluTessBeginPolygon(prtess, s);
    bgluTessBeginContour(prtess);

    i = 0;
    while (i < sec->wallnum)
    {
        bgluTessVertex(prtess, s->verts + (3 * i), (void *)i);
        if ((i != (sec->wallnum - 1)) && ((sec->wallptr + i) > wall[sec->wallptr + i].point2))
        {
            bgluTessEndContour(prtess);
            bgluTessBeginContour(prtess);
        }
        i++;
    }
    bgluTessEndContour(prtess);
    bgluTessEndPolygon(prtess);

    i = 0;
    while (i < s->indicescount)
    {
        s->floorindices[s->indicescount - i - 1] = s->ceilindices[i];

        i++;
    }

    if (pr_verbosity >= 2) OSD_Printf("PR : Tesselated floor of sector %i.\n", sectnum);

    return (1);
}

static void         polymer_drawsector(short sectnum)
{
    sectortype      *sec;
    _prsector*      s;

    if (pr_verbosity >= 3) OSD_Printf("PR : Drawing sector %i...\n", sectnum);

    sec = &sector[sectnum];
    s = prsectors[sectnum];

    if (!(sec->floorstat & 1) && (mirrorfrom[depth] != -2))
        polymer_drawplane(sectnum, -2, s->floorglpic, s->floorcolor,
                          s->floorbuffer, s->floorindices, s->indicescount,
                          s->floorplane);
    if (!(sec->ceilingstat & 1) && (mirrorfrom[depth] != -1))
        polymer_drawplane(sectnum, -1, s->ceilglpic, s->ceilcolor,
                          s->ceilbuffer, s->ceilindices, s->indicescount,
                          s->ceilplane);

    if (pr_verbosity >= 3) OSD_Printf("PR : Finished drawing sector %i...\n", sectnum);
}

// WALLS
static int          polymer_initwall(short wallnum)
{
    _prwall         *w;

    if (pr_verbosity >= 2) OSD_Printf("PR : Initalizing wall %i...\n", wallnum);

    w = calloc(1, sizeof(_prwall));
    if (w == NULL)
    {
        if (pr_verbosity >= 1) OSD_Printf("PR : Cannot initialize wall %i : malloc failed.\n", wallnum);
        return (0);
    }

    if (w->portal == NULL)
        w->portal = calloc(4, sizeof(GLfloat) * 5);
    if (w->bigportal == NULL)
        w->bigportal = calloc(4, sizeof(GLfloat) * 3);
    if (w->cap == NULL)
        w->cap = calloc(4, sizeof(GLfloat) * 3);

    w->controlstate = 2;

    prwalls[wallnum] = w;

    if (pr_verbosity >= 2) OSD_Printf("PR : Initalized wall %i.\n", wallnum);

    return (1);
}

static void         polymer_updatewall(short wallnum)
{
    short           nwallnum, nnwallnum, curpicnum, wallpicnum, walloverpicnum, nwallpicnum;
    char            curxpanning, curypanning, underwall, overwall;
    walltype        *wal;
    sectortype      *sec, *nsec;
    _prwall         *w;
    _prsector       *s, *ns;
    pthtyp*         pth;
    int             xref, yref;
    float           ypancoef, dist;
    int             i;
    unsigned int    invalid;

    // yes, this function is messy and unefficient
    // it also works, bitches
    wal = &wall[wallnum];
    nwallnum = wal->nextwall;
    sec = &sector[sectorofwall(wallnum)];
    w = prwalls[wallnum];
    s = prsectors[sectorofwall(wallnum)];
    invalid = s->invalidid;
    if (nwallnum != -1)
    {
        ns = prsectors[wal->nextsector];
        invalid += ns->invalidid;
        nsec = &sector[wal->nextsector];
    }
    else
    {
        ns = NULL;
        nsec = NULL;
    }

    if (w->wallbuffer == NULL)
        w->wallbuffer = calloc(4, sizeof(GLfloat) * 5);

