gl_backend.c

   1
   2 #include "quakedef.h"
   3
   4 cvar_t gl_mesh_maxverts = {0, "gl_mesh_maxverts", "1024"};
   5 cvar_t gl_mesh_floatcolors = {0, "gl_mesh_floatcolors", "1"};
   6 cvar_t gl_mesh_drawrangeelements = {0, "gl_mesh_drawrangeelements", "1"};
   7
   8 cvar_t r_render = {0, "r_render", "1"};
   9 cvar_t gl_dither = {CVAR_SAVE, "gl_dither", "1"}; // whether or not to use dithering
  10 cvar_t gl_lockarrays = {0, "gl_lockarrays", "1"};
  11
  12 int gl_maxdrawrangeelementsvertices;
  13 int gl_maxdrawrangeelementsindices;
  14
  15 #ifdef DEBUGGL
  16 int errornumber = 0;
  17
  18 void GL_PrintError(int errornumber, char *filename, int linenumber)
  19 {
  20         switch(errornumber)
  21         {
  22 #ifdef GL_INVALID_ENUM
  23         case GL_INVALID_ENUM:
  24                 Con_Printf("GL_INVALID_ENUM at %s:%i\n", filename, linenumber);
  25                 break;
  26 #endif
  27 #ifdef GL_INVALID_VALUE
  28         case GL_INVALID_VALUE:
  29                 Con_Printf("GL_INVALID_VALUE at %s:%i\n", filename, linenumber);
  30                 break;
  31 #endif
  32 #ifdef GL_INVALID_OPERATION
  33         case GL_INVALID_OPERATION:
  34                 Con_Printf("GL_INVALID_OPERATION at %s:%i\n", filename, linenumber);
  35                 break;
  36 #endif
  37 #ifdef GL_STACK_OVERFLOW
  38         case GL_STACK_OVERFLOW:
  39                 Con_Printf("GL_STACK_OVERFLOW at %s:%i\n", filename, linenumber);
  40                 break;
  41 #endif
  42 #ifdef GL_STACK_UNDERFLOW
  43         case GL_STACK_UNDERFLOW:
  44                 Con_Printf("GL_STACK_UNDERFLOW at %s:%i\n", filename, linenumber);
  45                 break;
  46 #endif
  47 #ifdef GL_OUT_OF_MEMORY
  48         case GL_OUT_OF_MEMORY:
  49                 Con_Printf("GL_OUT_OF_MEMORY at %s:%i\n", filename, linenumber);
  50                 break;
  51 #endif
  52 #ifdef GL_TABLE_TOO_LARGE
  53     case GL_TABLE_TOO_LARGE:
  54                 Con_Printf("GL_TABLE_TOO_LARGE at %s:%i\n", filename, linenumber);
  55                 break;
  56 #endif
  57         default:
  58                 Con_Printf("GL UNKNOWN (%i) at %s:%i\n", errornumber, filename, linenumber);
  59                 break;
  60         }
  61 }
  62 #endif
  63
  64 #define BACKENDACTIVECHECK if (!backendactive) Sys_Error("GL backend function called when backend is not active\n");
  65
  66 int c_meshs, c_meshelements;
  67
  68 void SCR_ScreenShot_f (void);
  69
  70 // these are externally accessible
  71 int r_lightmapscalebit;
  72 float r_colorscale;
  73 float *varray_vertex;
  74 float *varray_color;
  75 float *varray_texcoord[MAX_TEXTUREUNITS];
  76 int mesh_maxverts;
  77
  78 static matrix4x4_t backend_viewmatrix;
  79 static matrix4x4_t backend_modelmatrix;
  80 static matrix4x4_t backend_modelviewmatrix;
  81 static matrix4x4_t backend_glmodelviewmatrix;
  82
  83 static int backendunits, backendactive;
  84 static qbyte *varray_bcolor;
  85 static mempool_t *gl_backend_mempool;
  86
  87 int polygonelements[768];
  88
  89 void GL_Backend_AllocArrays(void)
  90 {
  91         int i;
  92
  93         for (i = 0;i < POLYGONELEMENTS_MAXPOINTS - 2;i++)
  94         {
  95                 polygonelements[i * 3 + 0] = 0;
  96                 polygonelements[i * 3 + 1] = i + 1;
  97                 polygonelements[i * 3 + 2] = i + 2;
  98         }
  99
 100         if (!gl_backend_mempool)
 101                 gl_backend_mempool = Mem_AllocPool("GL_Backend");
 102
 103         varray_vertex = Mem_Alloc(gl_backend_mempool, mesh_maxverts * sizeof(float[4]));
 104         varray_color = Mem_Alloc(gl_backend_mempool, mesh_maxverts * sizeof(float[4]));
 105         varray_bcolor = Mem_Alloc(gl_backend_mempool, mesh_maxverts * sizeof(qbyte[4]));
 106         for (i = 0;i < backendunits;i++)
 107                 varray_texcoord[i] = Mem_Alloc(gl_backend_mempool, mesh_maxverts * sizeof(float[2]));
 108         for (;i < MAX_TEXTUREUNITS;i++)
 109                 varray_texcoord[i] = NULL;
 110 }
 111
 112 void GL_Backend_FreeArrays(int resizingbuffers)
 113 {
 114         int i;
 115         if (resizingbuffers)
 116                 Mem_EmptyPool(gl_backend_mempool);
