src/subsidy.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file subsidy.cpp Handling of subsidies. */
  11
  12 #include "stdafx.h"
  13 #include "company_func.h"
  14 #include "industry.h"
  15 #include "town.h"
  16 #include "news_func.h"
  17 #include "ai/ai.hpp"
  18 #include "station_base.h"
  19 #include "strings_func.h"
  20 #include "window_func.h"
  21 #include "subsidy_base.h"
  22 #include "subsidy_func.h"
  23 #include "core/pool_func.hpp"
  24 #include "core/random_func.hpp"
  25 #include "game/game.hpp"
  26 #include "command_func.h"
  27
  28 #include "table/strings.h"
  29
  30 template<> Subsidy::Pool Subsidy::PoolItem::pool ("Subsidy");
  31 INSTANTIATE_POOL_METHODS(Subsidy)
  32
  33 /**
  34  * Marks subsidy as awarded, creates news and AI event
  35  * @param company awarded company
  36  */
  37 void Subsidy::AwardTo(CompanyID company)
  38 {
  39         assert(!this->IsAwarded());
  40
  41         this->awarded = company;
  42         this->remaining = SUBSIDY_CONTRACT_MONTHS;
  43
  44         char company_name[MAX_LENGTH_COMPANY_NAME_CHARS * MAX_CHAR_LENGTH];
  45         SetDParam(0, company);
  46         GetString(company_name, STR_COMPANY_NAME, lastof(company_name));
  47
  48         char *cn = strdup(company_name);
  49
  50         /* Add a news item */
  51         Pair reftype = SetupSubsidyDecodeParam(this, false);
  52         InjectDParam(1);
  53
  54         SetDParamStr(0, cn);
  55         AddNewsItem(
  56                 STR_NEWS_SERVICE_SUBSIDY_AWARDED_HALF + _settings_game.difficulty.subsidy_multiplier,
  57                 NT_SUBSIDIES, NF_NORMAL,
  58                 (NewsReferenceType)reftype.a, this->src, (NewsReferenceType)reftype.b, this->dst,
  59                 cn
  60         );
  61         AI::BroadcastNewEvent(new ScriptEventSubsidyAwarded(this->index));
  62         Game::NewEvent(new ScriptEventSubsidyAwarded(this->index));
  63
  64         InvalidateWindowData(WC_SUBSIDIES_LIST, 0);
  65 }
  66
  67 /**
  68  * Setup the string parameters for printing the subsidy at the screen, and compute the news reference for the subsidy.
  69  * @param s %Subsidy being printed.
  70  * @param mode Unit of cargo used, \c true means general name, \c false means singular form.
  71  * @return Reference of the subsidy in the news system.
  72  */
  73 Pair SetupSubsidyDecodeParam(const Subsidy *s, bool mode)
  74 {
  75         NewsReferenceType reftype1 = NR_NONE;
  76         NewsReferenceType reftype2 = NR_NONE;
  77
  78         /* if mode is false, use the singular form */
  79         const CargoSpec *cs = CargoSpec::Get(s->cargo_type);
  80         SetDParam(0, mode ? cs->name : cs->name_single);
  81
  82         switch (s->src_type) {
  83                 case ST_INDUSTRY:
  84                         reftype1 = NR_INDUSTRY;
  85                         SetDParam(1, STR_INDUSTRY_NAME);
  86                         break;
  87                 case ST_TOWN:
  88                         reftype1 = NR_TOWN;
  89                         SetDParam(1, STR_TOWN_NAME);
  90                         break;
  91                 default: NOT_REACHED();
  92         }
  93         SetDParam(2, s->src);
  94
  95         switch (s->dst_type) {
  96                 case ST_INDUSTRY:
  97                         reftype2 = NR_INDUSTRY;
  98                         SetDParam(4, STR_INDUSTRY_NAME);
  99                         break;
 100                 case ST_TOWN:
 101                         reftype2 = NR_TOWN;
 102                         SetDParam(4, STR_TOWN_NAME);
 103                         break;
 104                 default: NOT_REACHED();
 105         }
 106         SetDParam(5, s->dst);
 107
 108         Pair p;
 109         p.a = reftype1;
 110         p.b = reftype2;
 111         return p;
 112 }
 113
 114 /**
 115  * Sets a flag indicating that given town/industry is part of subsidised route.
 116  * @param type is it a town or an industry?