    wallpicnum = wal->picnum;
    if (picanm[wallpicnum]&192) wallpicnum += animateoffs(wallpicnum,wallnum+16384);
    walloverpicnum = wal->overpicnum;
    if (picanm[walloverpicnum]&192) walloverpicnum += animateoffs(walloverpicnum,wallnum+16384);
    if (nwallnum != -1)
    {
        nwallpicnum = wall[nwallnum].picnum;
        if (picanm[nwallpicnum]&192) nwallpicnum += animateoffs(nwallpicnum,wallnum+16384);
    }
    else
        nwallpicnum = 0;

    if ((w->controlstate != 2) &&
        (w->invalidid == invalid) &&
        (wal->cstat == w->cstat) &&
        (wallpicnum == w->picnum) &&
        (wal->pal == w->pal) &&
        (wal->xpanning == w->xpanning) &&
        (wal->ypanning == w->ypanning) &&
        (wal->xrepeat == w->xrepeat) &&
        (wal->yrepeat == w->yrepeat) &&
        (walloverpicnum == w->overpicnum) &&
        (wal->shade == w->shade) &&
        ((nwallnum == -1) ||
        ((nwallpicnum == w->nwallpicnum) &&
         (wall[nwallnum].xpanning == w->nwallxpanning) &&
         (wall[nwallnum].ypanning == w->nwallypanning) &&
         (wall[nwallnum].cstat == w->nwallcstat))))
    {
        w->controlstate = 1;
        return; // screw you guys I'm going home
    }
    else
    {
        w->invalidid = invalid;
        w->cstat = wal->cstat;
        w->picnum = wallpicnum;
        w->pal = wal->pal;
        w->xpanning = wal->xpanning;
        w->ypanning = wal->ypanning;
        w->xrepeat = wal->xrepeat;
        w->yrepeat = wal->yrepeat;
        w->overpicnum = walloverpicnum;
        w->shade = wal->shade;
        if (nwallnum != -1)
        {
            w->nwallpicnum = nwallpicnum;
            w->nwallxpanning = wall[nwallnum].xpanning;
            w->nwallypanning = wall[nwallnum].ypanning;
            w->nwallcstat = wall[nwallnum].cstat;
        }
    }

    w->underover = underwall = overwall = 0;

    w->wallcolor[0] = w->wallcolor[1] = w->wallcolor[2] = ((float)(numpalookups-min(max(wal->shade,0),numpalookups)))/((float)numpalookups);
    w->wallcolor[3] = 1.0f;

    if (wal->cstat & 8)
        xref = 1;
    else
        xref = 0;

    if ((wal->nextsector == -1) || (wal->cstat & 32))
    {
        memcpy(w->wallbuffer, &s->floorbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);
        memcpy(&w->wallbuffer[5], &s->floorbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
        memcpy(&w->wallbuffer[10], &s->ceilbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
        memcpy(&w->wallbuffer[15], &s->ceilbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);

        curpicnum = wallpicnum;

        if (!waloff[curpicnum])
            loadtile(curpicnum);

        pth = gltexcache(curpicnum, wal->pal, 0);
        w->wallglpic = pth ? pth->glpic : 0;

        if (pth && (pth->flags & 16))
            w->wallfbglpic = pth->ofb->glpic;
        else
            w->wallfbglpic = 0;

        if (pth && (pth->flags & 2) && (pth->palnum != wal->pal))
        {
            w->wallcolor[0] *= (float)hictinting[wal->pal].r / 255.0;
            w->wallcolor[1] *= (float)hictinting[wal->pal].g / 255.0;
            w->wallcolor[2] *= (float)hictinting[wal->pal].b / 255.0;
        }

        if (wal->cstat & 4)
            yref = sec->floorz;
        else
            yref = sec->ceilingz;

