road_cmd.cpp

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/*
 * 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 "road.h"
#include "road_internal.h"
#include "viewport_func.h"
#include "command_func.h"
#include "company_func.h"
#include "pathfinder/yapf/yapf_cache.h"
#include "depot_base.h"
#include "newgrf.h"
#include "autoslope.h"
#include "tunnelbridge_map.h"
#include "strings_func.h"
#include "vehicle_func.h"
#include "sound_func.h"
#include "tunnelbridge.h"
#include "cheat_type.h"
#include "effectvehicle_func.h"
#include "effectvehicle_base.h"
#include "elrail_func.h"
#include "roadveh.h"
#include "train.h"
#include "town.h"
#include "company_base.h"
#include "core/random_func.hpp"
#include "core/container_func.hpp"
#include "newgrf_debug.h"
#include "newgrf_railtype.h"
#include "newgrf_roadtype.h"
#include "timer/timer_game_calendar.h"
#include "genworld.h"
#include "company_gui.h"
#include "road_func.h"
#include "road_cmd.h"
#include "landscape_cmd.h"
#include "rail_cmd.h"
 
#include "table/strings.h"
#include "table/roadtypes.h"
 
#include "safeguards.h"

typedef std::vector<RoadVehicle *> RoadVehicleList;
 
RoadTypeInfo _roadtypes[ROADTYPE_END];
std::vector<RoadType> _sorted_roadtypes; 
RoadTypes _roadtypes_hidden_mask; 
RoadTypes _roadtypes_road; 
RoadTypes _roadtypes_tram; 

void ResetRoadTypes()
{
  static_assert(std::size(_original_roadtypes) <= std::size(_roadtypes));
 
  auto insert = std::copy(std::begin(_original_roadtypes), std::end(_original_roadtypes), std::begin(_roadtypes));
  std::fill(insert, std::end(_roadtypes), RoadTypeInfo{});
 
  _roadtypes_hidden_mask = {};
  _roadtypes_road = {ROADTYPE_ROAD};
  _roadtypes_tram = {ROADTYPE_TRAM};
}
 
void ResolveRoadTypeGUISprites(RoadTypeInfo *rti)
{
  SpriteID cursors_base = GetCustomRoadSprite(rti, INVALID_TILE, RoadSpriteType::UI);
  if (cursors_base != 0) {
    rti->gui_sprites.build_y_road = cursors_base +  0;
    rti->gui_sprites.build_x_road = cursors_base +  1;
    rti->gui_sprites.auto_road    = cursors_base +  2;
    rti->gui_sprites.build_depot  = cursors_base +  3;
    rti->gui_sprites.build_tunnel = cursors_base +  4;
    rti->gui_sprites.convert_road = cursors_base +  5;
    rti->cursor.road_swne         = cursors_base +  6;
    rti->cursor.road_nwse         = cursors_base +  7;
    rti->cursor.autoroad          = cursors_base +  8;
    rti->cursor.depot             = cursors_base +  9;
    rti->cursor.tunnel            = cursors_base + 10;
    rti->cursor.convert_road      = cursors_base + 11;
  }
}

static bool CompareRoadTypes(const RoadType &first, const RoadType &second)
{
  if (RoadTypeIsRoad(first) == RoadTypeIsRoad(second)) {
    return GetRoadTypeInfo(first)->sorting_order < GetRoadTypeInfo(second)->sorting_order;
  }
  return RoadTypeIsTram(first) < RoadTypeIsTram(second);
}

void InitRoadTypes()
{
  _sorted_roadtypes.clear();
  for (RoadTypeInfo &rti : _roadtypes) {
    RoadType rt = rti.Index();
 
    ResolveRoadTypeGUISprites(&rti);
    _roadtypes_hidden_mask.Set(rt, rti.flags.Test(RoadTypeFlag::Hidden));
 
    if (rti.label.Empty()) continue;
    _sorted_roadtypes.push_back(rt);
  }
  std::sort(_sorted_roadtypes.begin(), _sorted_roadtypes.end(), CompareRoadTypes);
}

RoadType AllocateRoadType(RoadTypeLabel label, RoadTramType rtt)
{
  auto it = std::ranges::find(_roadtypes, RoadTypeLabel{}, &RoadTypeInfo::label);
  if (it == std::end(_roadtypes)) return INVALID_ROADTYPE;
 
  RoadTypeInfo &rti = *it;
  RoadType rt = rti.Index();
 
  /* Set up new road type based on default tram or road. */
  rti = _original_roadtypes[(rtt == RoadTramType::Tram) ? ROADTYPE_TRAM : ROADTYPE_ROAD];
  rti.label = label;
  rti.alternate_labels.clear();
  rti.flags = {};
  rti.introduction_date = CalendarTime::INVALID_DATE;
 
  /* Make us compatible with ourself. */
  rti.powered_roadtypes = rt;
 
  /* We also introduce ourself. */
  rti.introduces_roadtypes = rt;
 
  /* Default sort order; order of allocation, but with some
   * offsets so it's easier for NewGRF to pick a spot without
   * changing the order of other (original) road types.
   * The << is so you can place other roadtypes in between the
   * other roadtypes, the 7 is to be able to place something
   * before the first (default) road type. */
  rti.sorting_order = rt << 2 | 7;
 
  /* Set bitmap of road/tram types */
  _roadtypes_road.Set(rt, rtt == RoadTramType::Road);
  _roadtypes_tram.Set(rt, rtt == RoadTramType::Tram);
 
  return rt;
}

bool RoadVehiclesAreBuilt()
{
  return !RoadVehicle::Iterate().empty();
}

void UpdateCompanyRoadInfrastructure(RoadType rt, Owner o, int count)
{
  if (rt == INVALID_ROADTYPE) return;
 
  Company *c = Company::GetIfValid(o);
  if (c == nullptr) return;
 
  c->infrastructure.road[rt] += count;
  DirtyCompanyInfrastructureWindows(c->index);
}

static const std::array<NonSteepSlopeIndexArray<RoadBits>, 2> _invalid_tileh_slopes_road = {{
  /* The inverse of the mixable RoadBits on a leveled slope */
  {{{
    {}, // SLOPE_FLAT
    {RoadBit::NE, RoadBit::SE}, // SLOPE_W
    {RoadBit::NE, RoadBit::NW}, // SLOPE_S
 
    RoadBit::NE, // SLOPE_SW
    {RoadBit::NW, RoadBit::SW}, // SLOPE_E
    {}, // SLOPE_EW
 
    RoadBit::NW, // SLOPE_SE
    {}, // SLOPE_WSE
    {RoadBit::SE, RoadBit::SW}, // SLOPE_N
 
    RoadBit::SE, // SLOPE_NW
    {}, // SLOPE_NS
    {}, // SLOPE_ENW
 
    RoadBit::SW, // SLOPE_NE
    {}, // SLOPE_SEN
    {}, // SLOPE_NWS
  }}},
  /* The inverse of the allowed straight roads on a slope
   * (with and without a foundation). */
  {{{
    {}, // SLOPE_FLAT
    {}, // SLOPE_W (Foundation)
    {}, // SLOPE_S (Foundation)
 
    ROAD_Y, // SLOPE_SW
    {}, // SLOPE_E (Foundation)
    ROAD_ALL, // SLOPE_EW
 
    ROAD_X, // SLOPE_SE
    ROAD_ALL, // SLOPE_WSE
    {}, // SLOPE_N (Foundation)
 
    ROAD_X, // SLOPE_NW
    ROAD_ALL, // SLOPE_NS
    ROAD_ALL, // SLOPE_ENW
 
    ROAD_Y, // SLOPE_NE
    ROAD_ALL, // SLOPE_SEN
    ROAD_ALL, // SLOPE_NW
  }}}
}};
 
static Foundation GetRoadFoundation(Slope tileh, RoadBits bits);

CommandCost CheckAllowRemoveRoad(TileIndex tile, RoadBits remove, Owner owner, RoadTramType rtt, DoCommandFlags flags, bool town_check)
{
  if (_game_mode == GameMode::Editor || remove.None()) return CommandCost();
 
  /* Water can always flood and towns can always remove "normal" road pieces.
   * Towns are not be allowed to remove non "normal" road pieces, like tram
   * tracks as that would result in trams that cannot turn. */
  if (_current_company == OWNER_WATER ||
      (rtt == RoadTramType::Road && !Company::IsValidID(_current_company))) return CommandCost();
 
  /* Only do the special processing if the road is owned
   * by a town */
  if (owner != OWNER_TOWN) {
    if (owner == OWNER_NONE) return CommandCost();
    CommandCost ret = CheckOwnership(owner);
    return ret;
  }
 
  if (!town_check) return CommandCost();
 
  if (_cheats.magic_bulldozer.value) return CommandCost();
 
  Town *t = ClosestTownFromTile(tile, UINT_MAX);
  if (t == nullptr) return CommandCost();
 
  /* check if you're allowed to remove the street owned by a town
   * removal allowance depends on difficulty setting */
  CommandCost ret = CheckforTownRating(flags, t, TownRatingCheckType::RoadRemove);
  if (ret.Failed()) return ret;
 
  /* Get a bitmask of which neighbouring roads has a tile */
  RoadBits n{};
  RoadBits present = GetAnyRoadBits(tile, rtt);
  if (present.Test(RoadBit::NE) && GetAnyRoadBits(TileAddXY(tile, -1,  0), rtt).Test(RoadBit::SW)) n.Set(RoadBit::NE);
  if (present.Test(RoadBit::SE) && GetAnyRoadBits(TileAddXY(tile,  0,  1), rtt).Test(RoadBit::NW)) n.Set(RoadBit::SE);
  if (present.Test(RoadBit::SW) && GetAnyRoadBits(TileAddXY(tile,  1,  0), rtt).Test(RoadBit::NE)) n.Set(RoadBit::SW);
  if (present.Test(RoadBit::NW) && GetAnyRoadBits(TileAddXY(tile,  0, -1), rtt).Test(RoadBit::SE)) n.Set(RoadBit::NW);
 
  int rating_decrease = RATING_ROAD_DOWN_STEP_EDGE;
  /* If 0 or 1 bits are set in n, or if no bits that match the bits to remove,
   * then allow it */
  if (n.Count() > 1 && n.Any(remove)) {
    /* you can remove all kind of roads with extra dynamite */
    if (!_settings_game.construction.extra_dynamite) {
      return CommandCostWithParam(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS, t->index);
    }
    rating_decrease = RATING_ROAD_DOWN_STEP_INNER;
  }
  ChangeTownRating(t, rating_decrease, RATING_ROAD_MINIMUM, flags);
 
  return CommandCost();
}
 

static CommandCost RemoveRoad(TileIndex tile, DoCommandFlags flags, RoadBits pieces, RoadTramType rtt, bool town_check)
{
  assert(pieces.Any());
 
  RoadType existing_rt = MayHaveRoad(tile) ? GetRoadType(tile, rtt) : INVALID_ROADTYPE;
  /* The tile doesn't have the given road type */
  if (existing_rt == INVALID_ROADTYPE) return CommandCost((rtt == RoadTramType::Tram) ? STR_ERROR_THERE_IS_NO_TRAMWAY : STR_ERROR_THERE_IS_NO_ROAD);
 
  switch (GetTileType(tile)) {
    case TileType::Road: {
      CommandCost ret = EnsureNoVehicleOnGround(tile);
      if (ret.Failed()) return ret;
      break;
    }
 
    case TileType::Station: {
      if (!IsDriveThroughStopTile(tile)) return CMD_ERROR;
 
      CommandCost ret = EnsureNoVehicleOnGround(tile);
      if (ret.Failed()) return ret;
      break;
    }
 
    case TileType::TunnelBridge: {
      if (GetTunnelBridgeTransportType(tile) != TransportType::Road) return CMD_ERROR;
      CommandCost ret = TunnelBridgeIsFree(tile, GetOtherTunnelBridgeEnd(tile));
      if (ret.Failed()) return ret;
      break;
    }
 
    default:
      return CMD_ERROR;
  }
 
  CommandCost ret = CheckAllowRemoveRoad(tile, pieces, GetRoadOwner(tile, rtt), rtt, flags, town_check);
  if (ret.Failed()) return ret;
 
  if (!IsTileType(tile, TileType::Road)) {
    /* If it's the last roadtype, just clear the whole tile */
    if (GetRoadType(tile, OtherRoadTramType(rtt)) == INVALID_ROADTYPE) return Command<Commands::LandscapeClear>::Do(flags, tile);
 
    CommandCost cost(ExpensesType::Construction);
    if (IsTileType(tile, TileType::TunnelBridge)) {
      /* Removing any roadbit in the bridge axis removes the roadtype (that's the behaviour remove-long-roads needs) */
      if (!AxisToRoadBits(DiagDirToAxis(GetTunnelBridgeDirection(tile))).Any(pieces)) return CommandCost((rtt == RoadTramType::Tram) ? STR_ERROR_THERE_IS_NO_TRAMWAY : STR_ERROR_THERE_IS_NO_ROAD);
 
      TileIndex other_end = GetOtherTunnelBridgeEnd(tile);
      /* Pay for *every* tile of the bridge or tunnel */
      uint len = GetTunnelBridgeLength(other_end, tile) + 2;
      cost.AddCost(len * 2 * RoadClearCost(existing_rt));
      if (flags.Test(DoCommandFlag::Execute)) {
        /* A full diagonal road tile has two road bits. */
        UpdateCompanyRoadInfrastructure(existing_rt, GetRoadOwner(tile, rtt), -(int)(len * 2 * TUNNELBRIDGE_TRACKBIT_FACTOR));
 
