newgrf_roadstop.cpp

Go to the documentation of this file.

/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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 <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

 
#include "stdafx.h"
#include "debug.h"
#include "station_base.h"
#include "roadstop_base.h"
#include "newgrf_badge.h"
#include "newgrf_roadstop.h"
#include "newgrf_cargo.h"
#include "newgrf_roadtype.h"
#include "gfx_type.h"
#include "company_func.h"
#include "road.h"
#include "window_type.h"
#include "timer/timer_game_calendar.h"
#include "town.h"
#include "tile_cmd.h"
#include "viewport_func.h"
#include "newgrf_animation_base.h"
#include "newgrf_sound.h"
 
#include "table/strings.h"
 
#include "newgrf_class_func.h"
 
#include "safeguards.h"
 
template <>
void RoadStopClass::InsertDefaults()
{
  /* Set up initial data */
  RoadStopClass::Get(RoadStopClass::Allocate(ROADSTOP_CLASS_LABEL_DEFAULT))->name = STR_STATION_CLASS_DFLT;
  RoadStopClass::Get(RoadStopClass::Allocate(ROADSTOP_CLASS_LABEL_DEFAULT))->Insert(nullptr);
  RoadStopClass::Get(RoadStopClass::Allocate(ROADSTOP_CLASS_LABEL_WAYPOINT))->name = STR_STATION_CLASS_WAYP;
  RoadStopClass::Get(RoadStopClass::Allocate(ROADSTOP_CLASS_LABEL_WAYPOINT))->Insert(nullptr);
}
 
template <>
bool RoadStopClass::IsUIAvailable(uint) const
{
  return true;
}
 
/* Instantiate RoadStopClass. */
template class NewGRFClass<RoadStopSpec, RoadStopClassID, ROADSTOP_CLASS_MAX>;
 
static const uint NUM_ROADSTOPSPECS_PER_STATION = 63; 
 
uint32_t RoadStopScopeResolver::GetRandomBits() const
{
  if (this->st == nullptr) return 0;
 
  uint32_t bits = this->st->random_bits;
  if (this->tile != INVALID_TILE && Station::IsExpected(this->st)) {
    bits |= Station::From(this->st)->GetRoadStopRandomBits(this->tile) << 16;
  }
  return bits;
}
 
uint32_t RoadStopScopeResolver::GetRandomTriggers() const
{
  if (this->st == nullptr) return 0;
 
  StationRandomTriggers triggers = st->waiting_random_triggers;
 
  auto it = this->st->tile_waiting_random_triggers.find(this->tile);
  if (it != std::end(this->st->tile_waiting_random_triggers)) triggers.Set(it->second);
 
  return triggers.base();
}
 
uint32_t RoadStopScopeResolver::GetVariable(uint8_t variable, [[maybe_unused]] uint32_t parameter, bool &available) const
{
  auto get_road_type_variable = [&](RoadTramType rtt) -> uint32_t {
    RoadType rt;
    if (this->tile == INVALID_TILE) {
      rt = (GetRoadTramType(this->roadtype) == rtt) ? this->roadtype : INVALID_ROADTYPE;
    } else {
      rt = GetRoadType(this->tile, rtt);
    }
    if (rt == INVALID_ROADTYPE) {
      return 0xFFFFFFFF;
    } else {
      return GetReverseRoadTypeTranslation(rt, this->roadstopspec->grf_prop.grffile);
    }
  };
 
  switch (variable) {
    /* View/rotation */
    case 0x40: return this->view;
 
    /* Stop type: 0: bus, 1: truck, 2: waypoint */
    case 0x41:
      if (this->type == StationType::Bus) return 0;
      if (this->type == StationType::Truck) return 1;
      return 2;
 
    /* Terrain type */
    case 0x42: return this->tile == INVALID_TILE ? 0 : (GetTileSlope(this->tile) << 8 | GetTerrainType(this->tile, TCX_NORMAL));
 
    /* Road type */
    case 0x43: return get_road_type_variable(RTT_ROAD);
 
    /* Tram type */
    case 0x44: return get_road_type_variable(RTT_TRAM);
 