        if ((wal->cstat & 32) && (wal->nextsector != -1))
        {
            if ((!(wal->cstat & 2) && (wal->cstat & 4)) || ((wal->cstat & 2) && (wall[nwallnum].cstat & 4)))
                yref = sec->ceilingz;
            else
                yref = nsec->floorz;
        }

        if (wal->ypanning)
        {
            ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
            if (ypancoef < tilesizy[curpicnum])
                ypancoef *= 2;
            ypancoef *= (float)(wal->ypanning) / (256.0f * (float)(tilesizy[curpicnum]));
        }
        else
            ypancoef = 0;

        i = 0;
        while (i < 4)
        {
            if ((i == 0) || (i == 3))
                dist = xref;
            else
                dist = (xref == 0);

            w->wallbuffer[(i * 5) + 3] = ((dist * 8.0f * wal->xrepeat) + wal->xpanning) / (float)(tilesizx[curpicnum]);
            w->wallbuffer[(i * 5) + 4] = (-(float)(yref + (w->wallbuffer[(i * 5) + 1] * 16)) / ((tilesizy[curpicnum] * 2048.0f) / (float)(wal->yrepeat))) + ypancoef;

            if (wal->cstat & 256) w->wallbuffer[(i * 5) + 4] = -w->wallbuffer[(i * 5) + 4];

            i++;
        }

        w->underover |= 1;
    }
    else
    {
        nnwallnum = wall[nwallnum].point2;

        if (((s->floorbuffer[((wallnum - sec->wallptr) * 5) + 1] != ns->floorbuffer[((nnwallnum - nsec->wallptr) * 5) + 1]) ||
             (s->floorbuffer[((wal->point2 - sec->wallptr) * 5) + 1] != ns->floorbuffer[((nwallnum - nsec->wallptr) * 5) + 1])) &&
            ((s->floorbuffer[((wallnum - sec->wallptr) * 5) + 1] <= ns->floorbuffer[((nnwallnum - nsec->wallptr) * 5) + 1]) ||
             (s->floorbuffer[((wal->point2 - sec->wallptr) * 5) + 1] <= ns->floorbuffer[((nwallnum - nsec->wallptr) * 5) + 1])))
            underwall = 1;

        if ((underwall) || (wal->cstat & 16))
        {
            memcpy(w->wallbuffer, &s->floorbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);
            memcpy(&w->wallbuffer[5], &s->floorbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
            memcpy(&w->wallbuffer[10], &ns->floorbuffer[(nwallnum - nsec->wallptr) * 5], sizeof(GLfloat) * 3);
            memcpy(&w->wallbuffer[15], &ns->floorbuffer[(nnwallnum - nsec->wallptr) * 5], sizeof(GLfloat) * 3);

            if (wal->cstat & 2)
            {
                curpicnum = nwallpicnum;
                curxpanning = wall[nwallnum].xpanning;
                curypanning = wall[nwallnum].ypanning;
            }
            else
            {
                curpicnum = wallpicnum;
                curxpanning = wal->xpanning;
                curypanning = wal->ypanning;
            }

            if (!waloff[curpicnum])
                loadtile(curpicnum);

            pth = gltexcache(curpicnum, wal->pal, 0);
            w->wallglpic = pth ? pth->glpic : 0;

            if (pth && (pth->flags & 16))
                w->wallfbglpic = pth->ofb->glpic;
            else
                w->wallfbglpic = 0;

            if (pth && (pth->flags & 2) && (pth->palnum != wal->pal))
            {
                w->wallcolor[0] *= (float)hictinting[wal->pal].r / 255.0;
                w->wallcolor[1] *= (float)hictinting[wal->pal].g / 255.0;
                w->wallcolor[2] *= (float)hictinting[wal->pal].b / 255.0;
            }

            if ((!(wal->cstat & 2) && (wal->cstat & 4)) || ((wal->cstat & 2) && (wall[nwallnum].cstat & 4)))
                yref = sec->ceilingz;
            else
                yref = nsec->floorz;