        SetRoadType(other_end, rtt, INVALID_ROADTYPE);
        SetRoadType(tile,      rtt, INVALID_ROADTYPE);
 
        /* If the owner of the bridge sells all its road, also move the ownership
         * to the owner of the other roadtype, unless the bridge owner is a town. */
        Owner other_owner = GetRoadOwner(tile, OtherRoadTramType(rtt));
        if (!IsTileOwner(tile, other_owner) && !IsTileOwner(tile, OWNER_TOWN)) {
          SetTileOwner(tile, other_owner);
          SetTileOwner(other_end, other_owner);
        }
 
        /* Mark tiles dirty that have been repaved */
        if (IsBridge(tile)) {
          MarkBridgeDirty(tile);
        } else {
          MarkTileDirtyByTile(tile);
          MarkTileDirtyByTile(other_end);
        }
      }
    } else {
      assert(IsDriveThroughStopTile(tile));
      cost.AddCost(RoadClearCost(existing_rt) * 2);
      if (flags.Test(DoCommandFlag::Execute)) {
        /* A full diagonal road tile has two road bits. */
        UpdateCompanyRoadInfrastructure(existing_rt, GetRoadOwner(tile, rtt), -2);
        SetRoadType(tile, rtt, INVALID_ROADTYPE);
        MarkTileDirtyByTile(tile);
      }
    }
    return cost;
  }
 
  switch (GetRoadTileType(tile)) {
    case RoadTileType::Normal: {
      Slope tileh = GetTileSlope(tile);
 
      /* Steep slopes behave the same as slopes with one corner raised. */
      if (IsSteepSlope(tileh)) {
        tileh = SlopeWithOneCornerRaised(GetHighestSlopeCorner(tileh));
      }
 
      RoadBits present = GetRoadBits(tile, rtt);
      const RoadBits other = GetRoadBits(tile, OtherRoadTramType(rtt));
      const Foundation f = GetRoadFoundation(tileh, present);
 
      if (HasRoadWorks(tile) && _current_company != OWNER_WATER) return CommandCost(STR_ERROR_ROAD_WORKS_IN_PROGRESS);
 
      /* Autocomplete to a straight road
       * @li if the bits of the other roadtypes result in another foundation
       * @li if build on slopes is disabled */
      if ((IsStraightRoad(other) && other.Any(_invalid_tileh_slopes_road[0][tileh & SLOPE_ELEVATED])) ||
          (tileh != SLOPE_FLAT && !_settings_game.construction.build_on_slopes)) {
        pieces.Set(MirrorRoadBits(pieces));
      }
 
      /* limit the bits to delete to the existing bits. */
      pieces &= present;
      if (pieces.None()) return CommandCost((rtt == RoadTramType::Tram) ? STR_ERROR_THERE_IS_NO_TRAMWAY : STR_ERROR_THERE_IS_NO_ROAD);
 
      /* Now set present what it will be after the remove */
      present.Flip(pieces);
 
      /* Check for invalid RoadBit combinations on slopes */
      if (tileh != SLOPE_FLAT && present.Any() &&
          _invalid_tileh_slopes_road[0][tileh & SLOPE_ELEVATED].All(present)) {
        return CMD_ERROR;
      }
 
      if (flags.Test(DoCommandFlag::Execute)) {
        if (HasRoadWorks(tile)) {
          /* flooding tile with road works, don't forget to remove the effect vehicle too */
          assert(_current_company == OWNER_WATER);
          for (EffectVehicle *v : EffectVehicle::Iterate()) {
            if (TileVirtXY(v->x_pos, v->y_pos) == tile) {
              delete v;
            }
          }
        }
 
        UpdateCompanyRoadInfrastructure(existing_rt, GetRoadOwner(tile, rtt), -static_cast<int>(pieces.Count()));
 
        if (present.None()) {
          /* No other road type, just clear tile. */
          if (GetRoadType(tile, OtherRoadTramType(rtt)) == INVALID_ROADTYPE) {
            /* Includes MarkTileDirtyByTile() */
            DoClearSquare(tile);
          } else {
            if (rtt == RoadTramType::Road && IsRoadOwner(tile, rtt, OWNER_TOWN)) {
              /* Update nearest-town index */
              const Town *town = CalcClosestTownFromTile(tile);
              SetTownIndex(tile, town == nullptr ? TownID::Invalid() : town->index);
            }
            if (rtt == RoadTramType::Road) SetDisallowedRoadDirections(tile, {});
            SetRoadBits(tile, {}, rtt);
            SetRoadType(tile, rtt, INVALID_ROADTYPE);
            MarkTileDirtyByTile(tile);
          }
        } else {
          /* When bits are removed, you *always* end up with something that
           * is not a complete straight road tile. However, trams do not have
           * onewayness, so they cannot remove it either. */
          if (rtt == RoadTramType::Road) SetDisallowedRoadDirections(tile, {});
          SetRoadBits(tile, present, rtt);
          MarkTileDirtyByTile(tile);
        }
      }
 
      CommandCost cost(ExpensesType::Construction, pieces.Count() * RoadClearCost(existing_rt));
      /* If we build a foundation we have to pay for it. */
      if (f == Foundation::None && GetRoadFoundation(tileh, present) != Foundation::None) cost.AddCost(_price[Price::BuildFoundation]);
 
      return cost;
    }
 
    case RoadTileType::Crossing: {
      if (pieces.Any(ComplementRoadBits(GetCrossingRoadBits(tile)))) {
        return CMD_ERROR;
      }
 
      if (flags.Test(DoCommandFlag::Execute)) {
        UpdateAdjacentLevelCrossingTilesOnLevelCrossingRemoval(tile, GetCrossingRoadAxis(tile));
 
        /* A full diagonal road tile has two road bits. */
        UpdateCompanyRoadInfrastructure(existing_rt, GetRoadOwner(tile, rtt), -2);
 
        Track track = GetCrossingRailTrack(tile);
        if (GetRoadType(tile, OtherRoadTramType(rtt)) == INVALID_ROADTYPE) {
          bool reserved = HasCrossingReservation(tile);
          MakeRailNormal(tile, GetTileOwner(tile), track, GetRailType(tile));
          if (reserved) SetTrackReservation(tile, track);
 
          /* Update rail count for level crossings. The plain track should still be accounted
           * for, so only subtract the difference to the level crossing cost. */
          Company *c = Company::GetIfValid(GetTileOwner(tile));
          if (c != nullptr) {
            c->infrastructure.rail[GetRailType(tile)] -= LEVELCROSSING_TRACKBIT_FACTOR - 1;
            DirtyCompanyInfrastructureWindows(c->index);
          }
        } else {
          SetRoadType(tile, rtt, INVALID_ROADTYPE);
        }
        MarkTileDirtyByTile(tile);
        YapfNotifyTrackLayoutChange(tile, track);
      }
      return CommandCost(ExpensesType::Construction, RoadClearCost(existing_rt) * 2);
    }
 
    default:
    case RoadTileType::Depot:
      return CMD_ERROR;
  }
}
 

static CommandCost CheckRoadSlope(Slope tileh, RoadBits *pieces, RoadBits existing, RoadBits other)
{
  /* Remove already build pieces */
  pieces->Reset(existing);
 
  /* If we can't build anything stop here */
  if (pieces->None()) return CMD_ERROR;
 
  /* All RoadBit combos are valid on flat land */
  if (tileh == SLOPE_FLAT) return CommandCost();
 
  /* Steep slopes behave the same as slopes with one corner raised. */
  if (IsSteepSlope(tileh)) {
    tileh = SlopeWithOneCornerRaised(GetHighestSlopeCorner(tileh));
  }
 
  /* Save the merge of all bits of the current type */
  RoadBits type_bits = existing | *pieces;
 
  /* Roads on slopes */
  if (_settings_game.construction.build_on_slopes && !_invalid_tileh_slopes_road[0][tileh].Any(other | type_bits)) {
 
    /* If we add leveling we've got to pay for it */
    if ((other | existing).None()) return CommandCost(ExpensesType::Construction, _price[Price::BuildFoundation]);
 
    return CommandCost();
  }
 
  /* Autocomplete uphill roads */
  pieces->Set(MirrorRoadBits(*pieces));
  type_bits = existing | *pieces;
 
  /* Uphill roads */
  if (IsStraightRoad(type_bits) && (other == type_bits || other.None()) &&
      !_invalid_tileh_slopes_road[1][tileh].Any(other | type_bits)) {
 
    /* Slopes with foundation ? */
    if (IsSlopeWithOneCornerRaised(tileh)) {
 
      /* Prevent build on slopes if it isn't allowed */
      if (_settings_game.construction.build_on_slopes) {
 
        /* If we add foundation we've got to pay for it */
        if ((other | existing).None()) return CommandCost(ExpensesType::Construction, _price[Price::BuildFoundation]);
 
        return CommandCost();
      }
    } else {
      if (existing.Count() == 1 && GetRoadFoundation(tileh, existing) == Foundation::None) return CommandCost(ExpensesType::Construction, _price[Price::BuildFoundation]);
      return CommandCost();
    }
  }
  return CMD_ERROR;
}

CommandCost CmdBuildRoad(DoCommandFlags flags, TileIndex tile, RoadBits pieces, RoadType rt, DisallowedRoadDirections toggle_drd, TownID town_id)
{
  CompanyID company = _current_company;
  CommandCost cost(ExpensesType::Construction);
 
  RoadBits existing{};
  RoadBits other_bits{};
 
  /* Road pieces are max 4 bitset values (NE, NW, SE, SW) and town can only be non-zero
   * if a non-company is building the road */
  if ((Company::IsValidID(company) && town_id != TownID::Invalid()) || (company == OWNER_TOWN && !Town::IsValidID(town_id)) || (company == OWNER_DEITY && town_id != TownID::Invalid())) return CMD_ERROR;
  if (company != OWNER_TOWN) {
    const Town *town = CalcClosestTownFromTile(tile);
    town_id = (town != nullptr) ? town->index : TownID::Invalid();
 
    if (company == OWNER_DEITY) {
      company = OWNER_TOWN;
 
      /* If we are not within a town, we are not owned by the town */
      if (town == nullptr || DistanceSquare(tile, town->xy) > town->cache.squared_town_zone_radius[to_underlying(HouseZone::TownEdge)]) {
        company = OWNER_NONE;
      }
    }
  }
 
  /* do not allow building 'zero' road bits, code wouldn't handle it */
  if (pieces.None() || !IsValidRoadBits(pieces) || !IsValidDisallowedRoadDirections(toggle_drd)) return CMD_ERROR;
  if (!ValParamRoadType(rt)) return CMD_ERROR;
 
  Slope tileh = GetTileSlope(tile);
  RoadTramType rtt = GetRoadTramType(rt);
 
  bool need_to_clear = false;
  switch (GetTileType(tile)) {
    case TileType::Road:
      switch (GetRoadTileType(tile)) {
        case RoadTileType::Normal: {
          if (HasRoadWorks(tile)) return CommandCost(STR_ERROR_ROAD_WORKS_IN_PROGRESS);
 
          other_bits = GetRoadBits(tile, OtherRoadTramType(rtt));
          if (!HasTileRoadType(tile, rtt)) break;
 
          existing = GetRoadBits(tile, rtt);
          bool crossing = !IsStraightRoad(existing | pieces);
          if (rtt == RoadTramType::Road && (GetDisallowedRoadDirections(tile).Any() || toggle_drd.Any()) && crossing) {
            /* Junctions cannot be one-way */
            return CommandCost(STR_ERROR_ONEWAY_ROADS_CAN_T_HAVE_JUNCTION);
          }
          if (existing.All(pieces)) {
            /* We only want to set the (dis)allowed road directions */
            if (toggle_drd.Any() && rtt == RoadTramType::Road) {
              Owner owner = GetRoadOwner(tile, rtt);
              if (owner != OWNER_NONE) {
                CommandCost ret = CheckOwnership(owner, tile);
                if (ret.Failed()) return ret;
              }
 
              DisallowedRoadDirections dis_existing = GetDisallowedRoadDirections(tile);
              DisallowedRoadDirections dis_new = GetDisallowedRoadDirections(tile).Flip(toggle_drd);
 
              /* We allow removing disallowed directions to break up
               * deadlocks, but adding them can break articulated
               * vehicles. As such, only when less is disallowed,
               * i.e. bits are removed, we skip the vehicle check. */
              if (dis_existing.Count() <= dis_new.Count()) {
                CommandCost ret = EnsureNoVehicleOnGround(tile);
                if (ret.Failed()) return ret;
              }
 
              /* Ignore half built tiles */
              if (flags.Test(DoCommandFlag::Execute) && IsStraightRoad(existing)) {
                SetDisallowedRoadDirections(tile, dis_new);
                MarkTileDirtyByTile(tile);
              }
              return CommandCost();
            }
            return CommandCost(STR_ERROR_ALREADY_BUILT);
          }
          /* Disallow breaking end-of-line of someone else
           * so trams can still reverse on this tile. */
          if (rtt == RoadTramType::Tram && existing.Count() == 1) {
            Owner owner = GetRoadOwner(tile, rtt);
            if (Company::IsValidID(owner)) {
              CommandCost ret = CheckOwnership(owner);
              if (ret.Failed()) return ret;
            }
          }
          break;
        }
 
        case RoadTileType::Crossing:
          if (RoadNoLevelCrossing(rt)) {
            return CommandCost(STR_ERROR_CROSSING_DISALLOWED_ROAD);
          }
 
          other_bits = GetCrossingRoadBits(tile);
          if (pieces.Any(ComplementRoadBits(other_bits))) goto do_clear;
          pieces = other_bits; // we need to pay for both roadbits
 
          if (HasTileRoadType(tile, rtt)) return CommandCost(STR_ERROR_ALREADY_BUILT);
          break;
 
        case RoadTileType::Depot:
          if (GetAnyRoadBits(tile, rtt).All(pieces)) return CommandCost(STR_ERROR_ALREADY_BUILT);
          goto do_clear;
 
        default: NOT_REACHED();
      }
      break;
 
    case TileType::Railway: {
      if (IsSteepSlope(tileh)) {
        return CommandCost(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
      }
 