 117         else
 118                 Mem_FreePool(&gl_backend_mempool);
 119         varray_vertex = NULL;
 120         varray_color = NULL;
 121         varray_bcolor = NULL;
 122         for (i = 0;i < MAX_TEXTUREUNITS;i++)
 123                 varray_texcoord[i] = NULL;
 124 }
 125
 126 static void gl_backend_start(void)
 127 {
 128         Con_Printf("OpenGL Backend started with gl_mesh_maxverts %i\n", gl_mesh_maxverts.integer);
 129         if (qglDrawRangeElements != NULL)
 130         {
 131                 qglGetIntegerv(GL_MAX_ELEMENTS_VERTICES, &gl_maxdrawrangeelementsvertices);
 132                 qglGetIntegerv(GL_MAX_ELEMENTS_INDICES, &gl_maxdrawrangeelementsindices);
 133                 CHECKGLERROR
 134                 Con_Printf("glDrawRangeElements detected (max vertices %i, max indices %i)\n", gl_maxdrawrangeelementsvertices, gl_maxdrawrangeelementsindices);
 135         }
 136         if (strstr(gl_renderer, "3Dfx"))
 137         {
 138                 Con_Printf("3Dfx driver detected, forcing gl_mesh_floatcolors to 0 to prevent crashs\n");
 139                 Cvar_SetValueQuick(&gl_mesh_floatcolors, 0);
 140         }
 141
 142         backendunits = min(MAX_TEXTUREUNITS, gl_textureunits);
 143
 144         GL_Backend_AllocArrays();
 145
 146         backendactive = true;
 147 }
 148
 149 static void gl_backend_shutdown(void)
 150 {
 151         backendunits = 0;
 152         backendactive = false;
 153
 154         Con_Printf("OpenGL Backend shutting down\n");
 155
 156         GL_Backend_FreeArrays(false);
 157 }
 158
 159 void GL_Backend_CheckCvars(void)
 160 {
 161         // 21760 is (65536 / 3) rounded off to a multiple of 128
 162         if (gl_mesh_maxverts.integer < 1024)
 163                 Cvar_SetValueQuick(&gl_mesh_maxverts, 1024);
 164         if (gl_mesh_maxverts.integer > 21760)
 165                 Cvar_SetValueQuick(&gl_mesh_maxverts, 21760);
 166 }
 167
 168 void GL_Backend_ResizeArrays(int numtriangles)
 169 {
 170         Cvar_SetValueQuick(&gl_mesh_maxverts, numtriangles);
 171         GL_Backend_CheckCvars();
 172         mesh_maxverts = gl_mesh_maxverts.integer;
 173         GL_Backend_FreeArrays(true);
 174         GL_Backend_AllocArrays();
 175 }
 176
 177 static void gl_backend_newmap(void)
 178 {
 179 }
 180
 181 void gl_backend_init(void)
 182 {
 183         Cvar_RegisterVariable(&r_render);
 184         Cvar_RegisterVariable(&gl_dither);
 185         Cvar_RegisterVariable(&gl_lockarrays);
 186 #ifdef NORENDER
 187         Cvar_SetValue("r_render", 0);
 188 #endif
 189
 190         Cvar_RegisterVariable(&gl_mesh_maxverts);
 191         Cvar_RegisterVariable(&gl_mesh_floatcolors);
 192         Cvar_RegisterVariable(&gl_mesh_drawrangeelements);
 193         GL_Backend_CheckCvars();
 194         R_RegisterModule("GL_Backend", gl_backend_start, gl_backend_shutdown, gl_backend_newmap);
 195 }
 196
 197 void GL_SetupView_ViewPort (int x, int y, int width, int height)
 198 {
 199         if (!r_render.integer)
 200                 return;
 201
 202         // y is weird beause OpenGL is bottom to top, we use top to bottom
 203         qglViewport(x, vid.realheight - (y + height), width, height);
 204         CHECKGLERROR
 205 }
 206
 207 void GL_SetupView_Orientation_Identity (void)
 208 {
 209         Matrix4x4_CreateIdentity(&backend_viewmatrix);
 210         memset(&backend_modelmatrix, 0, sizeof(backend_modelmatrix));
 211 }
 212
 213 void GL_SetupView_Orientation_FromEntity (vec3_t origin, vec3_t angles)
 214 {
 215         Matrix4x4_CreateRotate(&backend_viewmatrix, -90, 1, 0, 0);
 216         Matrix4x4_ConcatRotate(&backend_viewmatrix, 90, 0, 0, 1);
 217         Matrix4x4_ConcatRotate(&backend_viewmatrix, -angles[2], 1, 0, 0);
 218         Matrix4x4_ConcatRotate(&backend_viewmatrix, -angles[0], 0, 1, 0);
 219         Matrix4x4_ConcatRotate(&backend_viewmatrix, -angles[1], 0, 0, 1);
 220         Matrix4x4_ConcatTranslate(&backend_viewmatrix, -origin[0], -origin[1], -origin[2]);
 221         memset(&backend_modelmatrix, 0, sizeof(backend_modelmatrix));
 222 }
 223
 224 void GL_SetupView_Mode_Perspective (double aspect, double fovx, double fovy, double zNear, double zFar)
