gl_backend.c

   1
   2 #include "quakedef.h"
   3
   4 cvar_t gl_mesh_maxtriangles = {0, "gl_mesh_maxtriangles", "1024"};
   5 cvar_t gl_mesh_transtriangles = {0, "gl_mesh_transtriangles", "16384"};
   6 cvar_t gl_mesh_floatcolors = {0, "gl_mesh_floatcolors", "1"};
   7 cvar_t gl_mesh_drawmode = {CVAR_SAVE, "gl_mesh_drawmode", "3"};
   8
   9 cvar_t r_render = {0, "r_render", "1"};
  10 cvar_t gl_dither = {CVAR_SAVE, "gl_dither", "1"}; // whether or not to use dithering
  11 cvar_t gl_lockarrays = {0, "gl_lockarrays", "1"};
  12
  13 // this is used to increase gl_mesh_maxtriangles automatically if a mesh was
  14 // too large for the buffers in the previous frame
  15 int overflowedverts = 0;
  16 // increase transtriangles automatically too
  17 int overflowedtransverts = 0;
  18
  19 int gl_maxdrawrangeelementsvertices;
  20 int gl_maxdrawrangeelementsindices;
  21
  22 #ifdef DEBUGGL
  23 int errornumber = 0;
  24
  25 void GL_PrintError(int errornumber, char *filename, int linenumber)
  26 {
  27         switch(errornumber)
  28         {
  29 #ifdef GL_INVALID_ENUM
  30         case GL_INVALID_ENUM:
  31                 Con_Printf("GL_INVALID_ENUM at %s:%i\n", filename, linenumber);
  32                 break;
  33 #endif
  34 #ifdef GL_INVALID_VALUE
  35         case GL_INVALID_VALUE:
  36                 Con_Printf("GL_INVALID_VALUE at %s:%i\n", filename, linenumber);
  37                 break;
  38 #endif
  39 #ifdef GL_INVALID_OPERATION
  40         case GL_INVALID_OPERATION:
  41                 Con_Printf("GL_INVALID_OPERATION at %s:%i\n", filename, linenumber);
  42                 break;
  43 #endif
  44 #ifdef GL_STACK_OVERFLOW
  45         case GL_STACK_OVERFLOW:
  46                 Con_Printf("GL_STACK_OVERFLOW at %s:%i\n", filename, linenumber);
  47                 break;
  48 #endif
  49 #ifdef GL_STACK_UNDERFLOW
  50         case GL_STACK_UNDERFLOW:
  51                 Con_Printf("GL_STACK_UNDERFLOW at %s:%i\n", filename, linenumber);
  52                 break;
  53 #endif
  54 #ifdef GL_OUT_OF_MEMORY
  55         case GL_OUT_OF_MEMORY:
  56                 Con_Printf("GL_OUT_OF_MEMORY at %s:%i\n", filename, linenumber);
  57                 break;
  58 #endif
  59 #ifdef GL_TABLE_TOO_LARGE
  60     case GL_TABLE_TOO_LARGE:
  61                 Con_Printf("GL_TABLE_TOO_LARGE at %s:%i\n", filename, linenumber);
  62                 break;
  63 #endif
  64         default:
  65                 Con_Printf("GL UNKNOWN (%i) at %s:%i\n", errornumber, filename, linenumber);
  66                 break;
  67         }
  68 }
  69 #endif
  70
  71 float r_mesh_farclip;
  72
  73 static float viewdist;
  74 // sign bits (true if negative) for vpn[] entries, so quick integer compares can be used instead of float compares
  75 static int vpnbit0, vpnbit1, vpnbit2;
  76
  77 int c_meshs, c_meshtris, c_transmeshs, c_transtris;
  78
  79 int lightscalebit;
  80 float lightscale;
  81 float overbrightscale;
  82
  83 void SCR_ScreenShot_f (void);
  84
  85 static int max_meshs;
  86 static int max_transmeshs;
  87 static int max_verts; // always max_meshs * 3
  88 static int max_transverts; // always max_transmeshs * 3
  89 #define TRANSDEPTHRES 4096
  90
  91 typedef struct buf_mesh_s
  92 {
  93         int depthmask;
  94         int depthtest;
  95         int blendfunc1, blendfunc2;
  96         int textures[MAX_TEXTUREUNITS];
  97         int texturergbscale[MAX_TEXTUREUNITS];
  98         int firsttriangle;
  99         int triangles;
 100         int firstvert;
 101         int verts;
 102         struct buf_mesh_s *chain;
 103         struct buf_transtri_s *transchain;
 104 }
 105 buf_mesh_t;
 106
 107 typedef struct buf_transtri_s
 108 {
 109         struct buf_transtri_s *next;
 110         struct buf_transtri_s *meshsortchain;
 111         buf_mesh_t *mesh;
 112         int index[3];
 113 }
 114 buf_transtri_t;
 115
 116 typedef struct buf_tri_s
 117 {
 118         int index[3];
 119 }
 120 buf_tri_t;
 121
 122 typedef struct
 123 {
 124         float v[4];
 125 }
 126 buf_vertex_t;
 127
 128 typedef struct
 129 {
 130         float c[4];
 131 }
 132 buf_fcolor_t;
 133
 134 typedef struct
 135 {
 136         qbyte c[4];
 137 }
 138 buf_bcolor_t;
 139
 140 typedef struct
 141 {
 142         float t[2];
 143 }
 144 buf_texcoord_t;
 145
 146 static int currentmesh, currenttriangle, currentvertex, backendunits, backendactive, transranout;
 147 static buf_mesh_t *buf_mesh;
 148 static buf_tri_t *buf_tri;
 149 static buf_vertex_t *buf_vertex;
 150 static buf_fcolor_t *buf_fcolor;
 151 static buf_bcolor_t *buf_bcolor;
 152 static buf_texcoord_t *buf_texcoord[MAX_TEXTUREUNITS];
 153
 154 static int currenttransmesh, currenttransvertex, currenttranstriangle;
 155 static buf_mesh_t *buf_transmesh;
 156 static buf_transtri_t *buf_sorttranstri;
 157 static buf_transtri_t **buf_sorttranstri_list;
 158 static buf_tri_t *buf_transtri;
 159 static buf_vertex_t *buf_transvertex;
 160 static buf_fcolor_t *buf_transfcolor;
 161 static buf_texcoord_t *buf_transtexcoord[MAX_TEXTUREUNITS];
 162
 163 static mempool_t *gl_backend_mempool;
 164 static int resizingbuffers = false;
 165
 166 static void gl_backend_start(void)
 167 {
 168         int i;
 169
 170         qglGetIntegerv(GL_MAX_ELEMENTS_VERTICES, &gl_maxdrawrangeelementsvertices);
 171         qglGetIntegerv(GL_MAX_ELEMENTS_INDICES, &gl_maxdrawrangeelementsindices);
 172
 173         Con_Printf("OpenGL Backend started with gl_mesh_maxtriangles %i, gl_mesh_transtriangles %i\n", gl_mesh_maxtriangles.integer, gl_mesh_transtriangles.integer);
 174         if (qglDrawRangeElements != NULL)
 175                 Con_Printf("glDrawRangeElements detected (max vertices %i, max indices %i)\n", gl_maxdrawrangeelementsvertices, gl_maxdrawrangeelementsindices);