    /* Town zone and Manhattan distance of closest town */
    case 0x45: {
      if (this->tile == INVALID_TILE) return to_underlying(HouseZone::TownEdge) << 16;
      const Town *t = (this->st == nullptr) ? ClosestTownFromTile(this->tile, UINT_MAX) : this->st->town;
      return t != nullptr ? (to_underlying(GetTownRadiusGroup(t, this->tile)) << 16 | ClampTo<uint16_t>(DistanceManhattan(this->tile, t->xy))) : to_underlying(HouseZone::TownEdge) << 16;
    }
 
    /* Get square of Euclidean distance of closest town */
    case 0x46: {
      if (this->tile == INVALID_TILE) return 0;
      const Town *t = (this->st == nullptr) ? ClosestTownFromTile(this->tile, UINT_MAX) : this->st->town;
      return t != nullptr ? DistanceSquare(this->tile, t->xy) : 0;
    }
 
    /* Company information */
    case 0x47: return GetCompanyInfo(this->st == nullptr ? _current_company : this->st->owner);
 
    /* Animation frame */
    case 0x49: return this->tile == INVALID_TILE ? 0 : this->st->GetRoadStopAnimationFrame(this->tile);
 
    /* Misc info */
    case 0x50: {
      uint32_t result = 0;
      if (this->tile == INVALID_TILE) {
        SetBit(result, 4);
      }
      return result;
    }
 
    /* Variables which use the parameter */
    /* Variables 0x60 to 0x65 and 0x69 are handled separately below */
 
    /* Animation frame of nearby tile */
    case 0x66: {
      if (this->tile == INVALID_TILE) return UINT_MAX;
      TileIndex tile = this->tile;
      if (parameter != 0) tile = GetNearbyTile(parameter, tile);
      return (IsAnyRoadStopTile(tile) && GetStationIndex(tile) == this->st->index) ? this->st->GetRoadStopAnimationFrame(tile) : UINT_MAX;
    }
 
    /* Land info of nearby tile */
    case 0x67: {
      if (this->tile == INVALID_TILE) return 0;
      TileIndex tile = this->tile;
      if (parameter != 0) tile = GetNearbyTile(parameter, tile); // only perform if it is required
      return GetNearbyTileInformation(tile, this->ro.grffile->grf_version >= 8);
    }
 
    /* Road stop info of nearby tiles */
    case 0x68: {
      if (this->tile == INVALID_TILE) return 0xFFFFFFFF;
      TileIndex nearby_tile = GetNearbyTile(parameter, this->tile);
 
      if (!IsAnyRoadStopTile(nearby_tile)) return 0xFFFFFFFF;
 
      uint32_t grfid = this->st->roadstop_speclist[GetCustomRoadStopSpecIndex(this->tile)].grfid;
      bool same_orientation = GetStationGfx(this->tile) == GetStationGfx(nearby_tile);
      bool same_station = GetStationIndex(nearby_tile) == this->st->index;
      uint32_t res = GetStationGfx(nearby_tile) << 12 | !same_orientation << 11 | !!same_station << 10;
      StationType type = GetStationType(nearby_tile);
      if (type == StationType::Truck) res |= (1 << 16);
      if (type == StationType::RoadWaypoint) res |= (2 << 16);
      if (type == this->type) SetBit(res, 20);
 
      if (IsCustomRoadStopSpecIndex(nearby_tile)) {
        const auto &sm = BaseStation::GetByTile(nearby_tile)->roadstop_speclist[GetCustomRoadStopSpecIndex(nearby_tile)];
        res |= 1 << (sm.grfid != grfid ? 9 : 8) | ClampTo<uint8_t>(sm.localidx);
      }
      return res;
    }
 
    /* GRFID of nearby road stop tiles */
    case 0x6A: {
      if (this->tile == INVALID_TILE) return 0xFFFFFFFF;
      TileIndex nearby_tile = GetNearbyTile(parameter, this->tile);
 
      if (!IsAnyRoadStopTile(nearby_tile)) return 0xFFFFFFFF;
      if (!IsCustomRoadStopSpecIndex(nearby_tile)) return 0;
 
      const auto &sm = BaseStation::GetByTile(nearby_tile)->roadstop_speclist[GetCustomRoadStopSpecIndex(nearby_tile)];
      return sm.grfid;
    }
 