 225 {
 226         double xmax, ymax;
 227
 228         if (!r_render.integer)
 229                 return;
 230
 231         // set up viewpoint
 232         qglMatrixMode(GL_PROJECTION);CHECKGLERROR
 233         qglLoadIdentity ();CHECKGLERROR
 234         // pyramid slopes
 235         xmax = zNear * tan(fovx * M_PI / 360.0);
 236         ymax = zNear * tan(fovy * M_PI / 360.0);
 237         // set view pyramid
 238         qglFrustum(-xmax, xmax, -ymax, ymax, zNear, zFar);CHECKGLERROR
 239         qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
 240         GL_SetupView_Orientation_Identity();
 241 }
 242
 243 void GL_SetupView_Mode_Ortho (double x1, double y1, double x2, double y2, double zNear, double zFar)
 244 {
 245         if (!r_render.integer)
 246                 return;
 247
 248         // set up viewpoint
 249         qglMatrixMode(GL_PROJECTION);CHECKGLERROR
 250         qglLoadIdentity ();CHECKGLERROR
 251         qglOrtho(x1, y2, x2, y1, zNear, zFar);
 252         qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
 253         GL_SetupView_Orientation_Identity();
 254 }
 255
 256 static struct
 257 {
 258         int blendfunc1;
 259         int blendfunc2;
 260         int blend;
 261         GLboolean depthmask;
 262         int depthdisable;
 263         int unit;
 264         int clientunit;
 265         int texture[MAX_TEXTUREUNITS];
 266         float texturergbscale[MAX_TEXTUREUNITS];
 267 }
 268 gl_state;
 269
 270 void GL_SetupTextureState(void)
 271 {
 272         int i;
 273         if (backendunits > 1)
 274         {
 275                 for (i = 0;i < backendunits;i++)
 276                 {
 277                         qglActiveTexture(GL_TEXTURE0_ARB + (gl_state.unit = i));CHECKGLERROR
 278                         qglBindTexture(GL_TEXTURE_2D, gl_state.texture[i]);CHECKGLERROR
 279                         if (gl_combine.integer)
 280                         {
 281                                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);CHECKGLERROR
 282                                 qglTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);CHECKGLERROR
 283                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);CHECKGLERROR
 284                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);CHECKGLERROR
 285                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE2_RGB_ARB, GL_CONSTANT_ARB);CHECKGLERROR
 286                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);CHECKGLERROR
 287                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);CHECKGLERROR
 288                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND2_RGB_ARB, GL_SRC_ALPHA);CHECKGLERROR
 289                                 qglTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, GL_MODULATE);CHECKGLERROR
 290                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB, GL_TEXTURE);CHECKGLERROR
 291                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_ALPHA_ARB, GL_PREVIOUS_ARB);CHECKGLERROR
 292                                 qglTexEnvi(GL_TEXTURE_ENV, GL_SOURCE2_ALPHA_ARB, GL_CONSTANT_ARB);CHECKGLERROR
 293                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA_ARB, GL_SRC_ALPHA);CHECKGLERROR
 294                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_ALPHA_ARB, GL_SRC_ALPHA);CHECKGLERROR
 295                                 qglTexEnvi(GL_TEXTURE_ENV, GL_OPERAND2_ALPHA_ARB, GL_SRC_ALPHA);CHECKGLERROR
 296                                 qglTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, gl_state.texturergbscale[i]);CHECKGLERROR
 297                                 qglTexEnvi(GL_TEXTURE_ENV, GL_ALPHA_SCALE, 1);CHECKGLERROR
 298                         }
 299                         else
 300                         {
 301                                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 302                         }
 303                         if (gl_state.texture[i])
 304                         {
 305                                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 306                         }