 176         if (strstr(gl_renderer, "3Dfx"))
 177         {
 178                 Con_Printf("3Dfx driver detected, forcing gl_mesh_floatcolors to 0 to prevent crashs\n");
 179                 Cvar_SetValueQuick(&gl_mesh_floatcolors, 0);
 180         }
 181         Con_Printf("\n");
 182
 183         max_verts = max_meshs * 3;
 184         max_transverts = max_transmeshs * 3;
 185
 186         if (!gl_backend_mempool)
 187                 gl_backend_mempool = Mem_AllocPool("GL_Backend");
 188
 189 #define BACKENDALLOC(var, count, sizeofstruct, varname)\
 190         {\
 191                 var = Mem_Alloc(gl_backend_mempool, count * sizeof(sizeofstruct));\
 192                 if (var == NULL)\
 193                         Sys_Error("gl_backend_start: unable to allocate memory for %s (%d bytes)\n", (varname), count * sizeof(sizeofstruct));\
 194                 memset(var, 0, count * sizeof(sizeofstruct));\
 195         }
 196
 197         BACKENDALLOC(buf_mesh, max_meshs, buf_mesh_t, "buf_mesh")
 198         BACKENDALLOC(buf_tri, max_meshs, buf_tri_t, "buf_tri")
 199         BACKENDALLOC(buf_vertex, max_verts, buf_vertex_t, "buf_vertex")
 200         BACKENDALLOC(buf_fcolor, max_verts, buf_fcolor_t, "buf_fcolor")
 201         BACKENDALLOC(buf_bcolor, max_verts, buf_bcolor_t, "buf_bcolor")
 202
 203         BACKENDALLOC(buf_transmesh, max_transmeshs, buf_mesh_t, "buf_transmesh")
 204         BACKENDALLOC(buf_sorttranstri, max_transmeshs, buf_transtri_t, "buf_sorttranstri")
 205         BACKENDALLOC(buf_sorttranstri_list, TRANSDEPTHRES, buf_transtri_t *, "buf_sorttranstri_list")
 206         BACKENDALLOC(buf_transtri, max_transmeshs, buf_tri_t, "buf_transtri")
 207         BACKENDALLOC(buf_transvertex, max_transverts, buf_vertex_t, "buf_vertex")
 208         BACKENDALLOC(buf_transfcolor, max_transverts, buf_fcolor_t, "buf_fcolor")
 209
 210         for (i = 0;i < MAX_TEXTUREUNITS;i++)
 211         {
 212                 // only allocate as many texcoord arrays as we need
 213                 if (i < gl_textureunits)
 214                 {
 215                         BACKENDALLOC(buf_texcoord[i], max_verts, buf_texcoord_t, va("buf_texcoord[%d]", i))
 216                         BACKENDALLOC(buf_transtexcoord[i], max_transverts, buf_texcoord_t, va("buf_transtexcoord[%d]", i))
 217                 }
 218                 else
 219                 {
 220                         buf_texcoord[i] = NULL;
 221                         buf_transtexcoord[i] = NULL;
 222                 }
 223         }
 224         backendunits = min(MAX_TEXTUREUNITS, gl_textureunits);
 225         backendactive = true;
 226 }
 227
 228 static void gl_backend_shutdown(void)
 229 {
 230         Con_Printf("OpenGL Backend shutting down\n");
 231
 232         if (resizingbuffers)
 233                 Mem_EmptyPool(gl_backend_mempool);
 234         else
 235                 Mem_FreePool(&gl_backend_mempool);
 236
 237         backendunits = 0;
 238         backendactive = false;
 239 }
 240
 241 static void gl_backend_bufferchanges(int init)
 242 {
 243         if (overflowedverts > gl_mesh_maxtriangles.integer * 3)
 244                 Cvar_SetValueQuick(&gl_mesh_maxtriangles, (int) ((overflowedverts + 2) / 3));
 245         overflowedverts = 0;
 246
 247         if (overflowedtransverts > gl_mesh_transtriangles.integer * 3)
 248                 Cvar_SetValueQuick(&gl_mesh_transtriangles, (int) ((overflowedtransverts + 2) / 3));
 249         overflowedtransverts = 0;
 250
 251         if (gl_mesh_drawmode.integer < 0)
 252                 Cvar_SetValueQuick(&gl_mesh_drawmode, 0);
 253         if (gl_mesh_drawmode.integer > 3)
 254                 Cvar_SetValueQuick(&gl_mesh_drawmode, 3);
 255
 256         if (gl_mesh_drawmode.integer >= 3 && qglDrawRangeElements == NULL)
 257         {
 258                 // change drawmode 3 to 2 if 3 won't work at all
 259                 Cvar_SetValueQuick(&gl_mesh_drawmode, 2);
 260         }
 261
 262         // 21760 is (65536 / 3) rounded off to a multiple of 128
 263         if (gl_mesh_maxtriangles.integer < 1024)
 264                 Cvar_SetValueQuick(&gl_mesh_maxtriangles, 1024);
 265         if (gl_mesh_maxtriangles.integer > 21760)
 266                 Cvar_SetValueQuick(&gl_mesh_maxtriangles, 21760);
 267
 268         if (gl_mesh_transtriangles.integer < 1024)
 269                 Cvar_SetValueQuick(&gl_mesh_transtriangles, 1024);
 270         if (gl_mesh_transtriangles.integer > 65536)
 271                 Cvar_SetValueQuick(&gl_mesh_transtriangles, 65536);
 272
 273         if (max_meshs != gl_mesh_maxtriangles.integer || max_transmeshs != gl_mesh_transtriangles.integer)
 274         {
 275                 max_meshs = gl_mesh_maxtriangles.integer;
 276                 max_transmeshs = gl_mesh_transtriangles.integer;
 277
 278                 if (!init)
 279                 {
 280                         resizingbuffers = true;
 281                         gl_backend_shutdown();
 282                         gl_backend_start();
 283                         resizingbuffers = false;
 284                 }
 285         }
 286 }
 287
 288 static void gl_backend_newmap(void)
 289 {
 290 }
 291
 292 void gl_backend_init(void)
 293 {
 294         Cvar_RegisterVariable(&r_render);
 295         Cvar_RegisterVariable(&gl_dither);
 296         Cvar_RegisterVariable(&gl_lockarrays);
 297 #ifdef NORENDER
 298         Cvar_SetValue("r_render", 0);
 299 #endif
 300
 301         Cvar_RegisterVariable(&gl_mesh_maxtriangles);
 302         Cvar_RegisterVariable(&gl_mesh_transtriangles);
 303         Cvar_RegisterVariable(&gl_mesh_floatcolors);
