protocol.c

   1
   2 #include "quakedef.h"
   3
   4 entity_state_t defaultstate =
   5 {
   6         0,//double time; // time this state was built
   7         {0,0,0},//vec3_t origin;
   8         {0,0,0},//vec3_t angles;
   9         0,//int number; // entity number this state is for
  10         0,//unsigned short active; // true if a valid state
  11         0,//unsigned short modelindex;
  12         0,//unsigned short frame;
  13         0,//unsigned short effects;
  14         0,//unsigned short tagentity;
  15         0,//unsigned short specialvisibilityradius;
  16         0,//unsigned short viewmodelforclient;
  17         0,//unsigned short exteriormodelforclient;
  18         0,//unsigned short nodrawtoclient;
  19         0,//unsigned short drawonlytoclient;
  20         0,//qbyte colormap;
  21         0,//qbyte skin;
  22         255,//qbyte alpha;
  23         16,//qbyte scale;
  24         0,//qbyte glowsize;
  25         254,//qbyte glowcolor;
  26         0,//qbyte flags;
  27         0,//qbyte tagindex;
  28 };
  29
  30 void ClearStateToDefault(entity_state_t *s)
  31 {
  32         *s = defaultstate;
  33         /*
  34         memset(s, 0, sizeof(*s));
  35         s->alpha = 255;
  36         s->scale = 16;
  37         s->glowcolor = 254;
  38         */
  39 }
  40
  41 void EntityState_Write(entity_state_t *ent, sizebuf_t *msg, entity_state_t *delta)
  42 {
  43         int bits;
  44         vec3_t org, deltaorg;
  45         if (ent->active)
  46         {
  47                 // if not active last frame, delta from defaults
  48                 if (!delta->active)
  49                         delta = &defaultstate;
  50                 bits = 0;
  51                 VectorCopy(ent->origin, org);
  52                 VectorCopy(delta->origin, deltaorg);
  53                 if (ent->flags & RENDER_LOWPRECISION)
  54                 {
  55                         if (org[0] > 0)
  56                                 org[0] = (int) (org[0] + 0.5f);
  57                         else
  58                                 org[0] = (int) (org[0] - 0.5f);
  59                         if (org[1] > 0)
  60                                 org[1] = (int) (org[1] + 0.5f);
  61                         else
  62                                 org[1] = (int) (org[1] - 0.5f);
  63                         if (org[2] > 0)
  64                                 org[2] = (int) (org[2] + 0.5f);
  65                         else
  66                                 org[2] = (int) (org[2] - 0.5f);
  67                 }
  68                 if (delta->flags & RENDER_LOWPRECISION)
  69                 {
  70                         if (deltaorg[0] > 0)
  71                                 deltaorg[0] = (int) (deltaorg[0] + 0.5f);
  72                         else
  73                                 deltaorg[0] = (int) (deltaorg[0] - 0.5f);
  74                         if (deltaorg[1] > 0)
  75                                 deltaorg[1] = (int) (deltaorg[1] + 0.5f);
  76                         else
  77                                 deltaorg[1] = (int) (deltaorg[1] - 0.5f);
  78                         if (deltaorg[2] > 0)
  79                                 deltaorg[2] = (int) (deltaorg[2] + 0.5f);
  80                         else
  81                                 deltaorg[2] = (int) (deltaorg[2] - 0.5f);
  82                 }
  83                 if (fabs(org[0] - deltaorg[0]) > 0.01f)
  84                         bits |= E_ORIGIN1;
  85                 if (fabs(org[1] - deltaorg[1]) > 0.01f)
  86                         bits |= E_ORIGIN2;
  87                 if (fabs(org[2] - deltaorg[2]) > 0.01f)
  88                         bits |= E_ORIGIN3;
  89                 if ((qbyte) (ent->angles[0] * (256.0f / 360.0f)) != (qbyte) (delta->angles[0] * (256.0f / 360.0f)))
  90                         bits |= E_ANGLE1;
  91                 if ((qbyte) (ent->angles[1] * (256.0f / 360.0f)) != (qbyte) (delta->angles[1] * (256.0f / 360.0f)))
  92                         bits |= E_ANGLE2;
  93                 if ((qbyte) (ent->angles[2] * (256.0f / 360.0f)) != (qbyte) (delta->angles[2] * (256.0f / 360.0f)))
  94                         bits |= E_ANGLE3;
  95                 if ((ent->modelindex ^ delta->modelindex) & 0x00FF)
  96                         bits |= E_MODEL1;
  97                 if ((ent->modelindex ^ delta->modelindex) & 0xFF00)
  98                         bits |= E_MODEL2;
  99                 if ((ent->frame ^ delta->frame) & 0x00FF)
 100                         bits |= E_FRAME1;
 101                 if ((ent->frame ^ delta->frame) & 0xFF00)
 102                         bits |= E_FRAME2;
 103                 if ((ent->effects ^ delta->effects) & 0x00FF)
