gl_textures.c

   1 #include "quakedef.h"
   2
   3 cvar_t          r_max_size = {"r_max_size", "2048"};
   4 cvar_t          r_picmip = {"r_picmip", "0"};
   5 cvar_t          r_lerpimages = {"r_lerpimages", "1"};
   6 cvar_t          r_upload = {"r_upload", "1"};
   7 cvar_t          r_precachetextures = {"r_precachetextures", "1", true};
   8
   9 int             gl_filter_min = GL_LINEAR_MIPMAP_LINEAR; //NEAREST;
  10 int             gl_filter_max = GL_LINEAR;
  11
  12
  13 int             texels;
  14
  15 // 65536x65536
  16 #define MAXMIPS 16
  17
  18 #define GLTEXF_LERPED 1
  19 #define GLTEXF_UPLOADED 2
  20
  21 typedef struct
  22 {
  23         char    identifier[64];
  24         int             texnum; // GL texture slot number
  25         int             texeldatasize; // computed memory usage of this texture (including mipmaps, expansion to 32bit, etc)
  26         byte    *inputtexels; // copy of the original texture supplied to the upload function, for re-uploading or deferred uploads (non-precached)
  27         int             inputtexeldatasize; // size of the original texture
  28         unsigned short width, height;
  29 // LordHavoc: CRC to identify cache mismatchs
  30         unsigned short crc;
  31         int flags; // the requested flags when the texture was supplied to the upload function
  32         int internalflags; // internal notes (lerped, etc)
  33 } gltexture_t;
  34
  35 #define MAX_GLTEXTURES  4096
  36 gltexture_t     *gltextures;
  37 unsigned int numgltextures = 0, gl_texture_number = 1;
  38
  39 void GL_UploadTexture(gltexture_t *t);
  40
  41 int R_GetTexture(rtexture_t *rt)
  42 {
  43         gltexture_t *glt;
  44         if (!rt)
  45                 return 0;
  46         glt = (gltexture_t *)rt;
  47         if (!(glt->internalflags & GLTEXF_UPLOADED))
  48         {
  49                 GL_UploadTexture(glt);
  50                 if (!(glt->internalflags & GLTEXF_UPLOADED))
  51                         Host_Error("R_GetTexture: unable to upload texture\n");
  52         }
  53         return glt->texnum;
  54 }
  55
  56 typedef struct
  57 {
  58         char *name;
  59         int     minimize, maximize;
  60 } glmode_t;
  61
  62 glmode_t modes[] =
  63 {
  64         {"GL_NEAREST", GL_NEAREST, GL_NEAREST},
  65         {"GL_LINEAR", GL_LINEAR, GL_LINEAR},
  66         {"GL_NEAREST_MIPMAP_NEAREST", GL_NEAREST_MIPMAP_NEAREST, GL_NEAREST},
  67         {"GL_LINEAR_MIPMAP_NEAREST", GL_LINEAR_MIPMAP_NEAREST, GL_LINEAR},
  68         {"GL_NEAREST_MIPMAP_LINEAR", GL_NEAREST_MIPMAP_LINEAR, GL_NEAREST},
  69         {"GL_LINEAR_MIPMAP_LINEAR", GL_LINEAR_MIPMAP_LINEAR, GL_LINEAR}
  70 };
  71
  72 /*
  73 ===============
  74 Draw_TextureMode_f
  75 ===============
  76 */
  77 void Draw_TextureMode_f (void)
  78 {
  79         int             i;
  80         gltexture_t     *glt;
  81
  82         if (Cmd_Argc() == 1)
  83         {
  84                 for (i=0 ; i< 6 ; i++)
  85                         if (gl_filter_min == modes[i].minimize)
  86                         {
  87                                 Con_Printf ("%s\n", modes[i].name);
  88                                 return;
  89                         }
  90                 Con_Printf ("current filter is unknown???\n");
  91                 return;
  92         }
  93
  94         for (i=0 ; i< 6 ; i++)
  95         {
  96                 if (!Q_strcasecmp (modes[i].name, Cmd_Argv(1) ) )
  97                         break;
  98         }
  99         if (i == 6)
 100         {
 101                 Con_Printf ("bad filter name\n");
 102                 return;
 103         }
 104
 105         gl_filter_min = modes[i].minimize;
 106         gl_filter_max = modes[i].maximize;
 107
 108         if (!r_upload.value)
 109                 return;
 110         // change all the existing mipmap texture objects
 111         for (i=0, glt=gltextures ; i<numgltextures ; i++, glt++)
 112         {
 113                 if (glt->flags & TEXF_MIPMAP)
 114                 {
 115                         glBindTexture(GL_TEXTURE_2D, glt->texnum);
 116                         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_min);
 117                         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max);
 118                 }
 119         }
 120 }
 121
 122 void GL_TextureStats_Print(char *name, int total, int total2, int loaded, int crc, int mip, int alpha, int total2valid)