      /* Level crossings may only be built on these slopes */
      if (!HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh)) {
        return CommandCost(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
      }
 
      if (!_settings_game.construction.crossing_with_competitor && company != OWNER_TOWN && company != OWNER_DEITY) {
        CommandCost ret = CheckTileOwnership(tile);
        if (ret.Failed()) return ret;
      }
 
      if (GetRailTileType(tile) != RailTileType::Normal) goto do_clear;
 
      if (RoadNoLevelCrossing(rt)) {
        return CommandCost(STR_ERROR_CROSSING_DISALLOWED_ROAD);
      }
 
      if (RailNoLevelCrossings(GetRailType(tile))) {
        return CommandCost(STR_ERROR_CROSSING_DISALLOWED_RAIL);
      }
 
      Axis roaddir;
      switch (GetTrackBits(tile).base()) {
        case TrackBits{Track::X}.base():
          if (pieces.Any(ROAD_X)) goto do_clear;
          roaddir = Axis::Y;
          break;
 
        case TrackBits{Track::Y}.base():
          if (pieces.Any(ROAD_Y)) goto do_clear;
          roaddir = Axis::X;
          break;
 
        default: goto do_clear;
      }
 
      CommandCost ret = EnsureNoVehicleOnGround(tile);
      if (ret.Failed()) return ret;
 
      if (flags.Test(DoCommandFlag::Execute)) {
        Track railtrack = AxisToTrack(OtherAxis(roaddir));
        YapfNotifyTrackLayoutChange(tile, railtrack);
        /* Update company infrastructure counts. A level crossing has two road bits. */
        UpdateCompanyRoadInfrastructure(rt, company, 2);
 
        /* Update rail count for level crossings. The plain track is already
         * counted, so only add the difference to the level crossing cost. */
        Company *c = Company::GetIfValid(GetTileOwner(tile));
        if (c != nullptr) {
          c->infrastructure.rail[GetRailType(tile)] += LEVELCROSSING_TRACKBIT_FACTOR - 1;
          DirtyCompanyInfrastructureWindows(c->index);
        }
 
        /* Always add road to the roadtypes (can't draw without it) */
        bool reserved = GetRailReservationTrackBits(tile).Test(railtrack);
        MakeRoadCrossing(tile, company, company, GetTileOwner(tile), roaddir, GetRailType(tile), rtt == RoadTramType::Road ? rt : INVALID_ROADTYPE, (rtt == RoadTramType::Tram) ? rt : INVALID_ROADTYPE, town_id);
        SetCrossingReservation(tile, reserved);
        UpdateLevelCrossing(tile, false);
        MarkDirtyAdjacentLevelCrossingTiles(tile, GetCrossingRoadAxis(tile));
        MarkTileDirtyByTile(tile);
      }
      return CommandCost(ExpensesType::Construction, 2 * RoadBuildCost(rt));
    }
 
    case TileType::Station: {
      if (GetAnyRoadBits(tile, rtt).All(pieces)) return CommandCost(STR_ERROR_ALREADY_BUILT);
      if (!IsDriveThroughStopTile(tile)) goto do_clear;
 
      RoadBits curbits = AxisToRoadBits(GetDriveThroughStopAxis(tile));
      if (pieces.Any(ComplementRoadBits(curbits))) goto do_clear;
      pieces = curbits; // we need to pay for both roadbits
 
      if (HasTileRoadType(tile, rtt)) return CommandCost(STR_ERROR_ALREADY_BUILT);
      break;
    }
 
    case TileType::TunnelBridge: {
      if (GetTunnelBridgeTransportType(tile) != TransportType::Road) goto do_clear;
      /* Only allow building the outer roadbit, so building long roads stops at existing bridges */
      if (MirrorRoadBits(DiagDirToRoadBits(GetTunnelBridgeDirection(tile))) != pieces) goto do_clear;
      if (HasTileRoadType(tile, rtt)) return CommandCost(STR_ERROR_ALREADY_BUILT);
      /* Don't allow adding roadtype to the bridge/tunnel when vehicles are already driving on it */
      CommandCost ret = TunnelBridgeIsFree(tile, GetOtherTunnelBridgeEnd(tile));
      if (ret.Failed()) return ret;
      break;
    }
 
    default: {
do_clear:;
      need_to_clear = true;
      break;
    }
  }
 
  if (need_to_clear) {
    CommandCost ret = Command<Commands::LandscapeClear>::Do(flags, tile);
    if (ret.Failed()) return ret;
    cost.AddCost(ret.GetCost());
  }
 
  if (other_bits != pieces) {
    /* Check the foundation/slopes when adding road/tram bits */
    CommandCost ret = CheckRoadSlope(tileh, &pieces, existing, other_bits);
    /* Return an error if we need to build a foundation (ret != 0) but the
     * current setting is turned off */
    if (ret.Failed() || (ret.GetCost() != 0 && !_settings_game.construction.build_on_slopes)) {
      return CommandCost(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
    }
    cost.AddCost(ret.GetCost());
  }
 
  if (!need_to_clear) {
    if (IsTileType(tile, TileType::Road)) {
      /* Don't put the pieces that already exist */
      pieces.Reset(existing);
 
      /* Check if new road bits will have the same foundation as other existing road types */
      if (IsNormalRoad(tile)) {
        Slope slope = GetTileSlope(tile);
        Foundation found_new = GetRoadFoundation(slope, pieces | existing);
 
        RoadBits bits = GetRoadBits(tile, OtherRoadTramType(rtt));
        /* do not check if there are not road bits of given type */
        if (bits.Any() && GetRoadFoundation(slope, bits) != found_new) {
          return CommandCost(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
        }
      }
    }
 
    CommandCost ret = EnsureNoVehicleOnGround(tile);
    if (ret.Failed()) return ret;
 
    if (IsNormalRoadTile(tile)) {
      /* If the road types don't match, try to convert only if vehicles of
       * the new road type are not powered on the present road type and vehicles of
       * the present road type are powered on the new road type. */
      RoadType existing_rt = GetRoadType(tile, rtt);
      if (existing_rt != INVALID_ROADTYPE && existing_rt != rt) {
        if (HasPowerOnRoad(rt, existing_rt)) {
          rt = existing_rt;
        } else if (HasPowerOnRoad(existing_rt, rt)) {
          ret = Command<Commands::ConvertRoad>::Do(flags, tile, tile, rt, false);
          if (ret.Failed()) return ret;
          cost.AddCost(ret.GetCost());
        } else {
          return CMD_ERROR;
        }
      }
    }
  }
 
  uint num_pieces = (!need_to_clear && IsTileType(tile, TileType::TunnelBridge)) ?
      /* There are 2 pieces on *every* tile of the bridge or tunnel */
      2 * (GetTunnelBridgeLength(GetOtherTunnelBridgeEnd(tile), tile) + 2) :
      /* Count pieces */
      pieces.Count();
 
  cost.AddCost(num_pieces * RoadBuildCost(rt));
 
  if (flags.Test(DoCommandFlag::Execute)) {
    switch (GetTileType(tile)) {
      case TileType::Road: {
        RoadTileType rttype = GetRoadTileType(tile);
        if (existing.None() || rttype == RoadTileType::Crossing) {
          SetRoadType(tile, rtt, rt);
          SetRoadOwner(tile, rtt, company);
          if (rtt == RoadTramType::Road) SetTownIndex(tile, town_id);
        }
        if (rttype != RoadTileType::Crossing) SetRoadBits(tile, existing | pieces, rtt);
        break;
      }
 
      case TileType::TunnelBridge: {
        TileIndex other_end = GetOtherTunnelBridgeEnd(tile);
 
        SetRoadType(other_end, rtt, rt);
        SetRoadType(tile, rtt, rt);
        SetRoadOwner(other_end, rtt, company);
        SetRoadOwner(tile, rtt, company);
 
        /* Mark tiles dirty that have been repaved */
        if (IsBridge(tile)) {
          MarkBridgeDirty(tile);
        } else {
          MarkTileDirtyByTile(other_end);
          MarkTileDirtyByTile(tile);
        }
        break;
      }
 
      case TileType::Station: {
        assert(IsDriveThroughStopTile(tile));
        SetRoadType(tile, rtt, rt);
        SetRoadOwner(tile, rtt, company);
        break;
      }
 
      default:
        MakeRoadNormal(tile, pieces, (rtt == RoadTramType::Road) ? rt : INVALID_ROADTYPE, (rtt == RoadTramType::Tram) ? rt : INVALID_ROADTYPE, town_id, company, company);
        break;
    }
 
    /* Update company infrastructure count. */
    if (IsTileType(tile, TileType::TunnelBridge)) num_pieces *= TUNNELBRIDGE_TRACKBIT_FACTOR;
    UpdateCompanyRoadInfrastructure(rt, GetRoadOwner(tile, rtt), num_pieces);
 
    if (rtt == RoadTramType::Road && IsNormalRoadTile(tile)) {
      existing.Set(pieces);
      SetDisallowedRoadDirections(tile, IsStraightRoad(existing) ?
          GetDisallowedRoadDirections(tile).Flip(toggle_drd) : DisallowedRoadDirections{});
    }
 
    MarkTileDirtyByTile(tile);
  }
  return cost;
}

static bool CanConnectToRoad(TileIndex tile, RoadType rt, DiagDirection dir)
{
  tile += TileOffsByDiagDir(dir);
  if (!IsValidTile(tile) || !MayHaveRoad(tile)) return false;
 
  RoadTramType rtt = GetRoadTramType(rt);
  RoadType existing = GetRoadType(tile, rtt);
  if (existing == INVALID_ROADTYPE) return false;
  if (!HasPowerOnRoad(existing, rt) && !HasPowerOnRoad(rt, existing)) return false;
 
  RoadBits bits = GetAnyRoadBits(tile, rtt, false);
  return bits.Any(DiagDirToRoadBits(ReverseDiagDir(dir)));
}

CommandCost CmdBuildLongRoad(DoCommandFlags flags, TileIndex end_tile, TileIndex start_tile, RoadType rt, Axis axis, DisallowedRoadDirections drd, bool start_half, bool end_half, bool is_ai)
{
  if (start_tile >= Map::Size()) return CMD_ERROR;
 
  if (!ValParamRoadType(rt) || !IsValidAxis(axis) || !IsValidDisallowedRoadDirections(drd)) return CMD_ERROR;
 
  /* Only drag in X or Y direction dictated by the direction variable */
  if (axis == Axis::X && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
  if (axis == Axis::Y && TileX(start_tile) != TileX(end_tile)) return CMD_ERROR; // y-axis
 
  DiagDirection dir = AxisToDiagDir(axis);
 
  /* Swap direction, also the half-tile drag vars. */
  if (start_tile > end_tile || (start_tile == end_tile && start_half)) {
    dir = ReverseDiagDir(dir);
    start_half = !start_half;
    end_half = !end_half;
    if (drd == DisallowedRoadDirection::Northbound || drd == DisallowedRoadDirection::Southbound) drd.Flip({DisallowedRoadDirection::Northbound, DisallowedRoadDirection::Southbound});
  }
 
  /* On the X-axis, we have to swap the initial bits, so they
   * will be interpreted correctly in the GTTS. Furthermore
   * when you just 'click' on one tile to build them. */
  if ((drd == DisallowedRoadDirection::Northbound || drd == DisallowedRoadDirection::Southbound) && (axis == Axis::Y) == (start_tile == end_tile && start_half == end_half)) drd.Flip({DisallowedRoadDirection::Northbound, DisallowedRoadDirection::Southbound});
 
  CommandCost cost(ExpensesType::Construction);
  CommandCost last_error = CMD_ERROR;
  TileIndex tile = start_tile;
  bool had_bridge = false;
  bool had_tunnel = false;
  bool had_success = false;
 
  /* Start tile is the first tile clicked by the user. */
  for (;;) {
    RoadBits bits = AxisToRoadBits(axis);
 
    /* Determine which road parts should be built. */
    if (!is_ai && start_tile != end_tile) {
      /* Only build the first and last roadbit if they can connect to something. */
      if (tile == end_tile && !CanConnectToRoad(tile, rt, dir)) {
        bits = DiagDirToRoadBits(ReverseDiagDir(dir));
      } else if (tile == start_tile && !CanConnectToRoad(tile, rt, ReverseDiagDir(dir))) {
        bits = DiagDirToRoadBits(dir);
      }
    } else {
      /* Road parts only have to be built at the start tile or at the end tile. */
      if (tile == end_tile && !end_half) bits &= DiagDirToRoadBits(ReverseDiagDir(dir));
      if (tile == start_tile && start_half) bits &= DiagDirToRoadBits(dir);
    }
 
