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1 /*
2 Copyright (C) 1996-1997 Id Software, Inc.
3 
4 This program is free software; you can redistribute it and/or
5 modify it under the terms of the GNU General Public License
6 as published by the Free Software Foundation; either version 2
7 of the License, or (at your option) any later version.
8 
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 
13 See the GNU General Public License for more details.
14 
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
18 
19 */
20 // gl_warp.c -- sky and water polygons
21 
22 #include "quakedef.h"
23 
24 extern  model_t *loadmodel;
25 
26 //int       skytexturenum;
27 
28 int     solidskytexture;
29 int     alphaskytexture;
30 float   speedscale;     // for top sky and bottom sky
31 
32 msurface_t  *warpface;
33 
34 extern cvar_t gl_subdivide_size;
35 
BoundPoly(int numverts,float * verts,vec3_t mins,vec3_t maxs)36 void BoundPoly (int numverts, float *verts, vec3_t mins, vec3_t maxs)
37 {
38     int     i, j;
39     float   *v;
40 
41     mins[0] = mins[1] = mins[2] = 9999;
42     maxs[0] = maxs[1] = maxs[2] = -9999;
43     v = verts;
44     for (i=0 ; i<numverts ; i++)
45         for (j=0 ; j<3 ; j++, v++)
46         {
47             if (*v < mins[j])
48                 mins[j] = *v;
49             if (*v > maxs[j])
50                 maxs[j] = *v;
51         }
52 }
53 
SubdividePolygon(int numverts,float * verts)54 void SubdividePolygon (int numverts, float *verts)
55 {
56     int     i, j, k;
57     vec3_t  mins, maxs;
58     float   m;
59     float   *v;
60     vec3_t  front[64], back[64];
61     int     f, b;
62     float   dist[64];
63     float   frac;
64     glpoly_t    *poly;
65     float   s, t;
66 
67     if (numverts > 60)
68         Sys_Error ("numverts = %i", numverts);
69 
70     BoundPoly (numverts, verts, mins, maxs);
71 
72     for (i=0 ; i<3 ; i++)
73     {
74         m = (mins[i] + maxs[i]) * 0.5;
75         m = gl_subdivide_size.value * floor (m/gl_subdivide_size.value + 0.5);
76         if (maxs[i] - m < 8)
77             continue;
78         if (m - mins[i] < 8)
79             continue;
80 
81         // cut it
82         v = verts + i;
83         for (j=0 ; j<numverts ; j++, v+= 3)
84             dist[j] = *v - m;
85 
86         // wrap cases
87         dist[j] = dist[0];
88         v-=i;
89         VectorCopy (verts, v);
90 
91         f = b = 0;
92         v = verts;
93         for (j=0 ; j<numverts ; j++, v+= 3)
94         {
95             if (dist[j] >= 0)
96             {
97                 VectorCopy (v, front[f]);
98                 f++;
99             }
100             if (dist[j] <= 0)
101             {
102                 VectorCopy (v, back[b]);
103                 b++;
104             }
105             if (dist[j] == 0 || dist[j+1] == 0)
106                 continue;
107             if ( (dist[j] > 0) != (dist[j+1] > 0) )
108             {
109                 // clip point
110                 frac = dist[j] / (dist[j] - dist[j+1]);
111                 for (k=0 ; k<3 ; k++)
112                     front[f][k] = back[b][k] = v[k] + frac*(v[3+k] - v[k]);
113                 f++;
114                 b++;
115             }
116         }
117 
118         SubdividePolygon (f, front[0]);
119         SubdividePolygon (b, back[0]);
120         return;
121     }
122 
123     poly = (glpoly_t*) Hunk_Alloc (sizeof(glpoly_t) + (numverts-4) * VERTEXSIZE*sizeof(float));
124     poly->next = warpface->polys;
125     warpface->polys = poly;
126     poly->numverts = numverts;
127     for (i=0 ; i<numverts ; i++, verts+= 3)
128     {
129         VectorCopy (verts, poly->verts[i]);
130         s = DotProduct (verts, warpface->texinfo->vecs[0]);
131         t = DotProduct (verts, warpface->texinfo->vecs[1]);
132         poly->verts[i][3] = s;
133         poly->verts[i][4] = t;
134     }
135 }
136 
137 /*
138 ================
139 GL_SubdivideSurface
140 
141 Breaks a polygon up along axial 64 unit
142 boundaries so that turbulent and sky warps
143 can be done reasonably.
