r_light.c

   1 /*
   2 Copyright (C) 1996-1997 Id Software, Inc.
   3
   4 This program is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU General Public License
   6 as published by the Free Software Foundation; either version 2
   7 of the License, or (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  12
  13 See the GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18
  19 */
  20 // r_light.c
  21
  22 #include "quakedef.h"
  23 #include "cl_collision.h"
  24 #include "r_shadow.h"
  25
  26 rdlight_t r_dlight[MAX_DLIGHTS];
  27 int r_numdlights = 0;
  28
  29 cvar_t r_modellights = {CVAR_SAVE, "r_modellights", "4"};
  30 cvar_t r_vismarklights = {0, "r_vismarklights", "1"};
  31 cvar_t r_coronas = {CVAR_SAVE, "r_coronas", "1"};
  32 cvar_t gl_flashblend = {CVAR_SAVE, "gl_flashblend", "1"};
  33
  34 static rtexture_t *lightcorona;
  35 static rtexturepool_t *lighttexturepool;
  36
  37 void r_light_start(void)
  38 {
  39         float dx, dy;
  40         int x, y, a;
  41         qbyte pixels[32][32][4];
  42         lighttexturepool = R_AllocTexturePool();
  43         for (y = 0;y < 32;y++)
  44         {
  45                 dy = (y - 15.5f) * (1.0f / 16.0f);
  46                 for (x = 0;x < 32;x++)
  47                 {
  48                         dx = (x - 15.5f) * (1.0f / 16.0f);
  49                         a = ((1.0f / (dx * dx + dy * dy + 0.2f)) - (1.0f / (1.0f + 0.2))) * 32.0f / (1.0f / (1.0f + 0.2));
  50                         a = bound(0, a, 255);
  51                         pixels[y][x][0] = a;
  52                         pixels[y][x][1] = a;
  53                         pixels[y][x][2] = a;
  54                         pixels[y][x][3] = 255;
  55                 }
  56         }
  57         lightcorona = R_LoadTexture2D(lighttexturepool, "lightcorona", 32, 32, &pixels[0][0][0], TEXTYPE_RGBA, TEXF_PRECACHE, NULL);
  58 }
  59
  60 void r_light_shutdown(void)
  61 {
  62         lighttexturepool = NULL;
  63         lightcorona = NULL;
  64 }
  65
  66 void r_light_newmap(void)
  67 {
  68         int i;
  69         for (i = 0;i < 256;i++)
  70                 d_lightstylevalue[i] = 264;             // normal light value
  71 }
  72
  73 void R_Light_Init(void)
  74 {
  75         Cvar_RegisterVariable(&r_modellights);
  76         Cvar_RegisterVariable(&r_vismarklights);
  77         Cvar_RegisterVariable(&r_coronas);
  78         Cvar_RegisterVariable(&gl_flashblend);
  79         R_RegisterModule("R_Light", r_light_start, r_light_shutdown, r_light_newmap);
  80 }
  81
  82 /*
  83 ==================
  84 R_AnimateLight
  85 ==================
  86 */
  87 void R_AnimateLight (void)
  88 {
  89         int i, j, k;
  90
  91 //
  92 // light animations
  93 // 'm' is normal light, 'a' is no light, 'z' is double bright
  94         i = (int)(cl.time * 10);
  95         for (j = 0;j < MAX_LIGHTSTYLES;j++)
  96         {
  97                 if (!cl_lightstyle || !cl_lightstyle[j].length)
  98                 {
  99                         d_lightstylevalue[j] = 256;
 100                         continue;
 101                 }
 102                 k = i % cl_lightstyle[j].length;
 103                 k = cl_lightstyle[j].map[k] - 'a';
 104                 k = k*22;
 105                 d_lightstylevalue[j] = k;
 106         }
 107 }
 108
 109
 110 void R_BuildLightList(void)
 111 {
 112         int i;
 113         dlight_t *cd;
 114         rdlight_t *rd;
 115
 116         r_numdlights = 0;
 117         c_dlights = 0;
 118
 119         if (!r_dynamic.integer || !cl_dlights)
 120                 return;
 121
 122         for (i = 0;i < MAX_DLIGHTS;i++)
 123         {
 124                 cd = cl_dlights + i;
 125                 if (cd->radius <= 0)
 126                         continue;
 127                 rd = &r_dlight[r_numdlights++];
 128                 VectorCopy(cd->origin, rd->origin);
 129                 VectorScale(cd->color, cd->radius * 64.0f, rd->light);
 130                 rd->cullradius2 = DotProduct(rd->light, rd->light) * (0.25f / (64.0f * 64.0f)) + 4096.0f;
 131                 // clamp radius to avoid overflowing division table in lightmap code
