yapf_road.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 "yapf.hpp"
#include "yapf_node_road.hpp"
#include "../../roadstop_base.h"
 
#include "../../safeguards.h"
 
 
template <class Types>
class CYapfCostRoadT {
public:
  typedef typename Types::Tpf Tpf; 
  typedef typename Types::TrackFollower TrackFollower; 
  typedef typename Types::NodeList::Item Node; 
  typedef typename Node::Key Key; 
 
protected:
  int max_cost;
 
  CYapfCostRoadT() : max_cost(0) {};

  Tpf &Yapf()
  {
    return *static_cast<Tpf *>(this);
  }
 
  int SlopeCost(TileIndex tile, TileIndex next_tile, Trackdir)
  {
    /* height of the center of the current tile */
    int x1 = TileX(tile) * TILE_SIZE;
    int y1 = TileY(tile) * TILE_SIZE;
    int z1 = GetSlopePixelZ(x1 + TILE_SIZE / 2, y1 + TILE_SIZE / 2, true);
 
    /* height of the center of the next tile */
    int x2 = TileX(next_tile) * TILE_SIZE;
    int y2 = TileY(next_tile) * TILE_SIZE;
    int z2 = GetSlopePixelZ(x2 + TILE_SIZE / 2, y2 + TILE_SIZE / 2, true);
 
    if (z2 - z1 > 1) {
      /* Slope up */
      return Yapf().PfGetSettings().road_slope_penalty;
    }
    return 0;
  }

  inline int OneTileCost(TileIndex tile, Trackdir trackdir)
  {
    int cost = 0;
    /* set base cost */
    if (IsDiagonalTrackdir(trackdir)) {
      cost += YAPF_TILE_LENGTH;
      switch (GetTileType(tile)) {
        case TileType::Road:
          /* Increase the cost for level crossings */
          if (IsLevelCrossing(tile)) {
            cost += Yapf().PfGetSettings().road_crossing_penalty;
          }
          break;
 
        case TileType::Station: {
          if (IsRoadWaypoint(tile)) break;
 
          const RoadStop *rs = RoadStop::GetByTile(tile, GetRoadStopType(tile));
          if (IsDriveThroughStopTile(tile)) {
            /* Increase the cost for drive-through road stops */
            cost += Yapf().PfGetSettings().road_stop_penalty;
            DiagDirection dir = TrackdirToExitdir(trackdir);
            if (!RoadStop::IsDriveThroughRoadStopContinuation(tile, tile - TileOffsByDiagDir(dir))) {
              /* When we're the first road stop in a 'queue' of them we increase
               * cost based on the fill percentage of the whole queue. */
              const RoadStop::Entry &entry = rs->GetEntry(dir);
              cost += entry.GetOccupied() * Yapf().PfGetSettings().road_stop_occupied_penalty / entry.GetLength();
            }
          } else {
            /* Increase cost for filled road stops */
            cost += Yapf().PfGetSettings().road_stop_bay_occupied_penalty * (!rs->IsFreeBay(0) + !rs->IsFreeBay(1)) / 2;
          }
          break;
        }
 
        default:
          break;
      }
    } else {
      /* non-diagonal trackdir */
      cost = YAPF_TILE_CORNER_LENGTH + Yapf().PfGetSettings().road_curve_penalty;
    }
    return cost;
  }
 
public:
  inline void SetMaxCost(int max_cost)
  {
    this->max_cost = max_cost;
  }

  inline bool PfCalcCost(Node &n, [[maybe_unused]] const TrackFollower *follower)
  {
    int segment_cost = 0;
    uint tiles = 0;
    /* start at n.key.tile / n.key.td and walk to the end of segment */
    TileIndex tile = n.key.tile;
    Trackdir trackdir = n.key.td;
    int parent_cost = (n.parent != nullptr) ? n.parent->cost : 0;
 
    for (;;) {
      /* base tile cost depending on distance between edges */
      segment_cost += Yapf().OneTileCost(tile, trackdir);
 
      const RoadVehicle *v = Yapf().GetVehicle();
      /* we have reached the vehicle's destination - segment should end here to avoid target skipping */
      if (Yapf().PfDetectDestinationTile(tile, trackdir)) break;
 
      /* Finish if we already exceeded the maximum path cost (i.e. when
       * searching for the nearest depot). */
      if (this->max_cost > 0 && (parent_cost + segment_cost) > this->max_cost) {
        return false;
      }
 
      /* stop if we have just entered the depot */
      if (IsRoadDepotTile(tile) && trackdir == DiagDirToDiagTrackdir(ReverseDiagDir(GetRoadDepotDirection(tile)))) {
        /* next time we will reverse and leave the depot */
        break;
      }
 