 123 {
 124         if (!name[0])
 125                 name = "<unnamed>";
 126         Con_Printf("%5iK %c%5iK%c %04X %s %s %s %s\n", total, total2valid ? ' ' : '(', total2, total2valid ? ' ' : ')', crc, loaded ? "loaded" : "      ", mip ? "mip" : "   ", alpha ? "alpha" : "     ", name);
 127 }
 128
 129 void GL_TextureStats_PrintTotal(void)
 130 {
 131         int i, t = 0, p = 0, loaded = 0, loadedt = 0, loadedp = 0;
 132         gltexture_t *glt;
 133         for (i = 0, glt = gltextures;i < numgltextures;i++, glt++)
 134         {
 135                 t += glt->texeldatasize;
 136                 p += glt->inputtexeldatasize;
 137                 if (glt->internalflags & GLTEXF_UPLOADED)
 138                 {
 139                         loaded++;
 140                         loadedt += glt->texeldatasize;
 141                         loadedp += glt->inputtexeldatasize;
 142                 }
 143         }
 144         Con_Printf("total: %i (%.3fMB, %.3fMB original), uploaded %i (%.3fMB, %.3fMB original), upload on demand %i (%.3fMB, %.3fMB original)\n", numgltextures, t / 1048576.0, p / 1048576.0, loaded, loadedt / 1048576.0, loadedp / 1048576.0, numgltextures - loaded, (t - loadedt) / 1048576.0, (p - loadedp) / 1048576.0);
 145 }
 146
 147 void GL_TextureStats_f(void)
 148 {
 149         int i;
 150         gltexture_t *glt;
 151         Con_Printf("kbytes original crc  loaded mip alpha name\n");
 152         for (i = 0, glt = gltextures;i < numgltextures;i++, glt++)
 153                 GL_TextureStats_Print(glt->identifier, (glt->texeldatasize + 1023) / 1024, (glt->inputtexeldatasize + 1023) / 1024, glt->internalflags & GLTEXF_UPLOADED, glt->crc, glt->flags & TEXF_MIPMAP, glt->flags & TEXF_ALPHA, glt->inputtexels != NULL);
 154         GL_TextureStats_PrintTotal();
 155 }
 156
 157 char engineversion[40];
 158
 159 //void GL_UploadTexture (gltexture_t *glt);
 160 void r_textures_start()
 161 {
 162 //      int i;
 163 //      gltexture_t *glt;
 164 //      for (i=0, glt=gltextures ; i<numgltextures ; i++, glt++)
 165 //              GL_UploadTexture(glt);
 166 }
 167
 168 void r_textures_shutdown()
 169 {
 170 }
 171
 172 void r_textures_newmap()
 173 {
 174 }
 175
 176 void R_Textures_Init (void)
 177 {
 178         Cmd_AddCommand("r_texturestats", GL_TextureStats_f);
 179         Cvar_RegisterVariable (&r_max_size);
 180         Cvar_RegisterVariable (&r_picmip);
 181         Cvar_RegisterVariable (&r_lerpimages);
 182         Cvar_RegisterVariable (&r_upload);
 183         Cvar_RegisterVariable (&r_precachetextures);
 184 #ifdef NORENDER
 185         r_upload.value = 0;
 186 #endif
 187
 188         // 3dfx can only handle 256 wide textures
 189         if (!Q_strncasecmp ((char *)gl_renderer, "3dfx",4) || strstr((char *)gl_renderer, "Glide"))
 190                 Cvar_Set ("r_max_size", "256");
 191
 192         gltextures = qmalloc(sizeof(gltexture_t) * MAX_GLTEXTURES);
 193         memset(gltextures, 0, sizeof(gltexture_t) * MAX_GLTEXTURES);
 194         Cmd_AddCommand ("gl_texturemode", &Draw_TextureMode_f);
 195
 196         R_RegisterModule("R_Textures", r_textures_start, r_textures_shutdown, r_textures_newmap);
 197 }
 198
 199 /*
 200 ================
 201 R_FindTexture
 202 ================
 203 */
 204 int R_FindTexture (char *identifier)
 205 {
 206         int             i;
 207         gltexture_t     *glt;
 208
 209         for (i=0, glt=gltextures ; i<numgltextures ; i++, glt++)
 210         {
 211                 if (!strcmp (identifier, glt->identifier))
 212                         return gltextures[i].texnum;
 213         }
 214
 215         return -1;
 216 }
 217
 218 void R_ResampleTextureLerpLine (byte *in, byte *out, int inwidth, int outwidth)
 219 {
 220         int             j, xi, oldx = 0, f, fstep, endx;
 221         fstep = (int) (inwidth*65536.0f/outwidth);
 222         endx = (inwidth-1);
 223         for (j = 0,f = 0;j < outwidth;j++, f += fstep)
 224         {
 225                 xi = (int) f >> 16;
 226                 if (xi != oldx)
 227                 {
 228                         in += (xi - oldx) * 4;
 229                         oldx = xi;
 230                 }
 231                 if (xi < endx)
 232                 {
 233                         int lerp = f & 0xFFFF;
 234                         *out++ = (byte) ((((in[4] - in[0]) * lerp) >> 16) + in[0]);