 304         Cvar_RegisterVariable(&gl_mesh_drawmode);
 305         R_RegisterModule("GL_Backend", gl_backend_start, gl_backend_shutdown, gl_backend_newmap);
 306         gl_backend_bufferchanges(true);
 307 }
 308
 309 int arraylocked = false;
 310
 311 void GL_LockArray(int first, int count)
 312 {
 313         if (!arraylocked && gl_supportslockarrays && gl_lockarrays.integer && gl_mesh_drawmode.integer > 0)
 314         {
 315                 qglLockArraysEXT(first, count);
 316                 CHECKGLERROR
 317                 arraylocked = true;
 318         }
 319 }
 320
 321 void GL_UnlockArray(void)
 322 {
 323         if (arraylocked)
 324         {
 325                 qglUnlockArraysEXT();
 326                 CHECKGLERROR
 327                 arraylocked = false;
 328         }
 329 }
 330
 331 /*
 332 =============
 333 GL_SetupFrame
 334 =============
 335 */
 336 static void GL_SetupFrame (void)
 337 {
 338         double xmax, ymax;
 339         double fovx, fovy, zNear, zFar, aspect;
 340
 341         if (!r_render.integer)
 342                 return;
 343
 344         qglDepthFunc (GL_LEQUAL);CHECKGLERROR
 345
 346         // set up viewpoint
 347         qglMatrixMode(GL_PROJECTION);CHECKGLERROR
 348         qglLoadIdentity ();CHECKGLERROR
 349
 350         // y is weird beause OpenGL is bottom to top, we use top to bottom
 351         qglViewport(r_refdef.x, vid.realheight - (r_refdef.y + r_refdef.height), r_refdef.width, r_refdef.height);CHECKGLERROR
 352
 353         // depth range
 354         zNear = 1.0;
 355         zFar = r_mesh_farclip;
 356
 357         // fov angles
 358         fovx = r_refdef.fov_x;
 359         fovy = r_refdef.fov_y;
 360         aspect = r_refdef.width / r_refdef.height;
 361
 362         // pyramid slopes
 363         xmax = zNear * tan(fovx * M_PI / 360.0) * aspect;
 364         ymax = zNear * tan(fovy * M_PI / 360.0);
 365
 366         // set view pyramid
 367         qglFrustum(-xmax, xmax, -ymax, ymax, zNear, zFar);CHECKGLERROR
 368
 369         qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
 370         qglLoadIdentity ();CHECKGLERROR
 371
 372         // put Z going up
 373         qglRotatef (-90,  1, 0, 0);CHECKGLERROR
 374         qglRotatef (90,  0, 0, 1);CHECKGLERROR
 375         // camera rotation
 376         qglRotatef (-r_refdef.viewangles[2],  1, 0, 0);CHECKGLERROR
 377         qglRotatef (-r_refdef.viewangles[0],  0, 1, 0);CHECKGLERROR
 378         qglRotatef (-r_refdef.viewangles[1],  0, 0, 1);CHECKGLERROR
 379         // camera location
 380         qglTranslatef (-r_refdef.vieworg[0],  -r_refdef.vieworg[1],  -r_refdef.vieworg[2]);CHECKGLERROR
 381 }
 382
 383 static struct
 384 {
 385         int blendfunc1;
 386         int blendfunc2;
 387         int blend;
 388         GLboolean depthmask;
 389         int depthtest;
 390         int unit;
 391         int clientunit;
 392         int texture[MAX_TEXTUREUNITS];
 393         float texturergbscale[MAX_TEXTUREUNITS];
 394 }
 395 gl_state;
 396
 397 void GL_SetupTextureState(void)
 398 {
 399         int i;
 400         if (backendunits > 1)
 401         {
 402                 for (i = 0;i < backendunits;i++)
 403                 {
 404                         qglActiveTexture(GL_TEXTURE0_ARB + (gl_state.unit = i));CHECKGLERROR
 405                         qglBindTexture(GL_TEXTURE_2D, gl_state.texture[i]);CHECKGLERROR
 406                         if (gl_combine.integer)
 407                         {
 408                                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);CHECKGLERROR
 409                                 qglTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);CHECKGLERROR
 410                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);CHECKGLERROR
 411                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);CHECKGLERROR
 412                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE2_RGB_ARB, GL_CONSTANT_ARB);CHECKGLERROR
 413                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);CHECKGLERROR
 414                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);CHECKGLERROR
 415                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND2_RGB_ARB, GL_SRC_ALPHA);CHECKGLERROR
 416                                 qglTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, GL_MODULATE);CHECKGLERROR
 417                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB, GL_TEXTURE);CHECKGLERROR
 418                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_ALPHA_ARB, GL_PREVIOUS_ARB);CHECKGLERROR
 419                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE2_ALPHA_ARB, GL_CONSTANT_ARB);CHECKGLERROR
 420                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA_ARB, GL_SRC_ALPHA);CHECKGLERROR
 421                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_ALPHA_ARB, GL_SRC_ALPHA);CHECKGLERROR
 422                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND2_ALPHA_ARB, GL_SRC_ALPHA);CHECKGLERROR
 423                                 qglTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, gl_state.texturergbscale[i]);CHECKGLERROR
 424                                 qglTexEnvi(GL_TEXTURE_ENV, GL_ALPHA_SCALE, 1);CHECKGLERROR
 425                         }
 426                         else
 427                         {
 428                                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 429                         }
 430                         if (gl_state.texture[i])
 431                         {
 432                                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 433                         }