    CommandCost ret = Command<Commands::BuildRoad>::Do(flags, tile, bits, rt, drd, TownID::Invalid());
    if (!is_ai && ret.GetErrorMessage() == STR_ERROR_ALREADY_BUILT) had_success = true;
    if (ret.Failed()) {
      last_error = std::move(ret);
      if (last_error.GetErrorMessage() != STR_ERROR_ALREADY_BUILT) {
        if (is_ai) return last_error;
        if (had_success) break; // Keep going if we haven't constructed any road yet, skipping the start of the drag
      }
    } else {
      had_success = true;
      /* Only pay for the upgrade on one side of the bridges and tunnels */
      if (IsTileType(tile, TileType::TunnelBridge)) {
        if (IsBridge(tile)) {
          if (!had_bridge || GetTunnelBridgeDirection(tile) == dir) {
            cost.AddCost(ret.GetCost());
          }
          had_bridge = true;
        } else { // IsTunnel(tile)
          if (!had_tunnel || GetTunnelBridgeDirection(tile) == dir) {
            cost.AddCost(ret.GetCost());
          }
          had_tunnel = true;
        }
      } else {
        cost.AddCost(ret.GetCost());
      }
    }
 
    if (tile == end_tile) break;
 
    tile += TileOffsByDiagDir(dir);
  }
 
  return had_success ? cost : last_error;
}

std::tuple<CommandCost, Money> CmdRemoveLongRoad(DoCommandFlags flags, TileIndex end_tile, TileIndex start_tile, RoadType rt, Axis axis, bool start_half, bool end_half)
{
  CommandCost cost(ExpensesType::Construction);
 
  if (start_tile >= Map::Size()) return { CMD_ERROR, 0 };
  if (!ValParamRoadType(rt) || !IsValidAxis(axis)) return { CMD_ERROR, 0 };
 
  /* Only drag in X or Y direction dictated by the direction variable */
  if (axis == Axis::X && TileY(start_tile) != TileY(end_tile)) return { CMD_ERROR, 0 }; // x-axis
  if (axis == Axis::Y && TileX(start_tile) != TileX(end_tile)) return { CMD_ERROR, 0 }; // y-axis
 
  /* Swap start and ending tile, also the half-tile drag vars. */
  if (start_tile > end_tile || (start_tile == end_tile && start_half)) {
    std::swap(start_tile, end_tile);
    std::swap(start_half, end_half);
  }
 
  Money money_available = GetAvailableMoneyForCommand();
  Money money_spent = 0;
  TileIndex tile = start_tile;
  CommandCost last_error = CMD_ERROR;
  bool had_success = false;
  /* Start tile is the small number. */
  for (;;) {
    RoadBits bits = AxisToRoadBits(axis);
 
    if (tile == end_tile && !end_half) bits &= RoadBits{RoadBit::NW, RoadBit::NE};
    if (tile == start_tile && start_half) bits &= RoadBits{RoadBit::SE, RoadBit::SW};
 
    /* try to remove the halves. */
    if (bits.Any()) {
      RoadTramType rtt = GetRoadTramType(rt);
      CommandCost ret = RemoveRoad(tile, DoCommandFlags{flags}.Reset(DoCommandFlag::Execute), bits, rtt, true);
      if (ret.Succeeded()) {
        if (flags.Test(DoCommandFlag::Execute)) {
          money_spent += ret.GetCost();
          if (money_spent > 0 && money_spent > money_available) {
            return { cost, ExtractCommandCost(Command<Commands::RemoveRoadLong>::Do(DoCommandFlags{flags}.Reset(DoCommandFlag::Execute), end_tile, start_tile, rt, axis, start_half, end_half)).GetCost() };
          }
          RemoveRoad(tile, flags, bits, rtt, false);
        }
        cost.AddCost(ret.GetCost());
        had_success = true;
      } else {
        /* Some errors are more equal than others. */
        switch (last_error.GetErrorMessage()) {
          case STR_ERROR_OWNED_BY:
          case STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS:
            break;
          default:
            last_error = std::move(ret);
        }
      }
    }
 
    if (tile == end_tile) break;
 
    tile += TileOffsByAxis(axis);
  }
 
  return { had_success ? cost : last_error, 0 };
}

CommandCost CmdBuildRoadDepot(DoCommandFlags flags, TileIndex tile, RoadType rt, DiagDirection dir)
{
  if (!ValParamRoadType(rt) || !IsValidDiagDirection(dir)) return CMD_ERROR;
 
  CommandCost cost(ExpensesType::Construction);
 
  Slope tileh = GetTileSlope(tile);
  if (tileh != SLOPE_FLAT) {
    if (!_settings_game.construction.build_on_slopes) return CommandCost(STR_ERROR_FLAT_LAND_REQUIRED);
    if (!CanBuildDepotByTileh(dir, tileh)) return CommandCost(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
    cost.AddCost(_price[Price::BuildFoundation]);
  }
 
  /* Allow the user to rotate the depot instead of having to destroy it and build it again */
  bool rotate_existing_depot = false;
  if (IsRoadDepotTile(tile) && (HasRoadTypeTram(tile) ? rt == GetRoadTypeTram(tile) : rt == GetRoadTypeRoad(tile)))
  {
    CommandCost ret = CheckTileOwnership(tile);
    if (ret.Failed()) return ret;
 
    if (dir == GetRoadDepotDirection(tile)) return CommandCost();
 
    ret = EnsureNoVehicleOnGround(tile);
    if (ret.Failed()) return ret;
 
    rotate_existing_depot = true;
  }
 
  if (!rotate_existing_depot) {
    cost.AddCost(Command<Commands::LandscapeClear>::Do(flags, tile));
    if (cost.Failed()) return cost;
 
    if (IsBridgeAbove(tile)) {
      int height_diff = GetTileMaxZ(tile) + MINIMAL_DEPOT_BRIDGE_HEIGHT - GetBridgeHeight(GetSouthernBridgeEnd(tile));
      if (height_diff > 0) return CommandCostWithParam(STR_ERROR_BRIDGE_TOO_LOW_FOR_ROADVEH_DEPOT, height_diff * TILE_HEIGHT_STEP);
    }
 
    if (!Depot::CanAllocateItem()) return CMD_ERROR;
  }
 
  if (flags.Test(DoCommandFlag::Execute)) {
    if (rotate_existing_depot) {
      SetRoadDepotExitDirection(tile, dir);
    } else {
      Depot *dep = Depot::Create(tile);
      MakeRoadDepot(tile, _current_company, dep->index, dir, rt);
      MakeDefaultName(dep);
 
      /* A road depot has two road bits. */
      UpdateCompanyRoadInfrastructure(rt, _current_company, ROAD_DEPOT_TRACKBIT_FACTOR);
    }
 
    MarkTileDirtyByTile(tile);
  }
 
  cost.AddCost(_price[Price::BuildDepotRoad]);
  return cost;
}
 
static CommandCost RemoveRoadDepot(TileIndex tile, DoCommandFlags flags)
{
  if (_current_company != OWNER_WATER) {
    CommandCost ret = CheckTileOwnership(tile);
    if (ret.Failed()) return ret;
  }
 
  CommandCost ret = EnsureNoVehicleOnGround(tile);
  if (ret.Failed()) return ret;
 
  if (flags.Test(DoCommandFlag::Execute)) {
    Company *c = Company::GetIfValid(GetTileOwner(tile));
    if (c != nullptr) {
      /* A road depot has two road bits. */
      RoadType rt = GetRoadTypeRoad(tile);
      if (rt == INVALID_ROADTYPE) rt = GetRoadTypeTram(tile);
      c->infrastructure.road[rt] -= ROAD_DEPOT_TRACKBIT_FACTOR;
      DirtyCompanyInfrastructureWindows(c->index);
    }
 
    delete Depot::GetByTile(tile);
    DoClearSquare(tile);
  }
 
  return CommandCost(ExpensesType::Construction, _price[Price::ClearDepotRoad]);
}

static CommandCost ClearTile_Road(TileIndex tile, DoCommandFlags flags)
{
  switch (GetRoadTileType(tile)) {
    case RoadTileType::Normal: {
      RoadBits b = GetAllRoadBits(tile);
 
      /* Clear the road if only one piece is on the tile OR we are not using the DoCommandFlag::Auto flag */
      if ((b.Count() == 1 && GetRoadBits(tile, RoadTramType::Tram).None()) || !flags.Test(DoCommandFlag::Auto)) {
        CommandCost ret(ExpensesType::Construction);
        for (RoadTramType rtt : ROADTRAMTYPES_ALL) {
          if (!MayHaveRoad(tile) || GetRoadType(tile, rtt) == INVALID_ROADTYPE) continue;
 
          CommandCost tmp_ret = RemoveRoad(tile, flags, GetRoadBits(tile, rtt), rtt, true);
          if (tmp_ret.Failed()) return tmp_ret;
          ret.AddCost(tmp_ret.GetCost());
        }
        return ret;
      }
      return CommandCost(STR_ERROR_MUST_REMOVE_ROAD_FIRST);
    }
 
    case RoadTileType::Crossing: {
      CommandCost ret(ExpensesType::Construction);
 
      if (flags.Test(DoCommandFlag::Auto)) return CommandCost(STR_ERROR_MUST_REMOVE_ROAD_FIRST);
 
      /* Must iterate over the roadtypes in a reverse manner because
       * tram tracks must be removed before the road bits. */
      for (RoadTramType rtt : { RoadTramType::Tram, RoadTramType::Road }) {
        if (!MayHaveRoad(tile) || GetRoadType(tile, rtt) == INVALID_ROADTYPE) continue;
 
        CommandCost tmp_ret = RemoveRoad(tile, flags, GetCrossingRoadBits(tile), rtt, true);
        if (tmp_ret.Failed()) return tmp_ret;
        ret.AddCost(tmp_ret.GetCost());
      }
 
      if (flags.Test(DoCommandFlag::Execute)) {
        Command<Commands::LandscapeClear>::Do(flags, tile);
      }
      return ret;
    }
 
    default:
    case RoadTileType::Depot:
      if (flags.Test(DoCommandFlag::Auto)) {
        return CommandCost(STR_ERROR_BUILDING_MUST_BE_DEMOLISHED);
      }
      return RemoveRoadDepot(tile, flags);
  }
}
 
 
struct DrawRoadTileStruct {
  uint16_t image;
  uint8_t subcoord_x;
  uint8_t subcoord_y;
};
 
#include "table/road_land.h"

static Foundation GetRoadFoundation(Slope tileh, RoadBits bits)
{
  /* Flat land and land without a road doesn't require a foundation */
  if (tileh == SLOPE_FLAT || bits.None()) return Foundation::None;
 
  /* Steep slopes behave the same as slopes with one corner raised. */
  if (IsSteepSlope(tileh)) {
    tileh = SlopeWithOneCornerRaised(GetHighestSlopeCorner(tileh));
  }
 
  /* Leveled RoadBits on a slope */
  if (!_invalid_tileh_slopes_road[0][tileh].Any(bits)) return Foundation::Leveled;
 
  /* Straight roads without foundation on a slope */
  if (!IsSlopeWithOneCornerRaised(tileh) &&
      !_invalid_tileh_slopes_road[1][tileh].Any(bits))
    return Foundation::None;
 
  /* Roads on steep Slopes or on Slopes with one corner raised */
  return (bits == ROAD_X ? Foundation::InclinedX : Foundation::InclinedY);
}

static constexpr NonSteepSlopeIndexArray<uint8_t> _road_sloped_sprites = {
  0xFF, // Dummy value to prevent `index - 1` while accesing.
  0,  0,  2,  0,
  0,  1,  0,  0,
  3,  0,  0,  0,
  0,  0
};

static uint GetRoadSpriteOffset(Slope slope, RoadBits bits)
{
  if (slope != SLOPE_FLAT) {
    switch (slope) {
      case SLOPE_NE: return 11;
      case SLOPE_SE: return 12;
      case SLOPE_SW: return 13;
      case SLOPE_NW: return 14;
      default: NOT_REACHED();
    }
  } else {
    static const uint offsets[] = {
      0, 18, 17, 7,
      16, 0, 10, 5,
      15, 8, 1, 4,
      9, 3, 6, 2
    };
    return offsets[bits.base()];
  }
}

static bool DrawRoadAsSnowOrDesert(bool snow_or_desert, Roadside roadside)
{
  return (snow_or_desert &&
      !(_settings_game.game_creation.landscape == LandscapeType::Tropic && HasGrfMiscBit(GrfMiscBit::DesertPavedRoads) &&
        roadside != Roadside::Barren && roadside != Roadside::Grass && roadside != Roadside::GrassRoadWorks));
}

void DrawRoadTypeCatenary(const TileInfo *ti, RoadType rt, RoadBits rb)
{
  /* Don't draw the catenary under a low bridge */
  if (IsBridgeAbove(ti->tile) && !IsTransparencySet(TransparencyOption::Catenary)) {
    int height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));
 
    if (height <= GetTileMaxZ(ti->tile) + 1) return;
  }
 
  if (rb.Count() > 2) {
    /* On junctions we check whether neighbouring tiles also have catenary, and possibly
     * do not draw catenary towards those neighbours, which do not have catenary. */
    RoadBits rb_new{};
    for (DiagDirection dir : EnumRange(DiagDirection::End)) {
      if (rb.Any(DiagDirToRoadBits(dir))) {
        TileIndex neighbour = TileAddByDiagDir(ti->tile, dir);
        if (MayHaveRoad(neighbour)) {
          RoadType rt_road = GetRoadTypeRoad(neighbour);
          RoadType rt_tram = GetRoadTypeTram(neighbour);
 
          if ((rt_road != INVALID_ROADTYPE && HasRoadCatenary(rt_road)) ||
              (rt_tram != INVALID_ROADTYPE && HasRoadCatenary(rt_tram))) {
            rb_new.Set(DiagDirToRoadBits(dir));
          }
        }
      }
    }
    if (rb_new.Count() >= 2) rb = rb_new;
  }
 
  const RoadTypeInfo *rti = GetRoadTypeInfo(rt);
  SpriteID front = GetCustomRoadSprite(rti, ti->tile, RoadSpriteType::CatenaryFront);
  SpriteID back = GetCustomRoadSprite(rti, ti->tile, RoadSpriteType::CatenaryRear);
 
  if (front != 0 || back != 0) {
    if (front != 0) front += GetRoadSpriteOffset(ti->tileh, rb);
    if (back != 0) back += GetRoadSpriteOffset(ti->tileh, rb);
  } else if (ti->tileh != SLOPE_FLAT) {
    back = SPR_TRAMWAY_BACK_WIRES_SLOPED + _road_sloped_sprites[ti->tileh];
    front = SPR_TRAMWAY_FRONT_WIRES_SLOPED + _road_sloped_sprites[ti->tileh];
  } else {
    back  = SPR_TRAMWAY_BASE + _road_backpole_sprites_1[rb.base()];
    front = SPR_TRAMWAY_BASE + _road_frontwire_sprites_1[rb.base()];
  }
 