 235                         *out++ = (byte) ((((in[5] - in[1]) * lerp) >> 16) + in[1]);
 236                         *out++ = (byte) ((((in[6] - in[2]) * lerp) >> 16) + in[2]);
 237                         *out++ = (byte) ((((in[7] - in[3]) * lerp) >> 16) + in[3]);
 238                 }
 239                 else // last pixel of the line has no pixel to lerp to
 240                 {
 241                         *out++ = in[0];
 242                         *out++ = in[1];
 243                         *out++ = in[2];
 244                         *out++ = in[3];
 245                 }
 246         }
 247 }
 248
 249 /*
 250 ================
 251 R_ResampleTexture
 252 ================
 253 */
 254 void R_ResampleTexture (void *indata, int inwidth, int inheight, void *outdata,  int outwidth, int outheight)
 255 {
 256         if (outwidth & 3)
 257                 Sys_Error("R_ResampleTexture: output width must be a multiple of 4");
 258
 259         if (r_lerpimages.value)
 260         {
 261                 int             i, j, yi, oldy, f, fstep, endy = (inheight-1);
 262                 byte    *inrow, *out, *row1, *row2;
 263                 out = outdata;
 264                 fstep = (int) (inheight*65536.0f/outheight);
 265
 266                 row1 = qmalloc(outwidth*4);
 267                 row2 = qmalloc(outwidth*4);
 268                 inrow = indata;
 269                 oldy = 0;
 270                 R_ResampleTextureLerpLine (inrow, row1, inwidth, outwidth);
 271                 R_ResampleTextureLerpLine (inrow + inwidth*4, row2, inwidth, outwidth);
 272                 for (i = 0, f = 0;i < outheight;i++,f += fstep)
 273                 {
 274                         yi = f >> 16;
 275                         if (yi < endy)
 276                         {
 277                                 int lerp = f & 0xFFFF;
 278                                 if (yi != oldy)
 279                                 {
 280                                         inrow = (byte *)indata + inwidth*4*yi;
 281                                         if (yi == oldy+1)
 282                                                 memcpy(row1, row2, outwidth*4);
 283                                         else
 284                                                 R_ResampleTextureLerpLine (inrow, row1, inwidth, outwidth);
 285                                         R_ResampleTextureLerpLine (inrow + inwidth*4, row2, inwidth, outwidth);
 286                                         oldy = yi;
 287                                 }
 288                                 for (j = 0;j < outwidth;j += 4)
 289                                 {
 290                                         out[ 0] = (byte) ((((row2[ 0] - row1[ 0]) * lerp) >> 16) + row1[ 0]);
 291                                         out[ 1] = (byte) ((((row2[ 1] - row1[ 1]) * lerp) >> 16) + row1[ 1]);
 292                                         out[ 2] = (byte) ((((row2[ 2] - row1[ 2]) * lerp) >> 16) + row1[ 2]);
 293                                         out[ 3] = (byte) ((((row2[ 3] - row1[ 3]) * lerp) >> 16) + row1[ 3]);
 294                                         out[ 4] = (byte) ((((row2[ 4] - row1[ 4]) * lerp) >> 16) + row1[ 4]);
 295                                         out[ 5] = (byte) ((((row2[ 5] - row1[ 5]) * lerp) >> 16) + row1[ 5]);
 296                                         out[ 6] = (byte) ((((row2[ 6] - row1[ 6]) * lerp) >> 16) + row1[ 6]);
 297                                         out[ 7] = (byte) ((((row2[ 7] - row1[ 7]) * lerp) >> 16) + row1[ 7]);
 298                                         out[ 8] = (byte) ((((row2[ 8] - row1[ 8]) * lerp) >> 16) + row1[ 8]);
 299                                         out[ 9] = (byte) ((((row2[ 9] - row1[ 9]) * lerp) >> 16) + row1[ 9]);
 300                                         out[10] = (byte) ((((row2[10] - row1[10]) * lerp) >> 16) + row1[10]);
 301                                         out[11] = (byte) ((((row2[11] - row1[11]) * lerp) >> 16) + row1[11]);
 302                                         out[12] = (byte) ((((row2[12] - row1[12]) * lerp) >> 16) + row1[12]);
 303                                         out[13] = (byte) ((((row2[13] - row1[13]) * lerp) >> 16) + row1[13]);
 304                                         out[14] = (byte) ((((row2[14] - row1[14]) * lerp) >> 16) + row1[14]);