 117  * @param index index of town/industry
 118  * @param flag flag to set
 119  */
 120 static inline void SetPartOfSubsidyFlag(SourceType type, SourceID index, PartOfSubsidy flag)
 121 {
 122         switch (type) {
 123                 case ST_INDUSTRY: Industry::Get(index)->part_of_subsidy |= flag; return;
 124                 case ST_TOWN:   Town::Get(index)->cache.part_of_subsidy |= flag; return;
 125                 default: NOT_REACHED();
 126         }
 127 }
 128
 129 /** Perform a full rebuild of the subsidies cache. */
 130 void RebuildSubsidisedSourceAndDestinationCache()
 131 {
 132         Town *t;
 133         FOR_ALL_TOWNS(t) t->cache.part_of_subsidy = POS_NONE;
 134
 135         Industry *i;
 136         FOR_ALL_INDUSTRIES(i) i->part_of_subsidy = POS_NONE;
 137
 138         const Subsidy *s;
 139         FOR_ALL_SUBSIDIES(s) {
 140                 SetPartOfSubsidyFlag(s->src_type, s->src, POS_SRC);
 141                 SetPartOfSubsidyFlag(s->dst_type, s->dst, POS_DST);
 142         }
 143 }
 144
 145 /**
 146  * Delete the subsidies associated with a given cargo source type and id.
 147  * @param type  Cargo source type of the id.
 148  * @param index Id to remove.
 149  */
 150 void DeleteSubsidyWith(SourceType type, SourceID index)
 151 {
 152         bool dirty = false;
 153
 154         Subsidy *s;
 155         FOR_ALL_SUBSIDIES(s) {
 156                 if ((s->src_type == type && s->src == index) || (s->dst_type == type && s->dst == index)) {
 157                         delete s;
 158                         dirty = true;
 159                 }
 160         }
 161
 162         if (dirty) {
 163                 InvalidateWindowData(WC_SUBSIDIES_LIST, 0);
 164                 RebuildSubsidisedSourceAndDestinationCache();
 165         }
 166 }
 167
 168 /**
 169  * Check whether a specific subsidy already exists.
 170  * @param cargo Cargo type.
 171  * @param src_type Type of source of the cargo, affects interpretation of \a src.
 172  * @param src Id of the source.
 173  * @param dst_type Type of the destination of the cargo, affects interpretation of \a dst.
 174  * @param dst Id of the destination.
 175  * @return \c true if the subsidy already exists, \c false if not.
 176  */
 177 static bool CheckSubsidyDuplicate(CargoID cargo, SourceType src_type, SourceID src, SourceType dst_type, SourceID dst)
 178 {
 179         const Subsidy *s;
 180         FOR_ALL_SUBSIDIES(s) {
 181                 if (s->cargo_type == cargo &&
 182                                 s->src_type == src_type && s->src == src &&
 183                                 s->dst_type == dst_type && s->dst == dst) {
 184                         return true;
 185                 }
 186         }
 187         return false;
 188 }
 189
 190 /**
 191  * Checks if the source and destination of a subsidy are inside the distance limit.
 192  * @param src_type Type of \a src.
 193  * @param src      Index of source.
 194  * @param dst_type Type of \a dst.
 195  * @param dst      Index of destination.
 196  * @return True if they are inside the distance limit.
 197  */
 198 static bool CheckSubsidyDistance(SourceType src_type, SourceID src, SourceType dst_type, SourceID dst)
 199 {
 200         TileIndex tile_src = (src_type == ST_TOWN) ? Town::Get(src)->xy : Industry::Get(src)->location.tile;
 201         TileIndex tile_dst = (dst_type == ST_TOWN) ? Town::Get(dst)->xy : Industry::Get(dst)->location.tile;
 202
 203         return (DistanceManhattan(tile_src, tile_dst) <= SUBSIDY_MAX_DISTANCE);
 204 }
 205
 206 /**
 207  * Creates a subsidy with the given parameters.
 208  * @param cid      Subsidised cargo.
 209  * @param src_type Type of \a src.
 210  * @param src      Index of source.
 211  * @param dst_type Type of \a dst.
 212  * @param dst      Index of destination.
