main/lighting.c

   1 /*
   2 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
   3 SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
   4 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
   5 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
   6 IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
   7 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
   8 FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
   9 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
  10 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
  11 COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  12 */
  13
  14 /*
  15  *
  16  * Lighting functions.
  17  *
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include <conf.h>
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <string.h>     // for memset()
  26
  27 #include "fix.h"
  28 #include "vecmat.h"
  29 #include "gr.h"
  30 #include "inferno.h"
  31 #include "segment.h"
  32 #include "error.h"
  33 #include "mono.h"
  34 #include "render.h"
  35 #include "game.h"
  36 #include "vclip.h"
  37 #include "lighting.h"
  38 #include "3d.h"
  39 #include "laser.h"
  40 #include "timer.h"
  41 #include "player.h"
  42 #include "weapon.h"
  43 #include "powerup.h"
  44 #include "fvi.h"
  45 #include "robot.h"
  46 #include "multi.h"
  47
  48 int     Do_dynamic_light=1;
  49 //int   Use_fvi_lighting = 0;
  50
  51 fix     Dynamic_light[MAX_VERTICES];
  52
  53 #define LIGHTING_CACHE_SIZE     4096    //      Must be power of 2!
  54 #define LIGHTING_FRAME_DELTA    256     //      Recompute cache value every 8 frames.
  55 #define LIGHTING_CACHE_SHIFT    8
  56
  57 int     Lighting_frame_delta = 1;
  58
  59 int     Lighting_cache[LIGHTING_CACHE_SIZE];
  60
  61 int Cache_hits=0, Cache_lookups=1;
  62
  63 //      Return true if we think vertex vertnum is visible from segment segnum.
  64 //      If some amount of time has gone by, then recompute, else use cached value.
  65 int lighting_cache_visible(int vertnum, int segnum, int objnum, vms_vector *obj_pos, int obj_seg, vms_vector *vertpos)
  66 {
  67         int     cache_val, cache_frame, cache_vis;
  68
  69         cache_val = Lighting_cache[((segnum << LIGHTING_CACHE_SHIFT) ^ vertnum) & (LIGHTING_CACHE_SIZE-1)];
  70
  71         cache_frame = cache_val >> 1;
  72         cache_vis = cache_val & 1;
  73
  74 //mprintf((0, "%i %i %5i %i ", vertnum, segnum, cache_frame, cache_vis));
  75
  76 Cache_lookups++;
  77         if ((cache_frame == 0) || (cache_frame + Lighting_frame_delta <= FrameCount)) {
  78                 int                     apply_light=0;
  79                 fvi_query       fq;
  80                 fvi_info                hit_data;
  81                 int                     segnum, hit_type;
  82
  83                 segnum = -1;
  84
  85                 #ifndef NDEBUG
  86                 segnum = find_point_seg(obj_pos, obj_seg);
  87                 if (segnum == -1) {
  88                         Int3();         //      Obj_pos is not in obj_seg!
  89                         return 0;               //      Done processing this object.
  90                 }
  91                 #endif
  92
  93                 fq.p0                                           = obj_pos;
  94                 fq.startseg                             = obj_seg;
  95                 fq.p1                                           = vertpos;
  96                 fq.rad                                  = 0;
  97                 fq.thisobjnum                   = objnum;
  98                 fq.ignore_obj_list      = NULL;
  99                 fq.flags                                        = FQ_TRANSWALL;
 100
 101                 hit_type = find_vector_intersection(&fq, &hit_data);
 102
 103                 // Hit_pos = Hit_data.hit_pnt;
 104                 // Hit_seg = Hit_data.hit_seg;
 105
 106                 if (hit_type == HIT_OBJECT)
 107                         Int3(); //      Hey, we're not supposed to be checking objects!
 108
 109                 if (hit_type == HIT_NONE)
 110                         apply_light = 1;
 111                 else if (hit_type == HIT_WALL) {
 112                         fix     dist_dist;
 113                         dist_dist = vm_vec_dist_quick(&hit_data.hit_pnt, obj_pos);
 114                         if (dist_dist < F1_0/4) {
 115                                 apply_light = 1;
 116                                 // -- Int3();   //      Curious, did fvi detect intersection with wall containing vertex?