 305                                         out[15] = (byte) ((((row2[15] - row1[15]) * lerp) >> 16) + row1[15]);
 306                                         out += 16;
 307                                         row1 += 16;
 308                                         row2 += 16;
 309                                 }
 310                                 row1 -= outwidth*4;
 311                                 row2 -= outwidth*4;
 312                         }
 313                         else
 314                         {
 315                                 if (yi != oldy)
 316                                 {
 317                                         inrow = (byte *)indata + inwidth*4*yi;
 318                                         if (yi == oldy+1)
 319                                                 memcpy(row1, row2, outwidth*4);
 320                                         else
 321                                                 R_ResampleTextureLerpLine (inrow, row1, inwidth, outwidth);
 322                                         oldy = yi;
 323                                 }
 324                                 memcpy(out, row1, outwidth * 4);
 325                         }
 326                 }
 327                 qfree(row1);
 328                 qfree(row2);
 329         }
 330         else
 331         {
 332                 int i, j;
 333                 unsigned frac, fracstep;
 334                 // relies on int being 4 bytes
 335                 int *inrow, *out;
 336                 out = outdata;
 337
 338                 fracstep = inwidth*0x10000/outwidth;
 339                 for (i = 0;i < outheight;i++)
 340                 {
 341                         inrow = (int *)indata + inwidth*(i*inheight/outheight);
 342                         frac = fracstep >> 1;
 343                         for (j = 0;j < outwidth;j += 4)
 344                         {
 345                                 out[0] = inrow[frac >> 16];frac += fracstep;
 346                                 out[1] = inrow[frac >> 16];frac += fracstep;
 347                                 out[2] = inrow[frac >> 16];frac += fracstep;
 348                                 out[3] = inrow[frac >> 16];frac += fracstep;
 349                                 out += 4;
 350                         }
 351                 }
 352         }
 353 }
 354
 355 // in can be the same as out
 356 void GL_MipReduce(byte *in, byte *out, int width, int height, int destwidth, int destheight)
 357 {
 358         int x, y, width2, height2, nextrow;
 359         if (width > destwidth)
 360         {
 361                 if (height > destheight)
 362                 {
 363                         // reduce both
 364                         width2 = width >> 1;
 365                         height2 = height >> 1;
 366                         nextrow = width << 2;
 367                         for (y = 0;y < height2;y++)
 368                         {
 369                                 for (x = 0;x < width2;x++)
 370                                 {
 371                                         out[0] = (byte) ((in[0] + in[4] + in[nextrow  ] + in[nextrow+4]) >> 2);
 372                                         out[1] = (byte) ((in[1] + in[5] + in[nextrow+1] + in[nextrow+5]) >> 2);
 373                                         out[2] = (byte) ((in[2] + in[6] + in[nextrow+2] + in[nextrow+6]) >> 2);
 374                                         out[3] = (byte) ((in[3] + in[7] + in[nextrow+3] + in[nextrow+7]) >> 2);
 375                                         out += 4;
 376                                         in += 8;
 377                                 }
 378                                 in += nextrow; // skip a line
 379                         }
 380                 }
 381                 else
 382                 {
 383                         // reduce width
 384                         width2 = width >> 1;
 385                         for (y = 0;y < height;y++)
 386                         {
 387                                 for (x = 0;x < width2;x++)
 388                                 {
 389                                         out[0] = (byte) ((in[0] + in[4]) >> 1);
 390                                         out[1] = (byte) ((in[1] + in[5]) >> 1);
 391                                         out[2] = (byte) ((in[2] + in[6]) >> 1);