 213  */
 214 void CreateSubsidy(CargoID cid, SourceType src_type, SourceID src, SourceType dst_type, SourceID dst)
 215 {
 216         Subsidy *s = new Subsidy();
 217         s->cargo_type = cid;
 218         s->src_type = src_type;
 219         s->src = src;
 220         s->dst_type = dst_type;
 221         s->dst = dst;
 222         s->remaining = SUBSIDY_OFFER_MONTHS;
 223         s->awarded = INVALID_COMPANY;
 224
 225         Pair reftype = SetupSubsidyDecodeParam(s, false);
 226         AddNewsItem(STR_NEWS_SERVICE_SUBSIDY_OFFERED, NT_SUBSIDIES, NF_NORMAL, (NewsReferenceType)reftype.a, s->src, (NewsReferenceType)reftype.b, s->dst);
 227         SetPartOfSubsidyFlag(s->src_type, s->src, POS_SRC);
 228         SetPartOfSubsidyFlag(s->dst_type, s->dst, POS_DST);
 229         AI::BroadcastNewEvent(new ScriptEventSubsidyOffer(s->index));
 230         Game::NewEvent(new ScriptEventSubsidyOffer(s->index));
 231
 232         InvalidateWindowData(WC_SUBSIDIES_LIST, 0);
 233 }
 234
 235 /**
 236  * Create a new subsidy.
 237  * @param tile unused.
 238  * @param flags type of operation
 239  * @param p1 various bitstuffed elements
 240  * - p1 = (bit  0 -  7) - SourceType of source.
 241  * - p1 = (bit  8 - 23) - SourceID of source.
 242  * - p1 = (bit 24 - 31) - CargoID of subsidy.
 243  * @param p2 various bitstuffed elements
 244  * - p2 = (bit  0 -  7) - SourceType of destination.
 245  * - p2 = (bit  8 - 23) - SourceID of destination.
 246  * @param text unused.
 247  * @return the cost of this operation or an error
 248  */
 249 CommandCost CmdCreateSubsidy(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 250 {
 251         if (!Subsidy::CanAllocateItem()) return CMD_ERROR;
 252
 253         CargoID cid = GB(p1, 24, 8);
 254         SourceType src_type = (SourceType)GB(p1, 0, 8);
 255         SourceID src = GB(p1, 8, 16);
 256         SourceType dst_type = (SourceType)GB(p2, 0, 8);
 257         SourceID dst = GB(p2, 8, 16);
 258
 259         if (_current_company != OWNER_DEITY) return CMD_ERROR;
 260
 261         if (cid >= NUM_CARGO || !::CargoSpec::Get(cid)->IsValid()) return CMD_ERROR;
 262
 263         switch (src_type) {
 264                 case ST_TOWN:
 265                         if (!Town::IsValidID(src)) return CMD_ERROR;
 266                         break;
 267                 case ST_INDUSTRY:
 268                         if (!Industry::IsValidID(src)) return CMD_ERROR;
 269                         break;
 270                 default:
 271                         return CMD_ERROR;
 272         }
 273         switch (dst_type) {
 274                 case ST_TOWN:
 275                         if (!Town::IsValidID(dst)) return CMD_ERROR;
 276                         break;
 277                 case ST_INDUSTRY:
 278                         if (!Industry::IsValidID(dst)) return CMD_ERROR;
 279                         break;
 280                 default:
 281                         return CMD_ERROR;
 282         }
 283
 284         if (flags & DC_EXEC) {
 285                 CreateSubsidy(cid, src_type, src, dst_type, dst);
 286         }
 287
 288         return CommandCost();
 289 }
 290
 291 /**
 292  * Tries to create a passenger subsidy between two towns.
 293  * @return True iff the subsidy was created.
 294  */
 295 bool FindSubsidyPassengerRoute()
 296 {
 297         if (!Subsidy::CanAllocateItem()) return false;
 298
 299         const Town *src = Town::GetRandom();
 300         if (src->cache.population < SUBSIDY_PAX_MIN_POPULATION ||
 301                         src->GetPercentTransported(CT_PASSENGERS) > SUBSIDY_MAX_PCT_TRANSPORTED) {
 302                 return false;
 303         }
 304
 305         const Town *dst = Town::GetRandom();
 306         if (dst->cache.population < SUBSIDY_PAX_MIN_POPULATION || src == dst) {
 307                 return false;
 308         }
 309
 310         if (DistanceManhattan(src->xy, dst->xy) > SUBSIDY_MAX_DISTANCE) return false;
 311         if (CheckSubsidyDuplicate(CT_PASSENGERS, ST_TOWN, src->index, ST_TOWN, dst->index)) return false;
 312
 313         CreateSubsidy(CT_PASSENGERS, ST_TOWN, src->index, ST_TOWN, dst->index);
 314
 315         return true;
 316 }
 317
 318 bool FindSubsidyCargoDestination(CargoID cid, SourceType src_type, SourceID src);
 319
 320
 321 /**
 322  * Tries to create a cargo subsidy with a town as source.