      /* if there are no reachable trackdirs on new tile, we have end of road */
      TrackFollower F(Yapf().GetVehicle());
      if (!F.Follow(tile, trackdir)) break;
 
      /* if there are more trackdirs available & reachable, we are at the end of segment */
      if (KillFirstBit(F.new_td_bits) != TRACKDIR_BIT_NONE) break;
 
      Trackdir new_td = (Trackdir)FindFirstBit(F.new_td_bits);
 
      /* stop if RV is on simple loop with no junctions */
      if (F.new_tile == n.key.tile && new_td == n.key.td) return false;
 
      /* if we skipped some tunnel tiles, add their cost */
      segment_cost += F.tiles_skipped * YAPF_TILE_LENGTH;
      tiles += F.tiles_skipped + 1;
 
      /* add hilly terrain penalty */
      segment_cost += Yapf().SlopeCost(tile, F.new_tile, trackdir);
 
      /* add min/max speed penalties */
      int min_speed = 0;
      int max_veh_speed = std::min<int>(v->GetDisplayMaxSpeed(), v->current_order.GetMaxSpeed() * 2);
      int max_speed = F.GetSpeedLimit(&min_speed);
      if (max_speed < max_veh_speed) segment_cost += YAPF_TILE_LENGTH * (max_veh_speed - max_speed) * (4 + F.tiles_skipped) / max_veh_speed;
      if (min_speed > max_veh_speed) segment_cost += YAPF_TILE_LENGTH * (min_speed - max_veh_speed);
 
      /* move to the next tile */
      tile = F.new_tile;
      trackdir = new_td;
      if (tiles > MAX_MAP_SIZE) break;
    }
 
    /* save end of segment back to the node */
    n.segment_last_tile = tile;
    n.segment_last_td = trackdir;
 
    /* save also tile cost */
    n.cost = parent_cost + segment_cost;
    return true;
  }
};
 
 
template <class Types>
class CYapfDestinationAnyDepotRoadT {
public:
  typedef typename Types::Tpf Tpf; 
  typedef typename Types::TrackFollower TrackFollower;
  typedef typename Types::NodeList::Item Node; 
  typedef typename Node::Key Key; 

  Tpf &Yapf()
  {
    return *static_cast<Tpf *>(this);
  }

  inline bool PfDetectDestination(Node &n)
  {
    return IsRoadDepotTile(n.segment_last_tile);
  }

  inline bool PfDetectDestinationTile(TileIndex tile, [[maybe_unused]] Trackdir td)
  {
    return IsRoadDepotTile(tile);
  }

  inline bool PfCalcEstimate(Node &n)
  {
    n.estimate = n.cost;
    return true;
  }
};
 
 
template <class Types>
class CYapfDestinationTileRoadT {
public:
  typedef typename Types::Tpf Tpf; 
  typedef typename Types::TrackFollower TrackFollower;
  typedef typename Types::NodeList::Item Node; 
  typedef typename Node::Key Key; 
 
protected:
  TileIndex dest_tile;
  TrackdirBits dest_trackdirs;
  StationID dest_station;
  StationType station_type;
  bool non_artic;
 
public:
  void SetDestination(const RoadVehicle *v)
  {
    if (v->current_order.IsType(OT_GOTO_STATION)) {
      this->dest_station = v->current_order.GetDestination().ToStationID();
      this->station_type = v->IsBus() ? StationType::Bus : StationType::Truck;
      this->dest_tile = CalcClosestStationTile(this->dest_station, v->tile, this->station_type);
      this->non_artic = !v->HasArticulatedPart();
      this->dest_trackdirs = INVALID_TRACKDIR_BIT;
    } else if (v->current_order.IsType(OT_GOTO_WAYPOINT)) {
      this->dest_station = v->current_order.GetDestination().ToStationID();
      this->station_type = StationType::RoadWaypoint;
      this->dest_tile = CalcClosestStationTile(this->dest_station, v->tile, this->station_type);
      this->non_artic = !v->HasArticulatedPart();
      this->dest_trackdirs = INVALID_TRACKDIR_BIT;
    } else {
      this->dest_station = StationID::Invalid();
      this->dest_tile = v->dest_tile == INVALID_TILE ? TileIndex{} : v->dest_tile;
      this->dest_trackdirs = TrackStatusToTrackdirBits(GetTileTrackStatus(this->dest_tile, TRANSPORT_ROAD, GetRoadTramType(v->roadtype)));
    }
  }
 
  const Station *GetDestinationStation() const
  {
    return this->dest_station != StationID::Invalid() ? Station::GetIfValid(this->dest_station) : nullptr;
  }
 
protected:
  Tpf &Yapf()
  {
    return *static_cast<Tpf *>(this);
  }
 
public:
  inline bool PfDetectDestination(Node &n)
  {
    return this->PfDetectDestinationTile(n.segment_last_tile, n.segment_last_td);
  }