 307                         else
 308                         {
 309                                 qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 310                         }
 311                         qglClientActiveTexture(GL_TEXTURE0_ARB + (gl_state.clientunit = i));CHECKGLERROR
 312                         qglTexCoordPointer(2, GL_FLOAT, sizeof(float[2]), varray_texcoord[i]);CHECKGLERROR
 313                         if (gl_state.texture[i])
 314                         {
 315                                 qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 316                         }
 317                         else
 318                         {
 319                                 qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 320                         }
 321                 }
 322         }
 323         else
 324         {
 325                 qglBindTexture(GL_TEXTURE_2D, gl_state.texture[0]);CHECKGLERROR
 326                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 327                 if (gl_state.texture[0])
 328                 {
 329                         qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 330                 }
 331                 else
 332                 {
 333                         qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 334                 }
 335                 qglTexCoordPointer(2, GL_FLOAT, sizeof(float[2]), varray_texcoord[0]);CHECKGLERROR
 336                 if (gl_state.texture[0])
 337                 {
 338                         qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 339                 }
 340                 else
 341                 {
 342                         qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 343                 }
 344         }
 345 }
 346
 347 int usedarrays;
 348 void GL_Backend_ResetState(void)
 349 {
 350         int i;
 351         gl_state.unit = 0;
 352         gl_state.clientunit = 0;
 353
 354         for (i = 0;i < backendunits;i++)
 355         {
 356                 gl_state.texture[i] = 0;
 357                 gl_state.texturergbscale[i] = 1;
 358         }
 359
 360         qglEnable(GL_CULL_FACE);CHECKGLERROR
 361         qglCullFace(GL_FRONT);CHECKGLERROR
 362
 363         gl_state.depthdisable = false;
 364         qglEnable(GL_DEPTH_TEST);CHECKGLERROR
 365
 366         gl_state.blendfunc1 = GL_ONE;
 367         gl_state.blendfunc2 = GL_ZERO;
 368         qglBlendFunc(gl_state.blendfunc1, gl_state.blendfunc2);CHECKGLERROR
 369
 370         gl_state.blend = 0;
 371         qglDisable(GL_BLEND);CHECKGLERROR
 372
 373         gl_state.depthmask = GL_TRUE;
 374         qglDepthMask(gl_state.depthmask);CHECKGLERROR
 375
 376         usedarrays = false;
 377         usedarrays = true;
 378         qglVertexPointer(3, GL_FLOAT, sizeof(float[4]), varray_vertex);CHECKGLERROR
 379         qglEnableClientState(GL_VERTEX_ARRAY);CHECKGLERROR
 380         if (gl_mesh_floatcolors.integer)
 381         {
 382                 qglColorPointer(4, GL_FLOAT, sizeof(float[4]), varray_color);CHECKGLERROR
 383         }
 384         else
 385         {
 386                 qglColorPointer(4, GL_UNSIGNED_BYTE, sizeof(qbyte[4]), varray_bcolor);CHECKGLERROR
 387         }
 388         qglEnableClientState(GL_COLOR_ARRAY);CHECKGLERROR
 389
 390         GL_SetupTextureState();
 391 }
 392
 393 // called at beginning of frame
 394 void R_Mesh_Start(void)
 395 {
 396         BACKENDACTIVECHECK
 397
 398         CHECKGLERROR
 399
 400         GL_Backend_CheckCvars();
 401         if (mesh_maxverts != gl_mesh_maxverts.integer)
 402                 GL_Backend_ResizeArrays(gl_mesh_maxverts.integer);
 403
 404         GL_Backend_ResetState();
 405 }
 406
 407 int gl_backend_rebindtextures;
 408
 409 void GL_ConvertColorsFloatToByte(int numverts)
 410 {
 411         int i, k, total;
 412         // LordHavoc: to avoid problems with aliasing (treating memory as two
 413         // different types - exactly what this is doing), these must be volatile
 414         // (or a union)
 415         volatile int *icolor;
 416         volatile float *fcolor;
 417         qbyte *bcolor;
 418
 419         total = numverts * 4;