  /* Catenary uses 1st company colour to help identify owner.
   * For tiles with OWNER_TOWN or OWNER_NONE, recolour CC to grey as a neutral colour. */
  Owner owner = GetRoadOwner(ti->tile, GetRoadTramType(rt));
  PaletteID pal = (owner == OWNER_NONE || owner == OWNER_TOWN ? GetColourPalette(Colours::Grey) : GetCompanyPalette(owner));
  uint8_t z_wires = (ti->tileh == SLOPE_FLAT ? 0 : TILE_HEIGHT) + BB_HEIGHT_UNDER_BRIDGE;
  if (back != 0) {
    /* The "back" sprite contains the west, north and east pillars.
     * We cut the sprite at 3/8 of the west/east edges to create 3 sprites.
     * 3/8 is chosen so that sprites can somewhat graphically extend into the tile. */
    static const int INF = 1000; 
    static const SubSprite west  = { -INF, -INF, -12, INF };
    static const SubSprite north = {  -12, -INF,  12, INF };
    static const SubSprite east  = {   12, -INF, INF, INF };
    int8_t west_z = GetSlopePixelZInCorner(ti->tileh, CORNER_W);
    int8_t north_z = GetSlopePixelZInCorner(ti->tileh, CORNER_N);
    int8_t east_z = GetSlopePixelZInCorner(ti->tileh, CORNER_E);
    AddSortableSpriteToDraw(back, pal, *ti, {{15, 0, west_z}, {1, 1, z_wires}, {-15, 0, static_cast<int8_t>(-west_z)}}, IsTransparencySet(TransparencyOption::Catenary), &west);
    AddSortableSpriteToDraw(back, pal, *ti, {{0, 0, north_z}, {1, 1, z_wires}, {0, 0, static_cast<int8_t>(-north_z)}}, IsTransparencySet(TransparencyOption::Catenary), &north);
    AddSortableSpriteToDraw(back, pal, *ti, {{0, 15, east_z}, {1, 1, z_wires}, {0, -15, static_cast<int8_t>(-east_z)}}, IsTransparencySet(TransparencyOption::Catenary), &east);
  }
  if (front != 0) {
    /* Draw the "front" sprite (containing south pillar and wires) at a Z height that is both above the vehicles and above the "back" pillars. */
    AddSortableSpriteToDraw(front, pal, *ti, {{0, 0, static_cast<int8_t>(z_wires)}, {TILE_SIZE, TILE_SIZE, 1}, {0, 0, static_cast<int8_t>(-z_wires)}}, IsTransparencySet(TransparencyOption::Catenary));
  }
}

void DrawRoadCatenary(const TileInfo *ti)
{
  RoadBits road{};
  RoadBits tram{};
 
  if (IsTileType(ti->tile, TileType::Road)) {
    if (IsNormalRoad(ti->tile)) {
      road = GetRoadBits(ti->tile, RoadTramType::Road);
      tram = GetRoadBits(ti->tile, RoadTramType::Tram);
    } else if (IsLevelCrossing(ti->tile)) {
      tram = road = GetCrossingRoadBits(ti->tile);
    }
  } else if (IsTileType(ti->tile, TileType::Station)) {
    if (IsAnyRoadStop(ti->tile)) {
      if (IsDriveThroughStopTile(ti->tile)) {
        Axis axis = GetDriveThroughStopAxis(ti->tile);
        tram = road = AxisToRoadBits(axis);
      } else {
        tram = road = DiagDirToRoadBits(GetBayRoadStopDir(ti->tile));
      }
    }
  } else {
    /* No road here, no catenary to draw */
    return;
  }
 
  RoadType rt = GetRoadTypeRoad(ti->tile);
  if (rt != INVALID_ROADTYPE && HasRoadCatenaryDrawn(rt)) {
    DrawRoadTypeCatenary(ti, rt, road);
  }
 
  rt = GetRoadTypeTram(ti->tile);
  if (rt != INVALID_ROADTYPE && HasRoadCatenaryDrawn(rt)) {
    DrawRoadTypeCatenary(ti, rt, tram);
  }
}

static void DrawRoadDetail(SpriteID img, const TileInfo *ti, int8_t dx, int8_t dy, uint8_t h, bool transparent)
{
  int x = ti->x | dx;
  int y = ti->y | dy;
  int z = ti->z;
  if (ti->tileh != SLOPE_FLAT) z = GetSlopePixelZ(x, y);
  AddSortableSpriteToDraw(img, PAL_NONE, ti->x, ti->y, z, {{dx, dy, 0}, {2, 2, h}, {}}, transparent);
}

void DrawRoadOverlays(const TileInfo *ti, PaletteID pal, const RoadTypeInfo *road_rti, const RoadTypeInfo *tram_rti, uint road_offset, uint tram_offset, bool draw_underlay)
{
  if (draw_underlay) {
    /* Road underlay takes precedence over tram */
    if (road_rti != nullptr) {
      if (road_rti->UsesOverlay()) {
        SpriteID ground = GetCustomRoadSprite(road_rti, ti->tile, RoadSpriteType::Ground);
        DrawGroundSprite(ground + road_offset, pal);
      }
    } else {
      if (tram_rti->UsesOverlay()) {
        SpriteID ground = GetCustomRoadSprite(tram_rti, ti->tile, RoadSpriteType::Ground);
        DrawGroundSprite(ground + tram_offset, pal);
      } else {
        DrawGroundSprite(SPR_TRAMWAY_TRAM + tram_offset, pal);
      }
    }
  }
 
  /* Draw road overlay */
  if (road_rti != nullptr) {
    if (road_rti->UsesOverlay()) {
      SpriteID ground = GetCustomRoadSprite(road_rti, ti->tile, RoadSpriteType::Overlay);
      if (ground != 0) DrawGroundSprite(ground + road_offset, pal);
    }
  }
 
  /* Draw tram overlay */
  if (tram_rti != nullptr) {
    if (tram_rti->UsesOverlay()) {
      SpriteID ground = GetCustomRoadSprite(tram_rti, ti->tile, RoadSpriteType::Overlay);
      if (ground != 0) DrawGroundSprite(ground + tram_offset, pal);
    } else if (road_rti != nullptr) {
      DrawGroundSprite(SPR_TRAMWAY_OVERLAY + tram_offset, pal);
    }
  }
}

static SpriteID GetRoadGroundSprite(const TileInfo *ti, Roadside roadside, const RoadTypeInfo *rti, uint offset, bool snow_or_desert, PaletteID *pal)
{
  /* Draw bare ground sprite if no road or road uses overlay system. */
  if (rti == nullptr || rti->UsesOverlay()) {
    if (DrawRoadAsSnowOrDesert(snow_or_desert, roadside)) {
      return SPR_FLAT_SNOW_DESERT_TILE + SlopeToSpriteOffset(ti->tileh);
    }
 
    switch (roadside) {
      case Roadside::Barren:
        *pal = PALETTE_TO_BARE_LAND;
          return SPR_FLAT_GRASS_TILE + SlopeToSpriteOffset(ti->tileh);
 
      case Roadside::Grass:
      case Roadside::GrassRoadWorks:
        return SPR_FLAT_GRASS_TILE + SlopeToSpriteOffset(ti->tileh);
 
      default:
        break; // Paved
    }
  }
 
  /* Draw original road base sprite */
  SpriteID image = SPR_ROAD_Y + offset;
  if (DrawRoadAsSnowOrDesert(snow_or_desert, roadside)) {
    image += NUM_SLOPES;
  } else {
    switch (roadside) {
      case Roadside::Barren:
        *pal = PALETTE_TO_BARE_LAND;
        break;
 
      case Roadside::Grass:
      case Roadside::GrassRoadWorks:
        break;
 
      default:
        image -= NUM_SLOPES;
        break; // Paved
    }
  }
 
  return image;
}

void DrawRoadGroundSprites(const TileInfo *ti, RoadBits road, RoadBits tram, const RoadTypeInfo *road_rti, const RoadTypeInfo *tram_rti, Roadside roadside, bool snow_or_desert)
{
  /* Determine sprite offsets */
  uint road_offset = GetRoadSpriteOffset(ti->tileh, road);
  uint tram_offset = GetRoadSpriteOffset(ti->tileh, tram);
 
  /* Draw baseset underlay */
  PaletteID pal = PAL_NONE;
  SpriteID image = GetRoadGroundSprite(ti, roadside, road_rti, road.None() ? tram_offset : road_offset, snow_or_desert, &pal);
  DrawGroundSprite(image, pal);
 
  DrawRoadOverlays(ti, pal, road_rti, tram_rti, road_offset, tram_offset);
}

static void DrawRoadBits(TileInfo *ti)
{
  RoadBits road = GetRoadBits(ti->tile, RoadTramType::Road);
  RoadBits tram = GetRoadBits(ti->tile, RoadTramType::Tram);
 
  RoadType road_rt = GetRoadTypeRoad(ti->tile);
  RoadType tram_rt = GetRoadTypeTram(ti->tile);
  const RoadTypeInfo *road_rti = road_rt == INVALID_ROADTYPE ? nullptr : GetRoadTypeInfo(road_rt);
  const RoadTypeInfo *tram_rti = tram_rt == INVALID_ROADTYPE ? nullptr : GetRoadTypeInfo(tram_rt);
 
  if (ti->tileh != SLOPE_FLAT) {
    DrawFoundation(ti, GetRoadFoundation(ti->tileh, road | tram));
    /* DrawFoundation() modifies ti. */
  }
 
  DrawRoadGroundSprites(ti, road, tram, road_rti, tram_rti, GetRoadside(ti->tile), IsOnSnowOrDesert(ti->tile));
 
  /* Draw one way */
  if (road_rti != nullptr) {
    DisallowedRoadDirections drd = GetDisallowedRoadDirections(ti->tile);
    if (drd.Any()) {
      SpriteID oneway = GetCustomRoadSprite(road_rti, ti->tile, RoadSpriteType::Oneway);
 
      if (oneway == 0) oneway = SPR_ONEWAY_BASE;
 
      if ((ti->tileh == SLOPE_NE) || (ti->tileh == SLOPE_NW)) {
        oneway += ONEWAY_SLOPE_N_OFFSET;
      } else if ((ti->tileh == SLOPE_SE) || (ti->tileh == SLOPE_SW)) {
        oneway += ONEWAY_SLOPE_S_OFFSET;
      }
 
      DrawGroundSpriteAt(oneway + drd.base() - 1 + ((road == ROAD_X) ? 0 : 3), PAL_NONE, 8, 8, GetPartialPixelZ(8, 8, ti->tileh));
    }
  }
 
  if (HasRoadWorks(ti->tile)) {
    /* Road works */
    DrawGroundSprite((road | tram).Any(ROAD_X) ? SPR_EXCAVATION_X : SPR_EXCAVATION_Y, PAL_NONE);
    return;
  }
 
  /* Draw road, tram catenary */
  DrawRoadCatenary(ti);
 
  /* Return if full detail is disabled, or we are zoomed fully out. */
  if (!_display_opt.Test(DisplayOption::FullDetail) || _cur_dpi->zoom > ZoomLevel::Detail) return;
 
  /* Do not draw details (street lights, trees) under low bridge */
  Roadside roadside = GetRoadside(ti->tile);
  if (IsBridgeAbove(ti->tile) && (roadside == Roadside::Trees || roadside == Roadside::StreetLights)) {
    int height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));
    int minz = GetTileMaxZ(ti->tile) + 2;
 
    if (roadside == Roadside::Trees) minz++;
 
    if (height < minz) return;
  }
 
  /* If there are no road bits, return, as there is nothing left to do */
  if (road.Count() <= 1) return;
 
  /* Do not draw details when invisible. */
  if (roadside == Roadside::Trees && IsInvisibilitySet(TransparencyOption::Trees)) return;
  if (roadside == Roadside::StreetLights && IsInvisibilitySet(TransparencyOption::Houses)) return;
 
  /* Check whether details should be transparent. */
  bool is_transparent = false;
  if (roadside == Roadside::Trees && IsTransparencySet(TransparencyOption::Trees)) {
    is_transparent = true;
  }
  if (roadside == Roadside::StreetLights && IsTransparencySet(TransparencyOption::Houses)) {
    is_transparent = true;
  }
 