144 ================
145 */
GL_SubdivideSurface(msurface_t * fa)146 void GL_SubdivideSurface (msurface_t *fa)
147 {
148     vec3_t      verts[64];
149     int         numverts;
150     int         i;
151     int         lindex;
152     float       *vec;
153     texture_t   *t;
154 
155     warpface = fa;
156 
157     //
158     // convert edges back to a normal polygon
159     //
160     numverts = 0;
161     for (i=0 ; i<fa->numedges ; i++)
162     {
163         lindex = loadmodel->surfedges[fa->firstedge + i];
164 
165         if (lindex > 0)
166             vec = loadmodel->vertexes[loadmodel->edges[lindex].v[0]].position;
167         else
168             vec = loadmodel->vertexes[loadmodel->edges[-lindex].v[1]].position;
169         VectorCopy (vec, verts[numverts]);
170         numverts++;
171     }
172 
173     SubdividePolygon (numverts, verts[0]);
174 }
175 
176 //=========================================================
177 
178 
179 
180 // speed up sin calculations - Ed
181 float   turbsin[] =
182 {
183     #include "gl_warp_sin.h"
184 };
185 #define TURBSCALE (256.0 / (2 * M_PI))
186 
187 /*
188 =============
189 EmitWaterPolys
190 
191 Does a water warp on the pre-fragmented glpoly_t chain
192 =============
193 */
EmitWaterPolys(msurface_t * fa)194 void EmitWaterPolys (msurface_t *fa)
195 {
196     glpoly_t    *p;
197     float       *v;
198     int         i;
199     float       s, t, os, ot;
200 
201 
202     for (p=fa->polys ; p ; p=p->next)
203     {
204 #ifdef USE_OPENGLES
205         {
206             float* pUV = gTexCoordBuffer;
207             for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
208             {
209                 os = v[3];
210                 ot = v[4];
211 
212                 s = os + turbsin[(int)((ot*0.125+realtime) * TURBSCALE) & 255];
213                 s *= (1.0/64);
214 
215                 t = ot + turbsin[(int)((os*0.125+realtime) * TURBSCALE) & 255];
216                 t *= (1.0/64);
217 
218                 *pUV++ = s;
219                 *pUV++ = t;
220             }
221         }
222 
223         glVertexPointer(3, GL_FLOAT, VERTEXSIZE*sizeof(float), &p->verts[0][0]);
224         glTexCoordPointer(2, GL_FLOAT, 0, gTexCoordBuffer);
225         glDrawArrays(GL_TRIANGLE_FAN, 0, p->numverts);
226 #else
227         glBegin (GL_POLYGON);
228         for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
229         {
230             os = v[3];
231             ot = v[4];
232 
233             s = os + turbsin[(int)((ot*0.125+realtime) * TURBSCALE) & 255];
234             s *= (1.0/64);
235 
236             t = ot + turbsin[(int)((os*0.125+realtime) * TURBSCALE) & 255];
237             t *= (1.0/64);
238 
239             glTexCoord2f (s, t);
240             glVertex3fv (v);
241         }
242         glEnd ();
243 #endif
244     }
245 }
246 
247 
248 
249 
250 /*
251 =============
252 EmitSkyPolys
253 =============
254 */
EmitSkyPolys(msurface_t * fa)255 void EmitSkyPolys (msurface_t *fa)
256 {
257     glpoly_t    *p;
258     float       *v;
259     int         i;
260     float   s, t;
261     vec3_t  dir;
262     float   length;
263 
264     for (p=fa->polys ; p ; p=p->next)
265     {
266 #ifdef USE_OPENGLES
267         {
268             float* pUV = gTexCoordBuffer;
269             for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
270             {
271                 VectorSubtract (v, r_origin, dir);
272                 dir[2] *= 3;    // flatten the sphere
273 
274                 length = dir[0]*dir[0] + dir[1]*dir[1] + dir[2]*dir[2];
275                 length = sqrt (length);
276                 length = 6*63/length;
277 
278                 dir[0] *= length;
279                 dir[1] *= length;
280 
281                 s = (speedscale + dir[0]) * (1.0/128);
282                 t = (speedscale + dir[1]) * (1.0/128);
283 
284                 *pUV++ = s;
285                 *pUV++ = t;
286             }
287         }
288 
289         glVertexPointer(3, GL_FLOAT, VERTEXSIZE*sizeof(float), &p->verts[0][0]);
290         glTexCoordPointer(2, GL_FLOAT, 0, gTexCoordBuffer);
291         glDrawArrays(GL_TRIANGLE_FAN, 0, p->numverts);
292 #else
293         glBegin (GL_POLYGON);
294         for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
295         {
296             VectorSubtract (v, r_origin, dir);
297             dir[2] *= 3;    // flatten the sphere
298 
299             length = dir[0]*dir[0] + dir[1]*dir[1] + dir[2]*dir[2];
300             length = sqrt (length);
301             length = 6*63/length;
302 
303             dir[0] *= length;
304             dir[1] *= length;
305 
306             s = (speedscale + dir[0]) * (1.0/128);
307             t = (speedscale + dir[1]) * (1.0/128);
308 
309             glTexCoord2f (s, t);
310             glVertex3fv (v);
311         }
312         glEnd ();
313 #endif
314     }
315 }
316 
317 /*
318 ===============
319 EmitBothSkyLayers
320 
321 Does a sky warp on the pre-fragmented glpoly_t chain
322 This will be called for brushmodels, the world
323 will have them chained together.