 132                 if (rd->cullradius2 > (2048.0f * 2048.0f))
 133                         rd->cullradius2 = (2048.0f * 2048.0f);
 134                 rd->cullradius = sqrt(rd->cullradius2);
 135                 rd->subtract = 1.0f / rd->cullradius2;
 136                 rd->ent = cd->ent;
 137                 c_dlights++; // count every dlight in use
 138         }
 139 }
 140
 141 void R_DrawCoronas(void)
 142 {
 143         int i;
 144         float cscale, scale, viewdist, dist;
 145         rdlight_t *rd;
 146         if (!r_coronas.integer)
 147                 return;
 148         R_Mesh_Matrix(&r_identitymatrix);
 149         viewdist = DotProduct(r_origin, vpn);
 150         for (i = 0;i < r_numdlights;i++)
 151         {
 152                 rd = r_dlight + i;
 153                 dist = (DotProduct(rd->origin, vpn) - viewdist);
 154                 if (dist >= 24.0f && CL_TraceLine(rd->origin, r_origin, NULL, NULL, 0, true, NULL) == 1)
 155                 {
 156                         cscale = (1.0f / 131072.0f);
 157                         scale = rd->cullradius * 0.25f;
 158                         if (gl_flashblend.integer)
 159                         {
 160                                 cscale *= 4.0f;
 161                                 scale *= 2.0f;
 162                         }
 163                         R_DrawSprite(GL_ONE, GL_ONE, lightcorona, true, rd->origin, vright, vup, scale, -scale, -scale, scale, rd->light[0] * cscale, rd->light[1] * cscale, rd->light[2] * cscale, 1);
 164                 }
 165         }
 166 }
 167
 168 /*
 169 =============================================================================
 170
 171 DYNAMIC LIGHTS
 172
 173 =============================================================================
 174 */
 175
 176 static int lightpvsbytes;
 177 static qbyte lightpvs[(MAX_MAP_LEAFS+7)>>3];
 178
 179 /*
 180 =============
 181 R_MarkLights
 182 =============
 183 */
 184 static void R_RecursiveMarkLights(entity_render_t *ent, vec3_t lightorigin, rdlight_t *rd, int bit, int bitindex, mnode_t *node, qbyte *pvs, int pvsbits)
 185 {
 186         int i;
 187         mleaf_t *leaf;
 188         float dist;
 189
 190         // for comparisons to minimum acceptable light
 191         while(node->contents >= 0)
 192         {
 193                 dist = PlaneDiff(lightorigin, node->plane);
 194                 if (dist > rd->cullradius)
 195                         node = node->children[0];
 196                 else
 197                 {
 198                         if (dist >= -rd->cullradius)
 199                                 R_RecursiveMarkLights(ent, lightorigin, rd, bit, bitindex, node->children[0], pvs, pvsbits);
 200                         node = node->children[1];
 201                 }
 202         }
 203
 204         // check if leaf is visible according to pvs
 205         leaf = (mleaf_t *)node;
 206         i = (leaf - ent->model->brushq1.leafs) - 1;
 207         if (leaf->nummarksurfaces && (i >= pvsbits || pvs[i >> 3] & (1 << (i & 7))))
 208         {
 209                 int *surfacepvsframes, d, impacts, impactt;
 210                 float sdist, maxdist, dist2, impact[3];
 211                 msurface_t *surf;
 212                 // mark the polygons
 213                 maxdist = rd->cullradius2;
 214                 surfacepvsframes = ent->model->brushq1.surfacepvsframes;
 215                 for (i = 0;i < leaf->nummarksurfaces;i++)
 216                 {
 217                         if (surfacepvsframes[leaf->firstmarksurface[i]] != ent->model->brushq1.pvsframecount)
 218                                 continue;
 219                         surf = ent->model->brushq1.surfaces + leaf->firstmarksurface[i];
 220                         dist = sdist = PlaneDiff(lightorigin, surf->plane);
 221                         if (surf->flags & SURF_PLANEBACK)
 222                                 dist = -dist;
 223
 224                         if (dist < -0.25f && !(surf->flags & SURF_LIGHTBOTHSIDES))
 225                                 continue;
 226
 227                         dist2 = dist * dist;