  /* Draw extra details. */
  for (const DrawRoadTileStruct *drts = _road_display_table[to_underlying(roadside)][(road | tram).base()]; drts->image != 0; drts++) {
    DrawRoadDetail(drts->image, ti, drts->subcoord_x, drts->subcoord_y, 0x10, is_transparent);
  }
}

static void DrawTile_Road(TileInfo *ti)
{
  BridgePillarFlags blocked_pillars{};
  switch (GetRoadTileType(ti->tile)) {
    case RoadTileType::Normal:
      DrawRoadBits(ti);
 
      if (IsBridgeAbove(ti->tile)) {
        RoadBits bits = GetAllRoadBits(ti->tile);
        if (bits.Test(RoadBit::NE)) blocked_pillars.Set(BridgePillarFlag::EdgeNE);
        if (bits.Test(RoadBit::SE)) blocked_pillars.Set(BridgePillarFlag::EdgeSE);
        if (bits.Test(RoadBit::SW)) blocked_pillars.Set(BridgePillarFlag::EdgeSW);
        if (bits.Test(RoadBit::NW)) blocked_pillars.Set(BridgePillarFlag::EdgeNW);
      }
      break;
 
    case RoadTileType::Crossing: {
      if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, Foundation::Leveled);
 
      Axis axis = GetCrossingRailAxis(ti->tile);
 
      const RailTypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));
 
      RoadType road_rt = GetRoadTypeRoad(ti->tile);
      RoadType tram_rt = GetRoadTypeTram(ti->tile);
      const RoadTypeInfo *road_rti = road_rt == INVALID_ROADTYPE ? nullptr : GetRoadTypeInfo(road_rt);
      const RoadTypeInfo *tram_rti = tram_rt == INVALID_ROADTYPE ? nullptr : GetRoadTypeInfo(tram_rt);
 
      PaletteID pal = PAL_NONE;
 
      /* Draw base ground */
      if (rti->UsesOverlay()) {
        SpriteID image = SPR_ROAD_Y + to_underlying(axis);
 
        Roadside roadside = GetRoadside(ti->tile);
        if (DrawRoadAsSnowOrDesert(IsOnSnowOrDesert(ti->tile), roadside)) {
          image += NUM_SLOPES;
        } else {
          switch (roadside) {
            case Roadside::Barren:
              pal = PALETTE_TO_BARE_LAND;
              break;
 
            case Roadside::Grass:
              break;
 
            default:
              image -= NUM_SLOPES;
              break; // Paved
          }
        }
 
        DrawGroundSprite(image, pal);
      } else {
        SpriteID image = rti->base_sprites.crossing + to_underlying(axis);
        if (IsCrossingBarred(ti->tile)) image += 2;
 
        Roadside roadside = GetRoadside(ti->tile);
        if (DrawRoadAsSnowOrDesert(IsOnSnowOrDesert(ti->tile), roadside)) {
          image += 8;
        } else {
          switch (roadside) {
            case Roadside::Barren:
              pal = PALETTE_TO_BARE_LAND;
              break;
 
            case Roadside::Grass:
              break;
 
            default:
              image += 4;
              break; // Paved
          }
        }
 
        DrawGroundSprite(image, pal);
      }
 
      DrawRoadOverlays(ti, pal, road_rti, tram_rti, to_underlying(axis), to_underlying(axis));
 
      /* Draw rail/PBS overlay */
      bool draw_pbs = _game_mode != GameMode::Menu && _settings_client.gui.show_track_reservation && HasCrossingReservation(ti->tile);
      if (rti->UsesOverlay()) {
        pal = draw_pbs ? PALETTE_CRASH : PAL_NONE;
        SpriteID rail = GetCustomRailSprite(rti, ti->tile, RailSpriteType::Crossing) + to_underlying(axis);
        DrawGroundSprite(rail, pal);
 
        Axis road_axis = GetCrossingRoadAxis(ti->tile);
        DiagDirections adjacent_diagdirs{};
        for (DiagDirection dir : AxisToDiagDirs(road_axis)) {
          const TileIndex t = TileAddByDiagDir(ti->tile, dir);
          if (t < Map::Size() && IsLevelCrossingTile(t) && GetCrossingRoadAxis(t) == road_axis) {
            adjacent_diagdirs.Set(dir);
          }
        }
 
        switch (adjacent_diagdirs.base()) {
          case DiagDirections{}.base():
            DrawRailTileSeq(ti, &_crossing_layout, TransparencyOption::Catenary, rail, 0, PAL_NONE);
            break;
 
          case DiagDirections{DiagDirection::NE}.base():
            DrawRailTileSeq(ti, &_crossing_layout_SW, TransparencyOption::Catenary, rail, 0, PAL_NONE);
            break;
 
          case DiagDirections{DiagDirection::SE}.base():
            DrawRailTileSeq(ti, &_crossing_layout_NW, TransparencyOption::Catenary, rail, 0, PAL_NONE);
            break;
 
          case DiagDirections{DiagDirection::SW}.base():
            DrawRailTileSeq(ti, &_crossing_layout_NE, TransparencyOption::Catenary, rail, 0, PAL_NONE);
            break;
 
          case DiagDirections{DiagDirection::NW}.base():
            DrawRailTileSeq(ti, &_crossing_layout_SE, TransparencyOption::Catenary, rail, 0, PAL_NONE);
            break;
 
          default:
            /* Show no sprites */
            break;
        }
      } else if (draw_pbs || tram_rti != nullptr || road_rti->UsesOverlay()) {
        /* Add another rail overlay, unless there is only the base road sprite. */
        pal = draw_pbs ? PALETTE_CRASH : PAL_NONE;
        SpriteID rail = GetCrossingRoadAxis(ti->tile) == Axis::Y ? GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.single_x : GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.single_y;
        DrawGroundSprite(rail, pal);
      }
 
      /* Draw road, tram catenary */
      DrawRoadCatenary(ti);
 
      /* Draw rail catenary */
      if (HasRailCatenaryDrawn(GetRailType(ti->tile))) DrawRailCatenary(ti);
      blocked_pillars = {BridgePillarFlag::EdgeSW, BridgePillarFlag::EdgeNE, BridgePillarFlag::EdgeNW, BridgePillarFlag::EdgeSE};
      break;
    }
 
    default:
    case RoadTileType::Depot: {
      if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, Foundation::Leveled);
 
      PaletteID palette = GetCompanyPalette(GetTileOwner(ti->tile));
 
      RoadType road_rt = GetRoadTypeRoad(ti->tile);
      RoadType tram_rt = GetRoadTypeTram(ti->tile);
      const RoadTypeInfo *rti = GetRoadTypeInfo(road_rt == INVALID_ROADTYPE ? tram_rt : road_rt);
 
      int relocation = GetCustomRoadSprite(rti, ti->tile, RoadSpriteType::Depot);
      bool default_gfx = relocation == 0;
      if (default_gfx) {
        if (rti->flags.Test(RoadTypeFlag::Catenary)) {
          if (_loaded_newgrf_features.tram == TramDepotReplacement::WithTrack && road_rt == INVALID_ROADTYPE && !rti->UsesOverlay()) {
            /* Sprites with track only work for default tram */
            relocation = SPR_TRAMWAY_DEPOT_WITH_TRACK - SPR_ROAD_DEPOT;
            default_gfx = false;
          } else {
            /* Sprites without track are always better, if provided */
            relocation = SPR_TRAMWAY_DEPOT_NO_TRACK - SPR_ROAD_DEPOT;
          }
        }
      } else {
        relocation -= SPR_ROAD_DEPOT;
      }
 
      DiagDirection dir = GetRoadDepotDirection(ti->tile);
      const DrawTileSprites *dts = &_road_depot[dir];
      DrawGroundSprite(dts->ground.sprite, PAL_NONE);
 
      if (default_gfx) {
        uint offset = GetRoadSpriteOffset(SLOPE_FLAT, DiagDirToRoadBits(dir));
        if (rti->UsesOverlay()) {
          SpriteID ground = GetCustomRoadSprite(rti, ti->tile, RoadSpriteType::Overlay);
          if (ground != 0) DrawGroundSprite(ground + offset, PAL_NONE);
        } else if (road_rt == INVALID_ROADTYPE) {
          DrawGroundSprite(SPR_TRAMWAY_OVERLAY + offset, PAL_NONE);
        }
      }
 
      DrawRailTileSeq(ti, dts, TransparencyOption::Buildings, relocation, 0, palette);
      blocked_pillars = BRIDGEPILLARFLAGS_ALL;
      break;
    }
  }
  DrawBridgeMiddle(ti, blocked_pillars);
}

void DrawRoadDepotSprite(int x, int y, DiagDirection dir, RoadType rt)
{
  PaletteID palette = GetCompanyPalette(_local_company);
 
  const RoadTypeInfo *rti = GetRoadTypeInfo(rt);
  int relocation = GetCustomRoadSprite(rti, INVALID_TILE, RoadSpriteType::Depot);
  bool default_gfx = relocation == 0;
  if (default_gfx) {
    if (rti->flags.Test(RoadTypeFlag::Catenary)) {
      if (_loaded_newgrf_features.tram == TramDepotReplacement::WithTrack && RoadTypeIsTram(rt) && !rti->UsesOverlay()) {
        /* Sprites with track only work for default tram */
        relocation = SPR_TRAMWAY_DEPOT_WITH_TRACK - SPR_ROAD_DEPOT;
        default_gfx = false;
      } else {
        /* Sprites without track are always better, if provided */
        relocation = SPR_TRAMWAY_DEPOT_NO_TRACK - SPR_ROAD_DEPOT;
      }
    }
  } else {
    relocation -= SPR_ROAD_DEPOT;
  }
 
  const DrawTileSprites *dts = &_road_depot[dir];
  DrawSprite(dts->ground.sprite, PAL_NONE, x, y);
 
  if (default_gfx) {
    uint offset = GetRoadSpriteOffset(SLOPE_FLAT, DiagDirToRoadBits(dir));
    if (rti->UsesOverlay()) {
      SpriteID ground = GetCustomRoadSprite(rti, INVALID_TILE, RoadSpriteType::Overlay);
      if (ground != 0) DrawSprite(ground + offset, PAL_NONE, x, y);
    } else if (RoadTypeIsTram(rt)) {
      DrawSprite(SPR_TRAMWAY_OVERLAY + offset, PAL_NONE, x, y);
    }
  }
 
  DrawRailTileSeqInGUI(x, y, dts, relocation, 0, palette);
}

void UpdateNearestTownForRoadTiles(bool invalidate)
{
  assert(!invalidate || _generating_world);
 
  for (const auto t : Map::Iterate()) {
    if (IsTileType(t, TileType::Road) && !IsRoadDepot(t) && !HasTownOwnedRoad(t)) {
      TownID tid = TownID::Invalid();
      if (!invalidate) {
        const Town *town = CalcClosestTownFromTile(t);
        if (town != nullptr) tid = town->index;
      }
      SetTownIndex(t, tid);
    }
  }
}

static int GetSlopePixelZ_Road(TileIndex tile, uint x, uint y, [[maybe_unused]] bool ground_vehicle)
{
 
  if (IsNormalRoad(tile)) {
    auto [tileh, z] = GetTilePixelSlope(tile);
    if (tileh == SLOPE_FLAT) return z;
 
    Foundation f = GetRoadFoundation(tileh, GetAllRoadBits(tile));
    z += ApplyPixelFoundationToSlope(f, tileh);
    return z + GetPartialPixelZ(x & 0xF, y & 0xF, tileh);
  } else {
    return GetTileMaxPixelZ(tile);
  }
}

static Foundation GetFoundation_Road(TileIndex tile, Slope tileh)
{
  if (IsNormalRoad(tile)) {
    return GetRoadFoundation(tileh, GetAllRoadBits(tile));
  } else {
    return FlatteningFoundation(tileh);
  }
}
 
static const Roadside _town_road_types[][2] = {
  { Roadside::Grass,        Roadside::Grass },
  { Roadside::Paved,        Roadside::Paved },
  { Roadside::Paved,        Roadside::Paved },
  { Roadside::Trees,        Roadside::Trees },
  { Roadside::StreetLights, Roadside::Paved }
};
 
static_assert(lengthof(_town_road_types) == NUM_HOUSE_ZONES);
 
static const Roadside _town_road_types_2[][2] = {
  { Roadside::Grass,        Roadside::Grass },
  { Roadside::Paved,        Roadside::Paved },
  { Roadside::StreetLights, Roadside::Paved },
  { Roadside::StreetLights, Roadside::Paved },
  { Roadside::StreetLights, Roadside::Paved }
};
 
static_assert(lengthof(_town_road_types_2) == NUM_HOUSE_ZONES);
 

static void TileLoop_Road(TileIndex tile)
{
  switch (_settings_game.game_creation.landscape) {
    case LandscapeType::Arctic: {
      /* Roads use the snow level of their maximum height minus one, unless flat. */
      int tile_z = (std::get<Slope>(GetFoundationSlope(tile)) == SLOPE_FLAT) ? GetTileMaxZ(tile) : GetTileMaxZ(tile) - 1;
      if (IsOnSnowOrDesert(tile) != (tile_z > GetSnowLine())) {
        ToggleSnowOrDesert(tile);
        MarkTileDirtyByTile(tile);
      }
      break;
    }
 
    case LandscapeType::Tropic:
      if (GetTropicZone(tile) == TropicZone::Desert && !IsOnSnowOrDesert(tile)) {
        ToggleSnowOrDesert(tile);
        MarkTileDirtyByTile(tile);
      }
      break;
 
    default:
      break;
  }
 
  if (IsRoadDepot(tile)) return;
 
  const Town *t = ClosestTownFromTile(tile, UINT_MAX);
  if (!HasRoadWorks(tile)) {
    HouseZone grp = HouseZone::TownEdge;
 
    if (t != nullptr) {
      grp = GetTownRadiusGroup(t, tile);
 