    /* 16 bit road stop ID of nearby tiles */
    case 0x6B: {
      if (this->tile == INVALID_TILE) return 0xFFFFFFFF;
      TileIndex nearby_tile = GetNearbyTile(parameter, this->tile);
 
      if (!IsAnyRoadStopTile(nearby_tile)) return 0xFFFFFFFF;
      if (!IsCustomRoadStopSpecIndex(nearby_tile)) return 0xFFFE;
 
      uint32_t grfid = this->st->roadstop_speclist[GetCustomRoadStopSpecIndex(this->tile)].grfid;
 
      const auto &sm = BaseStation::GetByTile(nearby_tile)->roadstop_speclist[GetCustomRoadStopSpecIndex(nearby_tile)];
      if (sm.grfid == grfid) {
        return sm.localidx;
      }
 
      return 0xFFFE;
    }
 
    case 0x7A: return GetBadgeVariableResult(*this->ro.grffile, this->roadstopspec->badges, parameter);
 
    case 0xF0: return this->st == nullptr ? 0 : this->st->facilities.base(); // facilities
 
    case 0xFA: return ClampTo<uint16_t>((this->st == nullptr ? TimerGameCalendar::date : this->st->build_date) - CalendarTime::DAYS_TILL_ORIGINAL_BASE_YEAR); // build date
  }
 
  if (this->st != nullptr) return this->st->GetNewGRFVariable(this->ro, variable, parameter, available);
 
  available = false;
  return UINT_MAX;
}
 
RoadStopResolverObject::RoadStopResolverObject(const RoadStopSpec *roadstopspec, BaseStation *st, TileIndex tile, RoadType roadtype, StationType type, uint8_t view,
    CallbackID callback, uint32_t param1, uint32_t param2)
  : SpecializedResolverObject<StationRandomTriggers>(roadstopspec->grf_prop.grffile, callback, param1, param2), roadstop_scope(*this, st, roadstopspec, tile, roadtype, type, view)
{
  CargoType ctype = CargoGRFFileProps::SG_DEFAULT_NA;
 
  if (st == nullptr) {
    /* No station, so we are in a purchase list */
    ctype = CargoGRFFileProps::SG_PURCHASE;
  } else if (Station::IsExpected(st)) {
    const Station *station = Station::From(st);
    /* Pick the first cargo that we have waiting */
    for (const auto &[cargo, spritegroup] : roadstopspec->grf_prop.spritegroups) {
      if (cargo < NUM_CARGO && station->goods[cargo].TotalCount() > 0) {
        ctype = cargo;
        this->root_spritegroup = spritegroup;
        break;
      }
    }
  }
 
  this->root_spritegroup = this->roadstop_scope.roadstopspec->grf_prop.GetSpriteGroup(ctype);
  if (this->root_spritegroup == nullptr) {
    ctype = CargoGRFFileProps::SG_DEFAULT;
    this->root_spritegroup = this->roadstop_scope.roadstopspec->grf_prop.GetSpriteGroup(ctype);
  }
 
  /* Remember the cargo type we've picked */
  this->roadstop_scope.cargo_type = ctype;
}
 
TownScopeResolver *RoadStopResolverObject::GetTown()
{
  if (!this->town_scope.has_value()) {
    Town *t;
    if (this->roadstop_scope.st != nullptr) {
      t = this->roadstop_scope.st->town;
    } else {
      t = ClosestTownFromTile(this->roadstop_scope.tile, UINT_MAX);
    }
    if (t == nullptr) return nullptr;
    this->town_scope.emplace(*this, t, this->roadstop_scope.st == nullptr);
  }
  return &*this->town_scope;
}
 
uint16_t GetRoadStopCallback(CallbackID callback, uint32_t param1, uint32_t param2, const RoadStopSpec *roadstopspec, BaseStation *st, TileIndex tile, RoadType roadtype, StationType type, uint8_t view, std::span<int32_t> regs100)
{
  RoadStopResolverObject object(roadstopspec, st, tile, roadtype, type, view, callback, param1, param2);
  return object.ResolveCallback(regs100);
}