324 ===============
325 */
EmitBothSkyLayers(msurface_t * fa)326 void EmitBothSkyLayers (msurface_t *fa)
327 {
328     int         i;
329     int         lindex;
330     float       *vec;
331 
332     GL_DisableMultitexture();
333 
334     GL_Bind (solidskytexture);
335     speedscale = realtime*8;
336     speedscale -= (int)speedscale & ~127 ;
337 
338     EmitSkyPolys (fa);
339 
340     glEnable (GL_BLEND);
341     GL_Bind (alphaskytexture);
342     speedscale = realtime*16;
343     speedscale -= (int)speedscale & ~127 ;
344 
345     EmitSkyPolys (fa);
346 
347     glDisable (GL_BLEND);
348 }
349 
350 #ifndef QUAKE2
351 /*
352 =================
353 R_DrawSkyChain
354 =================
355 */
R_DrawSkyChain(msurface_t * s)356 void R_DrawSkyChain (msurface_t *s)
357 {
358     msurface_t  *fa;
359 
360     GL_DisableMultitexture();
361 
362     // used when gl_texsort is on
363     GL_Bind(solidskytexture);
364     speedscale = realtime*8;
365     speedscale -= (int)speedscale & ~127 ;
366 
367     for (fa=s ; fa ; fa=fa->texturechain)
368         EmitSkyPolys (fa);
369 
370     glEnable (GL_BLEND);
371     GL_Bind (alphaskytexture);
372     speedscale = realtime*16;
373     speedscale -= (int)speedscale & ~127 ;
374 
375     for (fa=s ; fa ; fa=fa->texturechain)
376         EmitSkyPolys (fa);
377 
378     glDisable (GL_BLEND);
379 }
380 
381 #endif
382 
383 /*
384 =================================================================
385 
386   Quake 2 environment sky
387 
388 =================================================================
389 */
390 
391 #ifdef QUAKE2
392 
393 
394 #define SKY_TEX     2000
395 
396 /*
397 =================================================================
398 
399   PCX Loading
400 
401 =================================================================
402 */
403 
404 typedef struct
405 {
406     char    manufacturer;
407     char    version;
408     char    encoding;
409     char    bits_per_pixel;
410     unsigned short  xmin,ymin,xmax,ymax;
411     unsigned short  hres,vres;
412     unsigned char   palette[48];
413     char    reserved;
414     char    color_planes;
415     unsigned short  bytes_per_line;
416     unsigned short  palette_type;
417     char    filler[58];
418     unsigned    data;           // unbounded
419 } pcx_t;
420 
421 byte    *pcx_rgb;
422 
423 /*
424 ============
425 LoadPCX
426 ============
427 */
LoadPCX(FILE * f)428 void LoadPCX (FILE *f)
429 {
430     pcx_t   *pcx, pcxbuf;
431     byte    palette[768];
432     byte    *pix;
433     int     x, y;
434     int     dataByte, runLength;
435     int     count;
436 
437 //
438 // parse the PCX file
439 //
440     fread (&pcxbuf, 1, sizeof(pcxbuf), f);
441 
442     pcx = &pcxbuf;
443 
444     if (pcx->manufacturer != 0x0a
445         || pcx->version != 5
446         || pcx->encoding != 1
447         || pcx->bits_per_pixel != 8
448         || pcx->xmax >= 320
449         || pcx->ymax >= 256)
450     {
451         Con_Printf ("Bad pcx file\n");
452         return;
453     }
454 
455     // seek to palette
456     fseek (f, -768, SEEK_END);
457     fread (palette, 1, 768, f);
458 
459     fseek (f, sizeof(pcxbuf) - 4, SEEK_SET);
460 
461     count = (pcx->xmax+1) * (pcx->ymax+1);
462     pcx_rgb = malloc( count * 4);
463 
464     for (y=0 ; y<=pcx->ymax ; y++)
465     {
466         pix = pcx_rgb + 4*y*(pcx->xmax+1);
467         for (x=0 ; x<=pcx->ymax ; )
468         {
469             dataByte = fgetc(f);
470 
471             if((dataByte & 0xC0) == 0xC0)
472             {
473                 runLength = dataByte & 0x3F;
474                 dataByte = fgetc(f);
475             }
476             else
477                 runLength = 1;
478 
479             while(runLength-- > 0)
480             {
481                 pix[0] = palette[dataByte*3];
482                 pix[1] = palette[dataByte*3+1];
483                 pix[2] = palette[dataByte*3+2];
484                 pix[3] = 255;
485                 pix += 4;