 228                         if (dist2 >= maxdist)
 229                                 continue;
 230
 231                         VectorCopy(lightorigin, impact);
 232                         if (surf->plane->type >= 3)
 233                                 VectorMA(impact, -sdist, surf->plane->normal, impact);
 234                         else
 235                                 impact[surf->plane->type] -= sdist;
 236
 237                         impacts = DotProduct (impact, surf->texinfo->vecs[0]) + surf->texinfo->vecs[0][3] - surf->texturemins[0];
 238
 239                         d = bound(0, impacts, surf->extents[0] + 16) - impacts;
 240                         dist2 += d * d;
 241                         if (dist2 > maxdist)
 242                                 continue;
 243
 244                         impactt = DotProduct (impact, surf->texinfo->vecs[1]) + surf->texinfo->vecs[1][3] - surf->texturemins[1];
 245
 246                         d = bound(0, impactt, surf->extents[1] + 16) - impactt;
 247                         dist2 += d * d;
 248                         if (dist2 > maxdist)
 249                                 continue;
 250
 251                         if (surf->dlightframe != r_framecount) // not dynamic until now
 252                         {
 253                                 surf->dlightbits[0] = surf->dlightbits[1] = surf->dlightbits[2] = surf->dlightbits[3] = surf->dlightbits[4] = surf->dlightbits[5] = surf->dlightbits[6] = surf->dlightbits[7] = 0;
 254                                 surf->dlightframe = r_framecount;
 255                                 if (r_dlightmap.integer)
 256                                         surf->cached_dlight = true;
 257                         }
 258                         surf->dlightbits[bitindex] |= bit;
 259                 }
 260         }
 261 }
 262
 263 void R_MarkLights(entity_render_t *ent)
 264 {
 265         int i, bit, bitindex;
 266         rdlight_t *rd;
 267         vec3_t lightorigin;
 268         if (!gl_flashblend.integer && r_dynamic.integer && ent->model)
 269         {
 270                 for (i = 0, rd = r_dlight;i < r_numdlights;i++, rd++)
 271                 {
 272                         bit = 1 << (i & 31);
 273                         bitindex = i >> 5;
 274                         Matrix4x4_Transform(&ent->inversematrix, rd->origin, lightorigin);
 275                         lightpvsbytes = 0;
 276                         if (r_vismarklights.integer && ent->model->brush.FatPVS)
 277                                 lightpvsbytes = ent->model->brush.FatPVS(ent->model, lightorigin, 0, lightpvs, sizeof(lightpvs));
 278                         R_RecursiveMarkLights(ent, lightorigin, rd, bit, bitindex, ent->model->brushq1.nodes + ent->model->brushq1.hulls[0].firstclipnode, lightpvs, min(lightpvsbytes * 8, ent->model->brushq1.num_leafs - 1));
 279                 }
 280         }
 281 }
 282
 283 /*
 284 =============================================================================
 285
 286 LIGHT SAMPLING
 287
 288 =============================================================================
 289 */
 290
 291 void R_CompleteLightPoint(vec3_t ambientcolor, vec3_t diffusecolor, vec3_t diffusenormal, const vec3_t p, int dynamic, const mleaf_t *leaf)
 292 {
 293         VectorClear(diffusecolor);
 294         VectorClear(diffusenormal);
 295
 296         if (!r_fullbright.integer && cl.worldmodel && cl.worldmodel->brush.LightPoint)
 297         {
 298                 ambientcolor[0] = ambientcolor[1] = ambientcolor[2] = r_ambient.value * (2.0f / 128.0f);
 299                 cl.worldmodel->brush.LightPoint(cl.worldmodel, p, ambientcolor, diffusecolor, diffusenormal);
 300         }
 301         else
 302                 VectorSet(ambientcolor, 1, 1, 1);
 303
 304         /*
 305         if (leaf == NULL && cl.worldmodel != NULL)
 306                 leaf = cl.worldmodel->brushq1.PointInLeaf(cl.worldmodel, p);
 307         if (!leaf || leaf->contents == CONTENTS_SOLID || !cl.worldmodel->brushq1.lightdata)
 308         {
 309                 VectorSet(ambientcolor, 1, 1, 1);
 310                 return;
 311         }