      /* Show an animation to indicate road work */
      if (t->road_build_months != 0 &&
          (DistanceManhattan(t->xy, tile) < 8 || grp != HouseZone::TownEdge) &&
          IsNormalRoad(tile) && GetAllRoadBits(tile).Count() > 1) {
        if (std::get<Slope>(GetFoundationSlope(tile)) == SLOPE_FLAT && EnsureNoVehicleOnGround(tile).Succeeded() && Chance16(1, 40)) {
          StartRoadWorks(tile);
 
          if (_settings_client.sound.ambient) SndPlayTileFx(SND_21_ROAD_WORKS, tile);
          CreateEffectVehicleAbove(
            TileX(tile) * TILE_SIZE + 7,
            TileY(tile) * TILE_SIZE + 7,
            0,
            EV_BULLDOZER);
          MarkTileDirtyByTile(tile);
          return;
        }
      }
    }
 
    {
      /* Adjust road ground type depending on 'grp' (grp is the distance to the center) */
      const Roadside *new_rs = (_settings_game.game_creation.landscape == LandscapeType::Toyland) ? _town_road_types_2[to_underlying(grp)] : _town_road_types[to_underlying(grp)];
      Roadside cur_rs = GetRoadside(tile);
 
      /* We have our desired type, do nothing */
      if (cur_rs == new_rs[0]) return;
 
      /* We have the pre-type of the desired type, switch to the desired type */
      if (cur_rs == new_rs[1]) {
        cur_rs = new_rs[0];
      /* We have barren land, install the pre-type */
      } else if (cur_rs == Roadside::Barren) {
        cur_rs = new_rs[1];
      /* We're totally off limits, remove any installation and make barren land */
      } else {
        cur_rs = Roadside::Barren;
      }
      SetRoadside(tile, cur_rs);
      MarkTileDirtyByTile(tile);
    }
  } else if (IncreaseRoadWorksCounter(tile)) {
    TerminateRoadWorks(tile);
 
    if (_settings_game.economy.mod_road_rebuild) {
      /* Generate a nicer town surface */
      RoadBits old_rb = GetAnyRoadBits(tile, RoadTramType::Road);
      RoadBits new_rb = CleanUpRoadBits(tile, old_rb);
 
      if (old_rb != new_rb) {
        RemoveRoad(tile, {DoCommandFlag::Execute, DoCommandFlag::Auto, DoCommandFlag::NoWater}, old_rb.Flip(new_rb), RoadTramType::Road, true);
 
        /* If new_rb is 0, there are now no road pieces left and the tile is no longer a road tile */
        if (new_rb.None()) {
          MarkTileDirtyByTile(tile);
          return;
        }
      }
    }
 
    /* Possibly change road type */
    if (GetRoadOwner(tile, RoadTramType::Road) == OWNER_TOWN) {
      RoadType rt = GetTownRoadType();
      if (rt != GetRoadTypeRoad(tile)) {
        SetRoadType(tile, RoadTramType::Road, rt);
      }
    }
 
    MarkTileDirtyByTile(tile);
  }
}

static bool ClickTile_Road(TileIndex tile)
{
  if (!IsRoadDepot(tile)) return false;
 
  ShowDepotWindow(tile, VehicleType::Road);
  return true;
}

static const TrackBits _road_trackbits[16] = {
  {}, // ROAD_NONE
  {}, // RoadBit::NW
  {}, // RoadBit::SW
  Track::Left, // ROAD_W
  {}, // RoadBit::SE
  Track::Y, // ROAD_Y
  Track::Lower, // ROAD_S
  {Track::Left, Track::Lower, Track::Y}, // ROAD_Y | RoadBit::SW
  {}, // RoadBit::NE
  Track::Upper, // ROAD_N
  Track::X, // ROAD_X
  {Track::Left, Track::Upper, Track::X}, // ROAD_X | RoadBit::NW
  Track::Right, // ROAD_E
  {Track::Right, Track::Upper, Track::Y}, // ROAD_Y | RoadBit::NE
  {Track::Right, Track::Lower, Track::X}, // ROAD_X | RoadBit::SE
  TRACK_BIT_ALL, // ROAD_ALL
};

static TrackStatus GetTileTrackStatus_Road(TileIndex tile, TransportType mode, RoadTramType sub_mode, DiagDirection side)
{
  TrackdirBits trackdirbits{};
  TrackdirBits red_signals{}; // crossing barred
  switch (mode) {
    case TransportType::Rail:
      if (IsLevelCrossing(tile)) trackdirbits = TrackBitsToTrackdirBits(GetCrossingRailTrack(tile));
      break;
 
    case TransportType::Road: {
      RoadTramType rtt = (RoadTramType)sub_mode;
      if (!HasTileRoadType(tile, rtt)) break;
      switch (GetRoadTileType(tile)) {
        case RoadTileType::Normal: {
          const uint drd_to_multiplier[] = { 0x101, 0x100, 0x1, 0x0 };
          RoadBits bits = GetRoadBits(tile, rtt);
 
          /* no roadbit at this side of tile, return 0 */
          if (side != DiagDirection::Invalid && !DiagDirToRoadBits(side).Any(bits)) break;
 
          uint multiplier = drd_to_multiplier[(rtt == RoadTramType::Tram) ? 0 : GetDisallowedRoadDirections(tile).base()];
          if (!HasRoadWorks(tile)) trackdirbits = static_cast<TrackdirBits>(_road_trackbits[bits.base()].base() * multiplier);
          break;
        }
 
        case RoadTileType::Crossing: {
          Axis axis = GetCrossingRoadAxis(tile);
 
          if (side != DiagDirection::Invalid && axis != DiagDirToAxis(side)) break;
 
          trackdirbits = TrackBitsToTrackdirBits(AxisToTrack(axis));
          if (IsCrossingBarred(tile)) {
            red_signals = trackdirbits;
            if (TrainOnCrossing(tile)) break;
 
            auto mask_red_signal_bits_if_crossing_barred = [&](TileIndex t, TrackdirBits mask) {
              if (IsLevelCrossingTile(t) && IsCrossingBarred(t)) red_signals &= mask;
            };
            /* Check for blocked adjacent crossing to south, keep only southbound red signal trackdirs, allow northbound traffic */
            mask_red_signal_bits_if_crossing_barred(TileAddByDiagDir(tile, AxisToDiagDir(axis)), {Trackdir::X_SW, Trackdir::Y_SE});
            /* Check for blocked adjacent crossing to north, keep only northbound red signal trackdirs, allow southbound traffic */
            mask_red_signal_bits_if_crossing_barred(TileAddByDiagDir(tile, ReverseDiagDir(AxisToDiagDir(axis))), {Trackdir::X_NE, Trackdir::Y_NW});
          }
          break;
        }
 
        default:
        case RoadTileType::Depot: {
          DiagDirection dir = GetRoadDepotDirection(tile);
 
          if (side != DiagDirection::Invalid && side != dir) break;
 
          trackdirbits = TrackBitsToTrackdirBits(DiagDirToDiagTrack(dir));
          break;
        }
      }
      break;
    }
 
    default: break;
  }
  return {trackdirbits, red_signals};
}
 
static const StringID _road_tile_strings[] = {
  STR_LAI_ROAD_DESCRIPTION_ROAD,
  STR_LAI_ROAD_DESCRIPTION_ROAD,
  STR_LAI_ROAD_DESCRIPTION_ROAD,
  STR_LAI_ROAD_DESCRIPTION_ROAD_WITH_STREETLIGHTS,
  STR_LAI_ROAD_DESCRIPTION_ROAD,
  STR_LAI_ROAD_DESCRIPTION_TREE_LINED_ROAD,
  STR_LAI_ROAD_DESCRIPTION_ROAD,
  STR_LAI_ROAD_DESCRIPTION_ROAD,
};

static void GetTileDesc_Road(TileIndex tile, TileDesc &td)
{
  Owner rail_owner = INVALID_OWNER;
  Owner road_owner = INVALID_OWNER;
  Owner tram_owner = INVALID_OWNER;
 
  RoadType road_rt = GetRoadTypeRoad(tile);
  RoadType tram_rt = GetRoadTypeTram(tile);
  if (road_rt != INVALID_ROADTYPE) {
    const RoadTypeInfo *rti = GetRoadTypeInfo(road_rt);
    td.roadtype = rti->strings.name;
    td.road_speed = rti->max_speed / 2;
    road_owner = GetRoadOwner(tile, RoadTramType::Road);
  }
  if (tram_rt != INVALID_ROADTYPE) {
    const RoadTypeInfo *rti = GetRoadTypeInfo(tram_rt);
    td.tramtype = rti->strings.name;
    td.tram_speed = rti->max_speed / 2;
    tram_owner = GetRoadOwner(tile, RoadTramType::Tram);
  }
 
  switch (GetRoadTileType(tile)) {
    case RoadTileType::Crossing: {
      td.str = STR_LAI_ROAD_DESCRIPTION_ROAD_RAIL_LEVEL_CROSSING;
      rail_owner = GetTileOwner(tile);
 
      const RailTypeInfo *rti = GetRailTypeInfo(GetRailType(tile));
      td.railtype = rti->strings.name;
      td.rail_speed = rti->max_speed;
 
      break;
    }
 
    case RoadTileType::Depot:
      td.str = STR_LAI_ROAD_DESCRIPTION_ROAD_VEHICLE_DEPOT;
      td.build_date = Depot::GetByTile(tile)->build_date;
      break;
 
    default: {
      td.str = (road_rt != INVALID_ROADTYPE ? _road_tile_strings[to_underlying(GetRoadside(tile))] : STR_LAI_ROAD_DESCRIPTION_TRAMWAY);
      break;
    }
  }
 
  /* Now we have to discover, if the tile has only one owner or many:
   *   - Find a first_owner of the tile. (Currently road or tram must be present, but this will break when the third type becomes available)
   *   - Compare the found owner with the other owners, and test if they differ.
   * Note: If road exists it will be the first_owner.
   */
  Owner first_owner = (road_owner == INVALID_OWNER ? tram_owner : road_owner);
  bool mixed_owners = (tram_owner != INVALID_OWNER && tram_owner != first_owner) || (rail_owner != INVALID_OWNER && rail_owner != first_owner);
 
  if (mixed_owners) {
    /* Multiple owners */
    td.owner_type[0] = (rail_owner == INVALID_OWNER ? STR_NULL : STR_LAND_AREA_INFORMATION_RAIL_OWNER);
    td.owner[0] = rail_owner;
    td.owner_type[1] = (road_owner == INVALID_OWNER ? STR_NULL : STR_LAND_AREA_INFORMATION_ROAD_OWNER);
    td.owner[1] = road_owner;
    td.owner_type[2] = (tram_owner == INVALID_OWNER ? STR_NULL : STR_LAND_AREA_INFORMATION_TRAM_OWNER);
    td.owner[2] = tram_owner;
  } else {
    /* One to rule them all */
    td.owner[0] = first_owner;
  }
}

static constexpr DiagDirectionIndexArray<Trackdir> _roadveh_enter_depot_dir{
  Trackdir::X_SW, Trackdir::Y_NW, Trackdir::X_NE, Trackdir::Y_SE
};

static VehicleEnterTileStates VehicleEnterTile_Road(Vehicle *v, TileIndex tile, [[maybe_unused]] int x, [[maybe_unused]] int y)
{
  switch (GetRoadTileType(tile)) {
    case RoadTileType::Depot: {
      if (v->type != VehicleType::Road) break;
 
      RoadVehicle *rv = RoadVehicle::From(v);
      if (rv->frame == RVC_DEPOT_STOP_FRAME &&
          _roadveh_enter_depot_dir[GetRoadDepotDirection(tile)] == static_cast<Trackdir>(rv->state)) {
        rv->state = RVSB_IN_DEPOT;
        rv->vehstatus.Set(VehState::Hidden);
        rv->direction = ReverseDir(rv->direction);
        if (rv->Next() == nullptr) VehicleEnterDepot(rv->First());
        rv->tile = tile;
 
        InvalidateWindowData(WindowClass::VehicleDepot, rv->tile);
        return VehicleEnterTileState::EnteredWormhole;
      }
      break;
    }
 
    default: break;
  }
  return {};
}
 

static void ChangeTileOwner_Road(TileIndex tile, Owner old_owner, Owner new_owner)
{
  if (IsRoadDepot(tile)) {
    if (GetTileOwner(tile) == old_owner) {
      if (new_owner == INVALID_OWNER) {
        Command<Commands::LandscapeClear>::Do({DoCommandFlag::Execute, DoCommandFlag::Bankrupt}, tile);
      } else {
        /* A road depot has two road bits. No need to dirty windows here, we'll redraw the whole screen anyway. */
        RoadType rt = GetRoadTypeRoad(tile);
        if (rt == INVALID_ROADTYPE) rt = GetRoadTypeTram(tile);
        Company::Get(old_owner)->infrastructure.road[rt] -= 2;
        Company::Get(new_owner)->infrastructure.road[rt] += 2;
 
        SetTileOwner(tile, new_owner);
        for (RoadTramType rtt : ROADTRAMTYPES_ALL) {
          if (GetRoadOwner(tile, rtt) == old_owner) {
            SetRoadOwner(tile, rtt, new_owner);
          }
        }
      }
    }
    return;
  }
 
  for (RoadTramType rtt : ROADTRAMTYPES_ALL) {
    /* Update all roadtypes, no matter if they are present */
    if (GetRoadOwner(tile, rtt) == old_owner) {
      RoadType rt = GetRoadType(tile, rtt);
      if (rt != INVALID_ROADTYPE) {
        /* A level crossing has two road bits. No need to dirty windows here, we'll redraw the whole screen anyway. */
        uint num_bits = IsLevelCrossing(tile) ? 2 : GetRoadBits(tile, rtt).Count();
        Company::Get(old_owner)->infrastructure.road[rt] -= num_bits;
        if (new_owner != INVALID_OWNER) Company::Get(new_owner)->infrastructure.road[rt] += num_bits;
      }
 