 420
 421         // shift float to have 8bit fraction at base of number
 422         fcolor = varray_color;
 423         for (i = 0;i < total;)
 424         {
 425                 fcolor[i    ] += 32768.0f;
 426                 fcolor[i + 1] += 32768.0f;
 427                 fcolor[i + 2] += 32768.0f;
 428                 fcolor[i + 3] += 32768.0f;
 429                 i += 4;
 430         }
 431
 432         // then read as integer and kill float bits...
 433         icolor = (int *)varray_color;
 434         bcolor = varray_bcolor;
 435         for (i = 0;i < total;)
 436         {
 437                 k = icolor[i    ] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i    ] = (qbyte) k;
 438                 k = icolor[i + 1] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i + 1] = (qbyte) k;
 439                 k = icolor[i + 2] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i + 2] = (qbyte) k;
 440                 k = icolor[i + 3] & 0x7FFFFF;if (k > 255) k = 255;bcolor[i + 3] = (qbyte) k;
 441                 i += 4;
 442         }
 443 }
 444
 445 /*
 446 void GL_TransformVertices(int numverts)
 447 {
 448         int i;
 449         float m[12], tempv[4], *v;
 450         m[0] = backendmatrix.m[0][0];
 451         m[1] = backendmatrix.m[0][1];
 452         m[2] = backendmatrix.m[0][2];
 453         m[3] = backendmatrix.m[0][3];
 454         m[4] = backendmatrix.m[1][0];
 455         m[5] = backendmatrix.m[1][1];
 456         m[6] = backendmatrix.m[1][2];
 457         m[7] = backendmatrix.m[1][3];
 458         m[8] = backendmatrix.m[2][0];
 459         m[9] = backendmatrix.m[2][1];
 460         m[10] = backendmatrix.m[2][2];
 461         m[11] = backendmatrix.m[2][3];
 462         for (i = 0, v = varray_vertex;i < numverts;i++, v += 4)
 463         {
 464                 VectorCopy(v, tempv);
 465                 v[0] = tempv[0] * m[0] + tempv[1] * m[1] + tempv[2] * m[2] + m[3];
 466                 v[1] = tempv[0] * m[4] + tempv[1] * m[5] + tempv[2] * m[6] + m[7];
 467                 v[2] = tempv[0] * m[8] + tempv[1] * m[9] + tempv[2] * m[10] + m[11];
 468         }
 469 }
 470 */
 471
 472 void GL_DrawRangeElements(int firstvert, int endvert, int indexcount, int *index)
 473 {
 474         int arraylocked = false;
 475         c_meshs++;
 476         c_meshelements += indexcount;
 477         if (gl_supportslockarrays && gl_lockarrays.integer)
 478         {
 479                 qglLockArraysEXT(firstvert, endvert - firstvert);
 480                 CHECKGLERROR
 481                 arraylocked = true;
 482         }
 483         if (gl_mesh_drawrangeelements.integer && qglDrawRangeElements != NULL)
 484                 qglDrawRangeElements(GL_TRIANGLES, firstvert, endvert, indexcount, GL_UNSIGNED_INT, (GLuint *) index);
 485         else
 486                 qglDrawElements(GL_TRIANGLES, indexcount, GL_UNSIGNED_INT, (GLuint *) index);
 487         CHECKGLERROR
 488         if (arraylocked)
 489         {
 490                 qglUnlockArraysEXT();
 491                 CHECKGLERROR
 492                 arraylocked = false;
 493         }
 494 }
 495
 496 // enlarges geometry buffers if they are too small
 497 void _R_Mesh_ResizeCheck(int numverts)
 498 {
 499         if (numverts > mesh_maxverts)
 500         {
 501                 BACKENDACTIVECHECK
 502                 GL_Backend_ResizeArrays(numverts + 100);
 503                 GL_Backend_ResetState();
 504         }
 505 }
 506
 507 // renders the mesh
 508 void R_Mesh_Draw(int numverts, int numtriangles, int *elements)
 509 {
 510         BACKENDACTIVECHECK
 511
 512         CHECKGLERROR
 513
 514         if (!gl_mesh_floatcolors.integer)
 515                 GL_ConvertColorsFloatToByte(numverts);
 516         //GL_TransformVertices(numverts);
 517         if (!r_render.integer)
 518                 return;
 519         GL_DrawRangeElements(0, numverts, numtriangles * 3, elements);
 520 }
 521
 522 // restores backend state, used when done with 3D rendering
 523 void R_Mesh_Finish(void)
 524 {
 525         int i;
 526         BACKENDACTIVECHECK
 527
 528         if (backendunits > 1)
 529         {
 530                 for (i = backendunits - 1;i >= 0;i--)