 392                                         out[3] = (byte) ((in[3] + in[7]) >> 1);
 393                                         out += 4;
 394                                         in += 8;
 395                                 }
 396                         }
 397                 }
 398         }
 399         else
 400         {
 401                 if (height > destheight)
 402                 {
 403                         // reduce height
 404                         height2 = height >> 1;
 405                         nextrow = width << 2;
 406                         for (y = 0;y < height2;y++)
 407                         {
 408                                 for (x = 0;x < width;x++)
 409                                 {
 410                                         out[0] = (byte) ((in[0] + in[nextrow  ]) >> 1);
 411                                         out[1] = (byte) ((in[1] + in[nextrow+1]) >> 1);
 412                                         out[2] = (byte) ((in[2] + in[nextrow+2]) >> 1);
 413                                         out[3] = (byte) ((in[3] + in[nextrow+3]) >> 1);
 414                                         out += 4;
 415                                         in += 4;
 416                                 }
 417                                 in += nextrow; // skip a line
 418                         }
 419                 }
 420                 else
 421                         Sys_Error("GL_MipReduce: desired size already achieved\n");
 422         }
 423 }
 424
 425 void GL_Upload32(int glslot, byte *data, int width, int height, int flags)
 426 {
 427         int mip, width2, height2, width3, height3, internalformat;
 428         byte *gammadata, *buffer;
 429
 430         if (!r_upload.value)
 431                 return;
 432
 433         // 3 and 4 are converted by the driver to it's preferred format for the current display mode
 434         internalformat = 3;
 435         if (flags & TEXF_ALPHA)
 436                 internalformat = 4;
 437
 438         // calculate power of 2 size
 439         width2 = 1;while (width2 < width) width2 <<= 1;
 440         height2 = 1;while (height2 < height) height2 <<= 1;
 441         // calculate final size (mipmapped downward to this)
 442         width3 = width2 >> (int) r_picmip.value;
 443         height3 = height2 >> (int) r_picmip.value;
 444         while (width3 > (int) r_max_size.value) width3 >>= 1;
 445         while (height3 > (int) r_max_size.value) height3 >>= 1;
 446         if (width3 < 1) width3 = 1;
 447         if (height3 < 1) height3 = 1;
 448
 449         gammadata = qmalloc(width*height*4);
 450         buffer = qmalloc(width2*height2*4);
 451         if (!gammadata || !buffer)
 452                 Host_Error("GL_Upload32: out of memory\n");
 453
 454         Image_CopyRGBAGamma(data, gammadata, width*height);
 455
 456         R_ResampleTexture(gammadata, width, height, buffer, width2, height2);
 457
 458         qfree(gammadata);
 459
 460         while (width2 > width3 || height2 > height3)
 461         {
 462                 GL_MipReduce(buffer, buffer, width2, height2, width3, height3);
 463
 464                 if (width2 > width3)
 465                         width2 >>= 1;
 466                 if (height2 > height3)
 467                         height2 >>= 1;
 468         }
 469
 470         glBindTexture(GL_TEXTURE_2D, glslot);
 471         mip = 0;
 472         glTexImage2D(GL_TEXTURE_2D, mip++, internalformat, width2, height2, 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
 473         if (flags & TEXF_MIPMAP)
 474         {
 475                 while (width2 > 1 || height2 > 1)
 476                 {
 477                         GL_MipReduce(buffer, buffer, width2, height2, 1, 1);
 478
 479                         if (width2 > 1)
 480                                 width2 >>= 1;
 481                         if (height2 > 1)
 482                                 height2 >>= 1;
 483
 484                         glTexImage2D(GL_TEXTURE_2D, mip++, internalformat, width2, height2, 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
 485                 }
 486
 487                 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_min);
 488                 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max);
 489         }
 490         else
 491         {
 492                 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_max);