 434                         else
 435                         {
 436                                 qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 437                         }
 438                         if (gl_mesh_drawmode.integer > 0)
 439                         {
 440                                 qglClientActiveTexture(GL_TEXTURE0_ARB + (gl_state.clientunit = i));CHECKGLERROR
 441                                 qglTexCoordPointer(2, GL_FLOAT, sizeof(buf_texcoord_t), buf_texcoord[i]);CHECKGLERROR
 442                                 if (gl_state.texture[i])
 443                                 {
 444                                         qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 445                                 }
 446                                 else
 447                                 {
 448                                         qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 449                                 }
 450                         }
 451                 }
 452         }
 453         else
 454         {
 455                 qglBindTexture(GL_TEXTURE_2D, gl_state.texture[0]);CHECKGLERROR
 456                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 457                 if (gl_state.texture[0])
 458                 {
 459                         qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 460                 }
 461                 else
 462                 {
 463                         qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 464                 }
 465                 if (gl_mesh_drawmode.integer > 0)
 466                 {
 467                         qglTexCoordPointer(2, GL_FLOAT, sizeof(buf_texcoord_t), buf_texcoord[0]);CHECKGLERROR
 468                         if (gl_state.texture[0])
 469                         {
 470                                 qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 471                         }
 472                         else
 473                         {
 474                                 qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 475                         }
 476                 }
 477         }
 478 }
 479
 480 // called at beginning of frame
 481 int usedarrays;
 482 void R_Mesh_Start(float farclip)
 483 {
 484         int i;
 485         if (!backendactive)
 486                 Sys_Error("R_Mesh_Clear: called when backend is not active\n");
 487
 488         CHECKGLERROR
 489
 490         gl_backend_bufferchanges(false);
 491
 492         currentmesh = 0;
 493         currenttriangle = 0;
 494         currentvertex = 0;
 495         currenttransmesh = 0;
 496         currenttranstriangle = 0;
 497         currenttransvertex = 0;
 498         transranout = false;
 499         r_mesh_farclip = farclip;
 500         viewdist = DotProduct(r_origin, vpn);
 501         vpnbit0 = vpn[0] < 0;
 502         vpnbit1 = vpn[1] < 0;
 503         vpnbit2 = vpn[2] < 0;
 504
 505         c_meshs = 0;
 506         c_meshtris = 0;
 507         c_transmeshs = 0;
 508         c_transtris = 0;
 509
 510         GL_SetupFrame();
 511
 512         gl_state.unit = 0;
 513         gl_state.clientunit = 0;
 514
 515         for (i = 0;i < backendunits;i++)
 516         {
 517                 gl_state.texture[i] = 0;
 518                 gl_state.texturergbscale[i] = 1;
 519         }
 520
 521         qglEnable(GL_CULL_FACE);CHECKGLERROR
 522         qglCullFace(GL_FRONT);CHECKGLERROR
 523
 524         gl_state.depthtest = true;
 525         qglEnable(GL_DEPTH_TEST);CHECKGLERROR
 526
 527         gl_state.blendfunc1 = GL_ONE;
 528         gl_state.blendfunc2 = GL_ZERO;
 529         qglBlendFunc(gl_state.blendfunc1, gl_state.blendfunc2);CHECKGLERROR
 530
 531         gl_state.blend = 0;
 532         qglDisable(GL_BLEND);CHECKGLERROR
 533
 534         gl_state.depthmask = GL_TRUE;
 535         qglDepthMask(gl_state.depthmask);CHECKGLERROR
 536
 537         usedarrays = false;
 538         if (gl_mesh_drawmode.integer > 0)
 539         {
 540                 usedarrays = true;
 541                 qglVertexPointer(3, GL_FLOAT, sizeof(buf_vertex_t), &buf_vertex[0].v[0]);CHECKGLERROR
 542                 qglEnableClientState(GL_VERTEX_ARRAY);CHECKGLERROR
 543                 if (gl_mesh_floatcolors.integer)
 544                 {
 545                         qglColorPointer(4, GL_FLOAT, sizeof(buf_fcolor_t), &buf_fcolor[0].c[0]);CHECKGLERROR
 546                 }
 547                 else
 548                 {
 549                         qglColorPointer(4, GL_UNSIGNED_BYTE, sizeof(buf_bcolor_t), &buf_bcolor[0].c[0]);CHECKGLERROR
 550                 }
 551                 qglEnableClientState(GL_COLOR_ARRAY);CHECKGLERROR
 552         }
 553
 554         GL_SetupTextureState();
 555 }
 556
 557 int gl_backend_rebindtextures;
 558
 559 void GL_ConvertColorsFloatToByte(void)
 560 {
 561         int i, k, total;
 562         // LordHavoc: to avoid problems with aliasing (treating memory as two
 563         // different types - exactly what this is doing), these must be volatile
 564         // (or a union)
 565         volatile int *icolor;
 566         volatile float *fcolor;
 567         qbyte *bcolor;
 568
 569         total = currentvertex * 4;
 570
 571         // shift float to have 8bit fraction at base of number
 572         fcolor = &buf_fcolor->c[0];
 573         for (i = 0;i < total;)
 574         {
 575                 fcolor[i    ] += 32768.0f;
 576                 fcolor[i + 1] += 32768.0f;
 577                 fcolor[i + 2] += 32768.0f;
 578                 fcolor[i + 3] += 32768.0f;
 579                 i += 4;
 580         }
 581
 582         // then read as integer and kill float bits...