            if (curypanning)
            {
                ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
                if (ypancoef < tilesizy[curpicnum])
                    ypancoef *= 2;
                ypancoef *= (float)(curypanning) / (256.0f * (float)(tilesizy[curpicnum]));
            }
            else
                ypancoef = 0;

            i = 0;
            while (i < 4)
            {
                if ((i == 0) || (i == 3))
                    dist = xref;
                else
                    dist = (xref == 0);

                w->wallbuffer[(i * 5) + 3] = ((dist * 8.0f * wal->xrepeat) + curxpanning) / (float)(tilesizx[curpicnum]);
                w->wallbuffer[(i * 5) + 4] = (-(float)(yref + (w->wallbuffer[(i * 5) + 1] * 16)) / ((tilesizy[curpicnum] * 2048.0f) / (float)(wal->yrepeat))) + ypancoef;

                if (wal->cstat & 256) w->wallbuffer[(i * 5) + 4] = -w->wallbuffer[(i * 5) + 4];

                i++;
            }

            if (underwall)
            {
                w->underover |= 1;
                if ((sec->floorstat & 1) && (nsec->floorstat & 1))
                    w->underover |= 4;
            }
            memcpy(w->portal, &w->wallbuffer[15], sizeof(GLfloat) * 5);
            memcpy(&w->portal[5], &w->wallbuffer[10], sizeof(GLfloat) * 5);
        }
        else
        {
            memcpy(w->portal, &s->floorbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 5);
            memcpy(&w->portal[5], &s->floorbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 5);
        }

        if (((s->ceilbuffer[((wallnum - sec->wallptr) * 5) + 1] != ns->ceilbuffer[((nnwallnum - nsec->wallptr) * 5) + 1]) ||
             (s->ceilbuffer[((wal->point2 - sec->wallptr) * 5) + 1] != ns->ceilbuffer[((nwallnum - nsec->wallptr) * 5) + 1])) &&
            ((s->ceilbuffer[((wallnum - sec->wallptr) * 5) + 1] >= ns->ceilbuffer[((nnwallnum - nsec->wallptr) * 5) + 1]) ||
             (s->ceilbuffer[((wal->point2 - sec->wallptr) * 5) + 1] >= ns->ceilbuffer[((nwallnum - nsec->wallptr) * 5) + 1])))
            overwall = 1;

        if ((overwall) || (wal->cstat & 16))
        {
            if (w->overbuffer == NULL)
                w->overbuffer = calloc(4, sizeof(GLfloat) * 5);

            memcpy(w->overbuffer, &ns->ceilbuffer[(nnwallnum - nsec->wallptr) * 5], sizeof(GLfloat) * 3);
            memcpy(&w->overbuffer[5], &ns->ceilbuffer[(nwallnum - nsec->wallptr) * 5], sizeof(GLfloat) * 3);
            memcpy(&w->overbuffer[10], &s->ceilbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
            memcpy(&w->overbuffer[15], &s->ceilbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);

            if ((wal->cstat & 16) || (wal->overpicnum == 0))
                curpicnum = wallpicnum;
            else
                curpicnum = wallpicnum;

            if (!waloff[curpicnum])
                loadtile(curpicnum);

            if (wal->cstat & 16)
            {
                // mask glpic and color
                if (!waloff[wal->overpicnum])
                    loadtile(wal->overpicnum);

                pth = gltexcache(wal->overpicnum, wal->pal, 0);
                w->maskglpic = pth ? pth->glpic : 0;

                memcpy(w->maskcolor, w->wallcolor, sizeof(GLfloat) * 3);