 117                         }
 118                 }
 119                 Lighting_cache[((segnum << LIGHTING_CACHE_SHIFT) ^ vertnum) & (LIGHTING_CACHE_SIZE-1)] = apply_light + (FrameCount << 1);
 120 //mprintf((0, "%i\n", apply_light));
 121                 return apply_light;
 122         } else {
 123 //mprintf((0, "\n"));
 124 Cache_hits++;
 125                 return cache_vis;
 126         }
 127 }
 128
 129 #define HEADLIGHT_CONE_DOT      (F1_0*9/10)
 130 #define HEADLIGHT_SCALE         (F1_0*10)
 131
 132 // ----------------------------------------------------------------------------------------------
 133 void apply_light(fix obj_intensity, int obj_seg, vms_vector *obj_pos, int n_render_vertices, short *render_vertices, int objnum)
 134 {
 135         int     vv;
 136
 137         if (obj_intensity) {
 138                 fix     obji_64 = obj_intensity*64;
 139
 140                 // for pretty dim sources, only process vertices in object's own segment.
 141                 //      12/04/95, MK, markers only cast light in own segment.
 142                 if ((abs(obji_64) <= F1_0*8) || (Objects[objnum].type == OBJ_MARKER)) {
 143                         short *vp = Segments[obj_seg].verts;
 144
 145                         for (vv=0; vv<MAX_VERTICES_PER_SEGMENT; vv++) {
 146                                 int                     vertnum;
 147                                 vms_vector      *vertpos;
 148                                 fix                     dist;
 149
 150                                 vertnum = vp[vv];
 151                                 if ((vertnum ^ FrameCount) & 1) {
 152                                         vertpos = &Vertices[vertnum];
 153                                         dist = vm_vec_dist_quick(obj_pos, vertpos);
 154                                         dist = fixmul(dist/4, dist/4);
 155                                         if (dist < abs(obji_64)) {
 156                                                 if (dist < MIN_LIGHT_DIST)
 157                                                         dist = MIN_LIGHT_DIST;
 158
 159                                                 Dynamic_light[vertnum] += fixdiv(obj_intensity, dist);
 160                                         }
 161                                 }
 162                         }
 163                 } else {
 164                         int     headlight_shift = 0;
 165                         fix     max_headlight_dist = F1_0*200;
 166
 167                         if (Objects[objnum].type == OBJ_PLAYER)
 168                                 if (Players[Objects[objnum].id].flags & PLAYER_FLAGS_HEADLIGHT_ON) {
 169                                         headlight_shift = 3;
 170                                         if (Objects[objnum].id != Player_num) {
 171                                                 vms_vector      tvec;
 172                                                 fvi_query       fq;
 173                                                 fvi_info                hit_data;
 174                                                 int                     fate;
 175
 176                                                 vm_vec_scale_add(&tvec, &Objects[objnum].pos, &Objects[objnum].orient.fvec, F1_0*200);
 177
 178                                                 fq.startseg                             = Objects[objnum].segnum;
 179                                                 fq.p0                                           = &Objects[objnum].pos;
 180                                                 fq.p1                                           = &tvec;
 181                                                 fq.rad                                  = 0;
 182                                                 fq.thisobjnum                   = objnum;
 183                                                 fq.ignore_obj_list      = NULL;
 184                                                 fq.flags                                        = FQ_TRANSWALL;
 185
 186                                                 fate = find_vector_intersection(&fq, &hit_data);
 187                                                 if (fate != HIT_NONE)
 188                                                         max_headlight_dist = vm_vec_mag_quick(vm_vec_sub(&tvec, &hit_data.hit_pnt, &Objects[objnum].pos)) + F1_0*4;
 189                                         }
 190                                 }
 191                         // -- for (vv=FrameCount&1; vv<n_render_vertices; vv+=2) {
 192                         for (vv=0; vv<n_render_vertices; vv++) {
 193                                 int                     vertnum;
 194                                 vms_vector      *vertpos;
 195                                 fix                     dist;
 196                                 int                     apply_light;
 197
 198                                 vertnum = render_vertices[vv];
 199                                 if ((vertnum ^ FrameCount) & 1) {
 200                                         vertpos = &Vertices[vertnum];
 201                                         dist = vm_vec_dist_quick(obj_pos, vertpos);
 202                                         apply_light = 0;
 203
 204                                         if ((dist >> headlight_shift) < abs(obji_64)) {
 205
 206                                                 if (dist < MIN_LIGHT_DIST)
 207                                                         dist = MIN_LIGHT_DIST;
 208
 209                                                 //if (Use_fvi_lighting) {
 210                                                 //      if (lighting_cache_visible(vertnum, obj_seg, objnum, obj_pos, obj_seg, vertpos)) {
 211                                                 //              apply_light = 1;
 212                                                 //      }
 213                                                 //} else
 214                                                         apply_light = 1;
 215
 216                                                 if (apply_light) {
 217                                                         if (headlight_shift) {
 218                                                                 fix                     dot;
 219                                                                 vms_vector      vec_to_point;
 220
 221                                                                 vm_vec_sub(&vec_to_point, vertpos, obj_pos);
 222                                                                 vm_vec_normalize_quick(&vec_to_point);          //      MK, Optimization note: You compute distance about 15 lines up, this is partially redundant
 223                                                                 dot = vm_vec_dot(&vec_to_point, &Objects[objnum].orient.fvec);
 224                                                                 if (dot < F1_0/2)
 225                                                                         Dynamic_light[vertnum] += fixdiv(obj_intensity, fixmul(HEADLIGHT_SCALE, dist)); //      Do the normal thing, but darken around headlight.