 583         icolor = (int *)&buf_fcolor->c[0];
 584         bcolor = &buf_bcolor->c[0];
 585         for (i = 0;i < total;)
 586         {
 587                 k = icolor[i    ] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i    ] = (qbyte) k;
 588                 k = icolor[i + 1] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i + 1] = (qbyte) k;
 589                 k = icolor[i + 2] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i + 2] = (qbyte) k;
 590                 k = icolor[i + 3] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i + 3] = (qbyte) k;
 591                 i += 4;
 592         }
 593 }
 594
 595 void GL_MeshState(buf_mesh_t *mesh)
 596 {
 597         int i;
 598         if (backendunits > 1)
 599         {
 600                 for (i = 0;i < backendunits;i++)
 601                 {
 602                         if (gl_state.texture[i] != mesh->textures[i])
 603                         {
 604                                 if (gl_state.unit != i)
 605                                 {
 606                                         qglActiveTexture(GL_TEXTURE0_ARB + (gl_state.unit = i));CHECKGLERROR
 607                                 }
 608                                 if (gl_state.texture[i] == 0)
 609                                 {
 610                                         qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 611                                         // have to disable texcoord array on disabled texture
 612                                         // units due to NVIDIA driver bug with
 613                                         // compiled_vertex_array
 614                                         if (gl_state.clientunit != i)
 615                                         {
 616                                                 qglClientActiveTexture(GL_TEXTURE0_ARB + (gl_state.clientunit = i));CHECKGLERROR
 617                                         }
 618                                         qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 619                                 }
 620                                 qglBindTexture(GL_TEXTURE_2D, (gl_state.texture[i] = mesh->textures[i]));CHECKGLERROR
 621                                 if (gl_state.texture[i] == 0)
 622                                 {
 623                                         qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 624                                         // have to disable texcoord array on disabled texture
 625                                         // units due to NVIDIA driver bug with
 626                                         // compiled_vertex_array
 627                                         if (gl_state.clientunit != i)
 628                                         {
 629                                                 qglClientActiveTexture(GL_TEXTURE0_ARB + (gl_state.clientunit = i));CHECKGLERROR
 630                                         }
 631                                         qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 632                                 }
 633                         }
 634                         if (gl_state.texturergbscale[i] != mesh->texturergbscale[i])
 635                         {
 636                                 if (gl_state.unit != i)
 637                                 {
 638                                         qglActiveTexture(GL_TEXTURE0_ARB + (gl_state.unit = i));CHECKGLERROR
 639                                 }
 640                                 qglTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, (gl_state.texturergbscale[i] = mesh->texturergbscale[i]));CHECKGLERROR
 641                         }
 642                 }
 643         }
 644         else
 645         {
 646                 if (gl_state.texture[0] != mesh->textures[0])
 647                 {
 648                         if (gl_state.texture[0] == 0)
 649                         {
 650                                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 651                                 qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 652                         }
 653                         qglBindTexture(GL_TEXTURE_2D, (gl_state.texture[0] = mesh->textures[0]));CHECKGLERROR
 654                         if (gl_state.texture[0] == 0)
 655                         {
 656                                 qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 657                                 qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 658                         }
 659                 }
 660         }
 661         if (gl_state.blendfunc1 != mesh->blendfunc1 || gl_state.blendfunc2 != mesh->blendfunc2)
 662         {
 663                 qglBlendFunc(gl_state.blendfunc1 = mesh->blendfunc1, gl_state.blendfunc2 = mesh->blendfunc2);CHECKGLERROR
 664                 if (gl_state.blendfunc2 == GL_ZERO)
 665                 {
 666                         if (gl_state.blendfunc1 == GL_ONE)
 667                         {
 668                                 if (gl_state.blend)
 669                                 {
 670                                         gl_state.blend = 0;
 671                                         qglDisable(GL_BLEND);CHECKGLERROR
 672                                 }
 673                         }
 674                         else
 675                         {
 676                                 if (!gl_state.blend)
 677                                 {
 678                                         gl_state.blend = 1;
 679                                         qglEnable(GL_BLEND);CHECKGLERROR
 680                                 }
 681                         }
 682                 }
 683                 else
 684                 {
 685                         if (!gl_state.blend)
 686                         {
 687                                 gl_state.blend = 1;
 688                                 qglEnable(GL_BLEND);CHECKGLERROR
 689                         }
 690                 }
 691         }
 692         if (gl_state.depthtest != mesh->depthtest)
 693         {
 694                 gl_state.depthtest = mesh->depthtest;
 695                 if (gl_state.depthtest)
 696                         qglEnable(GL_DEPTH_TEST);
 697                 else
 698                         qglDisable(GL_DEPTH_TEST);
 699         }
 700         if (gl_state.depthmask != mesh->depthmask)
 701         {
 702                 qglDepthMask(gl_state.depthmask = mesh->depthmask);CHECKGLERROR
 703         }
 704 }
 705
 706 void GL_DrawRangeElements(int firstvert, int endvert, int indexcount, GLuint *index)
 707 {
 708         unsigned int i, j, in;
 709         if (gl_mesh_drawmode.integer >= 3/* && (endvert - firstvert) <= gl_maxdrawrangeelementsvertices && (indexcount) <= gl_maxdrawrangeelementsindices*/)
 710         {
 711                 // GL 1.2 or GL 1.1 with extension
 712                 qglDrawRangeElements(GL_TRIANGLES, firstvert, endvert, indexcount, GL_UNSIGNED_INT, index);
 713         }
 714         else if (gl_mesh_drawmode.integer >= 2)
 715         {
 716                 // GL 1.1