                if (pth && (pth->flags & 2) && (pth->palnum != wal->pal))
                {
                    w->maskcolor[0] *= (float)hictinting[wal->pal].r / 255.0;
                    w->maskcolor[1] *= (float)hictinting[wal->pal].g / 255.0;
                    w->maskcolor[2] *= (float)hictinting[wal->pal].b / 255.0;
                }
                if (wal->cstat & 128)
                {
                    if (wal->cstat & 512)
                        w->maskcolor[3] = 0.33f;
                    else
                        w->maskcolor[3] = 0.66f;
                }
                else
                    w->maskcolor[3] = 1.0f;
            }

            pth = gltexcache(curpicnum, wal->pal, 0);
            w->overglpic = pth ? pth->glpic : 0;

            if (pth && (pth->flags & 16))
                w->overfbglpic = pth->ofb->glpic;
            else
                w->overfbglpic = 0;

            memcpy(w->overcolor, w->wallcolor, sizeof(GLfloat) * 4);

            if (pth && (pth->flags & 2) && (pth->palnum != wal->pal))
            {
                w->overcolor[0] *= (float)hictinting[wal->pal].r / 255.0;
                w->overcolor[1] *= (float)hictinting[wal->pal].g / 255.0;
                w->overcolor[2] *= (float)hictinting[wal->pal].b / 255.0;
            }

            if (wal->cstat & 4)
                yref = sec->ceilingz;
            else
                yref = nsec->ceilingz;

            if (wal->ypanning)
            {
                ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
                if (ypancoef < tilesizy[curpicnum])
                    ypancoef *= 2;
                ypancoef *= (float)(wal->ypanning) / (256.0f * (float)(tilesizy[curpicnum]));
            }
            else
                ypancoef = 0;

            i = 0;
            while (i < 4)
            {
                if ((i == 0) || (i == 3))
                    dist = xref;
                else
                    dist = (xref == 0);

                w->overbuffer[(i * 5) + 3] = ((dist * 8.0f * wal->xrepeat) + wal->xpanning) / (float)(tilesizx[curpicnum]);
                w->overbuffer[(i * 5) + 4] = (-(float)(yref + (w->overbuffer[(i * 5) + 1] * 16)) / ((tilesizy[curpicnum] * 2048.0f) / (float)(wal->yrepeat))) + ypancoef;

                if (wal->cstat & 256) w->overbuffer[(i * 5) + 4] = -w->overbuffer[(i * 5) + 4];

                i++;
            }

            if (overwall)
            {
                w->underover |= 2;
                if ((sec->ceilingstat & 1) && (nsec->ceilingstat & 1))
                    w->underover |= 8;
            }
            memcpy(&w->portal[10], &w->overbuffer[5], sizeof(GLfloat) * 5);
            memcpy(&w->portal[15], &w->overbuffer[0], sizeof(GLfloat) * 5);

            if (wal->cstat & 16)
            {
                // mask wall pass
                if (wal->cstat & 4)
                    yref = min(sec->floorz, nsec->floorz);
                else
                    yref = max(sec->ceilingz, nsec->ceilingz);

                curpicnum = wal->overpicnum;

                if (wal->ypanning)
                {
                    ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
                    if (ypancoef < tilesizy[curpicnum])
                        ypancoef *= 2;
                    ypancoef *= (float)(wal->ypanning) / (256.0f * (float)(tilesizy[curpicnum]));
                }
                else
                    ypancoef = 0;

                i = 0;
                while (i < 4)
                {
                    if ((i == 0) || (i == 3))
                        dist = xref;
                    else
                        dist = (xref == 0);

                    w->portal[(i * 5) + 3] = ((dist * 8.0f * wal->xrepeat) + wal->xpanning) / (float)(tilesizx[curpicnum]);
                    w->portal[(i * 5) + 4] = (-(float)(yref + (w->portal[(i * 5) + 1] * 16)) / ((tilesizy[curpicnum] * 2048.0f) / (float)(wal->yrepeat))) + ypancoef;

                    if (wal->cstat & 256) w->portal[(i * 5) + 4] = -w->portal[(i * 5) + 4];