  inline bool PfDetectDestinationTile(TileIndex tile, Trackdir td)
  {
    if (this->dest_station != StationID::Invalid()) {
      return IsTileType(tile, TileType::Station) &&
        GetStationIndex(tile) == this->dest_station &&
        (this->station_type == GetStationType(tile)) &&
        (this->non_artic || IsDriveThroughStopTile(tile));
    }
 
    return tile == this->dest_tile && HasTrackdir(this->dest_trackdirs, td);
  }

  inline bool PfCalcEstimate(Node &n)
  {
    if (this->PfDetectDestination(n)) {
      n.estimate = n.cost;
      return true;
    }
 
    n.estimate = n.cost + OctileDistanceCost(n.segment_last_tile, n.segment_last_td, this->dest_tile);
    assert(n.estimate >= n.parent->estimate);
    return true;
  }
};
 
 
 
template <class Types>
class CYapfFollowRoadT {
public:
  typedef typename Types::Tpf Tpf; 
  typedef typename Types::TrackFollower TrackFollower;
  typedef typename Types::NodeList::Item Node; 
  typedef typename Node::Key Key; 
 
protected:
  inline Tpf &Yapf()
  {
    return *static_cast<Tpf *>(this);
  }
 
public:

  inline void PfFollowNode(Node &old_node)
  {
    TrackFollower F(Yapf().GetVehicle());
    if (F.Follow(old_node.segment_last_tile, old_node.segment_last_td)) {
      Yapf().AddMultipleNodes(&old_node, F);
    }
  }

  inline char TransportTypeChar() const
  {
    return 'r';
  }
 
  static Trackdir stChooseRoadTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, bool &path_found, RoadVehPathCache &path_cache)
  {
    Tpf pf;
    return pf.ChooseRoadTrack(v, tile, enterdir, path_found, path_cache);
  }
 
  inline Trackdir ChooseRoadTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, bool &path_found, RoadVehPathCache &path_cache)
  {
    /* Handle special case - when next tile is destination tile.
     * However, when going to a station the (initial) destination
     * tile might not be a station, but a junction, in which case
     * this method forces the vehicle to jump in circles. */
    if (tile == v->dest_tile && !v->current_order.IsType(OT_GOTO_STATION)) {
      /* choose diagonal trackdir reachable from enterdir */
      return DiagDirToDiagTrackdir(enterdir);
    }
    /* our source tile will be the next vehicle tile (should be the given one) */
    TileIndex src_tile = tile;
    /* get available trackdirs on the start tile */
    TrackdirBits src_trackdirs = GetTrackdirBitsForRoad(tile, GetRoadTramType(v->roadtype));
    /* select reachable trackdirs only */
    src_trackdirs &= DiagdirReachesTrackdirs(enterdir);
 
    /* set origin and destination nodes */
    Yapf().SetOrigin(src_tile, src_trackdirs);
    Yapf().SetDestination(v);
 
    /* find the best path */
    path_found = Yapf().FindPath(v);
 
    /* if path not found - return INVALID_TRACKDIR */
    Trackdir next_trackdir = INVALID_TRACKDIR;
    Node *node = Yapf().GetBestNode();
    if (node != nullptr) {
      uint steps = 0;
      for (Node *n = node; n->parent != nullptr; n = n->parent) steps++;
 
      /* path was found or at least suggested
       * walk through the path back to its origin */
      while (node->parent != nullptr) {
        steps--;
        if (node->GetIsChoice() && steps < YAPF_ROADVEH_PATH_CACHE_SEGMENTS) {
          path_cache.emplace_back(node->GetTrackdir(), node->GetTile());
        }
        node = node->parent;
      }
      /* return trackdir from the best origin node (one of start nodes) */
      Node &best_next_node = *node;
      assert(best_next_node.GetTile() == tile);
      next_trackdir = best_next_node.GetTrackdir();
 
      /* Check if target is a station, and cached path leads to within YAPF_ROADVEH_PATH_CACHE_DESTINATION_LIMIT
       * tiles of the dest tile */
      const Station *st = Yapf().GetDestinationStation();
      if (st) {
        const RoadStop *stop = st->GetPrimaryRoadStop(v);
        if (stop != nullptr && (IsDriveThroughStopTile(stop->xy) || stop->GetNextRoadStop(v) != nullptr)) {
          /* Destination station has at least 2 usable road stops, or first is a drive-through stop,
           * trim end of path cache within a number of tiles of road stop tile area */
          TileArea non_cached_area = v->IsBus() ? st->bus_station : st->truck_station;
          non_cached_area.Expand(YAPF_ROADVEH_PATH_CACHE_DESTINATION_LIMIT);
 