 717                 qglDrawElements(GL_TRIANGLES, indexcount, GL_UNSIGNED_INT, index);
 718         }
 719         else if (gl_mesh_drawmode.integer >= 1)
 720         {
 721                 // GL 1.1
 722                 // feed it manually using glArrayElement
 723                 qglBegin(GL_TRIANGLES);
 724                 for (i = 0;i < indexcount;i++)
 725                         qglArrayElement(index[i]);
 726                 qglEnd();
 727         }
 728         else
 729         {
 730                 // GL 1.1 but not using vertex arrays - 3dfx glquake minigl driver
 731                 // feed it manually
 732                 qglBegin(GL_TRIANGLES);
 733                 if (gl_state.texture[1]) // if the mesh uses multiple textures
 734                 {
 735                         // the minigl doesn't have this (because it does not have ARB_multitexture)
 736                         for (i = 0;i < indexcount;i++)
 737                         {
 738                                 in = index[i];
 739                                 qglColor4ub(buf_bcolor[in].c[0], buf_bcolor[in].c[1], buf_bcolor[in].c[2], buf_bcolor[in].c[3]);
 740                                 for (j = 0;j < backendunits;j++)
 741                                         if (gl_state.texture[j])
 742                                                 qglMultiTexCoord2f(GL_TEXTURE0_ARB + j, buf_texcoord[j][in].t[0], buf_texcoord[j][in].t[1]);
 743                                 qglVertex3f(buf_vertex[in].v[0], buf_vertex[in].v[1], buf_vertex[in].v[2]);
 744                         }
 745                 }
 746                 else
 747                 {
 748                         for (i = 0;i < indexcount;i++)
 749                         {
 750                                 in = index[i];
 751                                 qglColor4ub(buf_bcolor[in].c[0], buf_bcolor[in].c[1], buf_bcolor[in].c[2], buf_bcolor[in].c[3]);
 752                                 if (gl_state.texture[0])
 753                                         qglTexCoord2f(buf_texcoord[0][in].t[0], buf_texcoord[0][in].t[1]);
 754                                 qglVertex3f(buf_vertex[in].v[0], buf_vertex[in].v[1], buf_vertex[in].v[2]);
 755                         }
 756                 }
 757                 qglEnd();
 758         }
 759 }
 760
 761 // renders mesh buffers, called to flush buffers when full
 762 void R_Mesh_Render(void)
 763 {
 764         int k;
 765         buf_mesh_t *mesh;
 766
 767         if (!backendactive)
 768                 Sys_Error("R_Mesh_Render: called when backend is not active\n");
 769
 770         if (!currentmesh)
 771                 return;
 772
 773         if (!r_render.integer)
 774         {
 775                 currentmesh = 0;
 776                 currenttriangle = 0;
 777                 currentvertex = 0;
 778                 return;
 779         }
 780
 781         CHECKGLERROR
 782
 783         // drawmode 0 always uses byte colors
 784         if (!gl_mesh_floatcolors.integer || gl_mesh_drawmode.integer <= 0)
 785                 GL_ConvertColorsFloatToByte();
 786
 787         if (gl_backend_rebindtextures)
 788         {
 789                 gl_backend_rebindtextures = false;
 790                 GL_SetupTextureState();
 791         }
 792
 793         GL_MeshState(buf_mesh);
 794         GL_LockArray(0, currentvertex);
 795         GL_DrawRangeElements(buf_mesh->firstvert, buf_mesh->firstvert + buf_mesh->verts, buf_mesh->triangles * 3, (unsigned int *)&buf_tri[buf_mesh->firsttriangle].index[0]);CHECKGLERROR
 796
 797         if (currentmesh >= 2)
 798         {
 799                 for (k = 1, mesh = buf_mesh + k;k < currentmesh;k++, mesh++)
 800                 {
 801                         GL_MeshState(mesh);
 802                         GL_DrawRangeElements(mesh->firstvert, mesh->firstvert + mesh->verts, mesh->triangles * 3, buf_tri[mesh->firsttriangle].index);CHECKGLERROR
 803                 }
 804         }
 805
 806         currentmesh = 0;
 807         currenttriangle = 0;
 808         currentvertex = 0;
 809
 810         GL_UnlockArray();CHECKGLERROR
 811 }
 812
 813 // restores backend state, used when done with 3D rendering
 814 void R_Mesh_Finish(void)
 815 {
 816         int i;
 817         // flush any queued meshs
 818         if (currentmesh)
 819                 R_Mesh_Render();
 820
 821         if (backendunits > 1)
 822         {
 823                 for (i = backendunits - 1;i >= 0;i--)
 824                 {
 825                         qglActiveTexture(GL_TEXTURE0_ARB + i);CHECKGLERROR
 826                         qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 827                         if (gl_combine.integer)
 828                         {
 829                                 qglTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 1);CHECKGLERROR
 830                         }
 831                         if (i > 0)
 832                         {
 833                                 qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 834                         }
 835                         else
 836                         {
 837                                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 838                         }
 839                         qglBindTexture(GL_TEXTURE_2D, 0);CHECKGLERROR
 840
 841                         if (usedarrays)
 842                         {
 843                                 qglClientActiveTexture(GL_TEXTURE0_ARB + i);CHECKGLERROR
 844                                 qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 845                         }
 846                 }
 847         }
 848         else
 849         {
 850                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 851                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 852                 if (usedarrays)
 853                 {
 854                         qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 855                 }
 856         }
 857         if (usedarrays)
 858         {
 859                 qglDisableClientState(GL_COLOR_ARRAY);CHECKGLERROR
 860                 qglDisableClientState(GL_VERTEX_ARRAY);CHECKGLERROR
 861         }
 862
 863         qglDisable(GL_BLEND);CHECKGLERROR
 864         qglEnable(GL_DEPTH_TEST);CHECKGLERROR
 865         qglDepthMask(GL_TRUE);CHECKGLERROR
 866         qglBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);CHECKGLERROR
 867 }
 868
 869 void R_Mesh_ClearDepth(void)
 870 {
 871         if (currenttransmesh)
 872                 R_Mesh_AddTransparent();
 873         if (currentmesh)
 874                 R_Mesh_Render();
 875         R_Mesh_Finish();
 876         qglClear(GL_DEPTH_BUFFER_BIT);
 877         R_Mesh_Start(r_mesh_farclip);
 878 }
 879
 880 void R_Mesh_AddTransparent(void)
 881 {
 882         int i, j, k, *index;
 883         float viewdistcompare, centerscaler, dist1, dist2, dist3, center, maxdist;
 884         buf_vertex_t *vert1, *vert2, *vert3;
 885         buf_transtri_t *tri;
 886         buf_mesh_t *mesh, *transmesh;
 887
 888         if (!currenttransmesh)
 889                 return;
 890