 312         */
 313
 314         // FIXME: this .lights related stuff needs to be ported into the Mod_Q1BSP code
 315         if (cl.worldmodel->brushq1.numlights)
 316         {
 317                 int i;
 318                 vec3_t v;
 319                 float f;
 320                 mlight_t *sl;
 321                 for (i = 0;i < cl.worldmodel->brushq1.numlights;i++)
 322                 {
 323                         sl = cl.worldmodel->brushq1.lights + i;
 324                         if (d_lightstylevalue[sl->style] > 0)
 325                         {
 326                                 VectorSubtract (p, sl->origin, v);
 327                                 f = ((1.0f / (DotProduct(v, v) * sl->falloff + sl->distbias)) - sl->subtract);
 328                                 if (f > 0 && CL_TraceLine(p, sl->origin, NULL, NULL, 0, false, NULL) == 1)
 329                                 {
 330                                         f *= d_lightstylevalue[sl->style] * (1.0f / 65536.0f);
 331                                         VectorMA(ambientcolor, f, sl->light, ambientcolor);
 332                                 }
 333                         }
 334                 }
 335         }
 336
 337         if (dynamic)
 338         {
 339                 int i;
 340                 float f, v[3];
 341                 rdlight_t *rd;
 342                 // FIXME: this really should handle dlights as diffusecolor/diffusenormal somehow
 343                 for (i = 0;i < r_numdlights;i++)
 344                 {
 345                         rd = r_dlight + i;
 346                         VectorSubtract(p, rd->origin, v);
 347                         f = DotProduct(v, v);
 348                         if (f < rd->cullradius2 && CL_TraceLine(p, rd->origin, NULL, NULL, 0, false, NULL) == 1)
 349                         {
 350                                 f = (1.0f / (f + LIGHTOFFSET)) - rd->subtract;
 351                                 VectorMA(ambientcolor, f, rd->light, ambientcolor);
 352                         }
 353                 }
 354         }
 355 }
 356
 357 typedef struct
 358 {
 359         vec3_t origin;
 360         //vec_t cullradius2;
 361         vec3_t light;
 362         // how much this light would contribute to ambient if replaced
 363         vec3_t ambientlight;
 364         vec_t subtract;
 365         vec_t falloff;
 366         vec_t offset;
 367         // used for choosing only the brightest lights
 368         vec_t intensity;
 369 }
 370 nearlight_t;
 371
 372 static int nearlights;
 373 static nearlight_t nearlight[MAX_DLIGHTS];
 374
 375 int R_LightModel(float *ambient4f, float *diffusecolor, float *diffusenormal, const entity_render_t *ent, float colorr, float colorg, float colorb, float colora, int worldcoords)
 376 {
 377         int i, j, maxnearlights;
 378         float v[3], f, mscale, stylescale, intensity, ambientcolor[3];
 379         nearlight_t *nl;
 380         mlight_t *sl;
 381         rdlight_t *rd;
 382
 383         nearlights = 0;
 384         maxnearlights = r_modellights.integer;
 385         ambient4f[0] = ambient4f[1] = ambient4f[2] = r_ambient.value * (2.0f / 128.0f);
 386         VectorClear(diffusecolor);
 387         VectorClear(diffusenormal);
 388         if (r_fullbright.integer || (ent->effects & EF_FULLBRIGHT))
 389         {
 390                 // highly rare
 391                 VectorSet(ambient4f, 1, 1, 1);
 392                 maxnearlights = 0;
 393         }
 394         else if (r_shadow_realtime_world.integer)
 395                 maxnearlights = 0;
 396         else
 397         {
 398                 if (cl.worldmodel && cl.worldmodel->brush.LightPoint)
 399                         cl.worldmodel->brush.LightPoint(cl.worldmodel, ent->origin, ambient4f, diffusecolor, diffusenormal);
 400                 else
 401                         VectorSet(ambient4f, 1, 1, 1);
 402         }
 403
 404         // scale of the model's coordinate space, to alter light attenuation to match
 405         // make the mscale squared so it can scale the squared distance results
 406         mscale = ent->scale * ent->scale;