 323  * @return True iff the subsidy was created.
 324  */
 325 bool FindSubsidyTownCargoRoute()
 326 {
 327         if (!Subsidy::CanAllocateItem()) return false;
 328
 329         SourceType src_type = ST_TOWN;
 330
 331         /* Select a random town. */
 332         const Town *src_town = Town::GetRandom();
 333
 334         uint32 town_cargo_produced = src_town->cargo_produced;
 335
 336         /* Passenger subsidies are not handled here. */
 337         ClrBit(town_cargo_produced, CT_PASSENGERS);
 338
 339         /* No cargo produced at all? */
 340         if (town_cargo_produced == 0) return false;
 341
 342         /* Choose a random cargo that is produced in the town. */
 343         uint8 cargo_number = RandomRange(CountBits(town_cargo_produced));
 344         CargoID cid;
 345         FOR_EACH_SET_CARGO_ID(cid, town_cargo_produced) {
 346                 if (cargo_number == 0) break;
 347                 cargo_number--;
 348         }
 349
 350         /* Avoid using invalid NewGRF cargoes. */
 351         if (!CargoSpec::Get(cid)->IsValid() ||
 352                         _settings_game.linkgraph.GetDistributionType(cid) != DT_MANUAL) {
 353                 return false;
 354         }
 355
 356         /* Quit if the percentage transported is large enough. */
 357         if (src_town->GetPercentTransported(cid) > SUBSIDY_MAX_PCT_TRANSPORTED) return false;
 358
 359         SourceID src = src_town->index;
 360
 361         return FindSubsidyCargoDestination(cid, src_type, src);
 362 }
 363
 364 /**
 365  * Tries to create a cargo subsidy with an industry as source.
 366  * @return True iff the subsidy was created.
 367  */
 368 bool FindSubsidyIndustryCargoRoute()
 369 {
 370         if (!Subsidy::CanAllocateItem()) return false;
 371
 372         SourceType src_type = ST_INDUSTRY;
 373
 374         /* Select a random industry. */
 375         const Industry *src_ind = Industry::GetRandom();
 376         if (src_ind == NULL) return false;
 377
 378         uint trans, total;
 379
 380         CargoID cid;
 381
 382         /* Randomize cargo type */
 383         if (src_ind->produced_cargo[1] != CT_INVALID && HasBit(Random(), 0)) {
 384                 cid = src_ind->produced_cargo[1];
 385                 trans = src_ind->last_month_pct_transported[1];
 386                 total = src_ind->last_month_production[1];
 387         } else {
 388                 cid = src_ind->produced_cargo[0];
 389                 trans = src_ind->last_month_pct_transported[0];
 390                 total = src_ind->last_month_production[0];
 391         }
 392
 393         /* Quit if no production in this industry
 394          * or if the pct transported is already large enough
 395          * or if the cargo is automatically distributed */
 396         if (total == 0 || trans > SUBSIDY_MAX_PCT_TRANSPORTED ||
 397                         cid == CT_INVALID ||
 398                         _settings_game.linkgraph.GetDistributionType(cid) != DT_MANUAL) {
 399                 return false;
 400         }
 401
 402         SourceID src = src_ind->index;
 403
 404         return FindSubsidyCargoDestination(cid, src_type, src);
 405 }
 406
 407 /**
 408  * Tries to find a suitable destination for the given source and cargo.
 409  * @param cid      Subsidized cargo.
 410  * @param src_type Type of \a src.
 411  * @param src      Index of source.
 412  * @return True iff the subsidy was created.