 891         // convert index data to transtris for sorting
 892         for (j = 0;j < currenttransmesh;j++)
 893         {
 894                 mesh = buf_transmesh + j;
 895                 k = mesh->firsttriangle;
 896                 index = &buf_transtri[k].index[0];
 897                 for (i = 0;i < mesh->triangles;i++)
 898                 {
 899                         tri = &buf_sorttranstri[k++];
 900                         tri->mesh = mesh;
 901                         tri->index[0] = *index++;
 902                         tri->index[1] = *index++;
 903                         tri->index[2] = *index++;
 904                 }
 905         }
 906
 907         // map farclip to 0-4095 list range
 908         centerscaler = (TRANSDEPTHRES / r_mesh_farclip) * (1.0f / 3.0f);
 909         viewdistcompare = viewdist + 4.0f;
 910
 911         memset(buf_sorttranstri_list, 0, TRANSDEPTHRES * sizeof(buf_transtri_t *));
 912
 913         k = 0;
 914         for (j = 0;j < currenttranstriangle;j++)
 915         {
 916                 tri = &buf_sorttranstri[j];
 917                 i = tri->mesh->firstvert;
 918
 919                 vert1 = &buf_transvertex[tri->index[0] + i];
 920                 vert2 = &buf_transvertex[tri->index[1] + i];
 921                 vert3 = &buf_transvertex[tri->index[2] + i];
 922
 923                 dist1 = DotProduct(vert1->v, vpn);
 924                 dist2 = DotProduct(vert2->v, vpn);
 925                 dist3 = DotProduct(vert3->v, vpn);
 926
 927                 maxdist = max(dist1, max(dist2, dist3));
 928                 if (maxdist < viewdistcompare)
 929                         continue;
 930
 931                 center = (dist1 + dist2 + dist3) * centerscaler - viewdist;
 932 #if SLOWMATH
 933                 i = (int) center;
 934                 i = bound(0, i, (TRANSDEPTHRES - 1));
 935 #else
 936                 if (center < 0.0f)
 937                         center = 0.0f;
 938                 center += 8388608.0f;
 939                 i = *((int *)&center) & 0x7FFFFF;
 940                 i = min(i, (TRANSDEPTHRES - 1));
 941 #endif
 942                 tri->next = buf_sorttranstri_list[i];
 943                 buf_sorttranstri_list[i] = tri;
 944                 k++;
 945         }
 946
 947         for (i = 0;i < currenttransmesh;i++)
 948                 buf_transmesh[i].transchain = NULL;
 949         transmesh = NULL;
 950         for (j = 0;j < TRANSDEPTHRES;j++)
 951         {
 952                 if ((tri = buf_sorttranstri_list[j]))
 953                 {
 954                         for (;tri;tri = tri->next)
 955                         {
 956                                 if (!tri->mesh->transchain)
 957                                 {
 958                                         tri->mesh->chain = transmesh;
 959                                         transmesh = tri->mesh;
 960                                 }
 961                                 tri->meshsortchain = tri->mesh->transchain;
 962                                 tri->mesh->transchain = tri;
 963                         }
 964                 }
 965         }
 966
 967         R_Mesh_Render();
 968         for (;transmesh;transmesh = transmesh->chain)
 969         {
 970                 mesh = &buf_mesh[currentmesh++];
 971                 *mesh = *transmesh; // copy mesh properties
 972
 973                 mesh->firstvert = currentvertex;
 974                 memcpy(&buf_vertex[currentvertex], &buf_transvertex[transmesh->firstvert], transmesh->verts * sizeof(buf_vertex_t));
 975                 memcpy(&buf_fcolor[currentvertex], &buf_transfcolor[transmesh->firstvert], transmesh->verts * sizeof(buf_fcolor_t));
 976                 for (i = 0;i < backendunits && transmesh->textures[i];i++)
 977                         memcpy(&buf_texcoord[i][currentvertex], &buf_transtexcoord[i][transmesh->firstvert], transmesh->verts * sizeof(buf_texcoord_t));
 978                 currentvertex += mesh->verts;
 979
 980                 mesh->firsttriangle = currenttriangle;
 981                 for (tri = transmesh->transchain;tri;tri = tri->meshsortchain)
 982                 {
 983                         buf_tri[currenttriangle].index[0] = tri->index[0];
 984                         buf_tri[currenttriangle].index[1] = tri->index[1];
 985                         buf_tri[currenttriangle].index[2] = tri->index[2];
 986                         currenttriangle++;
 987                 }
 988                 mesh->triangles = currenttriangle - mesh->firsttriangle;
 989                 R_Mesh_Render();
 990         }
 991
 992         currenttransmesh = 0;
 993         currenttranstriangle = 0;
 994         currenttransvertex = 0;
 995 }
 996
 997 // allocates space in geometry buffers, and fills in pointers to the buffers in passsed struct
 998 // (this is used for very high speed rendering, no copying)
 999 int R_Mesh_Draw_GetBuffer(rmeshbufferinfo_t *m, int wantoverbright)
1000 {
1001         // these are static because gcc runs out of virtual registers otherwise
1002         int i, j, overbright;
1003         float scaler;
1004         buf_mesh_t *mesh;
1005
1006         if (!backendactive)
1007                 Sys_Error("R_Mesh_Draw_GetBuffer: called when backend is not active\n");
1008
1009         if (!m->numtriangles
1010          || !m->numverts)
1011                 Host_Error("R_Mesh_Draw_GetBuffer: no triangles or verts\n");
1012
1013         // LordHavoc: removed this error condition because with floatcolors 0,
1014         // the 3DFX driver works with very large meshs
1015         // FIXME: we can work around this by falling back on non-array renderer if buffers are too big
1016         //if (m->numtriangles > 1024 || m->numverts > 3072)
1017         //{
1018         //      Con_Printf("R_Mesh_Draw_GetBuffer: mesh too big for 3DFX drivers, rejected\n");
1019         //      return false;
1020         //}
1021
1022         i = max(m->numtriangles * 3, m->numverts);
1023         if (overflowedverts < i)
1024                 overflowedverts = i;
1025
1026         if (m->numtriangles > max_meshs || m->numverts > max_verts)
1027         {
1028                 Con_Printf("R_Mesh_Draw_GetBuffer: mesh too big for current gl_mesh_maxtriangles setting, increasing limits\n");
1029                 return false;
1030         }
1031
1032         if (m->transparent)
1033         {
1034                 overflowedtransverts += max(m->numtriangles * 3, m->numverts);
1035                 if (currenttransmesh >= max_transmeshs || (currenttranstriangle + m->numtriangles) > max_transmeshs || (currenttransvertex + m->numverts) > max_transverts)
1036                 {
1037                         if (!transranout)
1038                         {
1039                                 Con_Printf("R_Mesh_Draw_GetBuffer: ran out of room for transparent meshs\n");
1040                                 transranout = true;
1041                         }
1042                         return false;
1043                 }
1044
1045                 c_transmeshs++;
1046                 c_transtris += m->numtriangles;
1047                 m->index = &buf_transtri[currenttranstriangle].index[0];