 407         // FIXME: no support for .lights on non-Q1BSP?
 408         nl = &nearlight[0];
 409         for (i = 0;i < ent->numentlights;i++)
 410         {
 411                 sl = cl.worldmodel->brushq1.lights + ent->entlights[i];
 412                 stylescale = d_lightstylevalue[sl->style] * (1.0f / 65536.0f);
 413                 VectorSubtract (ent->origin, sl->origin, v);
 414                 f = ((1.0f / (DotProduct(v, v) * sl->falloff + sl->distbias)) - sl->subtract) * stylescale;
 415                 VectorScale(sl->light, f, ambientcolor);
 416                 intensity = DotProduct(ambientcolor, ambientcolor);
 417                 if (f < 0)
 418                         intensity *= -1.0f;
 419                 if (nearlights < maxnearlights)
 420                         j = nearlights++;
 421                 else
 422                 {
 423                         for (j = 0;j < maxnearlights;j++)
 424                         {
 425                                 if (nearlight[j].intensity < intensity)
 426                                 {
 427                                         if (nearlight[j].intensity > 0)
 428                                                 VectorAdd(ambient4f, nearlight[j].ambientlight, ambient4f);
 429                                         break;
 430                                 }
 431                         }
 432                 }
 433                 if (j >= maxnearlights)
 434                 {
 435                         // this light is less significant than all others,
 436                         // add it to ambient
 437                         if (intensity > 0)
 438                                 VectorAdd(ambient4f, ambientcolor, ambient4f);
 439                 }
 440                 else
 441                 {
 442                         nl = nearlight + j;
 443                         nl->intensity = intensity;
 444                         // transform the light into the model's coordinate system
 445                         if (worldcoords)
 446                                 VectorCopy(sl->origin, nl->origin);
 447                         else
 448                                 Matrix4x4_Transform(&ent->inversematrix, sl->origin, nl->origin);
 449                         // integrate mscale into falloff, for maximum speed
 450                         nl->falloff = sl->falloff * mscale;
 451                         VectorCopy(ambientcolor, nl->ambientlight);
 452                         nl->light[0] = sl->light[0] * stylescale * colorr * 4.0f;
 453                         nl->light[1] = sl->light[1] * stylescale * colorg * 4.0f;
 454                         nl->light[2] = sl->light[2] * stylescale * colorb * 4.0f;
 455                         nl->subtract = sl->subtract;
 456                         nl->offset = sl->distbias;
 457                 }
 458         }
 459         if (!r_shadow_realtime_dlight.integer)
 460         {
 461                 for (i = 0;i < r_numdlights;i++)
 462                 {
 463                         rd = r_dlight + i;
 464                         VectorCopy(rd->origin, v);
 465                         if (v[0] < ent->mins[0]) v[0] = ent->mins[0];if (v[0] > ent->maxs[0]) v[0] = ent->maxs[0];
 466                         if (v[1] < ent->mins[1]) v[1] = ent->mins[1];if (v[1] > ent->maxs[1]) v[1] = ent->maxs[1];
 467                         if (v[2] < ent->mins[2]) v[2] = ent->mins[2];if (v[2] > ent->maxs[2]) v[2] = ent->maxs[2];
 468                         VectorSubtract (v, rd->origin, v);
 469                         if (DotProduct(v, v) < rd->cullradius2)
 470                         {
 471                                 if (CL_TraceLine(ent->origin, rd->origin, NULL, NULL, 0, false, NULL) != 1)
 472                                         continue;
 473                                 VectorSubtract (ent->origin, rd->origin, v);
 474                                 f = ((1.0f / (DotProduct(v, v) + LIGHTOFFSET)) - rd->subtract);
 475                                 VectorScale(rd->light, f, ambientcolor);
 476                                 intensity = DotProduct(ambientcolor, ambientcolor);