 226                                                                 else {
 227                                                                         if (Game_mode & GM_MULTI) {
 228                                                                                 if (dist < max_headlight_dist)
 229                                                                                         Dynamic_light[vertnum] += fixmul(fixmul(dot, dot), obj_intensity)/8;
 230                                                                         } else
 231                                                                                 Dynamic_light[vertnum] += fixmul(fixmul(dot, dot), obj_intensity)/8;
 232                                                                 }
 233                                                         } else
 234                                                                 Dynamic_light[vertnum] += fixdiv(obj_intensity, dist);
 235                                                 }
 236                                         }
 237                                 }
 238                         }
 239                 }
 240         }
 241 }
 242
 243 #define FLASH_LEN_FIXED_SECONDS (F1_0/3)
 244 #define FLASH_SCALE                                     (3*F1_0/FLASH_LEN_FIXED_SECONDS)
 245
 246 // ----------------------------------------------------------------------------------------------
 247 void cast_muzzle_flash_light(int n_render_vertices, short *render_vertices)
 248 {
 249         fix current_time;
 250         int     i;
 251         short   time_since_flash;
 252
 253         current_time = timer_get_fixed_seconds();
 254
 255         for (i=0; i<MUZZLE_QUEUE_MAX; i++) {
 256                 if (Muzzle_data[i].create_time) {
 257                         time_since_flash = current_time - Muzzle_data[i].create_time;
 258                         if (time_since_flash < FLASH_LEN_FIXED_SECONDS)
 259                                 apply_light((FLASH_LEN_FIXED_SECONDS - time_since_flash) * FLASH_SCALE, Muzzle_data[i].segnum, &Muzzle_data[i].pos, n_render_vertices, render_vertices, -1);
 260                         else
 261                                 Muzzle_data[i].create_time = 0;         // turn off this muzzle flash
 262                 }
 263         }
 264 }
 265
 266 //      Translation table to make flares flicker at different rates
 267 fix     Obj_light_xlate[16] =
 268         {0x1234, 0x3321, 0x2468, 0x1735,
 269          0x0123, 0x19af, 0x3f03, 0x232a,
 270          0x2123, 0x39af, 0x0f03, 0x132a,
 271          0x3123, 0x29af, 0x1f03, 0x032a};
 272
 273 //      Flag array of objects lit last frame.  Guaranteed to process this frame if lit last frame.
 274 sbyte   Lighting_objects[MAX_OBJECTS];
 275
 276 #define MAX_HEADLIGHTS  8
 277 object  *Headlights[MAX_HEADLIGHTS];
 278 int             Num_headlights;
 279
 280 // ---------------------------------------------------------
 281 fix compute_light_intensity(int objnum)
 282 {
 283         object          *obj = &Objects[objnum];
 284         int                     objtype = obj->type;
 285    fix hoardlight,s;
 286
 287         switch (objtype) {
 288                 case OBJ_PLAYER:
 289                          if (Players[obj->id].flags & PLAYER_FLAGS_HEADLIGHT_ON) {
 290                                 if (Num_headlights < MAX_HEADLIGHTS)
 291                                         Headlights[Num_headlights++] = obj;
 292                                 return HEADLIGHT_SCALE;
 293                          } else if ((Game_mode & GM_HOARD) && Players[obj->id].secondary_ammo[PROXIMITY_INDEX]) {
 294
 295                    // If hoard game and player, add extra light based on how many orbs you have
 296                         // Pulse as well.