 493                 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max);
 494         }
 495         glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 496
 497         qfree(buffer);
 498 }
 499
 500 void GL_Upload8 (int glslot, byte *data, int width, int height, int flags)
 501 {
 502         byte *data32;
 503         data32 = qmalloc(width*height*4);
 504         Image_Copy8bitRGBA(data, data32, width*height, d_8to24table);
 505         GL_Upload32(glslot, data32, width, height, flags);
 506         qfree(data32);
 507 }
 508
 509 void GL_UploadTexture (gltexture_t *glt)
 510 {
 511         if (glt->inputtexels == NULL)
 512                 return;
 513         if (glt->flags & TEXF_RGBA)
 514                 GL_Upload32(glt->texnum, glt->inputtexels, glt->width, glt->height, glt->flags);
 515         else // 8bit
 516                 GL_Upload8(glt->texnum, glt->inputtexels, glt->width, glt->height, glt->flags);
 517         glt->internalflags |= GLTEXF_UPLOADED;
 518         qfree(glt->inputtexels);
 519         glt->inputtexels = NULL;
 520 }
 521
 522 int R_CalcTexelDataSize (int width, int height, int mipmapped)
 523 {
 524         int width2, height2, size;
 525         width2 = 1;while (width2 < width) width2 <<= 1;
 526         height2 = 1;while (height2 < height) height2 <<= 1;
 527         // calculate final size (mipmapped downward to this)
 528         width2 >>= (int) r_picmip.value;
 529         height2 >>= (int) r_picmip.value;
 530         while (width2 > (int) r_max_size.value) width2 >>= 1;
 531         while (height2 > (int) r_max_size.value) height2 >>= 1;
 532         if (width2 < 1) width2 = 1;
 533         if (height2 < 1) height2 = 1;
 534
 535         size = 0;
 536         if (mipmapped)
 537         {
 538                 while (width2 > 1 || height2 > 1)
 539                 {
 540                         size += width2 * height2;
 541                         if (width2 > 1)
 542                                 width2 >>= 1;
 543                         if (height2 > 1)
 544                                 height2 >>= 1;
 545                 }
 546                 size++; // count the last 1x1 mipmap
 547         }
 548         else
 549                 size = width2*height2;
 550
 551         size *= 4; // RGBA
 552
 553         return size;
 554 }
 555
 556 /*
 557 ================
 558 GL_LoadTexture
 559 ================
 560 */
 561 rtexture_t *R_LoadTexture (char *identifier, int width, int height, byte *data, int flags)
 562 {
 563         int                             i, bytesperpixel, internalflags, precache;
 564         gltexture_t             *glt;
 565         unsigned short  crc;
 566
 567         if (isDedicated)
 568                 return NULL;
 569
 570         if (!identifier[0])
 571                 Host_Error("R_LoadTexture: no identifier\n");
 572
 573         // clear the alpha flag if the texture has no transparent pixels
 574         if (flags & TEXF_ALPHA)
 575         {
 576                 int alpha = false;
 577                 if (flags & TEXF_RGBA)
 578                 {
 579                         for (i = 0;i < width * height;i++)
 580                         {
 581                                 if (data[i * 4 + 3] < 255)
 582                                 {
 583                                         alpha = true;
 584                                         break;
 585                                 }
 586                         }
 587                 }
 588                 else
 589                 {
 590                         for (i = 0;i < width * height;i++)
 591                         {
 592                                 if (data[i] == 255)
 593                                 {
 594                                         alpha = true;
 595                                         break;
 596                                 }
 597                         }
 598                 }
 599                 if (!alpha)
 600                         flags &= ~TEXF_ALPHA;
 601         }
 602
 603         if (flags & TEXF_RGBA)
 604                 bytesperpixel = 4;
 605         else
 606                 bytesperpixel = 1;
 607
 608         internalflags = 0;
 609         if (r_lerpimages.value != 0)
 610                 internalflags |= GLTEXF_LERPED;
 611
 612         // LordHavoc: do a CRC to confirm the data really is the same as previous occurances.