 477                                 if (f < 0)
 478                                         intensity *= -1.0f;
 479                                 if (nearlights < maxnearlights)
 480                                         j = nearlights++;
 481                                 else
 482                                 {
 483                                         for (j = 0;j < maxnearlights;j++)
 484                                         {
 485                                                 if (nearlight[j].intensity < intensity)
 486                                                 {
 487                                                         if (nearlight[j].intensity > 0)
 488                                                                 VectorAdd(ambient4f, nearlight[j].ambientlight, ambient4f);
 489                                                         break;
 490                                                 }
 491                                         }
 492                                 }
 493                                 if (j >= maxnearlights)
 494                                 {
 495                                         // this light is less significant than all others,
 496                                         // add it to ambient
 497                                         if (intensity > 0)
 498                                                 VectorAdd(ambient4f, ambientcolor, ambient4f);
 499                                 }
 500                                 else
 501                                 {
 502                                         nl = nearlight + j;
 503                                         nl->intensity = intensity;
 504                                         // transform the light into the model's coordinate system
 505                                         if (worldcoords)
 506                                                 VectorCopy(rd->origin, nl->origin);
 507                                         else
 508                                         {
 509                                                 Matrix4x4_Transform(&ent->inversematrix, rd->origin, nl->origin);
 510                                                 /*
 511                                                 Con_Printf("%i %s : %f %f %f : %f %f %f\n%f %f %f %f\n%f %f %f %f\n%f %f %f %f\n%f %f %f %f\n"
 512                                                 , rd - r_dlight, ent->model->name
 513                                                 , rd->origin[0], rd->origin[1], rd->origin[2]
 514                                                 , nl->origin[0], nl->origin[1], nl->origin[2]
 515                                                 , ent->inversematrix.m[0][0], ent->inversematrix.m[0][1], ent->inversematrix.m[0][2], ent->inversematrix.m[0][3]
 516                                                 , ent->inversematrix.m[1][0], ent->inversematrix.m[1][1], ent->inversematrix.m[1][2], ent->inversematrix.m[1][3]
 517                                                 , ent->inversematrix.m[2][0], ent->inversematrix.m[2][1], ent->inversematrix.m[2][2], ent->inversematrix.m[2][3]
 518                                                 , ent->inversematrix.m[3][0], ent->inversematrix.m[3][1], ent->inversematrix.m[3][2], ent->inversematrix.m[3][3]);
 519                                                 */
 520                                         }
 521                                         // integrate mscale into falloff, for maximum speed
 522                                         nl->falloff = mscale;
 523                                         VectorCopy(ambientcolor, nl->ambientlight);
 524                                         nl->light[0] = rd->light[0] * colorr * 4.0f;
 525                                         nl->light[1] = rd->light[1] * colorg * 4.0f;
 526                                         nl->light[2] = rd->light[2] * colorb * 4.0f;
 527                                         nl->subtract = rd->subtract;
 528                                         nl->offset = LIGHTOFFSET;
 529                                 }
 530                         }