486                 x++;
487             }
488         }
489     }
490 }
491 
492 /*
493 =========================================================
494 
495 TARGA LOADING
496 
497 =========================================================
498 */
499 
500 typedef struct _TargaHeader {
501     unsigned char   id_length, colormap_type, image_type;
502     unsigned short  colormap_index, colormap_length;
503     unsigned char   colormap_size;
504     unsigned short  x_origin, y_origin, width, height;
505     unsigned char   pixel_size, attributes;
506 } TargaHeader;
507 
508 
509 TargaHeader     targa_header;
510 byte            *targa_rgba;
511 
fgetLittleShort(FILE * f)512 int fgetLittleShort (FILE *f)
513 {
514     byte    b1, b2;
515 
516     b1 = fgetc(f);
517     b2 = fgetc(f);
518 
519     return (short)(b1 + b2*256);
520 }
521 
fgetLittleLong(FILE * f)522 int fgetLittleLong (FILE *f)
523 {
524     byte    b1, b2, b3, b4;
525 
526     b1 = fgetc(f);
527     b2 = fgetc(f);
528     b3 = fgetc(f);
529     b4 = fgetc(f);
530 
531     return b1 + (b2<<8) + (b3<<16) + (b4<<24);
532 }
533 
534 
535 /*
536 =============
537 LoadTGA
538 =============
539 */
LoadTGA(FILE * fin)540 void LoadTGA (FILE *fin)
541 {
542     int             columns, rows, numPixels;
543     byte            *pixbuf;
544     int             row, column;
545 
546     targa_header.id_length = fgetc(fin);
547     targa_header.colormap_type = fgetc(fin);
548     targa_header.image_type = fgetc(fin);
549 
550     targa_header.colormap_index = fgetLittleShort(fin);
551     targa_header.colormap_length = fgetLittleShort(fin);
552     targa_header.colormap_size = fgetc(fin);
553     targa_header.x_origin = fgetLittleShort(fin);
554     targa_header.y_origin = fgetLittleShort(fin);
555     targa_header.width = fgetLittleShort(fin);
556     targa_header.height = fgetLittleShort(fin);
557     targa_header.pixel_size = fgetc(fin);
558     targa_header.attributes = fgetc(fin);
559 
560     if (targa_header.image_type!=2
561         && targa_header.image_type!=10)
562         Sys_Error ("LoadTGA: Only type 2 and 10 targa RGB images supported\n");
563 
564     if (targa_header.colormap_type !=0
565         || (targa_header.pixel_size!=32 && targa_header.pixel_size!=24))
566         Sys_Error ("Texture_LoadTGA: Only 32 or 24 bit images supported (no colormaps)\n");
567 
568     columns = targa_header.width;
569     rows = targa_header.height;
570     numPixels = columns * rows;
571 
572     targa_rgba = malloc (numPixels*4);
573 
574     if (targa_header.id_length != 0)
575         fseek(fin, targa_header.id_length, SEEK_CUR);  // skip TARGA image comment
576 
577     if (targa_header.image_type==2) {  // Uncompressed, RGB images
578         for(row=rows-1; row>=0; row--) {
579             pixbuf = targa_rgba + row*columns*4;
580             for(column=0; column<columns; column++) {
581                 unsigned char red,green,blue,alphabyte;
582                 switch (targa_header.pixel_size) {
583                     case 24:
584 
585                             blue = getc(fin);
586                             green = getc(fin);
587                             red = getc(fin);
588                             *pixbuf++ = red;
589                             *pixbuf++ = green;
590                             *pixbuf++ = blue;
591                             *pixbuf++ = 255;
592                             break;
593                     case 32:
594                             blue = getc(fin);
595                             green = getc(fin);
596                             red = getc(fin);
597                             alphabyte = getc(fin);
598                             *pixbuf++ = red;
599                             *pixbuf++ = green;
600                             *pixbuf++ = blue;
601                             *pixbuf++ = alphabyte;
602                             break;
603                 }
604             }
605         }
606     }