 613         crc = CRC_Block(data, width*height*bytesperpixel);
 614         // see if the texture is already present
 615         for (i=0, glt=gltextures ; i<numgltextures ; i++, glt++)
 616         {
 617                 if (!strcmp (identifier, glt->identifier))
 618                 {
 619                         // LordHavoc: everyone hates cache mismatchs, so I fixed it
 620                         if (crc != glt->crc || width != glt->width || height != glt->height || flags != glt->flags)
 621                         {
 622                                 Con_DPrintf("GL_LoadTexture: cache mismatch, replacing old texture\n");
 623                                 goto GL_LoadTexture_setup; // drop out with glt pointing to the texture to replace
 624                         }
 625                         if (internalflags != glt->internalflags)
 626                                 goto GL_LoadTexture_setup; // drop out with glt pointing to the texture to replace
 627                         return (rtexture_t *)glt;
 628                 }
 629         }
 630
 631 /*
 632         if (freeglt)
 633         {
 634                 glt = freeglt;
 635                 strcpy (glt->identifier, identifier);
 636         }
 637         else
 638         {
 639 */
 640                 // LordHavoc: check if there are still slots available
 641                 if (numgltextures >= MAX_GLTEXTURES)
 642                         Sys_Error ("GL_LoadTexture: ran out of texture slots (%d)\n", MAX_GLTEXTURES);
 643                 glt = &gltextures[numgltextures++];
 644                 glt->texnum = gl_texture_number++;
 645                 strcpy (glt->identifier, identifier);
 646 //      }
 647
 648 // LordHavoc: label to drop out of the loop into the setup code
 649 GL_LoadTexture_setup:
 650         glt->crc = crc; // LordHavoc: used to verify textures are identical
 651         glt->width = width;
 652         glt->height = height;
 653         glt->flags = flags;
 654         glt->internalflags = internalflags;
 655
 656         if (glt->inputtexels)
 657                 qfree(glt->inputtexels);
 658         glt->inputtexeldatasize = width*height*bytesperpixel;
 659         glt->inputtexels = qmalloc(glt->inputtexeldatasize);
 660
 661         memcpy(glt->inputtexels, data, glt->inputtexeldatasize);
 662
 663         glt->texeldatasize = R_CalcTexelDataSize(width, height, flags & TEXF_MIPMAP);
 664
 665         precache = false;
 666         if (r_precachetextures.value >= 1)
 667         {
 668                 if (flags & TEXF_PRECACHE)
 669                         precache = true;
 670                 if (r_precachetextures.value >= 2)
 671                         precache = true;
 672         }
 673
 674         if (precache)
 675                 GL_UploadTexture(glt);
 676
 677         return (rtexture_t *)glt;
 678 }
 679
 680 // only used for lightmaps
 681 int R_GetTextureSlots(int count)
 682 {
 683         int i;
 684         i = gl_texture_number;
 685         gl_texture_number += count;
 686         return i;
 687 }