 104                         bits |= E_EFFECTS1;
 105                 if ((ent->effects ^ delta->effects) & 0xFF00)
 106                         bits |= E_EFFECTS2;
 107                 if (ent->colormap != delta->colormap)
 108                         bits |= E_COLORMAP;
 109                 if (ent->skin != delta->skin)
 110                         bits |= E_SKIN;
 111                 if (ent->alpha != delta->alpha)
 112                         bits |= E_ALPHA;
 113                 if (ent->scale != delta->scale)
 114                         bits |= E_SCALE;
 115                 if (ent->glowsize != delta->glowsize)
 116                         bits |= E_GLOWSIZE;
 117                 if (ent->glowcolor != delta->glowcolor)
 118                         bits |= E_GLOWCOLOR;
 119                 if (ent->flags != delta->flags)
 120                         bits |= E_FLAGS;
 121                 if (ent->tagindex != delta->tagindex || ent->tagentity != delta->tagentity)
 122                         bits |= E_TAGATTACHMENT;
 123
 124                 if (bits) // don't send anything if it hasn't changed
 125                 {
 126                         if (bits & 0xFF000000)
 127                                 bits |= E_EXTEND3;
 128                         if (bits & 0x00FF0000)
 129                                 bits |= E_EXTEND2;
 130                         if (bits & 0x0000FF00)
 131                                 bits |= E_EXTEND1;
 132
 133                         MSG_WriteShort(msg, ent->number);
 134                         MSG_WriteByte(msg, bits & 0xFF);
 135                         if (bits & E_EXTEND1)
 136                         {
 137                                 MSG_WriteByte(msg, (bits >> 8) & 0xFF);
 138                                 if (bits & E_EXTEND2)
 139                                 {
 140                                         MSG_WriteByte(msg, (bits >> 16) & 0xFF);
 141                                         if (bits & E_EXTEND3)
 142                                                 MSG_WriteByte(msg, (bits >> 24) & 0xFF);
 143                                 }
 144                         }
 145                         // LordHavoc: have to write flags first, as they can modify protocol
 146                         if (bits & E_FLAGS)
 147                                 MSG_WriteByte(msg, ent->flags);
 148                         if (ent->flags & RENDER_LOWPRECISION)
 149                         {
 150                                 if (bits & E_ORIGIN1)
 151                                         MSG_WriteShort(msg, org[0]);
 152                                 if (bits & E_ORIGIN2)
 153                                         MSG_WriteShort(msg, org[1]);
 154                                 if (bits & E_ORIGIN3)
 155                                         MSG_WriteShort(msg, org[2]);
 156                         }
 157                         else
 158                         {
 159                                 if (bits & E_ORIGIN1)
 160                                         MSG_WriteFloat(msg, org[0]);
 161                                 if (bits & E_ORIGIN2)
 162                                         MSG_WriteFloat(msg, org[1]);
 163                                 if (bits & E_ORIGIN3)
 164                                         MSG_WriteFloat(msg, org[2]);
 165                         }
 166                         if (bits & E_ANGLE1)
 167                                 MSG_WriteAngle(msg, ent->angles[0]);
 168                         if (bits & E_ANGLE2)
 169                                 MSG_WriteAngle(msg, ent->angles[1]);
 170                         if (bits & E_ANGLE3)
 171                                 MSG_WriteAngle(msg, ent->angles[2]);
 172                         if (bits & E_MODEL1)
 173                                 MSG_WriteByte(msg, ent->modelindex & 0xFF);
 174                         if (bits & E_MODEL2)
 175                                 MSG_WriteByte(msg, (ent->modelindex >> 8) & 0xFF);
 176                         if (bits & E_FRAME1)
 177                                 MSG_WriteByte(msg, ent->frame & 0xFF);
 178                         if (bits & E_FRAME2)
 179                                 MSG_WriteByte(msg, (ent->frame >> 8) & 0xFF);
 180                         if (bits & E_EFFECTS1)
 181                                 MSG_WriteByte(msg, ent->effects & 0xFF);
 182                         if (bits & E_EFFECTS2)
 183                                 MSG_WriteByte(msg, (ent->effects >> 8) & 0xFF);
 184                         if (bits & E_COLORMAP)
 185                                 MSG_WriteByte(msg, ent->colormap);
 186                         if (bits & E_SKIN)