                    i++;
                }
            }
        }
        else
        {
            memcpy(&w->portal[10], &s->ceilbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 5);
            memcpy(&w->portal[15], &s->ceilbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 5);
        }
    }

    if ((wal->nextsector == -1) || (wal->cstat & 32))
        memcpy(w->portal, w->wallbuffer, sizeof(GLfloat) * 4 * 5);

    memcpy(w->bigportal, &s->floorbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);
    memcpy(&w->bigportal[3], &s->floorbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
    memcpy(&w->bigportal[6], &s->ceilbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
    memcpy(&w->bigportal[9], &s->ceilbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);

    memcpy(&w->cap[0], &s->ceilbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);
    memcpy(&w->cap[3], &s->ceilbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
    memcpy(&w->cap[6], &s->ceilbuffer[(wal->point2 - sec->wallptr) * 5], sizeof(GLfloat) * 3);
    memcpy(&w->cap[9], &s->ceilbuffer[(wallnum - sec->wallptr) * 5], sizeof(GLfloat) * 3);
    w->cap[7] += 1048576; // this number is the result of 1048574 + 2
    w->cap[10] += 1048576; // this one is arbitrary

    polymer_buffertoplane(w->bigportal, NULL, 4, w->plane);

    w->controlstate = 1;

    if (pr_verbosity >= 3) OSD_Printf("PR : Updated wall %i.\n", wallnum);
}

static void         polymer_drawwall(short sectnum, short wallnum)
{
    _prwall         *w;

    if (pr_verbosity >= 3) OSD_Printf("PR : Drawing wall %i...\n", wallnum);

    w = prwalls[wallnum];

    if ((w->underover & 1) && !(w->underover & 4))
    {
        polymer_drawplane(sectnum, wallnum, w->wallglpic, w->wallcolor,
                          w->wallbuffer, NULL, 0, w->plane);
    }

    if ((w->underover & 2) && !(w->underover & 8))
    {
        polymer_drawplane(sectnum, wallnum, w->overglpic, w->overcolor,
                          w->overbuffer, NULL, 0, w->plane);
    }

    if ((sector[sectnum].ceilingstat & 1) &&
         ((wall[wallnum].nextsector == -1) ||
         !(sector[wall[wallnum].nextsector].ceilingstat & 1)))
    {
        bglColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
        bglVertexPointer(3, GL_FLOAT, 0, w->cap);
        bglDrawArrays(GL_QUADS, 0, 4);
        bglColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    }

    if (pr_verbosity >= 3) OSD_Printf("PR : Finished drawing wall %i...\n", wallnum);
}

#define INDICE(n) ((indices) ? (indices[i+n]*5) : ((i+n)*3))

// HSR
static void         polymer_buffertoplane(GLfloat* buffer, GLushort* indices, int indicecount, GLdouble* plane)
{
    GLfloat         vec1[3], vec2[3];
    int             i;

    i = 0;
    do {
        vec1[0] = buffer[(INDICE(1)) + 0] - buffer[(INDICE(0)) + 0];
        vec1[1] = buffer[(INDICE(1)) + 1] - buffer[(INDICE(0)) + 1];
        vec1[2] = buffer[(INDICE(1)) + 2] - buffer[(INDICE(0)) + 2];

        vec2[0] = buffer[(INDICE(2)) + 0] - buffer[(INDICE(1)) + 0];
        vec2[1] = buffer[(INDICE(2)) + 1] - buffer[(INDICE(1)) + 1];
        vec2[2] = buffer[(INDICE(2)) + 2] - buffer[(INDICE(1)) + 2];

        polymer_crossproduct(vec2, vec1, plane);