1048                 m->vertex = &buf_transvertex[currenttransvertex].v[0];
1049                 m->color = &buf_transfcolor[currenttransvertex].c[0];
1050                 for (i = 0;i < backendunits;i++)
1051                         m->texcoords[i] = &buf_transtexcoord[i][currenttransvertex].t[0];
1052
1053                 // transmesh is only for storage of transparent meshs until they
1054                 // are inserted into the main mesh array
1055                 mesh = &buf_transmesh[currenttransmesh++];
1056                 mesh->firsttriangle = currenttranstriangle;
1057                 mesh->firstvert = currenttransvertex;
1058                 currenttranstriangle += m->numtriangles;
1059                 currenttransvertex += m->numverts;
1060         }
1061         else
1062         {
1063                 if (currentmesh)
1064                 {
1065                         R_Mesh_Render();
1066                         Con_Printf("mesh queue not empty, flushing.\n");
1067                 }
1068
1069                 c_meshs++;
1070                 c_meshtris += m->numtriangles;
1071                 m->index = &buf_tri[currenttriangle].index[0];
1072                 m->vertex = &buf_vertex[currentvertex].v[0];
1073                 m->color = &buf_fcolor[currentvertex].c[0];
1074                 for (i = 0;i < backendunits;i++)
1075                         m->texcoords[i] = &buf_texcoord[i][currentvertex].t[0];
1076
1077                 // opaque meshs are rendered directly
1078                 mesh = &buf_mesh[currentmesh++];
1079                 mesh->firsttriangle = currenttriangle;
1080                 mesh->firstvert = currentvertex;
1081                 currenttriangle += m->numtriangles;
1082                 currentvertex += m->numverts;
1083         }
1084
1085         // code shared for transparent and opaque meshs
1086         mesh->blendfunc1 = m->blendfunc1;
1087         mesh->blendfunc2 = m->blendfunc2;
1088         mesh->depthmask = (m->blendfunc2 == GL_ZERO || m->depthwrite);
1089         mesh->depthtest = !m->depthdisable;
1090         mesh->triangles = m->numtriangles;
1091         mesh->verts = m->numverts;
1092
1093         overbright = false;
1094         scaler = 1;
1095         if (m->blendfunc1 == GL_DST_COLOR)
1096         {
1097                 // check if it is a 2x modulate with framebuffer
1098                 if (m->blendfunc2 == GL_SRC_COLOR)
1099                         scaler *= 0.5f;
1100         }
1101         else if (m->blendfunc2 != GL_SRC_COLOR)
1102         {
1103                 if (m->tex[0])
1104                 {
1105                         overbright = wantoverbright && gl_combine.integer;
1106                         if (overbright)
1107                                 scaler *= 0.25f;
1108                 }
1109                 scaler *= overbrightscale;
1110         }
1111         m->colorscale = scaler;
1112
1113         j = -1;
1114         for (i = 0;i < MAX_TEXTUREUNITS;i++)
1115         {
1116                 if ((mesh->textures[i] = m->tex[i]))
1117                 {
1118                         j = i;
1119                         if (i >= backendunits)
1120                                 Sys_Error("R_Mesh_Draw_GetBuffer: texture %i supplied when there are only %i texture units\n", j + 1, backendunits);
1121                 }
1122                 mesh->texturergbscale[i] = m->texrgbscale[i];
1123                 if (mesh->texturergbscale[i] != 1 && mesh->texturergbscale[i] != 2 && mesh->texturergbscale[i] != 4)
1124                         mesh->texturergbscale[i] = 1;
1125         }
1126         if (overbright && j >= 0)
1127                 mesh->texturergbscale[j] = 4;
1128
1129         return true;
1130 }
1131
1132 /*
1133 ==============================================================================
1134
1135                                                 SCREEN SHOTS
1136
1137 ==============================================================================
1138 */
1139
1140 qboolean SCR_ScreenShot(char *filename, int x, int y, int width, int height)
1141 {
1142         qboolean ret;
1143         int i;
1144         qbyte *buffer;
1145
1146         if (!r_render.integer)
1147                 return false;
1148
1149         buffer = Mem_Alloc(tempmempool, width*height*3);
1150         qglReadPixels (x, y, width, height, GL_RGB, GL_UNSIGNED_BYTE, buffer);
1151         CHECKGLERROR
1152
1153         // LordHavoc: compensate for v_overbrightbits when using hardware gamma
1154         if (v_hwgamma.integer)
1155                 for (i = 0;i < width * height * 3;i++)
1156                         buffer[i] <<= v_overbrightbits.integer;
1157
1158         ret = Image_WriteTGARGB_preflipped(filename, width, height, buffer);
1159
1160         Mem_Free(buffer);
1161         return ret;
1162 }
1163
1164 //=============================================================================
1165
1166 void R_ClearScreen(void)
1167 {
1168         if (r_render.integer)
1169         {
1170                 // clear to black
1171                 qglClearColor(0,0,0,0);CHECKGLERROR
1172                 // clear the screen
1173                 qglClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);CHECKGLERROR
1174                 // set dithering mode
1175                 if (gl_dither.integer)
1176                 {
1177                         qglEnable(GL_DITHER);CHECKGLERROR
1178                 }
1179                 else
1180                 {
1181                         qglDisable(GL_DITHER);CHECKGLERROR
1182                 }
1183         }
1184 }
1185
1186 /*
1187 ==================
1188 SCR_UpdateScreen
1189
1190 This is called every frame, and can also be called explicitly to flush
1191 text to the screen.
1192 ==================
1193 */
1194 void SCR_UpdateScreen (void)
1195 {
1196         VID_Finish ();
1197
1198         R_TimeReport("finish");
1199
1200         if (r_textureunits.integer > gl_textureunits)
1201                 Cvar_SetValueQuick(&r_textureunits, gl_textureunits);
1202         if (r_textureunits.integer < 1)
1203                 Cvar_SetValueQuick(&r_textureunits, 1);
1204
1205         if (gl_combine.integer && (!gl_combine_extension || r_textureunits.integer < 2))
1206                 Cvar_SetValueQuick(&gl_combine, 0);
1207
1208         // lighting scale
1209         overbrightscale = 1.0f / (float) (1 << v_overbrightbits.integer);
1210
1211         // lightmaps only
1212         lightscalebit = v_overbrightbits.integer;
1213         if (gl_combine.integer && r_textureunits.integer > 1)
1214                 lightscalebit += 2;
1215         lightscale = 1.0f / (float) (1 << lightscalebit);
1216
1217         R_TimeReport("setup");
1218
1219         R_ClearScreen();
1220
1221         R_TimeReport("clear");
1222
1223         if (scr_conlines < vid.conheight)
1224                 R_RenderView();
1225
1226         // draw 2D stuff
1227         R_DrawQueue();
1228
1229         // tell driver to commit it's partially full geometry queue to the rendering queue
1230         // (this doesn't wait for the commands themselves to complete)
1231         qglFlush();
1232 }
1233