      SetRoadOwner(tile, rtt, new_owner == INVALID_OWNER ? OWNER_NONE : new_owner);
    }
  }
 
  if (IsLevelCrossing(tile)) {
    if (GetTileOwner(tile) == old_owner) {
      if (new_owner == INVALID_OWNER) {
        Command<Commands::RemoveRail>::Do({DoCommandFlag::Execute, DoCommandFlag::Bankrupt}, tile, GetCrossingRailTrack(tile));
      } else {
        /* Update infrastructure counts. No need to dirty windows here, we'll redraw the whole screen anyway. */
        Company::Get(old_owner)->infrastructure.rail[GetRailType(tile)] -= LEVELCROSSING_TRACKBIT_FACTOR;
        Company::Get(new_owner)->infrastructure.rail[GetRailType(tile)] += LEVELCROSSING_TRACKBIT_FACTOR;
 
        SetTileOwner(tile, new_owner);
      }
    }
  }
}

static CommandCost TerraformTile_Road(TileIndex tile, DoCommandFlags flags, int z_new, Slope tileh_new)
{
  if (_settings_game.construction.build_on_slopes && AutoslopeEnabled()) {
    switch (GetRoadTileType(tile)) {
      case RoadTileType::Crossing:
        if (!IsSteepSlope(tileh_new) && (GetTileMaxZ(tile) == z_new + GetSlopeMaxZ(tileh_new)) && HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh_new)) return CommandCost(ExpensesType::Construction, _price[Price::BuildFoundation]);
        break;
 
      case RoadTileType::Depot:
        if (AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRoadDepotDirection(tile))) return CommandCost(ExpensesType::Construction, _price[Price::BuildFoundation]);
        break;
 
      case RoadTileType::Normal: {
        RoadBits bits = GetAllRoadBits(tile);
        RoadBits bits_copy = bits;
        /* Check if the slope-road_bits combination is valid at all, i.e. it is safe to call GetRoadFoundation(). */
        if (CheckRoadSlope(tileh_new, &bits_copy, {}, {}).Succeeded()) {
          /* CheckRoadSlope() sometimes changes the road_bits, if it does not agree with them. */
          if (bits == bits_copy) {
            auto [tileh_old, z_old] = GetTileSlopeZ(tile);
 
            /* Get the slope on top of the foundation */
            z_old += ApplyFoundationToSlope(GetRoadFoundation(tileh_old, bits), tileh_old);
            z_new += ApplyFoundationToSlope(GetRoadFoundation(tileh_new, bits), tileh_new);
 
            /* The surface slope must not be changed */
            if ((z_old == z_new) && (tileh_old == tileh_new)) return CommandCost(ExpensesType::Construction, _price[Price::BuildFoundation]);
          }
        }
        break;
      }
 
      default: NOT_REACHED();
    }
  }
 
  return Command<Commands::LandscapeClear>::Do(flags, tile);
}

static bool CanConvertUnownedRoadType(Owner owner, RoadTramType rtt)
{
  return (owner == OWNER_NONE || (owner == OWNER_TOWN && rtt == RoadTramType::Road));
}

static void ConvertRoadTypeOwner(TileIndex tile, uint num_pieces, Owner owner, RoadType from_type, RoadType to_type)
{
  /* Scenario editor, maybe? Don't touch the owners when converting roadtypes... */
  if (_current_company >= MAX_COMPANIES) return;
 
  /* We can't get a company from invalid owners but we can get ownership of roads without an owner */
  if (owner >= MAX_COMPANIES && owner != OWNER_NONE) return;
 
  Company *c;
 
  switch (owner.base()) {
  case OWNER_NONE.base():
    SetRoadOwner(tile, GetRoadTramType(to_type), (Owner)_current_company);
    UpdateCompanyRoadInfrastructure(to_type, _current_company, num_pieces);
    break;
 
  default:
    c = Company::Get(owner);
    c->infrastructure.road[from_type] -= num_pieces;
    c->infrastructure.road[to_type] += num_pieces;
    DirtyCompanyInfrastructureWindows(c->index);
    break;
  }
}

CommandCost CmdConvertRoad(DoCommandFlags flags, TileIndex tile, TileIndex area_start, RoadType to_type, bool diagonal)
{
  TileIndex area_end = tile;
 
  if (!ValParamRoadType(to_type)) return CMD_ERROR;
  if (area_start >= Map::Size()) return CMD_ERROR;
 
  RoadVehicleList affected_rvs;
  RoadTramType rtt = GetRoadTramType(to_type);
 
  CommandCost cost(ExpensesType::Construction);
  CommandCost error = CommandCost((rtt == RoadTramType::Tram) ? STR_ERROR_NO_SUITABLE_TRAMWAY : STR_ERROR_NO_SUITABLE_ROAD); // by default, there is no road to convert.
  bool found_convertible_road = false; // whether we actually did convert any road/tram (see bug #7633)
 
  std::unique_ptr<TileIterator> iter = TileIterator::Create(area_start, area_end, diagonal);
  for (; (tile = *iter) != INVALID_TILE; ++(*iter)) {
    /* Is road present on tile? */
    if (!MayHaveRoad(tile)) continue;
 
    /* Converting to the same subtype? */
    RoadType from_type = GetRoadType(tile, rtt);
    if (from_type == INVALID_ROADTYPE || from_type == to_type) continue;
 
    /* Check if there is any infrastructure on tile */
    TileType tt = GetTileType(tile);
    switch (tt) {
      case TileType::Station:
        if (!IsAnyRoadStop(tile)) continue;
        break;
      case TileType::Road:
        if (IsLevelCrossing(tile) && RoadNoLevelCrossing(to_type)) {
          error.MakeError(STR_ERROR_CROSSING_DISALLOWED_ROAD);
          continue;
        }
        break;
      case TileType::TunnelBridge:
        if (GetTunnelBridgeTransportType(tile) != TransportType::Road) continue;
        break;
      default: continue;
    }
 
    /* Trying to convert other's road */
    Owner owner = GetRoadOwner(tile, rtt);
    if (!CanConvertUnownedRoadType(owner, rtt)) {
      CommandCost ret = CheckOwnership(owner, tile);
      if (ret.Failed()) {
        error = std::move(ret);
        continue;
      }
    }
 
    /* Base the ability to replace town roads and bridges on the town's
     * acceptance of destructive actions. */
    if (owner == OWNER_TOWN) {
      Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
      CommandCost ret = CheckforTownRating({}, t, tt == TileType::TunnelBridge ? TownRatingCheckType::TunnelBridgeRemove : TownRatingCheckType::RoadRemove);
      if (ret.Failed()) {
        error = std::move(ret);
        continue;
      }
    }
 
    /* Vehicle on the tile when not converting normal <-> powered
     * Tunnels and bridges have special check later */
    if (tt != TileType::TunnelBridge) {
      if (!HasPowerOnRoad(from_type, to_type)) {
        CommandCost ret = EnsureNoVehicleOnGround(tile);
        if (ret.Failed()) {
          error = std::move(ret);
          continue;
        }
 
        if (rtt == RoadTramType::Road && owner == OWNER_TOWN) {
          error.MakeError(STR_ERROR_OWNED_BY);
          if (IsLocalCompany()) {
            auto params = GetParamsForOwnedBy(OWNER_TOWN, tile);
            error.SetEncodedMessage(GetEncodedStringWithArgs(STR_ERROR_OWNED_BY, params));
          }
          continue;
        }
      }
 
      uint num_pieces = GetAnyRoadBits(tile, rtt).Count();
      if (tt == TileType::Station && IsBayRoadStopTile(tile)) {
        num_pieces *= ROAD_STOP_TRACKBIT_FACTOR;
      } else if (tt == TileType::Road && IsRoadDepot(tile)) {
        num_pieces *= ROAD_DEPOT_TRACKBIT_FACTOR;
      }
 
      found_convertible_road = true;
      cost.AddCost(num_pieces * RoadConvertCost(from_type, to_type));
 
      if (flags.Test(DoCommandFlag::Execute)) { // we can safely convert, too
        /* Call ConvertRoadTypeOwner() to update the company infrastructure counters. */
        if (owner == _current_company) {
          ConvertRoadTypeOwner(tile, num_pieces, owner, from_type, to_type);
        }
 
        /* Perform the conversion */
        SetRoadType(tile, rtt, to_type);
        MarkTileDirtyByTile(tile);
 
        /* update power of train on this tile */
        for (Vehicle *v : VehiclesOnTile(tile)) {
          if (v->type == VehicleType::Road) include(affected_rvs, RoadVehicle::From(v)->First());
        }
 
        if (IsRoadDepotTile(tile)) {
          /* Update build vehicle window related to this depot */
          InvalidateWindowData(WindowClass::VehicleDepot, tile);
          InvalidateWindowData(WindowClass::BuildVehicle, tile);
        }
      }
    } else {
      TileIndex endtile = GetOtherTunnelBridgeEnd(tile);
 
      /* If both ends of tunnel/bridge are in the range, do not try to convert twice -
       * it would cause assert because of different test and exec runs */
      if (endtile < tile) {
        if (diagonal) {
          if (DiagonalTileArea(area_start, area_end).Contains(endtile)) continue;
        } else {
          if (OrthogonalTileArea(area_start, area_end).Contains(endtile)) continue;
        }
      }
 
      /* When not converting rail <-> el. rail, any vehicle cannot be in tunnel/bridge */
      if (!HasPowerOnRoad(from_type, to_type)) {
        CommandCost ret = TunnelBridgeIsFree(tile, endtile);
        if (ret.Failed()) {
          error = std::move(ret);
          continue;
        }
 
        if (rtt == RoadTramType::Road && owner == OWNER_TOWN) {
          error.MakeError(STR_ERROR_OWNED_BY);
          if (IsLocalCompany()) {
            auto params = GetParamsForOwnedBy(OWNER_TOWN, tile);
            error.SetEncodedMessage(GetEncodedStringWithArgs(STR_ERROR_OWNED_BY, params));
          }
          continue;
        }
      }
 
      /* There are 2 pieces on *every* tile of the bridge or tunnel */
      uint num_pieces = (GetTunnelBridgeLength(tile, endtile) + 2) * 2;
      found_convertible_road = true;
      cost.AddCost(num_pieces * RoadConvertCost(from_type, to_type));
 
      if (flags.Test(DoCommandFlag::Execute)) {
        /* Update the company infrastructure counters. */
        if (owner == _current_company) {
          /* Each piece should be counted TUNNELBRIDGE_TRACKBIT_FACTOR times
           * for the infrastructure counters (cause of #8297). */
          ConvertRoadTypeOwner(tile, num_pieces * TUNNELBRIDGE_TRACKBIT_FACTOR, owner, from_type, to_type);
          SetTunnelBridgeOwner(tile, endtile, _current_company);
        }
 
        /* Perform the conversion */
        SetRoadType(tile,    rtt, to_type);
        SetRoadType(endtile, rtt, to_type);
 
        for (Vehicle *v : VehiclesOnTile(tile)) {
          if (v->type == VehicleType::Road) include(affected_rvs, RoadVehicle::From(v)->First());
        }
        for (Vehicle *v : VehiclesOnTile(endtile)) {
          if (v->type == VehicleType::Road) include(affected_rvs, RoadVehicle::From(v)->First());
        }
 
        if (IsBridge(tile)) {
          MarkBridgeDirty(tile);
        } else {
          MarkTileDirtyByTile(tile);
          MarkTileDirtyByTile(endtile);
        }
      }
    }
  }
 
  if (flags.Test(DoCommandFlag::Execute)) {
    /* Roadtype changed, update roadvehicles as when entering different track */
    for (RoadVehicle *v : affected_rvs) {
      v->CargoChanged();
    }
  }
 
  return found_convertible_road ? cost : error;
}

static CommandCost CheckBuildAbove_Road(TileIndex tile, [[maybe_unused]] DoCommandFlags flags, [[maybe_unused]] Axis axis, int height)
{
  if (!IsRoadDepot(tile)) return CommandCost();
 
  int height_diff = GetTileMaxZ(tile) + MINIMAL_DEPOT_BRIDGE_HEIGHT - height;
  if (height_diff <= 0) return CommandCost();
  return CommandCostWithParam(STR_ERROR_BRIDGE_TOO_LOW_FOR_ROADVEH_DEPOT, height_diff * TILE_HEIGHT_STEP);
}

extern const TileTypeProcs _tile_type_road_procs = {
  .draw_tile_proc = DrawTile_Road,
  .get_slope_pixel_z_proc = GetSlopePixelZ_Road,
  .clear_tile_proc = ClearTile_Road,
  .get_tile_desc_proc = GetTileDesc_Road,
  .get_tile_track_status_proc = GetTileTrackStatus_Road,
  .click_tile_proc = ClickTile_Road,
  .tile_loop_proc = TileLoop_Road,
  .change_tile_owner_proc = ChangeTileOwner_Road,
  .vehicle_enter_tile_proc = VehicleEnterTile_Road,
  .get_foundation_proc = GetFoundation_Road,
  .terraform_tile_proc = TerraformTile_Road,
  .check_build_above_proc = CheckBuildAbove_Road,
};