void DrawRoadStopTile(int x, int y, RoadType roadtype, const RoadStopSpec *spec, StationType type, int view)
{
  assert(roadtype != INVALID_ROADTYPE);
  assert(spec != nullptr);
 
  const RoadTypeInfo *rti = GetRoadTypeInfo(roadtype);
  RoadStopResolverObject object(spec, nullptr, INVALID_TILE, roadtype, type, view);
  const auto *group = object.Resolve<TileLayoutSpriteGroup>();
  if (group == nullptr) return;
  auto processor = group->ProcessRegisters(object, nullptr);
  auto dts = processor.GetLayout();
 
  PaletteID palette = GetCompanyPalette(_local_company);
 
  SpriteID image = dts.ground.sprite;
  PaletteID pal = dts.ground.pal;
 
  RoadStopDrawModes draw_mode;
  if (spec->flags.Test(RoadStopSpecFlag::DrawModeRegister)) {
    draw_mode = static_cast<RoadStopDrawModes>(object.GetRegister(0x100));
  } else {
    draw_mode = spec->draw_mode;
  }
 
  if (type == StationType::RoadWaypoint) {
    DrawSprite(SPR_ROAD_PAVED_STRAIGHT_X, PAL_NONE, x, y);
    if (draw_mode.Test(RoadStopDrawMode::WaypGround) && GB(image, 0, SPRITE_WIDTH) != 0) {
      DrawSprite(image, GroundSpritePaletteTransform(image, pal, palette), x, y);
    }
  } else if (GB(image, 0, SPRITE_WIDTH) != 0) {
    DrawSprite(image, GroundSpritePaletteTransform(image, pal, palette), x, y);
  }
 
  if (view >= 4) {
    /* Drive-through stop */
    uint sprite_offset = 5 - view;
 
    /* Road underlay takes precedence over tram */
    if (type == StationType::RoadWaypoint || draw_mode.Test(RoadStopDrawMode::Overlay)) {
      if (rti->UsesOverlay()) {
        SpriteID ground = GetCustomRoadSprite(rti, INVALID_TILE, ROTSG_GROUND);
        DrawSprite(ground + sprite_offset, PAL_NONE, x, y);
 
        SpriteID overlay = GetCustomRoadSprite(rti, INVALID_TILE, ROTSG_OVERLAY);
        if (overlay) DrawSprite(overlay + sprite_offset, PAL_NONE, x, y);
      } else if (RoadTypeIsTram(roadtype)) {
        DrawSprite(SPR_TRAMWAY_TRAM + sprite_offset, PAL_NONE, x, y);
      }
    }
  } else {
    /* Bay stop */
    if (draw_mode.Test(RoadStopDrawMode::Road) && rti->UsesOverlay()) {
      SpriteID ground = GetCustomRoadSprite(rti, INVALID_TILE, ROTSG_ROADSTOP);
      DrawSprite(ground + view, PAL_NONE, x, y);
    }
  }
 
  DrawCommonTileSeqInGUI(x, y, &dts, 0, 0, palette, true);
}
 
std::optional<SpriteLayoutProcessor> GetRoadStopLayout(TileInfo *ti, const RoadStopSpec *spec, BaseStation *st, StationType type, int view, std::span<int32_t> regs100)
{
  RoadStopResolverObject object(spec, st, ti->tile, INVALID_ROADTYPE, type, view);
  auto group = object.Resolve<TileLayoutSpriteGroup>();
  if (group == nullptr) return std::nullopt;
  for (uint i = 0; i < regs100.size(); ++i) {
    regs100[i] = object.GetRegister(0x100 + i);
  }
  return group->ProcessRegisters(object, nullptr);
}

uint16_t GetAnimRoadStopCallback(CallbackID callback, uint32_t param1, uint32_t param2, const RoadStopSpec *roadstopspec, BaseStation *st, TileIndex tile, int)
{
  return GetRoadStopCallback(callback, param1, param2, roadstopspec, st, tile, INVALID_ROADTYPE, GetStationType(tile), GetStationGfx(tile));
}
 