 297
 298                            hoardlight=i2f(Players[obj->id].secondary_ammo[PROXIMITY_INDEX])/2; //i2f(12));
 299                                 hoardlight++;
 300                       fix_sincos ((GameTime/2) & 0xFFFF,&s,NULL); // probably a bad way to do it
 301                            s+=F1_0;
 302                                 s>>=1;
 303                            hoardlight=fixmul (s,hoardlight);
 304                  //     mprintf ((0,"Hoardlight is %f!\n",f2fl(hoardlight)));
 305                       return (hoardlight);
 306                           }
 307                         else
 308                                 return max(vm_vec_mag_quick(&obj->mtype.phys_info.thrust)/4, F1_0*2) + F1_0/2;
 309                         break;
 310                 case OBJ_FIREBALL:
 311                         if (obj->id != 0xff) {
 312                                 if (obj->lifeleft < F1_0*4)
 313                                         return fixmul(fixdiv(obj->lifeleft, Vclip[obj->id].play_time), Vclip[obj->id].light_value);
 314                                 else
 315                                         return Vclip[obj->id].light_value;
 316                         } else
 317                                  return 0;
 318                         break;
 319                 case OBJ_ROBOT:
 320                         return F1_0*Robot_info[obj->id].lightcast;
 321                         break;
 322                 case OBJ_WEAPON: {
 323                         fix tval = Weapon_info[obj->id].light;
 324                         if (Game_mode & GM_MULTI)
 325                                 if (obj->id == OMEGA_ID)
 326                                         if (d_rand() > 8192)
 327                                                 return 0;               //      3/4 of time, omega blobs will cast 0 light!
 328
 329                         if (obj->id == FLARE_ID )
 330                                 return 2* (min(tval, obj->lifeleft) + ((GameTime ^ Obj_light_xlate[objnum&0x0f]) & 0x3fff));
 331                         else
 332                                 return tval;
 333                 }
 334
 335                 case OBJ_MARKER: {
 336                         fix     lightval = obj->lifeleft;
 337
 338                         lightval &= 0xffff;
 339
 340                         lightval = 8 * abs(F1_0/2 - lightval);
 341
 342                         if (obj->lifeleft < F1_0*1000)
 343                                 obj->lifeleft += F1_0;  //      Make sure this object doesn't go out.
 344
 345                         return lightval;
 346                 }
 347
 348                 case OBJ_POWERUP:
 349                         return Powerup_info[obj->id].light;
 350                         break;
 351                 case OBJ_DEBRIS:
 352                         return F1_0/4;
 353                         break;
 354                 case OBJ_LIGHT:
 355                         return obj->ctype.light_info.intensity;
 356                         break;
 357                 default:
 358                         return 0;
 359                         break;
 360         }
 361 }
 362
 363 // ----------------------------------------------------------------------------------------------
 364 void set_dynamic_light(void)
 365 {
 366         int     vv;
 367         int     objnum;
 368         int     n_render_vertices;
 369         short   render_vertices[MAX_VERTICES];
 370         sbyte   render_vertex_flags[MAX_VERTICES];
 371         int     render_seg,segnum, v;
 372         sbyte   new_lighting_objects[MAX_OBJECTS];
 373
 374         Num_headlights = 0;
 375
 376         if (!Do_dynamic_light)
 377                 return;
 378
 379 //if (Use_fvi_lighting)
 380 //      mprintf((0, "hits = %8i, misses = %8i, lookups = %8i, hit ratio = %7.4f\n", Cache_hits, Cache_lookups - Cache_hits, Cache_lookups, (float) Cache_hits / Cache_lookups));
 381
 382         memset(render_vertex_flags, 0, Highest_vertex_index+1);
 383
 384         //      Create list of vertices that need to be looked at for setting of ambient light.