 531                 {
 532                         qglActiveTexture(GL_TEXTURE0_ARB + i);CHECKGLERROR
 533                         qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 534                         if (gl_combine.integer)
 535                         {
 536                                 qglTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 1);CHECKGLERROR
 537                         }
 538                         if (i > 0)
 539                         {
 540                                 qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 541                         }
 542                         else
 543                         {
 544                                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 545                         }
 546                         qglBindTexture(GL_TEXTURE_2D, 0);CHECKGLERROR
 547
 548                         if (usedarrays)
 549                         {
 550                                 qglClientActiveTexture(GL_TEXTURE0_ARB + i);CHECKGLERROR
 551                                 qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 552                         }
 553                 }
 554         }
 555         else
 556         {
 557                 qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
 558                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 559                 if (usedarrays)
 560                 {
 561                         qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 562                 }
 563         }
 564         if (usedarrays)
 565         {
 566                 qglDisableClientState(GL_COLOR_ARRAY);CHECKGLERROR
 567                 qglDisableClientState(GL_VERTEX_ARRAY);CHECKGLERROR
 568         }
 569
 570         qglDisable(GL_BLEND);CHECKGLERROR
 571         qglEnable(GL_DEPTH_TEST);CHECKGLERROR
 572         qglDepthMask(GL_TRUE);CHECKGLERROR
 573         qglBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);CHECKGLERROR
 574 }
 575
 576 void GL_DepthFunc(int value)
 577 {
 578         if (!r_render.integer)
 579                 return;
 580
 581         qglDepthFunc (value);
 582         CHECKGLERROR
 583 }
 584
 585 void GL_ClearDepth(void)
 586 {
 587         BACKENDACTIVECHECK
 588
 589         if (!r_render.integer)
 590                 return;
 591
 592         qglClear(GL_DEPTH_BUFFER_BIT);
 593         CHECKGLERROR
 594 }
 595
 596 void R_Mesh_Matrix(const matrix4x4_t *matrix)
 597 {
 598         if (memcmp(matrix, &backend_modelmatrix, sizeof(matrix4x4_t)))
 599         {
 600                 backend_modelmatrix = *matrix;
 601                 Matrix4x4_Concat(&backend_modelviewmatrix, &backend_viewmatrix, matrix);
 602                 Matrix4x4_Transpose(&backend_glmodelviewmatrix, &backend_modelviewmatrix);
 603                 qglLoadMatrixf(&backend_glmodelviewmatrix.m[0][0]);
 604         }
 605 }
 606
 607 // sets up the requested state
 608 void R_Mesh_MainState(const rmeshstate_t *m)
 609 {
 610         BACKENDACTIVECHECK
 611
 612         if (gl_state.blendfunc1 != m->blendfunc1 || gl_state.blendfunc2 != m->blendfunc2)
 613         {
 614                 qglBlendFunc(gl_state.blendfunc1 = m->blendfunc1, gl_state.blendfunc2 = m->blendfunc2);CHECKGLERROR
 615                 if (gl_state.blendfunc2 == GL_ZERO)
 616                 {
 617                         if (gl_state.blendfunc1 == GL_ONE)
 618                         {
 619                                 if (gl_state.blend)
 620                                 {
 621                                         gl_state.blend = 0;
 622                                         qglDisable(GL_BLEND);CHECKGLERROR
 623                                 }
 624                         }
 625                         else
 626                         {
 627                                 if (!gl_state.blend)
 628                                 {
 629                                         gl_state.blend = 1;
 630                                         qglEnable(GL_BLEND);CHECKGLERROR
 631                                 }
 632                         }
 633                 }
 634                 else