 187                                 MSG_WriteByte(msg, ent->skin);
 188                         if (bits & E_ALPHA)
 189                                 MSG_WriteByte(msg, ent->alpha);
 190                         if (bits & E_SCALE)
 191                                 MSG_WriteByte(msg, ent->scale);
 192                         if (bits & E_GLOWSIZE)
 193                                 MSG_WriteByte(msg, ent->glowsize);
 194                         if (bits & E_GLOWCOLOR)
 195                                 MSG_WriteByte(msg, ent->glowcolor);
 196                         if (bits & E_TAGATTACHMENT)
 197                         {
 198                                 MSG_WriteShort(msg, ent->tagentity);
 199                                 MSG_WriteByte(msg, ent->tagindex);
 200                         }
 201                 }
 202         }
 203         else if (delta->active)
 204                 MSG_WriteShort(msg, ent->number | 0x8000);
 205 }
 206
 207 void EntityState_ReadUpdate(entity_state_t *e, int number)
 208 {
 209         int bits;
 210         if (!e->active)
 211         {
 212                 *e = defaultstate;
 213                 e->active = true;
 214         }
 215         e->time = cl.mtime[0];
 216         e->number = number;
 217
 218         bits = MSG_ReadByte();
 219         if (bits & E_EXTEND1)
 220         {
 221                 bits |= MSG_ReadByte() << 8;
 222                 if (bits & E_EXTEND2)
 223                 {
 224                         bits |= MSG_ReadByte() << 16;
 225                         if (bits & E_EXTEND3)
 226                                 bits |= MSG_ReadByte() << 24;
 227                 }
 228         }
 229
 230         if (dpprotocol == DPPROTOCOL_VERSION2)
 231         {
 232                 if (bits & E_ORIGIN1)
 233                         e->origin[0] = (signed short) MSG_ReadShort();
 234                 if (bits & E_ORIGIN2)
 235                         e->origin[1] = (signed short) MSG_ReadShort();
 236                 if (bits & E_ORIGIN3)
 237                         e->origin[2] = (signed short) MSG_ReadShort();
 238         }
 239         else
 240         {
 241                 if (bits & E_FLAGS)
 242                         e->flags = MSG_ReadByte();
 243                 if (e->flags & RENDER_LOWPRECISION || dpprotocol == DPPROTOCOL_VERSION2)
 244                 {
 245                         if (bits & E_ORIGIN1)
 246                                 e->origin[0] = (signed short) MSG_ReadShort();
 247                         if (bits & E_ORIGIN2)
 248                                 e->origin[1] = (signed short) MSG_ReadShort();
 249                         if (bits & E_ORIGIN3)
 250                                 e->origin[2] = (signed short) MSG_ReadShort();
 251                 }
 252                 else
 253                 {
 254                         if (bits & E_ORIGIN1)
 255                                 e->origin[0] = MSG_ReadFloat();
 256                         if (bits & E_ORIGIN2)
 257                                 e->origin[1] = MSG_ReadFloat();
 258                         if (bits & E_ORIGIN3)
 259                                 e->origin[2] = MSG_ReadFloat();
 260                 }
 261         }
 262         if (bits & E_ANGLE1)
 263                 e->angles[0] = MSG_ReadAngle();
 264         if (bits & E_ANGLE2)
 265                 e->angles[1] = MSG_ReadAngle();
 266         if (bits & E_ANGLE3)
 267                 e->angles[2] = MSG_ReadAngle();
 268         if (bits & E_MODEL1)
 269                 e->modelindex = (e->modelindex & 0xFF00) | (unsigned int) MSG_ReadByte();
 270         if (bits & E_MODEL2)
 271                 e->modelindex = (e->modelindex & 0x00FF) | ((unsigned int) MSG_ReadByte() << 8);
 272         if (bits & E_FRAME1)
 273                 e->frame = (e->frame & 0xFF00) | (unsigned int) MSG_ReadByte();
 274         if (bits & E_FRAME2)
 275                 e->frame = (e->frame & 0x00FF) | ((unsigned int) MSG_ReadByte() << 8);
 276         if (bits & E_EFFECTS1)
 277                 e->effects = (e->effects & 0xFF00) | (unsigned int) MSG_ReadByte();
 278         if (bits & E_EFFECTS2)
 279                 e->effects = (e->effects & 0x00FF) | ((unsigned int) MSG_ReadByte() << 8);
 280         if (bits & E_COLORMAP)
 281                 e->colormap = MSG_ReadByte();
 282         if (bits & E_SKIN)
 283                 e->skin = MSG_ReadByte();
 284         if (bits & E_ALPHA)
 285                 e->alpha = MSG_ReadByte();
 286         if (bits & E_SCALE)
 287                 e->scale = MSG_ReadByte();
 288         if (bits & E_GLOWSIZE)
 289                 e->glowsize = MSG_ReadByte();
 290         if (bits & E_GLOWCOLOR)
 291                 e->glowcolor = MSG_ReadByte();