 385         n_render_vertices = 0;
 386         for (render_seg=0; render_seg<N_render_segs; render_seg++) {
 387                 segnum = Render_list[render_seg];
 388                 if (segnum != -1) {
 389                         short   *vp = Segments[segnum].verts;
 390                         for (v=0; v<MAX_VERTICES_PER_SEGMENT; v++) {
 391                                 int     vnum = vp[v];
 392                                 if (vnum<0 || vnum>Highest_vertex_index) {
 393                                         Int3();         //invalid vertex number
 394                                         continue;       //ignore it, and go on to next one
 395                                 }
 396                                 if (!render_vertex_flags[vnum]) {
 397                                         render_vertex_flags[vnum] = 1;
 398                                         render_vertices[n_render_vertices++] = vnum;
 399                                 }
 400                                 //--old way-- for (s=0; s<n_render_vertices; s++)
 401                                 //--old way--   if (render_vertices[s] == vnum)
 402                                 //--old way--           break;
 403                                 //--old way-- if (s == n_render_vertices)
 404                                 //--old way--   render_vertices[n_render_vertices++] = vnum;
 405                         }
 406                 }
 407         }
 408
 409         // -- for (vertnum=FrameCount&1; vertnum<n_render_vertices; vertnum+=2) {
 410         for (vv=0; vv<n_render_vertices; vv++) {
 411                 int     vertnum;
 412
 413                 vertnum = render_vertices[vv];
 414                 Assert(vertnum >= 0 && vertnum <= Highest_vertex_index);
 415                 if ((vertnum ^ FrameCount) & 1)
 416                         Dynamic_light[vertnum] = 0;
 417         }
 418
 419         cast_muzzle_flash_light(n_render_vertices, render_vertices);
 420
 421         for (objnum=0; objnum<=Highest_object_index; objnum++)
 422                 new_lighting_objects[objnum] = 0;
 423
 424         //      July 5, 1995: New faster dynamic lighting code.  About 5% faster on the PC (un-optimized).
 425         //      Only objects which are in rendered segments cast dynamic light.  We might wad6 to extend this
 426         //      one or two segments if we notice light changing as objects go offscreen.  I couldn't see any
 427         //      serious visual degradation.  In fact, I could see no humorous degradation, either. --MK
 428         for (render_seg=0; render_seg<N_render_segs; render_seg++) {
 429                 int     segnum = Render_list[render_seg];
 430
 431                 objnum = Segments[segnum].objects;
 432
 433                 while (objnum != -1) {
 434                         object          *obj = &Objects[objnum];
 435                         vms_vector      *objpos = &obj->pos;
 436                         fix                     obj_intensity;
 437
 438                         obj_intensity = compute_light_intensity(objnum);
 439
 440                         if (obj_intensity) {
 441                                 apply_light(obj_intensity, obj->segnum, objpos, n_render_vertices, render_vertices, OBJECT_NUMBER(obj));
 442                                 new_lighting_objects[objnum] = 1;
 443                         }
 444
 445                         objnum = obj->next;
 446                 }
 447         }
 448
 449         //      Now, process all lights from last frame which haven't been processed this frame.
 450         for (objnum=0; objnum<=Highest_object_index; objnum++) {
 451                 //      In multiplayer games, process even unprocessed objects every 4th frame, else don't know about player sneaking up.
 452                 if ((Lighting_objects[objnum]) || ((Game_mode & GM_MULTI) && (((objnum ^ FrameCount) & 3) == 0))) {
 453                         if (!new_lighting_objects[objnum]) {
 454                                 //      Lighted last frame, but not this frame.  Get intensity...
 455                                 object          *obj = &Objects[objnum];
 456                                 vms_vector      *objpos = &obj->pos;
 457                                 fix                     obj_intensity;
 458
 459                                 obj_intensity = compute_light_intensity(objnum);
 460
 461                                 if (obj_intensity) {
 462                                         apply_light(obj_intensity, obj->segnum, objpos, n_render_vertices, render_vertices, objnum);
 463                                         Lighting_objects[objnum] = 1;
 464                                 } else
 465                                         Lighting_objects[objnum] = 0;
 466                         }
 467                 } else {
 468                         //      Not lighted last frame, so we don't need to light it.  (Already lit if casting light this frame.)
 469                         //      But copy value from new_lighting_objects to update Lighting_objects array.