 635                 {
 636                         if (!gl_state.blend)
 637                         {
 638                                 gl_state.blend = 1;
 639                                 qglEnable(GL_BLEND);CHECKGLERROR
 640                         }
 641                 }
 642         }
 643         if (gl_state.depthdisable != m->depthdisable)
 644         {
 645                 gl_state.depthdisable = m->depthdisable;
 646                 if (gl_state.depthdisable)
 647                         qglDisable(GL_DEPTH_TEST);
 648                 else
 649                         qglEnable(GL_DEPTH_TEST);
 650         }
 651         if (gl_state.depthmask != (m->blendfunc2 == GL_ZERO || m->depthwrite))
 652         {
 653                 qglDepthMask(gl_state.depthmask = (m->blendfunc2 == GL_ZERO || m->depthwrite));CHECKGLERROR
 654         }
 655 }
 656
 657 void R_Mesh_TextureState(const rmeshstate_t *m)
 658 {
 659         int i;
 660         int texturergbscale[MAX_TEXTUREUNITS];
 661
 662         BACKENDACTIVECHECK
 663
 664         if (gl_backend_rebindtextures)
 665         {
 666                 gl_backend_rebindtextures = false;
 667                 GL_SetupTextureState();
 668         }
 669
 670         for (i = 0;i < backendunits;i++)
 671         {
 672                 if (m->texrgbscale[i])
 673                         texturergbscale[i] = m->texrgbscale[i];
 674                 else
 675                         texturergbscale[i] = 1;
 676         }
 677
 678         if (backendunits > 1)
 679         {
 680                 for (i = 0;i < backendunits;i++)
 681                 {
 682                         if (gl_state.texture[i] != m->tex[i])
 683                         {
 684                                 if (gl_state.unit != i)
 685                                 {
 686                                         qglActiveTexture(GL_TEXTURE0_ARB + (gl_state.unit = i));CHECKGLERROR
 687                                 }
 688                                 if (gl_state.texture[i] == 0)
 689                                 {
 690                                         qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 691                                         if (gl_state.clientunit != i)
 692                                         {
 693                                                 qglClientActiveTexture(GL_TEXTURE0_ARB + (gl_state.clientunit = i));CHECKGLERROR
 694                                         }
 695                                         qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 696                                 }
 697                                 qglBindTexture(GL_TEXTURE_2D, (gl_state.texture[i] = m->tex[i]));CHECKGLERROR
 698                                 if (gl_state.texture[i] == 0)
 699                                 {
 700                                         qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 701                                         if (gl_state.clientunit != i)
 702                                         {
 703                                                 qglClientActiveTexture(GL_TEXTURE0_ARB + (gl_state.clientunit = i));CHECKGLERROR
 704                                         }
 705                                         qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 706                                 }
 707                         }
 708                         if (gl_state.texturergbscale[i] != texturergbscale[i])
 709                         {
 710                                 if (gl_state.unit != i)
 711                                 {
 712                                         qglActiveTexture(GL_TEXTURE0_ARB + (gl_state.unit = i));CHECKGLERROR
 713                                 }
 714                                 qglTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, (gl_state.texturergbscale[i] = texturergbscale[i]));CHECKGLERROR
 715                         }
 716                 }
 717         }
 718         else
 719         {
 720                 if (gl_state.texture[0] != m->tex[0])
 721                 {
 722                         if (gl_state.texture[0] == 0)