struct RoadStopAnimationFrameAnimationHelper {
  static uint8_t Get(BaseStation *st, TileIndex tile) { return st->GetRoadStopAnimationFrame(tile); }
  static bool Set(BaseStation *st, TileIndex tile, uint8_t frame) { return st->SetRoadStopAnimationFrame(tile, frame); }
};

struct RoadStopAnimationBase : public AnimationBase<RoadStopAnimationBase, RoadStopSpec, BaseStation, int, GetAnimRoadStopCallback, RoadStopAnimationFrameAnimationHelper> {
  static constexpr CallbackID cb_animation_speed      = CBID_STATION_ANIMATION_SPEED;
  static constexpr CallbackID cb_animation_next_frame = CBID_STATION_ANIMATION_NEXT_FRAME;
 
  static constexpr RoadStopCallbackMask cbm_animation_speed      = RoadStopCallbackMask::AnimationSpeed;
  static constexpr RoadStopCallbackMask cbm_animation_next_frame = RoadStopCallbackMask::AnimationNextFrame;
};
 
void AnimateRoadStopTile(TileIndex tile)
{
  const RoadStopSpec *ss = GetRoadStopSpec(tile);
  if (ss == nullptr) return;
 
  RoadStopAnimationBase::AnimateTile(ss, BaseStation::GetByTile(tile), tile, ss->flags.Test(RoadStopSpecFlag::Cb141RandomBits));
}
 
void TriggerRoadStopAnimation(BaseStation *st, TileIndex trigger_tile, StationAnimationTrigger trigger, CargoType cargo_type)
{
  assert(st != nullptr);
 
  /* Check the cached animation trigger bitmask to see if we need
   * to bother with any further processing. */
  if (!st->cached_roadstop_anim_triggers.Test(trigger)) return;
 
  uint16_t random_bits = Random();
  auto process_tile = [&](TileIndex cur_tile) {
    const RoadStopSpec *ss = GetRoadStopSpec(cur_tile);
    if (ss != nullptr && ss->animation.triggers.Test(trigger)) {
      uint8_t var18_extra = 0;
      if (IsValidCargoType(cargo_type)) {
        var18_extra |= ss->grf_prop.grffile->cargo_map[cargo_type] << 8;
      }
      RoadStopAnimationBase::ChangeAnimationFrame(CBID_STATION_ANIMATION_TRIGGER, ss, st, cur_tile, (random_bits << 16) | GB(Random(), 0, 16), to_underlying(trigger) | var18_extra);
    }
  };
 
  if (trigger == StationAnimationTrigger::NewCargo || trigger == StationAnimationTrigger::CargoTaken || trigger == StationAnimationTrigger::AcceptanceTick) {
    for (const RoadStopTileData &tile_data : st->custom_roadstop_tile_data) {
      process_tile(tile_data.tile);
    }
  } else {
    process_tile(trigger_tile);
  }
}

void TriggerRoadStopRandomisation(BaseStation *st, TileIndex tile, StationRandomTrigger trigger, CargoType cargo_type)
{
  enum TriggerArea : uint8_t {
    TA_TILE,
    TA_PLATFORM,
    TA_WHOLE,
  };
 
  /* List of coverage areas for each animation trigger */
  static constexpr TriggerArea tas[] = {
    TA_WHOLE, TA_WHOLE, TA_PLATFORM, TA_PLATFORM, TA_PLATFORM, TA_PLATFORM
  };
 
  assert(st != nullptr);
 
  /* Check the cached cargo trigger bitmask to see if we need
   * to bother with any further processing.
   * Note: cached_roadstop_cargo_triggers must be non-zero even for cargo-independent triggers. */
  if (st->cached_roadstop_cargo_triggers == 0) return;
  if (IsValidCargoType(cargo_type) && !HasBit(st->cached_roadstop_cargo_triggers, cargo_type)) return;
 
  TriggerArea ta = tas[to_underlying(trigger)];
  if (ta == TA_WHOLE) st->waiting_random_triggers.Set(trigger);
  StationRandomTriggers used_random_triggers;
 
  uint32_t whole_reseed = 0;
 