 413  */
 414 bool FindSubsidyCargoDestination(CargoID cid, SourceType src_type, SourceID src)
 415 {
 416         /* Choose a random destination. Only consider towns if they can accept the cargo. */
 417         SourceType dst_type = (HasBit(_town_cargoes_accepted, cid) && Chance16(1, 2)) ? ST_TOWN : ST_INDUSTRY;
 418
 419         SourceID dst;
 420         switch (dst_type) {
 421                 case ST_TOWN: {
 422                         /* Select a random town. */
 423                         const Town *dst_town = Town::GetRandom();
 424
 425                         /* Check if the town can accept this cargo. */
 426                         if (!HasBit(dst_town->cargo_accepted_total, cid)) return false;
 427
 428                         dst = dst_town->index;
 429                         break;
 430                 }
 431
 432                 case ST_INDUSTRY: {
 433                         /* Select a random industry. */
 434                         const Industry *dst_ind = Industry::GetRandom();
 435
 436                         /* The industry must accept the cargo */
 437                         if (dst_ind == NULL ||
 438                                         (cid != dst_ind->accepts_cargo[0] &&
 439                                          cid != dst_ind->accepts_cargo[1] &&
 440                                          cid != dst_ind->accepts_cargo[2])) {
 441                                 return false;
 442                         }
 443
 444                         dst = dst_ind->index;
 445                         break;
 446                 }
 447
 448                 default: NOT_REACHED();
 449         }
 450
 451         /* Check that the source and the destination are not the same. */
 452         if (src_type == dst_type && src == dst) return false;
 453
 454         /* Check distance between source and destination. */
 455         if (!CheckSubsidyDistance(src_type, src, dst_type, dst)) return false;
 456
 457         /* Avoid duplicate subsidies. */
 458         if (CheckSubsidyDuplicate(cid, src_type, src, dst_type, dst)) return false;
 459
 460         CreateSubsidy(cid, src_type, src, dst_type, dst);
 461
 462         return true;
 463 }
 464
 465 /** Perform the monthly update of open subsidies, and try to create a new one. */
 466 void SubsidyMonthlyLoop()
 467 {
 468         bool modified = false;
 469
 470         Subsidy *s;
 471         FOR_ALL_SUBSIDIES(s) {
 472                 if (--s->remaining == 0) {
 473                         if (!s->IsAwarded()) {
 474                                 Pair reftype = SetupSubsidyDecodeParam(s, true);
 475                                 AddNewsItem(STR_NEWS_OFFER_OF_SUBSIDY_EXPIRED, NT_SUBSIDIES, NF_NORMAL, (NewsReferenceType)reftype.a, s->src, (NewsReferenceType)reftype.b, s->dst);
 476                                 AI::BroadcastNewEvent(new ScriptEventSubsidyOfferExpired(s->index));
 477                                 Game::NewEvent(new ScriptEventSubsidyOfferExpired(s->index));
 478                         } else {
 479                                 if (s->awarded == _local_company) {
 480                                         Pair reftype = SetupSubsidyDecodeParam(s, true);
 481                                         AddNewsItem(STR_NEWS_SUBSIDY_WITHDRAWN_SERVICE, NT_SUBSIDIES, NF_NORMAL, (NewsReferenceType)reftype.a, s->src, (NewsReferenceType)reftype.b, s->dst);
 482                                 }
 483                                 AI::BroadcastNewEvent(new ScriptEventSubsidyExpired(s->index));
 484                                 Game::NewEvent(new ScriptEventSubsidyExpired(s->index));
 485                         }
 486                         delete s;
 487                         modified = true;
 488                 }
 489         }
 490
 491         if (modified) {
 492                 RebuildSubsidisedSourceAndDestinationCache();
 493         } else if (_settings_game.linkgraph.distribution_pax != DT_MANUAL &&
 494                            _settings_game.linkgraph.distribution_mail != DT_MANUAL &&
 495                            _settings_game.linkgraph.distribution_armoured != DT_MANUAL &&
 496                            _settings_game.linkgraph.distribution_default != DT_MANUAL) {
 497                 /* Return early if there are no manually distributed cargoes and if we
 498                  * don't need to invalidate the subsidies window. */
 499                 return;
 500         }
 501
 502         bool passenger_subsidy = false;
 503         bool town_subsidy = false;
 504         bool industry_subsidy = false;
 505
 506         int random_chance = RandomRange(16);
 507
 508         if (random_chance < 2 && _settings_game.linkgraph.distribution_pax == DT_MANUAL) {
 509                 /* There is a 1/8 chance each month of generating a passenger subsidy. */
 510                 int n = 1000;
 511
 512                 do {
 513                         passenger_subsidy = FindSubsidyPassengerRoute();
 514                 } while (!passenger_subsidy && n--);
 515         } else if (random_chance == 2) {
 516                 /* Cargo subsidies with a town as a source have a 1/16 chance. */
 517                 int n = 1000;
 518
 519                 do {
 520                         town_subsidy = FindSubsidyTownCargoRoute();
 521                 } while (!town_subsidy && n--);
 522         } else if (random_chance == 3) {
 523                 /* Cargo subsidies with an industry as a source have a 1/16 chance. */
 524                 int n = 1000;
 525
 526                 do {
 527                         industry_subsidy = FindSubsidyIndustryCargoRoute();
 528                 } while (!industry_subsidy && n--);
 529         }
 530
 531         modified |= passenger_subsidy || town_subsidy || industry_subsidy;
 532
 533         if (modified) InvalidateWindowData(WC_SUBSIDIES_LIST, 0);
 534 }
 535
 536 /**
 537  * Tests whether given delivery is subsidised and possibly awards the subsidy to delivering company
 538  * @param cargo_type type of cargo
 539  * @param company company delivering the cargo
 540  * @param src_type type of \a src
 541  * @param src index of source
 542  * @param st station where the cargo is delivered to
 543  * @return is the delivery subsidised?