 531                 }
 532         }
 533         ambient4f[0] *= colorr;
 534         ambient4f[1] *= colorg;
 535         ambient4f[2] *= colorb;
 536         ambient4f[3] = colora;
 537         diffusecolor[0] *= colorr;
 538         diffusecolor[1] *= colorg;
 539         diffusecolor[2] *= colorb;
 540         return nearlights != 0 || DotProduct(diffusecolor, diffusecolor) > 0;
 541 }
 542
 543 void R_LightModel_CalcVertexColors(const float *ambientcolor4f, const float *diffusecolor, const float *diffusenormal, int numverts, const float *vertex3f, const float *normal3f, float *color4f)
 544 {
 545         int i, j, usediffuse;
 546         float color[4], v[3], dot, dist2, f, dnormal[3];
 547         nearlight_t *nl;
 548         usediffuse = DotProduct(diffusecolor, diffusecolor) > 0;
 549         VectorCopy(diffusenormal, dnormal);
 550         if (usediffuse)
 551                 VectorNormalize(dnormal);
 552         // directional shading code here
 553         for (i = 0;i < numverts;i++, vertex3f += 3, normal3f += 3, color4f += 4)
 554         {
 555                 VectorCopy4(ambientcolor4f, color);
 556
 557                 // silly directional diffuse shading
 558                 if (usediffuse)
 559                 {
 560                         dot = DotProduct(normal3f, dnormal);
 561                         if (dot > 0)
 562                                 VectorMA(color, dot, diffusecolor, color);
 563                 }
 564
 565                 // pretty good lighting
 566                 for (j = 0, nl = &nearlight[0];j < nearlights;j++, nl++)
 567                 {
 568                         VectorSubtract(vertex3f, nl->origin, v);
 569                         // first eliminate negative lighting (back side)
 570                         dot = DotProduct(normal3f, v);
 571                         if (dot > 0)
 572                         {
 573                                 // we'll need this again later to normalize the dotproduct
 574                                 dist2 = DotProduct(v,v);
 575                                 // do the distance attenuation math
 576                                 f = (1.0f / (dist2 * nl->falloff + nl->offset)) - nl->subtract;
 577                                 if (f > 0)
 578                                 {
 579                                         // we must divide dot by sqrt(dist2) to compensate for
 580                                         // the fact we did not normalize v before doing the
 581                                         // dotproduct, the result is in the range 0 to 1 (we
 582                                         // eliminated negative numbers already)
 583                                         f *= dot / sqrt(dist2);
 584                                         // blend in the lighting
 585                                         VectorMA(color, f, nl->light, color);
 586                                 }
 587                         }
 588                 }
 589                 VectorCopy4(color, color4f);
 590         }
 591 }
 592
 593 void R_UpdateEntLights(entity_render_t *ent)
 594 {
 595         int i;
 596         const mlight_t *sl;
 597         vec3_t v;
 598         if (r_shadow_realtime_dlight.integer || gl_flashblend.integer)
 599                 return;
 600         VectorSubtract(ent->origin, ent->entlightsorigin, v);
 601         if (ent->entlightsframe != (r_framecount - 1) || (realtime > ent->entlightstime && DotProduct(v,v) >= 1.0f))
 602         {
 603                 ent->entlightstime = realtime + 0.1;
 604                 VectorCopy(ent->origin, ent->entlightsorigin);
 605                 ent->numentlights = 0;
 606                 if (cl.worldmodel)
 607                         for (i = 0, sl = cl.worldmodel->brushq1.lights;i < cl.worldmodel->brushq1.numlights && ent->numentlights < MAXENTLIGHTS;i++, sl++)
 608                                 if (CL_TraceLine(ent->origin, sl->origin, NULL, NULL, 0, false, NULL) == 1)
 609                                         ent->entlights[ent->numentlights++] = i;
 610         }
 611         ent->entlightsframe = r_framecount;
 612 }
 613