 470                         Lighting_objects[objnum] = new_lighting_objects[objnum];
 471                 }
 472         }
 473 }
 474
 475 // ---------------------------------------------------------
 476
 477 void toggle_headlight_active()
 478 {
 479         if (Players[Player_num].flags & PLAYER_FLAGS_HEADLIGHT) {
 480                 Players[Player_num].flags ^= PLAYER_FLAGS_HEADLIGHT_ON;
 481 #ifdef NETWORK
 482                 if (Game_mode & GM_MULTI)
 483                         multi_send_flags(Player_num);
 484 #endif
 485         }
 486 }
 487
 488 #define HEADLIGHT_BOOST_SCALE 8         //how much to scale light when have headlight boost
 489
 490 fix     Beam_brightness = (F1_0/2);     //global saying how bright the light beam is
 491
 492 #define MAX_DIST_LOG    6                                                       //log(MAX_DIST-expressed-as-integer)
 493 #define MAX_DIST                (f1_0<<MAX_DIST_LOG)    //no light beyond this dist
 494
 495 fix compute_headlight_light_on_object(object *objp)
 496 {
 497         int     i;
 498         fix     light;
 499
 500         //      Let's just illuminate players and robots for speed reasons, ok?
 501         if ((objp->type != OBJ_ROBOT) && (objp->type    != OBJ_PLAYER))
 502                 return 0;
 503
 504         light = 0;
 505
 506         for (i=0; i<Num_headlights; i++) {
 507                 fix                     dot, dist;
 508                 vms_vector      vec_to_obj;
 509                 object          *light_objp;
 510
 511                 light_objp = Headlights[i];
 512
 513                 vm_vec_sub(&vec_to_obj, &objp->pos, &light_objp->pos);
 514                 dist = vm_vec_normalize_quick(&vec_to_obj);
 515                 if (dist > 0) {
 516                         dot = vm_vec_dot(&light_objp->orient.fvec, &vec_to_obj);
 517
 518                         if (dot < F1_0/2)
 519                                 light += fixdiv(HEADLIGHT_SCALE, fixmul(HEADLIGHT_SCALE, dist));        //      Do the normal thing, but darken around headlight.
 520                         else
 521                                 light += fixmul(fixmul(dot, dot), HEADLIGHT_SCALE)/8;
 522                 }
 523         }
 524
 525         return light;
 526 }
 527
 528
 529 // -- Unused -- //Compute the lighting from the headlight for a given vertex on a face.
 530 // -- Unused -- //Takes:
 531 // -- Unused -- //  point - the 3d coords of the point
 532 // -- Unused -- //  face_light - a scale factor derived from the surface normal of the face
 533 // -- Unused -- //If no surface normal effect is wanted, pass F1_0 for face_light
 534 // -- Unused -- fix compute_headlight_light(vms_vector *point,fix face_light)
 535 // -- Unused -- {
 536 // -- Unused --         fix light;
 537 // -- Unused --         int use_beam = 0;               //flag for beam effect
 538 // -- Unused --
 539 // -- Unused --         light = Beam_brightness;
 540 // -- Unused --
 541 // -- Unused --         if ((Players[Player_num].flags & PLAYER_FLAGS_HEADLIGHT) && (Players[Player_num].flags & PLAYER_FLAGS_HEADLIGHT_ON) && Viewer==&Objects[Players[Player_num].objnum] && Players[Player_num].energy > 0) {
 542 // -- Unused --                 light *= HEADLIGHT_BOOST_SCALE;
 543 // -- Unused --                 use_beam = 1;   //give us beam effect
 544 // -- Unused --         }
 545 // -- Unused --
 546 // -- Unused --         if (light) {                            //if no beam, don't bother with the rest of this
 547 // -- Unused --                 fix point_dist;
 548 // -- Unused --
 549 // -- Unused --                 point_dist = vm_vec_mag_quick(point);
 550 // -- Unused --
 551 // -- Unused --                 if (point_dist >= MAX_DIST)
 552 // -- Unused --
 553 // -- Unused --                         light = 0;
 554 // -- Unused --
 555 // -- Unused --                 else {
 556 // -- Unused --                         fix dist_scale,face_scale;
 557 // -- Unused --
 558 // -- Unused --                         dist_scale = (MAX_DIST - point_dist) >> MAX_DIST_LOG;
 559 // -- Unused --                         light = fixmul(light,dist_scale);
 560 // -- Unused --
 561 // -- Unused --                         if (face_light < 0)