 292         if (dpprotocol == DPPROTOCOL_VERSION2)
 293                 if (bits & E_FLAGS)
 294                         e->flags = MSG_ReadByte();
 295         if (bits & E_TAGATTACHMENT)
 296         {
 297                 e->tagentity = MSG_ReadShort();
 298                 e->tagindex = MSG_ReadByte();
 299         }
 300 }
 301
 302 // (server) clears the database to contain no frames (thus delta compression compresses against nothing)
 303 void EntityFrame_ClearDatabase(entity_database_t *d)
 304 {
 305         memset(d, 0, sizeof(*d));
 306 }
 307
 308 // (server and client) removes frames older than 'frame' from database
 309 void EntityFrame_AckFrame(entity_database_t *d, int frame)
 310 {
 311         int i;
 312         if (d->ackframe < frame)
 313                 d->ackframe = frame;
 314         for (i = 0;i < d->numframes && d->frames[i].framenum < frame;i++);
 315         // ignore outdated frame acks (out of order packets)
 316         if (i == 0)
 317                 return;
 318         d->numframes -= i;
 319         // if some queue is left, slide it down to beginning of array
 320         if (d->numframes)
 321                 memmove(&d->frames[0], &d->frames[i], sizeof(d->frames[0]) * d->numframes);
 322 }
 323
 324 // (server) clears frame, to prepare for adding entities
 325 void EntityFrame_Clear(entity_frame_t *f, vec3_t eye, int framenum)
 326 {
 327         f->time = 0;
 328         f->framenum = framenum;
 329         f->numentities = 0;
 330         if (eye == NULL)
 331         {
 332                 VectorClear(f->eye);
 333         }
 334         else
 335         {
 336                 VectorCopy(eye, f->eye);
 337         }
 338 }
 339
 340 // (server) adds an entity to frame
 341 void EntityFrame_AddEntity(entity_frame_t *f, entity_state_t *s)
 342 {
 343         if (f->numentities < MAX_ENTITY_DATABASE)
 344         {
 345                 f->entitydata[f->numentities] = *s;
 346                 f->entitydata[f->numentities++].active = true;
 347         }
 348 }
 349
 350 // (server and client) reads a frame from the database
 351 void EntityFrame_FetchFrame(entity_database_t *d, int framenum, entity_frame_t *f)
 352 {
 353         int i, n;
 354         EntityFrame_Clear(f, NULL, -1);
 355         for (i = 0;i < d->numframes && d->frames[i].framenum < framenum;i++);
 356         if (i < d->numframes && framenum == d->frames[i].framenum)
 357         {
 358                 f->framenum = framenum;
 359                 f->numentities = d->frames[i].endentity - d->frames[i].firstentity;
 360                 n = MAX_ENTITY_DATABASE - (d->frames[i].firstentity % MAX_ENTITY_DATABASE);
 361                 if (n > f->numentities)
 362                         n = f->numentities;
 363                 memcpy(f->entitydata, d->entitydata + d->frames[i].firstentity % MAX_ENTITY_DATABASE, sizeof(*f->entitydata) * n);
 364                 if (f->numentities > n)
 365                         memcpy(f->entitydata + n, d->entitydata, sizeof(*f->entitydata) * (f->numentities - n));
 366                 VectorCopy(d->eye, f->eye);
 367         }
 368 }
 369
 370 // (server and client) adds a entity_frame to the database, for future reference
 371 void EntityFrame_AddFrame(entity_database_t *d, entity_frame_t *f)
 372 {
 373         int n, e;
 374         entity_frameinfo_t *info;
 375
 376         VectorCopy(f->eye, d->eye);
 377
 378         // figure out how many entity slots are used already
 379         if (d->numframes)
 380         {
 381                 n = d->frames[d->numframes - 1].endentity - d->frames[0].firstentity;
 382                 if (n + f->numentities > MAX_ENTITY_DATABASE || d->numframes >= MAX_ENTITY_HISTORY)
 383                 {
 384                         // ran out of room, dump database
 385                         EntityFrame_ClearDatabase(d);
 386                 }
 387         }
 388
 389         info = &d->frames[d->numframes];
 390         info->framenum = f->framenum;
 391         e = -1000;
 392         // make sure we check the newly added frame as well, but we haven't incremented numframes yet
 393         for (n = 0;n <= d->numframes;n++)
 394         {
 395                 if (e >= d->frames[n].framenum)
 396                 {
 397                         if (e == f->framenum)
 398                                 Con_Printf("EntityFrame_AddFrame: tried to add out of sequence frame to database\n");
 399                         else
 400                                 Con_Printf("EntityFrame_AddFrame: out of sequence frames in database\n");
 401                         return;
 402                 }
 403                 e = d->frames[n].framenum;
 404         }
 405         // if database still has frames after that...