607     else if (targa_header.image_type==10) {   // Runlength encoded RGB images
608         unsigned char red,green,blue,alphabyte,packetHeader,packetSize,j;
609         for(row=rows-1; row>=0; row--) {
610             pixbuf = targa_rgba + row*columns*4;
611             for(column=0; column<columns; ) {
612                 packetHeader=getc(fin);
613                 packetSize = 1 + (packetHeader & 0x7f);
614                 if (packetHeader & 0x80) {        // run-length packet
615                     switch (targa_header.pixel_size) {
616                         case 24:
617                                 blue = getc(fin);
618                                 green = getc(fin);
619                                 red = getc(fin);
620                                 alphabyte = 255;
621                                 break;
622                         case 32:
623                                 blue = getc(fin);
624                                 green = getc(fin);
625                                 red = getc(fin);
626                                 alphabyte = getc(fin);
627                                 break;
628                     }
629 
630                     for(j=0;j<packetSize;j++) {
631                         *pixbuf++=red;
632                         *pixbuf++=green;
633                         *pixbuf++=blue;
634                         *pixbuf++=alphabyte;
635                         column++;
636                         if (column==columns) { // run spans across rows
637                             column=0;
638                             if (row>0)
639                                 row--;
640                             else
641                                 goto breakOut;
642                             pixbuf = targa_rgba + row*columns*4;
643                         }
644                     }
645                 }
646                 else {                            // non run-length packet
647                     for(j=0;j<packetSize;j++) {
648                         switch (targa_header.pixel_size) {
649                             case 24:
650                                     blue = getc(fin);
651                                     green = getc(fin);
652                                     red = getc(fin);
653                                     *pixbuf++ = red;
654                                     *pixbuf++ = green;
655                                     *pixbuf++ = blue;
656                                     *pixbuf++ = 255;
657                                     break;
658                             case 32:
659                                     blue = getc(fin);
660                                     green = getc(fin);
661                                     red = getc(fin);
662                                     alphabyte = getc(fin);
663                                     *pixbuf++ = red;
664                                     *pixbuf++ = green;
665                                     *pixbuf++ = blue;
666                                     *pixbuf++ = alphabyte;
667                                     break;
668                         }
669                         column++;
670                         if (column==columns) { // pixel packet run spans across rows
671                             column=0;
672                             if (row>0)
673                                 row--;
674                             else
675                                 goto breakOut;
676                             pixbuf = targa_rgba + row*columns*4;
677                         }
678                     }
679                 }
680             }
681             breakOut:;
682         }
683     }
684 
685     fclose(fin);
686 }
687 
688 /*
689 ==================
690 R_LoadSkys
691 ==================
692 */
693 char    *suf[6] = {"rt", "bk", "lf", "ft", "up", "dn"};
R_LoadSkys(void)694 void R_LoadSkys (void)
695 {
696     int     i;
697     FILE    *f;
698     char    name[64];