 723                         {
 724                                 qglEnable(GL_TEXTURE_2D);CHECKGLERROR
 725                                 qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 726                         }
 727                         qglBindTexture(GL_TEXTURE_2D, (gl_state.texture[0] = m->tex[0]));CHECKGLERROR
 728                         if (gl_state.texture[0] == 0)
 729                         {
 730                                 qglDisable(GL_TEXTURE_2D);CHECKGLERROR
 731                                 qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
 732                         }
 733                 }
 734         }
 735 }
 736
 737 void R_Mesh_State(const rmeshstate_t *m)
 738 {
 739         R_Mesh_MainState(m);
 740         R_Mesh_TextureState(m);
 741 }
 742
 743 /*
 744 ==============================================================================
 745
 746                                                 SCREEN SHOTS
 747
 748 ==============================================================================
 749 */
 750
 751 qboolean SCR_ScreenShot(char *filename, int x, int y, int width, int height)
 752 {
 753         qboolean ret;
 754         int i;
 755         qbyte *buffer;
 756
 757         if (!r_render.integer)
 758                 return false;
 759
 760         buffer = Mem_Alloc(tempmempool, width*height*3);
 761         qglReadPixels (x, y, width, height, GL_RGB, GL_UNSIGNED_BYTE, buffer);
 762         CHECKGLERROR
 763
 764         // LordHavoc: compensate for v_overbrightbits when using hardware gamma
 765         if (v_hwgamma.integer)
 766                 for (i = 0;i < width * height * 3;i++)
 767                         buffer[i] <<= v_overbrightbits.integer;
 768
 769         ret = Image_WriteTGARGB_preflipped(filename, width, height, buffer);
 770
 771         Mem_Free(buffer);
 772         return ret;
 773 }
 774
 775 //=============================================================================
 776
 777 void R_ClearScreen(void)
 778 {
 779         if (r_render.integer)
 780         {
 781                 // clear to black
 782                 qglClearColor(0,0,0,0);CHECKGLERROR
 783                 // clear the screen
 784                 qglClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);CHECKGLERROR
 785                 // set dithering mode
 786                 if (gl_dither.integer)
 787                 {
 788                         qglEnable(GL_DITHER);CHECKGLERROR
 789                 }
 790                 else
 791                 {
 792                         qglDisable(GL_DITHER);CHECKGLERROR
 793                 }
 794         }
 795 }
 796
 797 /*
 798 ==================
 799 SCR_UpdateScreen
 800
 801 This is called every frame, and can also be called explicitly to flush
 802 text to the screen.
 803 ==================
 804 */
 805 void SCR_UpdateScreen (void)
 806 {
 807         VID_Finish ();
 808
 809         R_TimeReport("finish");
 810
 811         if (r_textureunits.integer > gl_textureunits)
 812                 Cvar_SetValueQuick(&r_textureunits, gl_textureunits);
 813         if (r_textureunits.integer < 1)
 814                 Cvar_SetValueQuick(&r_textureunits, 1);
 815
 816         if (gl_combine.integer && (!gl_combine_extension || r_textureunits.integer < 2))
 817                 Cvar_SetValueQuick(&gl_combine, 0);
 818
 819         // lighting scale
 820         r_colorscale = 1.0f / (float) (1 << v_overbrightbits.integer);
 821
 822         // lightmaps only
 823         r_lightmapscalebit = v_overbrightbits.integer;
 824         if (gl_combine.integer && r_textureunits.integer > 1)
 825                 r_lightmapscalebit += 2;
 826
 827         R_TimeReport("setup");
 828
 829         R_ClearScreen();
 830
 831         R_TimeReport("clear");
 832
 833         if (scr_conlines < vid.conheight && cls.signon == SIGNONS)
 834                 R_RenderView();
 835
 836         // draw 2D stuff
 837         R_DrawQueue();
 838
 839         // tell driver to commit it's partially full geometry queue to the rendering queue
 840         // (this doesn't wait for the commands themselves to complete)
 841         qglFlush();
 842 }
 843