 406         if (d->numframes)
 407                 info->firstentity = d->frames[d->numframes - 1].endentity;
 408         else
 409                 info->firstentity = 0;
 410         info->endentity = info->firstentity + f->numentities;
 411         d->numframes++;
 412
 413         n = info->firstentity % MAX_ENTITY_DATABASE;
 414         e = MAX_ENTITY_DATABASE - n;
 415         if (e > f->numentities)
 416                 e = f->numentities;
 417         memcpy(d->entitydata + n, f->entitydata, sizeof(entity_state_t) * e);
 418         if (f->numentities > e)
 419                 memcpy(d->entitydata, f->entitydata + e, sizeof(entity_state_t) * (f->numentities - e));
 420 }
 421
 422 // (server) writes a frame to network stream
 423 static entity_frame_t deltaframe; // FIXME?
 424 void EntityFrame_Write(entity_database_t *d, entity_frame_t *f, sizebuf_t *msg)
 425 {
 426         int i, onum, number;
 427         entity_frame_t *o = &deltaframe;
 428         entity_state_t *ent, *delta;
 429
 430         EntityFrame_AddFrame(d, f);
 431
 432         EntityFrame_FetchFrame(d, d->ackframe > 0 ? d->ackframe : -1, o);
 433         MSG_WriteByte (msg, svc_entities);
 434         MSG_WriteLong (msg, o->framenum);
 435         MSG_WriteLong (msg, f->framenum);
 436         MSG_WriteFloat (msg, f->eye[0]);
 437         MSG_WriteFloat (msg, f->eye[1]);
 438         MSG_WriteFloat (msg, f->eye[2]);
 439
 440         onum = 0;
 441         for (i = 0;i < f->numentities;i++)
 442         {
 443                 ent = f->entitydata + i;
 444                 number = ent->number;
 445                 for (;onum < o->numentities && o->entitydata[onum].number < number;onum++)
 446                 {
 447                         // write remove message
 448                         MSG_WriteShort(msg, o->entitydata[onum].number | 0x8000);
 449                 }
 450                 if (onum < o->numentities && (o->entitydata[onum].number == number))
 451                 {
 452                         // delta from previous frame
 453                         delta = o->entitydata + onum;
 454                         // advance to next entity in delta frame
 455                         onum++;
 456                 }
 457                 else
 458                 {
 459                         // delta from defaults
 460                         delta = &defaultstate;
 461                 }
 462                 EntityState_Write(ent, msg, delta);
 463         }
 464         for (;onum < o->numentities;onum++)
 465         {
 466                 // write remove message
 467                 MSG_WriteShort(msg, o->entitydata[onum].number | 0x8000);
 468         }
 469         MSG_WriteShort(msg, 0xFFFF);
 470 }
 471
 472 // (client) reads a frame from network stream
 473 static entity_frame_t framedata; // FIXME?