          /* Find the first tile not contained by the non-cacheable area, and remove from the cache. */
          auto it = std::find_if(std::begin(path_cache), std::end(path_cache), [&non_cached_area](const auto &pc) { return !non_cached_area.Contains(pc.tile); });
          path_cache.erase(std::begin(path_cache), it);
        }
      }
    }
    return next_trackdir;
  }
 
  inline uint DistanceToTile(const RoadVehicle *v, TileIndex dst_tile)
  {
    /* handle special case - when current tile is the destination tile */
    if (dst_tile == v->tile) {
      /* distance is zero in this case */
      return 0;
    }
 
    if (!this->SetOriginFromVehiclePos(v)) return UINT_MAX;
 
    /* get available trackdirs on the destination tile */
    Yapf().SetDestination(v);
 
    /* if path not found - return distance = UINT_MAX */
    uint dist = UINT_MAX;
 
    /* find the best path */
    if (!Yapf().FindPath(v)) return dist;
 
    Node *node = Yapf().GetBestNode();
    if (node != nullptr) {
      /* path was found
       * get the path cost estimate */
      dist = node->GetCostEstimate();
    }
 
    return dist;
  }

  inline bool SetOriginFromVehiclePos(const RoadVehicle *v)
  {
    /* set origin (tile, trackdir) */
    TileIndex src_tile = v->tile;
    Trackdir src_td = v->GetVehicleTrackdir();
    if (!HasTrackdir(GetTrackdirBitsForRoad(src_tile, Yapf().IsTram() ? RoadTramType::Tram : RoadTramType::Road), src_td)) {
      /* sometimes the roadveh is not on the road (it resides on non-existing track)
       * how should we handle that situation? */
      return false;
    }
    Yapf().SetOrigin(src_tile, TrackdirToTrackdirBits(src_td));
    return true;
  }
 
  static FindDepotData stFindNearestDepot(const RoadVehicle *v, TileIndex tile, Trackdir td, int max_distance)
  {
    Tpf pf;
    return pf.FindNearestDepot(v, tile, td, max_distance);
  }

  inline FindDepotData FindNearestDepot(const RoadVehicle *v, TileIndex tile, Trackdir td, int max_distance)
  {
    /* Set origin. */
    Yapf().SetOrigin(tile, TrackdirToTrackdirBits(td));
    Yapf().SetMaxCost(max_distance);
 
    /* Find the best path and return if no depot is found. */
    if (!Yapf().FindPath(v)) return FindDepotData();
 
    /* Return the cost of the best path and its depot. */
    Node *n = Yapf().GetBestNode();
    return FindDepotData(n->segment_last_tile, n->cost);
  }
};
 
template <class Tpf_, template <class Types> class Tdestination>
struct CYapfRoad_TypesT {
  typedef CYapfRoad_TypesT<Tpf_, Tdestination>  Types;
 
  typedef Tpf_                              Tpf;
  typedef CFollowTrackRoad                  TrackFollower;
  typedef CRoadNodeList                     NodeList;
  typedef RoadVehicle                       VehicleType;
  typedef CYapfBaseT<Types>                 PfBase;
  typedef CYapfFollowRoadT<Types>           PfFollow;
  typedef CYapfOriginTileT<Types>           PfOrigin;
  typedef Tdestination<Types>               PfDestination;
  typedef CYapfSegmentCostCacheNoneT<Types> PfCache;
  typedef CYapfCostRoadT<Types>             PfCost;
};
 
struct CYapfRoad : CYapfT<CYapfRoad_TypesT<CYapfRoad, CYapfDestinationTileRoadT>> {};
 
struct CYapfRoadAnyDepot : CYapfT<CYapfRoad_TypesT<CYapfRoadAnyDepot, CYapfDestinationAnyDepotRoadT>> {};
 
Trackdir YapfRoadVehicleChooseTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool &path_found, RoadVehPathCache &path_cache)
{
  Trackdir td_ret = CYapfRoad::stChooseRoadTrack(v, tile, enterdir, path_found, path_cache);
 
  return (td_ret != INVALID_TRACKDIR) ? td_ret : (Trackdir)FindFirstBit(trackdirs);
}
 
FindDepotData YapfRoadVehicleFindNearestDepot(const RoadVehicle *v, int max_distance)
{
  TileIndex tile = v->tile;
  Trackdir trackdir = v->GetVehicleTrackdir();
 
  if (!HasTrackdir(GetTrackdirBitsForRoad(tile, GetRoadTramType(v->roadtype)), trackdir)) {
    return FindDepotData();
  }
 
  return CYapfRoadAnyDepot::stFindNearestDepot(v, tile, trackdir, max_distance);
}