  /* Bitmask of completely empty cargo types to be matched. */
  CargoTypes empty_mask{};
  if (trigger == StationRandomTrigger::CargoTaken) {
    empty_mask = GetEmptyMask(Station::From(st));
  }
 
  auto process_tile = [&](TileIndex cur_tile) {
    const RoadStopSpec *ss = GetRoadStopSpec(cur_tile);
    if (ss == nullptr) return;
 
    st->tile_waiting_random_triggers[tile].Set(trigger);
 
    /* Cargo taken "will only be triggered if all of those
     * cargo types have no more cargo waiting." */
    if (trigger == StationRandomTrigger::CargoTaken) {
      if ((ss->cargo_triggers & ~empty_mask) != 0) return;
    }
 
    if (!IsValidCargoType(cargo_type) || HasBit(ss->cargo_triggers, cargo_type)) {
      RoadStopResolverObject object(ss, st, cur_tile, INVALID_ROADTYPE, GetStationType(cur_tile), GetStationGfx(cur_tile));
      object.SetWaitingRandomTriggers(st->waiting_random_triggers | st->tile_waiting_random_triggers[tile]);
 
      object.ResolveRerandomisation();
 
      st->tile_waiting_random_triggers[tile].Reset(object.GetUsedRandomTriggers());
      used_random_triggers.Set(object.GetUsedRandomTriggers());
 
      uint32_t reseed = object.GetReseedSum();
      if (reseed != 0) {
        whole_reseed |= reseed;
        reseed >>= 16;
 
        /* Set individual tile random bits */
        uint8_t random_bits = st->GetRoadStopRandomBits(cur_tile);
        random_bits &= ~reseed;
        random_bits |= Random() & reseed;
        st->SetRoadStopRandomBits(cur_tile, random_bits);
 
        MarkTileDirtyByTile(cur_tile);
      }
    }
  };
  if (ta == TA_WHOLE) {
    for (const RoadStopTileData &tile_data : st->custom_roadstop_tile_data) {
      process_tile(tile_data.tile);
    }
  } else {
    process_tile(tile);
  }
 
  /* Update whole station random bits */
  st->waiting_random_triggers.Reset(used_random_triggers);
  if ((whole_reseed & 0xFFFF) != 0) {
    st->random_bits &= ~whole_reseed;
    st->random_bits |= Random() & whole_reseed;
  }
}

bool GetIfNewStopsByType(RoadStopType rs, RoadType roadtype)
{
  for (const auto &cls : RoadStopClass::Classes()) {
    /* Ignore the waypoint class. */
    if (IsWaypointClass(cls)) continue;
    /* Ignore the default class with only the default station. */
    if (cls.Index() == ROADSTOP_CLASS_DFLT && cls.GetSpecCount() == 1) continue;
    if (GetIfClassHasNewStopsByType(&cls, rs, roadtype)) return true;
  }
  return false;
}

bool GetIfClassHasNewStopsByType(const RoadStopClass *roadstopclass, RoadStopType rs, RoadType roadtype)
{
  for (const auto spec : roadstopclass->Specs()) {
    if (GetIfStopIsForType(spec, rs, roadtype)) return true;
  }
  return false;
}

bool GetIfStopIsForType(const RoadStopSpec *roadstopspec, RoadStopType rs, RoadType roadtype)
{
  /* The roadstopspec is nullptr, must be the default station, always return true. */
  if (roadstopspec == nullptr) return true;
 
  if (roadstopspec->flags.Test(RoadStopSpecFlag::RoadOnly) && !RoadTypeIsRoad(roadtype)) return false;
  if (roadstopspec->flags.Test(RoadStopSpecFlag::TramOnly) && !RoadTypeIsTram(roadtype)) return false;
 
  if (roadstopspec->stop_type == ROADSTOPTYPE_ALL) return true;
 
  switch (rs) {
    case RoadStopType::Bus:
      if (roadstopspec->stop_type == ROADSTOPTYPE_PASSENGER) return true;
      break;
 