        // normalize
        vec1[0] = plane[0] * plane[0] + plane[1] * plane[1] + plane[2] * plane[2];
        i+= 3;
    }
    while ((i < indicecount) && (vec1[0] == 0));

    vec1[0] = sqrt(vec1[0]);
    plane[0] /= vec1[0];
    plane[1] /= vec1[0];
    plane[2] /= vec1[0];

    plane[3] = -(plane[0] * buffer[0] + plane[1] * buffer[1] + plane[2] * buffer[2]);
}

static void         polymer_crossproduct(GLfloat* in_a, GLfloat* in_b, GLdouble* out)
{
    out[0] = in_a[1] * in_b[2] - in_a[2] * in_b[1];
    out[1] = in_a[2] * in_b[0] - in_a[0] * in_b[2];
    out[2] = in_a[0] * in_b[1] - in_a[1] * in_b[0];
}

static void         polymer_pokesector(short sectnum)
{
    sectortype      *sec;
    _prsector       *s;
    walltype        *wal;
    int             i;

    sec = &sector[sectnum];
    s = prsectors[sectnum];
    wal = &wall[sec->wallptr];

    if (!s->controlstate)
        polymer_updatesector(sectnum);

    i = 0;
    while (i < sec->wallnum)
    {
        if ((wal->nextsector != -1) && (!prsectors[wal->nextsector]->controlstate))
            polymer_updatesector(wal->nextsector);
        if (!prwalls[sec->wallptr + i]->controlstate)
            polymer_updatewall(sec->wallptr + i);

        i++;
        wal = &wall[sec->wallptr + i];
    }
}

static void         polymer_extractfrustum(GLdouble* modelview, GLdouble* projection, float* frustum)
{
    GLdouble        matrix[16];
    int             i;

    bglMatrixMode(GL_TEXTURE);
    bglLoadMatrixd(projection);
    bglMultMatrixd(modelview);
    bglGetDoublev(GL_TEXTURE_MATRIX, matrix);
    bglLoadIdentity();
    bglMatrixMode(GL_MODELVIEW);

    i = 0;
    while (i < 4)
    {
        frustum[i] = matrix[(4 * i) + 3] + matrix[4 * i];               // left
        frustum[i + 4] = matrix[(4 * i) + 3] - matrix[4 * i];           // right
        frustum[i + 8] = matrix[(4 * i) + 3] - matrix[(4 * i) + 1];     // top
        frustum[i + 12] = matrix[(4 * i) + 3] + matrix[(4 * i) + 1];    // bottom
        frustum[i + 16] = matrix[(4 * i) + 3] + matrix[(4 * i) + 2];    // near
        i++;
    }
    i = 0;

    if (pr_verbosity >= 3) OSD_Printf("PR : Frustum extracted.\n");
}

static int          polymer_portalinfrustum(short wallnum, float* frustum)
{
    int             i, j, k;
    float           sqdist;
    _prwall         *w;

    w = prwalls[wallnum];

    i = 0;
    while (i < 4)
    {
        j = k = 0;
        while (j < 4)
        {
            sqdist = frustum[(i * 4) + 0] * w->bigportal[(j * 3) + 0] +
                     frustum[(i * 4) + 1] * w->bigportal[(j * 3) + 1] +
                     frustum[(i * 4) + 2] * w->bigportal[(j * 3) + 2] +
                     frustum[(i * 4) + 3];
            if (sqdist < 0)
                k++;
            j++;
        }
        if (k == 4)
            return (0); // OUT !
        i++;
    }

    return (1);
}

static void         polymer_scansprites(short sectnum, spritetype* localtsprite, int* localspritesortcnt)
{
    int             i;
    spritetype      *spr;

    for (i = headspritesect[sectnum];i >=0;i = nextspritesect[i])
    {
        spr = &sprite[i];
        if ((((spr->cstat&0x8000) == 0) || (showinvisibility)) &&
               (spr->xrepeat > 0) && (spr->yrepeat > 0) &&
               (*localspritesortcnt < MAXSPRITESONSCREEN))
        {
            copybufbyte(spr,&localtsprite[*localspritesortcnt],sizeof(spritetype));
            localtsprite[(*localspritesortcnt)++].owner = i;
        }
    }
}