699 
700     for (i=0 ; i<6 ; i++)
701     {
702         GL_Bind (SKY_TEX + i);
703         sprintf (name, "gfx/env/bkgtst%s.tga", suf[i]);
704         COM_FOpenFile (name, &f);
705         if (!f)
706         {
707             Con_Printf ("Couldn't load %s\n", name);
708             continue;
709         }
710         LoadTGA (f);
711 //      LoadPCX (f);
712 
713         glTexImage2DHelper (GL_TEXTURE_2D, 0, gl_solid_format, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, targa_rgba);
714 //      glTexImage2DHelper (GL_TEXTURE_2D, 0, gl_solid_format, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, pcx_rgb);
715 
716         free (targa_rgba);
717 //      free (pcx_rgb);
718 
719         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
720         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
721     }
722 }
723 
724 
725 vec3_t  skyclip[6] = {
726     {1,1,0},
727     {1,-1,0},
728     {0,-1,1},
729     {0,1,1},
730     {1,0,1},
731     {-1,0,1}
732 };
733 int c_sky;
734 
735 // 1 = s, 2 = t, 3 = 2048
736 int st_to_vec[6][3] =
737 {
738     {3,-1,2},
739     {-3,1,2},
740 
741     {1,3,2},
742     {-1,-3,2},
743 
744     {-2,-1,3},      // 0 degrees yaw, look straight up
745     {2,-1,-3}       // look straight down
746 
747 //  {-1,2,3},
748 //  {1,2,-3}
749 };
750 
751 // s = [0]/[2], t = [1]/[2]
752 int vec_to_st[6][3] =
753 {
754     {-2,3,1},
755     {2,3,-1},
756 
757     {1,3,2},
758     {-1,3,-2},
759 
760     {-2,-1,3},
761     {-2,1,-3}
762 
763 //  {-1,2,3},
764 //  {1,2,-3}
765 };
766 
767 float   skymins[2][6], skymaxs[2][6];
768 
DrawSkyPolygon(int nump,vec3_t vecs)769 void DrawSkyPolygon (int nump, vec3_t vecs)
770 {
771     int     i,j;
772     vec3_t  v, av;
773     float   s, t, dv;
774     int     axis;
775     float   *vp;
776 
777     c_sky++;
778 #if 0
779 glBegin (GL_POLYGON);
780 for (i=0 ; i<nump ; i++, vecs+=3)
781 {
782     VectorAdd(vecs, r_origin, v);
783     glVertex3fv (v);
784 }
785 glEnd();
786 return;
787 #endif
788     // decide which face it maps to
789     VectorCopy (vec3_origin, v);
790     for (i=0, vp=vecs ; i<nump ; i++, vp+=3)
791     {
792         VectorAdd (vp, v, v);
793     }
794     av[0] = fabs(v[0]);
795     av[1] = fabs(v[1]);
796     av[2] = fabs(v[2]);
797     if (av[0] > av[1] && av[0] > av[2])
798     {
799         if (v[0] < 0)
800             axis = 1;
801         else
802             axis = 0;
803     }
804     else if (av[1] > av[2] && av[1] > av[0])
805     {
806         if (v[1] < 0)
807             axis = 3;
808         else
809             axis = 2;
810     }
811     else
812     {
813         if (v[2] < 0)
814             axis = 5;
815         else
816             axis = 4;
817     }
818 
819     // project new texture coords
820     for (i=0 ; i<nump ; i++, vecs+=3)
821     {
822         j = vec_to_st[axis][2];
823         if (j > 0)
824             dv = vecs[j - 1];
825         else
826             dv = -vecs[-j - 1];
827 
828         j = vec_to_st[axis][0];
829         if (j < 0)
830             s = -vecs[-j -1] / dv;
831         else
832             s = vecs[j-1] / dv;
833         j = vec_to_st[axis][1];
834         if (j < 0)
835             t = -vecs[-j -1] / dv;
836         else
837             t = vecs[j-1] / dv;
838 
839         if (s < skymins[0][axis])
840             skymins[0][axis] = s;
841         if (t < skymins[1][axis])
842             skymins[1][axis] = t;
843         if (s > skymaxs[0][axis])
844             skymaxs[0][axis] = s;
845         if (t > skymaxs[1][axis])
846             skymaxs[1][axis] = t;
847     }
848 }
849 
850 #define MAX_CLIP_VERTS  64
ClipSkyPolygon(int nump,vec3_t vecs,int stage)851 void ClipSkyPolygon (int nump, vec3_t vecs, int stage)
852 {
853     float   *norm;
854     float   *v;
855     qboolean    front, back;
856     float   d, e;
857     float   dists[MAX_CLIP_VERTS];
858     int     sides[MAX_CLIP_VERTS];
859     vec3_t  newv[2][MAX_CLIP_VERTS];