    case RoadStopType::Truck:
      if (roadstopspec->stop_type == ROADSTOPTYPE_FREIGHT) return true;
      break;
 
    default:
      NOT_REACHED();
  }
  return false;
}
 
const RoadStopSpec *GetRoadStopSpec(TileIndex t)
{
  if (!IsCustomRoadStopSpecIndex(t)) return nullptr;
 
  const BaseStation *st = BaseStation::GetByTile(t);
  uint specindex = GetCustomRoadStopSpecIndex(t);
  return specindex < st->roadstop_speclist.size() ? st->roadstop_speclist[specindex].spec : nullptr;
}

std::optional<uint8_t> AllocateSpecToRoadStop(const RoadStopSpec *spec, BaseStation *st)
{
  uint i;
 
  if (spec == nullptr) return 0;
 
  /* If station doesn't exist yet then the first slot is available. */
  if (st == nullptr) return 1;
 
  /* Try to find the same spec and return that one */
  for (i = 1; i < st->roadstop_speclist.size() && i < NUM_ROADSTOPSPECS_PER_STATION; i++) {
    if (st->roadstop_speclist[i].spec == spec) return i;
  }
 
  /* Try to find an unused spec slot */
  for (i = 1; i < st->roadstop_speclist.size() && i < NUM_ROADSTOPSPECS_PER_STATION; i++) {
    if (st->roadstop_speclist[i].spec == nullptr && st->roadstop_speclist[i].grfid == 0) break;
  }
 
  if (i == NUM_ROADSTOPSPECS_PER_STATION) {
    /* Full, give up */
    return std::nullopt;
  }
 
  return i;
}

void AssignSpecToRoadStop(const RoadStopSpec *spec, BaseStation *st, uint8_t specindex)
{
  if (specindex == 0) return;
  if (specindex >= st->roadstop_speclist.size()) st->roadstop_speclist.resize(specindex + 1);
 
  st->roadstop_speclist[specindex].spec = spec;
  st->roadstop_speclist[specindex].grfid = spec->grf_prop.grfid;
  st->roadstop_speclist[specindex].localidx = spec->grf_prop.local_id;
 
  RoadStopUpdateCachedTriggers(st);
}

void DeallocateSpecFromRoadStop(BaseStation *st, uint8_t specindex)
{
  /* specindex of 0 (default) is never freeable */
  if (specindex == 0) return;
 
  /* Check custom road stop tiles if the specindex is still in use */
  for (const RoadStopTileData &tile_data : st->custom_roadstop_tile_data) {
    if (GetCustomRoadStopSpecIndex(tile_data.tile) == specindex) {
      return;
    }
  }
 
  /* This specindex is no longer in use, so deallocate it */
  st->roadstop_speclist[specindex].spec     = nullptr;
  st->roadstop_speclist[specindex].grfid    = 0;
  st->roadstop_speclist[specindex].localidx = 0;
 
  /* If this was the highest spec index, reallocate */
  if (specindex == st->roadstop_speclist.size() - 1) {
    size_t num_specs;
    for (num_specs = st->roadstop_speclist.size() - 1; num_specs > 0; num_specs--) {
      if (st->roadstop_speclist[num_specs].grfid != 0) break;
    }
 
    if (num_specs > 0) {
      st->roadstop_speclist.resize(num_specs + 1);
    } else {
      st->roadstop_speclist.clear();
      st->cached_roadstop_anim_triggers = {};
      st->cached_roadstop_cargo_triggers = 0;
      return;
    }
  }
 
  RoadStopUpdateCachedTriggers(st);
}

void RoadStopUpdateCachedTriggers(BaseStation *st)
{
  st->cached_roadstop_anim_triggers = {};
  st->cached_roadstop_cargo_triggers = 0;
 
  /* Combine animation trigger bitmask for all road stop specs
   * of this station. */
  for (const auto &sm : GetStationSpecList<RoadStopSpec>(st)) {
    if (sm.spec == nullptr) continue;
    st->cached_roadstop_anim_triggers.Set(sm.spec->animation.triggers);
    st->cached_roadstop_cargo_triggers |= sm.spec->cargo_triggers;
  }
}