 474 void EntityFrame_Read(entity_database_t *d)
 475 {
 476         int number, removed;
 477         entity_frame_t *f = &framedata, *delta = &deltaframe;
 478         entity_state_t *e, *old, *oldend;
 479
 480         EntityFrame_Clear(f, NULL, -1);
 481
 482         // read the frame header info
 483         f->time = cl.mtime[0];
 484         number = MSG_ReadLong();
 485         f->framenum = MSG_ReadLong();
 486         f->eye[0] = MSG_ReadFloat();
 487         f->eye[1] = MSG_ReadFloat();
 488         f->eye[2] = MSG_ReadFloat();
 489         EntityFrame_AckFrame(d, number);
 490         EntityFrame_FetchFrame(d, number, delta);
 491         old = delta->entitydata;
 492         oldend = old + delta->numentities;
 493         // read entities until we hit the magic 0xFFFF end tag
 494         while ((number = (unsigned short) MSG_ReadShort()) != 0xFFFF)
 495         {
 496                 if (msg_badread)
 497                         Host_Error("EntityFrame_Read: read error\n");
 498                 removed = number & 0x8000;
 499                 number &= 0x7FFF;
 500                 if (number >= MAX_EDICTS)
 501                         Host_Error("EntityFrame_Read: number (%i) >= MAX_EDICTS (%i)\n", number, MAX_EDICTS);
 502
 503                 // seek to entity, while copying any skipped entities (assume unchanged)
 504                 while (old < oldend && old->number < number)
 505                 {
 506                         if (f->numentities >= MAX_ENTITY_DATABASE)
 507                                 Host_Error("EntityFrame_Read: entity list too big\n");
 508                         memcpy(f->entitydata + f->numentities, old, sizeof(entity_state_t));
 509                         f->entitydata[f->numentities].time = cl.mtime[0];
 510                         old++;
 511                         f->numentities++;
 512                 }
 513                 if (removed)
 514                 {
 515                         if (old < oldend && old->number == number)
 516                                 old++;
 517                         else
 518                                 Con_Printf("EntityFrame_Read: REMOVE on unused entity %i\n", number);
 519                 }
 520                 else
 521                 {
 522                         if (f->numentities >= MAX_ENTITY_DATABASE)
 523                                 Host_Error("EntityFrame_Read: entity list too big\n");
 524
 525                         // reserve this slot
 526                         e = f->entitydata + f->numentities++;
 527
 528                         if (old < oldend && old->number == number)
 529                         {
 530                                 // delta from old entity
 531                                 *e = *old++;
 532                         }
 533                         else
 534                         {
 535                                 // delta from defaults
 536                                 *e = defaultstate;
 537                         }
 538
 539                         EntityState_ReadUpdate(e, number);
 540                 }
 541         }
 542         while (old < oldend)
 543         {
 544                 if (f->numentities >= MAX_ENTITY_DATABASE)
 545                         Host_Error("EntityFrame_Read: entity list too big\n");
 546                 f->entitydata[f->numentities] = *old++;
 547                 f->entitydata[f->numentities++].time = cl.mtime[0];
 548         }
 549         EntityFrame_AddFrame(d, f);
 550 }
 551
 552
 553 // (client) returns the frame number of the most recent frame recieved
 554 int EntityFrame_MostRecentlyRecievedFrameNum(entity_database_t *d)
 555 {
 556         if (d->numframes)
 557                 return d->frames[d->numframes - 1].framenum;
 558         else
 559                 return -1;
 560 }
 561
 562
 563
 564
 565
 566
 567 int EntityFrame4_SV_ChooseCommitToReplace(entity_database4_t *d)
 568 {
 569         int i, best, bestframenum;
 570         best = 0;
 571         bestframenum = d->commit[0].framenum;
 572         for (i = 0;i < MAX_ENTITY_HISTORY;i++)
 573         {
 574                 if (!d->commit[i].numentities)
 575                         return i;
 576                 if (bestframenum > d->commit[i].framenum)
 577                 {
 578                         bestframenum = d->commit[i].framenum;
 579                         best = i;
 580                 }
 581         }
 582         return best;
 583 }
 584
 585 entity_state_t *EntityFrame4_GetReferenceEntity(entity_database4_t *d, int number)
 586 {
 587         if (d->maxreferenceentities <= number)
 588         {
 589                 int oldmax = d->maxreferenceentities;
 590                 entity_state_t *oldentity = d->referenceentity;
 591                 d->maxreferenceentities = (number + 15) & ~7;
 592                 d->referenceentity = Mem_Alloc(d->mempool, d->maxreferenceentities * sizeof(*d->referenceentity));
 593                 if (oldentity)
 594                 {