 562 // -- Unused --                                 face_light = 0;
 563 // -- Unused --
 564 // -- Unused --                         face_scale = f1_0/4 + face_light/2;
 565 // -- Unused --                         light = fixmul(light,face_scale);
 566 // -- Unused --
 567 // -- Unused --                         if (use_beam) {
 568 // -- Unused --                                 fix beam_scale;
 569 // -- Unused --
 570 // -- Unused --                                 if (face_light > f1_0*3/4 && point->z > i2f(12)) {
 571 // -- Unused --                                         beam_scale = fixdiv(point->z,point_dist);
 572 // -- Unused --                                         beam_scale = fixmul(beam_scale,beam_scale);     //square it
 573 // -- Unused --                                         light = fixmul(light,beam_scale);
 574 // -- Unused --                                 }
 575 // -- Unused --                         }
 576 // -- Unused --                 }
 577 // -- Unused --         }
 578 // -- Unused --
 579 // -- Unused --         return light;
 580 // -- Unused -- }
 581
 582 //compute the average dynamic light in a segment.  Takes the segment number
 583 fix compute_seg_dynamic_light(int segnum)
 584 {
 585         fix sum;
 586         segment *seg;
 587         short *verts;
 588
 589         seg = &Segments[segnum];
 590
 591         verts = seg->verts;
 592         sum = 0;
 593
 594         sum += Dynamic_light[*verts++];
 595         sum += Dynamic_light[*verts++];
 596         sum += Dynamic_light[*verts++];
 597         sum += Dynamic_light[*verts++];
 598         sum += Dynamic_light[*verts++];
 599         sum += Dynamic_light[*verts++];
 600         sum += Dynamic_light[*verts++];
 601         sum += Dynamic_light[*verts];
 602
 603         return sum >> 3;
 604
 605 }
 606
 607 fix object_light[MAX_OBJECTS];
 608 int object_sig[MAX_OBJECTS];
 609 object *old_viewer;
 610 int reset_lighting_hack;
 611
 612 #define LIGHT_RATE i2f(4)               //how fast the light ramps up
 613
 614 void start_lighting_frame(object *viewer)
 615 {
 616         reset_lighting_hack = (viewer != old_viewer);
 617
 618         old_viewer = viewer;
 619 }
 620
 621 //compute the lighting for an object.  Takes a pointer to the object,
 622 //and possibly a rotated 3d point.  If the point isn't specified, the
 623 //object's center point is rotated.
 624 fix compute_object_light(object *obj,vms_vector *rotated_pnt)
 625 {
 626         fix light;
 627         g3s_point objpnt;
 628         int objnum = OBJECT_NUMBER(obj);
 629
 630         if (!rotated_pnt) {
 631                 g3_rotate_point(&objpnt,&obj->pos);
 632                 rotated_pnt = &objpnt.p3_vec;
 633         }
 634
 635         //First, get static light for this segment
 636
 637         light = Segment2s[obj->segnum].static_light;
 638
 639         //return light;
 640
 641
 642         //Now, maybe return different value to smooth transitions
 643
 644         if (!reset_lighting_hack && object_sig[objnum] == obj->signature) {
 645                 fix delta_light,frame_delta;
 646
 647                 delta_light = light - object_light[objnum];
 648
 649                 frame_delta = fixmul(LIGHT_RATE,FrameTime);
 650
 651                 if (abs(delta_light) <= frame_delta)
 652
 653                         object_light[objnum] = light;           //we've hit the goal
 654
 655                 else
 656
 657                         if (delta_light < 0)
 658                                 light = object_light[objnum] -= frame_delta;
 659                         else
 660                                 light = object_light[objnum] += frame_delta;
 661
 662         }
 663         else {          //new object, initialize
 664
 665                 object_sig[objnum] = obj->signature;
 666                 object_light[objnum] = light;
 667         }
 668
 669
 670
 671         //Next, add in headlight on this object
 672
 673         // -- Matt code: light += compute_headlight_light(rotated_pnt,f1_0);
 674         light += compute_headlight_light_on_object(obj);
 675
 676         //Finally, add in dynamic light for this segment
 677
 678         light += compute_seg_dynamic_light(obj->segnum);
 679
 680
 681         return light;
 682 }
 683
 684