// SKIES
static void         polymer_initskybox(void)
{
    GLfloat         halfsqrt2 = 0.70710678f;

    skybox[0] = -1.0f;          skybox[1] = 0.0f;           // 0
    skybox[2] = -halfsqrt2;     skybox[3] = halfsqrt2;      // 1
    skybox[4] = 0.0f;           skybox[5] = 1.0f;           // 2
    skybox[6] = halfsqrt2;      skybox[7] = halfsqrt2;      // 3
    skybox[8] = 1.0f;           skybox[9] = 0.0f;           // 4
    skybox[10] = halfsqrt2;     skybox[11] = -halfsqrt2;    // 5
    skybox[12] = 0.0f;          skybox[13] = -1.0f;         // 6
    skybox[14] = -halfsqrt2;    skybox[15] = -halfsqrt2;    // 7

    /*skybox[0] = -1.0f;          skybox[1] = 0.0f;           // 0
    skybox[2] = -1.0f;          skybox[3] = 1.0;      // 1
    skybox[4] = 0.0f;           skybox[5] = 1.0f;           // 2
    skybox[6] = 1.0f;           skybox[7] = 1.0f;      // 3
    skybox[8] = 1.0f;           skybox[9] = 0.0f;           // 4
    skybox[10] = 1.0;           skybox[11] = -1.0;    // 5
    skybox[12] = 0.0f;          skybox[13] = -1.0f;         // 6
    skybox[14] = -1.0;          skybox[15] = -1.0;    // 7*/
}

static void         polymer_getsky(void)
{
    int             i;

    i = 0;
    while (i < numsectors)
    {
        if (sector[i].ceilingstat & 1)
        {
            cursky = sector[i].ceilingpicnum;
            return;
        }
        i++;
    }
}

static void         polymer_drawskyquad(int p1, int p2, GLfloat height)
{
    bglBegin(GL_QUADS);
    bglTexCoord2f(0.0f, 0.0f);
    //OSD_Printf("PR: drawing %f %f %f\n", skybox[(p1 * 2) + 1], height, skybox[p1 * 2]);
    bglVertex3f(skybox[(p1 * 2) + 1], height, skybox[p1 * 2]);
    bglTexCoord2f(0.0f, 1.0f);
    //OSD_Printf("PR: drawing %f %f %f\n", skybox[(p1 * 2) + 1], -height, skybox[p1 * 2]);
    bglVertex3f(skybox[(p1 * 2) + 1], -height, skybox[p1 * 2]);
    bglTexCoord2f(1.0f, 1.0f);
    //OSD_Printf("PR: drawing %f %f %f\n", skybox[(p2 * 2) + 1], -height, skybox[p2 * 2]);
    bglVertex3f(skybox[(p2 * 2) + 1], -height, skybox[p2 * 2]);
    bglTexCoord2f(1.0f, 0.0f);
    //OSD_Printf("PR: drawing %f %f %f\n", skybox[(p2 * 2) + 1], height, skybox[p2 * 2]);
    bglVertex3f(skybox[(p2 * 2) + 1], height, skybox[p2 * 2]);
    bglEnd();
}

static void         polymer_drawartsky(short tilenum)
{
    pthtyp*         pth;
    GLuint          glpics[5];
    int             i, j;
    GLfloat         height = 2.45f / 2.0f;

    i = 0;
    while (i < 5)
    {
        if (!waloff[tilenum + i])
            loadtile(tilenum + i);
        pth = gltexcache(tilenum + i, 0, 0);
        glpics[i] = pth ? pth->glpic : 0;
        i++;
    }

    i = 0;
    j = (1<<pskybits);
    while (i < j)
    {
        bglBindTexture(GL_TEXTURE_2D, glpics[pskyoff[i]]);
        polymer_drawskyquad(i, (i + 1) & (j - 1), height);
        i++;
    }
}
#endif