 595                         memcpy(d->referenceentity, oldentity, oldmax * sizeof(*d->referenceentity));
 596                         Mem_Free(oldentity);
 597                 }
 598                 // clear the newly created entities
 599                 for (;oldmax < d->maxreferenceentities;oldmax++)
 600                         d->referenceentity[oldmax] = defaultstate;
 601         }
 602         return d->referenceentity + number;
 603 }
 604
 605 void EntityFrame4_AddCommitEntity(entity_database4_t *d, entity_state_t *s)
 606 {
 607         // resize commit's entity list if full
 608         if (d->currentcommit->maxentities <= d->currentcommit->numentities)
 609         {
 610                 entity_state_t *oldentity = d->currentcommit->entity;
 611                 d->currentcommit->maxentities += 8;
 612                 d->currentcommit->entity = Mem_Alloc(d->mempool, d->currentcommit->maxentities * sizeof(*d->currentcommit->entity));
 613                 if (oldentity)
 614                 {
 615                         memcpy(d->currentcommit->entity, oldentity, d->currentcommit->numentities * sizeof(*d->currentcommit->entity));
 616                         Mem_Free(oldentity);
 617                 }
 618         }
 619         d->currentcommit->entity[d->currentcommit->numentities++] = *s;
 620 }
 621
 622 entity_database4_t *EntityFrame4_AllocDatabase(mempool_t *pool)
 623 {
 624         entity_database4_t *d;
 625         d = Mem_Alloc(pool, sizeof(*d));
 626         d->mempool = pool;
 627         EntityFrame4_ResetDatabase(d);
 628         return d;
 629 }
 630
 631 void EntityFrame4_FreeDatabase(entity_database4_t *d)
 632 {
 633         int i;
 634         for (i = 0;i < MAX_ENTITY_HISTORY;i++)
 635                 if (d->commit[i].entity)
 636                         Mem_Free(d->commit[i].entity);
 637         if (d->referenceentity)
 638                 Mem_Free(d->referenceentity);
 639         Mem_Free(d);
 640 }
 641
 642 void EntityFrame4_ResetDatabase(entity_database4_t *d)
 643 {
 644         int i;
 645         d->referenceframenum = -1;
 646         d->ackframenum = -1;
 647         for (i = 0;i < MAX_ENTITY_HISTORY;i++)
 648                 d->commit[i].numentities = 0;
 649 }
 650
 651 void EntityFrame4_AckFrame(entity_database4_t *d, int framenum)
 652 {
 653         int i, foundit = false;
 654         entity_state_t *s;
 655         entity_database4_commit_t *commit;
 656         // check if client is requesting no delta compression
 657         if (framenum == -1)
 658         {
 659                 EntityFrame4_ResetDatabase(d);
 660                 return;
 661         }
 662         for (i = 0;i < MAX_ENTITY_HISTORY;i++)
 663         {
 664                 if (d->commit[i].numentities && d->commit[i].framenum <= framenum)
 665                 {
 666                         if (d->commit[i].framenum == framenum)
 667                         {
 668                                 // apply commit to database
 669                                 commit = d->commit + i;
 670                                 d->referenceframenum = commit->framenum;
 671                                 while (commit->numentities--)
 672                                 {
 673                                         s = commit->entity + commit->numentities;
 674                                         *EntityFrame4_GetReferenceEntity(d, s->number) = *s;
 675                                 }
 676                                 foundit = true;
 677                         }
 678                         d->commit[i].numentities = 0;
 679                         d->commit[i].framenum = -1;
 680                 }
 681         }
 682         if (!foundit)
 683                 Con_DPrintf("EntityFrame4_AckFrame: frame %i not found in database, expect glitches!\n", framenum);
 684 }
 685
 686 void EntityFrame4_SV_WriteFrame_Begin(entity_database4_t *d, sizebuf_t *msg, int framenum)
 687 {
 688         d->currentcommit = d->commit + EntityFrame4_SV_ChooseCommitToReplace(d);
 689         d->currentcommit->numentities = 0;
 690         d->currentcommit->framenum = framenum;
 691         MSG_WriteByte(msg, svc_entities);
 692         MSG_WriteLong(msg, d->referenceframenum);
 693         MSG_WriteLong(msg, d->currentcommit->framenum);
 694 }
 695
 696 int EntityFrame4_SV_WriteFrame_Entity(entity_database4_t *d, sizebuf_t *msg, int maxbytes, entity_state_t *s)
 697 {
 698         qbyte data[128];
 699         sizebuf_t buf;
 700         entity_state_t *e;
 701         // prepare the buffer
 702         memset(&buf, 0, sizeof(buf));
 703         buf.data = data;
 704         buf.maxsize = sizeof(data);
 705         // make the message
 706         e = EntityFrame4_GetReferenceEntity(d, s->number);
 707         // send an update (may update or remove the entity)
 708         EntityState_Write(s, &buf, e);
 709         // if the message is empty, skip out now
 710         if (!buf.cursize)
 711                 return true;
 712         // if the commit is full, we're done