860     int     newc[2];
861     int     i, j;
862 
863     if (nump > MAX_CLIP_VERTS-2)
864         Sys_Error ("ClipSkyPolygon: MAX_CLIP_VERTS");
865     if (stage == 6)
866     {   // fully clipped, so draw it
867         DrawSkyPolygon (nump, vecs);
868         return;
869     }
870 
871     front = back = false;
872     norm = skyclip[stage];
873     for (i=0, v = vecs ; i<nump ; i++, v+=3)
874     {
875         d = DotProduct (v, norm);
876         if (d > ON_EPSILON)
877         {
878             front = true;
879             sides[i] = SIDE_FRONT;
880         }
881         else if (d < ON_EPSILON)
882         {
883             back = true;
884             sides[i] = SIDE_BACK;
885         }
886         else
887             sides[i] = SIDE_ON;
888         dists[i] = d;
889     }
890 
891     if (!front || !back)
892     {   // not clipped
893         ClipSkyPolygon (nump, vecs, stage+1);
894         return;
895     }
896 
897     // clip it
898     sides[i] = sides[0];
899     dists[i] = dists[0];
900     VectorCopy (vecs, (vecs+(i*3)) );
901     newc[0] = newc[1] = 0;
902 
903     for (i=0, v = vecs ; i<nump ; i++, v+=3)
904     {
905         switch (sides[i])
906         {
907         case SIDE_FRONT:
908             VectorCopy (v, newv[0][newc[0]]);
909             newc[0]++;
910             break;
911         case SIDE_BACK:
912             VectorCopy (v, newv[1][newc[1]]);
913             newc[1]++;
914             break;
915         case SIDE_ON:
916             VectorCopy (v, newv[0][newc[0]]);
917             newc[0]++;
918             VectorCopy (v, newv[1][newc[1]]);
919             newc[1]++;
920             break;
921         }
922 
923         if (sides[i] == SIDE_ON || sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
924             continue;
925 
926         d = dists[i] / (dists[i] - dists[i+1]);
927         for (j=0 ; j<3 ; j++)
928         {
929             e = v[j] + d*(v[j+3] - v[j]);
930             newv[0][newc[0]][j] = e;
931             newv[1][newc[1]][j] = e;
932         }
933         newc[0]++;
934         newc[1]++;
935     }
936 
937     // continue
938     ClipSkyPolygon (newc[0], newv[0][0], stage+1);
939     ClipSkyPolygon (newc[1], newv[1][0], stage+1);
940 }
941 
942 /*
943 =================
944 R_DrawSkyChain
945 =================
946 */
R_DrawSkyChain(msurface_t * s)947 void R_DrawSkyChain (msurface_t *s)
948 {
949     msurface_t  *fa;
950 
951     int     i;
952     vec3_t  verts[MAX_CLIP_VERTS];
953     glpoly_t    *p;
954 
955     c_sky = 0;
956     GL_Bind(solidskytexture);
957 
958     // calculate vertex values for sky box
959 
960     for (fa=s ; fa ; fa=fa->texturechain)
961     {
962         for (p=fa->polys ; p ; p=p->next)
963         {
964             for (i=0 ; i<p->numverts ; i++)
965             {
966                 VectorSubtract (p->verts[i], r_origin, verts[i]);
967             }
968             ClipSkyPolygon (p->numverts, verts[0], 0);
969         }
970     }
971 }
972 
973 
974 /*
975 ==============
976 R_ClearSkyBox
977 ==============
978 */
R_ClearSkyBox(void)979 void R_ClearSkyBox (void)
980 {
981     int     i;
982 
983     for (i=0 ; i<6 ; i++)
984     {
985         skymins[0][i] = skymins[1][i] = 9999;
986         skymaxs[0][i] = skymaxs[1][i] = -9999;
987     }
988 }
989 
990 
MakeSkyVec(float s,float t,int axis)991 void MakeSkyVec (float s, float t, int axis)
992 {
993     vec3_t      v, b;
994     int         j, k;
995 
996     b[0] = s*2048;
997     b[1] = t*2048;
998     b[2] = 2048;
999 
1000     for (j=0 ; j<3 ; j++)
1001     {
1002         k = st_to_vec[axis][j];
1003         if (k < 0)
1004             v[j] = -b[-k - 1];
1005         else
1006             v[j] = b[k - 1];
1007         v[j] += r_origin[j];
1008     }
1009 
1010     // avoid bilerp seam
1011     s = (s+1)*0.5;
1012     t = (t+1)*0.5;
1013 
1014     if (s < 1.0/512)
1015         s = 1.0/512;
1016     else if (s > 511.0/512)
1017         s = 511.0/512;
1018     if (t < 1.0/512)