 544  */
 545 bool CheckSubsidised(CargoID cargo_type, CompanyID company, SourceType src_type, SourceID src, const Station *st)
 546 {
 547         /* If the source isn't subsidised, don't continue */
 548         if (src == INVALID_SOURCE) return false;
 549         switch (src_type) {
 550                 case ST_INDUSTRY:
 551                         if (!(Industry::Get(src)->part_of_subsidy & POS_SRC)) return false;
 552                         break;
 553                 case ST_TOWN:
 554                         if (!(Town::Get(src)->cache.part_of_subsidy & POS_SRC)) return false;
 555                         break;
 556                 default: return false;
 557         }
 558
 559         /* Remember all towns near this station (at least one house in its catchment radius)
 560          * which are destination of subsidised path. Do that only if needed */
 561         SmallVector<const Town *, 2> towns_near;
 562         if (!st->rect.IsEmpty()) {
 563                 Subsidy *s;
 564                 FOR_ALL_SUBSIDIES(s) {
 565                         /* Don't create the cache if there is no applicable subsidy with town as destination */
 566                         if (s->dst_type != ST_TOWN) continue;
 567                         if (s->cargo_type != cargo_type || s->src_type != src_type || s->src != src) continue;
 568                         if (s->IsAwarded() && s->awarded != company) continue;
 569
 570                         Rect rect = st->GetCatchmentRect();
 571
 572                         for (int y = rect.top; y <= rect.bottom; y++) {
 573                                 for (int x = rect.left; x <= rect.right; x++) {
 574                                         TileIndex tile = TileXY(x, y);
 575                                         if (!IsHouseTile(tile)) continue;
 576                                         const Town *t = Town::GetByTile(tile);
 577                                         if (t->cache.part_of_subsidy & POS_DST) towns_near.Include(t);
 578                                 }
 579                         }
 580                         break;
 581                 }
 582         }
 583
 584         bool subsidised = false;
 585
 586         /* Check if there's a (new) subsidy that applies. There can be more subsidies triggered by this delivery!
 587          * Think about the case that subsidies are A->B and A->C and station has both B and C in its catchment area */
 588         Subsidy *s;
 589         FOR_ALL_SUBSIDIES(s) {
 590                 if (s->cargo_type == cargo_type && s->src_type == src_type && s->src == src && (!s->IsAwarded() || s->awarded == company)) {
 591                         switch (s->dst_type) {
 592                                 case ST_INDUSTRY:
 593                                         for (const Industry * const *ip = st->industries_near.Begin(); ip != st->industries_near.End(); ip++) {
 594                                                 if (s->dst == (*ip)->index) {
 595                                                         assert((*ip)->part_of_subsidy & POS_DST);
 596                                                         subsidised = true;
 597                                                         if (!s->IsAwarded()) s->AwardTo(company);
 598                                                 }
 599                                         }
 600                                         break;
 601                                 case ST_TOWN:
 602                                         for (const Town * const *tp = towns_near.Begin(); tp != towns_near.End(); tp++) {
 603                                                 if (s->dst == (*tp)->index) {
 604                                                         assert((*tp)->cache.part_of_subsidy & POS_DST);
 605                                                         subsidised = true;
 606                                                         if (!s->IsAwarded()) s->AwardTo(company);
 607                                                 }
 608                                         }
 609                                         break;
 610                                 default:
 611                                         NOT_REACHED();
 612                         }
 613                 }
 614         }
 615
 616         return subsidised;
 617 }