 713         if (msg->cursize + buf.cursize + 2 >= min(msg->maxsize, maxbytes))
 714                 return false;
 715         // add the entity to the commit
 716         EntityFrame4_AddCommitEntity(d, s);
 717         // write the message to the packet
 718         SZ_Write(msg, buf.data, buf.cursize);
 719         // carry on
 720         return true;
 721 }
 722
 723 void EntityFrame4_SV_WriteFrame_End(entity_database4_t *d, sizebuf_t *msg)
 724 {
 725         // remove world message (invalid, and thus a good terminator)
 726         MSG_WriteShort(msg, 0x8000);
 727         // just to be sure
 728         d->currentcommit = NULL;
 729 }
 730
 731 extern void CL_MoveLerpEntityStates(entity_t *ent);
 732 void EntityFrame4_CL_ReadFrame(entity_database4_t *d)
 733 {
 734         int i, n, cnumber, referenceframenum, framenum, enumber, done, stopnumber;
 735         entity_state_t *e;
 736         // read the number of the frame this refers to
 737         referenceframenum = MSG_ReadLong();
 738         // read the number of this frame
 739         framenum = MSG_ReadLong();
 740         // read the start number
 741         enumber = MSG_ReadShort();
 742         EntityFrame4_AckFrame(d, referenceframenum);
 743         for (i = 0;i < MAX_ENTITY_HISTORY;i++)
 744                 if (!d->commit[i].numentities)
 745                         break;
 746         if (i < MAX_ENTITY_HISTORY)
 747         {
 748                 d->currentcommit = d->commit + i;
 749                 d->ackframenum = d->currentcommit->framenum = framenum;
 750                 d->currentcommit->numentities = 0;
 751         }
 752         else
 753         {
 754                 Con_Printf("EntityFrame4_CL_ReadFrame: error while decoding frame %i: database full, resetting, expect glitches!!\n", framenum);
 755                 d->currentcommit = NULL;
 756                 EntityFrame4_ResetDatabase(d);
 757         }
 758         done = false;
 759         while (!done && !msg_badread)
 760         {
 761                 n = (unsigned short)MSG_ReadShort();
 762                 if (n == 0x8000)
 763                 {
 764                         // no more entities in this update, but we still need to copy the
 765                         // rest of the reference entities
 766                         done = true;
 767                         // read end of range number, then process normally
 768                         n = (unsigned short)MSG_ReadShort();
 769                 }
 770                 // high bit means it's a remove message
 771                 cnumber = n & 0x7FFF;
 772                 // add one (the changed one) if not done
 773                 stopnumber = cnumber + !done;
 774                 // process entities in range from the last one to the changed one
 775                 for (;enumber < stopnumber;enumber++)
 776                 {
 777                         e = EntityFrame4_GetReferenceEntity(d, enumber);
 778                         cl_entities[enumber].state_previous = cl_entities[enumber].state_current;
 779                         // skipped (unchanged), copy from reference database
 780                         cl_entities[enumber].state_current = *e;
 781                         if (enumber == cnumber)
 782                         {
 783                                 // modified
 784                                 if (n & 0x8000)
 785                                 {
 786                                         // simply removed
 787                                         cl_entities[enumber].state_current = defaultstate;
 788                                 }
 789                                 else
 790                                 {
 791                                         // read the changes
 792                                         EntityState_ReadUpdate(&cl_entities[enumber].state_current, enumber);
 793                                 }
 794                         }
 795                         cl_entities[enumber].state_current.number = enumber;
 796 #if 0
 797                         // debugging code
 798                         if (cl_entities[enumber].state_current.active != cl_entities[enumber].state_previous.active)
 799                         {
 800                                 if (cl_entities[enumber].state_current.active)
 801                                         Con_Printf("entity #%i has become active\n");
 802                                 else if (cl_entities[enumber].state_current.active)
 803                                         Con_Printf("entity #%i has become inactive\n");
 804                         }
 805 #endif
 806                         CL_MoveLerpEntityStates(&cl_entities[enumber]);
 807                         cl_entities_active[enumber] = true;
 808                         if (d->currentcommit)
 809                                 EntityFrame4_AddCommitEntity(d, &cl_entities[enumber].state_current);
 810                 }
 811         }
 812         d->currentcommit = NULL;
 813 }
 814
 815