1019         t = 1.0/512;
1020     else if (t > 511.0/512)
1021         t = 511.0/512;
1022 
1023     t = 1.0 - t;
1024     glTexCoord2f (s, t);
1025     glVertex3fv (v);
1026 }
1027 
1028 /*
1029 ==============
1030 R_DrawSkyBox
1031 ==============
1032 */
1033 int skytexorder[6] = {0,2,1,3,4,5};
R_DrawSkyBox(void)1034 void R_DrawSkyBox (void)
1035 {
1036     int     i, j, k;
1037     vec3_t  v;
1038     float   s, t;
1039 
1040 #if 0
1041 glEnable (GL_BLEND);
1042 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
1043 glColor4f (1,1,1,0.5);
1044 glDisable (GL_DEPTH_TEST);
1045 #endif
1046     for (i=0 ; i<6 ; i++)
1047     {
1048         if (skymins[0][i] >= skymaxs[0][i]
1049         || skymins[1][i] >= skymaxs[1][i])
1050             continue;
1051 
1052         GL_Bind (SKY_TEX+skytexorder[i]);
1053 #if 0
1054 skymins[0][i] = -1;
1055 skymins[1][i] = -1;
1056 skymaxs[0][i] = 1;
1057 skymaxs[1][i] = 1;
1058 #endif
1059         glBegin (GL_QUADS);
1060         MakeSkyVec (skymins[0][i], skymins[1][i], i);
1061         MakeSkyVec (skymins[0][i], skymaxs[1][i], i);
1062         MakeSkyVec (skymaxs[0][i], skymaxs[1][i], i);
1063         MakeSkyVec (skymaxs[0][i], skymins[1][i], i);
1064         glEnd ();
1065     }
1066 #if 0
1067 glDisable (GL_BLEND);
1068 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
1069 glColor4f (1,1,1,0.5);
1070 glEnable (GL_DEPTH_TEST);
1071 #endif
1072 }
1073 
1074 
1075 #endif
1076 
1077 //===============================================================
1078 
1079 static texture_t* current_sky_mt;
1080 
1081 /*
1082 =============
1083 R_InitSky
1084 
1085 A sky texture is 256*128, with the right side being a masked overlay
1086 ==============
1087 */
R_InitSky(texture_t * mt)1088 void R_InitSky (texture_t *mt)
1089 {
1090     int         i, j, p;
1091     byte        *src;
1092     unsigned    trans[128*128];
1093     unsigned    transpix;
1094     int         r, g, b;
1095     unsigned    *rgba;
1096     // extern   int         skytexturenum;
1097 
1098     current_sky_mt = mt;
1099 
1100     src = (byte *)mt + mt->offsets[0];
1101 
1102     // make an average value for the back to avoid
1103     // a fringe on the top level
1104 
1105     r = g = b = 0;
1106     for (i=0 ; i<128 ; i++)
1107         for (j=0 ; j<128 ; j++)
1108         {
1109             p = src[i*256 + j + 128];
1110             rgba = &d_8to24table[p];
1111             trans[(i*128) + j] = *rgba;
1112             r += ((byte *)rgba)[0];
1113             g += ((byte *)rgba)[1];
1114             b += ((byte *)rgba)[2];
1115         }
1116 
1117     ((byte *)&transpix)[0] = r/(128*128);
1118     ((byte *)&transpix)[1] = g/(128*128);
1119     ((byte *)&transpix)[2] = b/(128*128);
1120     ((byte *)&transpix)[3] = 0;
1121 
1122 
1123     if (!solidskytexture)
1124         solidskytexture = texture_extension_number++;
1125     GL_Bind (solidskytexture );
1126     glTexImage2DHelper (GL_TEXTURE_2D, 0, gl_solid_format, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
1127     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1128     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
1129 
1130 
1131     for (i=0 ; i<128 ; i++)
1132         for (j=0 ; j<128 ; j++)
1133         {
1134             p = src[i*256 + j];
1135             if (p == 0)
1136                 trans[(i*128) + j] = transpix;
1137             else
1138                 trans[(i*128) + j] = d_8to24table[p];
1139         }
1140 
1141     if (!alphaskytexture)
1142         alphaskytexture = texture_extension_number++;
1143     GL_Bind(alphaskytexture);
1144     glTexImage2DHelper (GL_TEXTURE_2D, 0, gl_alpha_format, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
1145     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1146     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
1147 }
1148 
R_ReloadSky()1149 void R_ReloadSky() {
1150     if (current_sky_mt) {
1151         R_InitSky(current_sky_mt);
1152     }
1153 }
1154