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/* $Id$ */
/*
* 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 <http://www.gnu.org/licenses/>.
*/
/** @file follow_track.hpp Template function for track followers */
#ifndef FOLLOW_TRACK_HPP
#define FOLLOW_TRACK_HPP
#include "../pbs.h"
#include "../roadveh.h"
#include "../station_base.h"
#include "../train.h"
#include "../tunnelbridge.h"
#include "../tunnelbridge_map.h"
#include "../depot_map.h"
#include "pf_performance_timer.hpp"
/**
* Track follower helper template class (can serve pathfinders and vehicle
* controllers). See 6 different typedefs below for 3 different transport
* types w/ or w/o 90-deg turns allowed
*/
template <TransportType Ttr_type_, typename VehicleType, bool T90deg_turns_allowed_ = true, bool Tmask_reserved_tracks = false>
struct CFollowTrackT
{
enum ErrorCode {
EC_NONE,
EC_OWNER,
EC_RAIL_TYPE,
EC_90DEG,
EC_NO_WAY,
EC_RESERVED,
};
const VehicleType *m_veh; ///< moving vehicle
Owner m_veh_owner; ///< owner of the vehicle
TileIndex m_old_tile; ///< the origin (vehicle moved from) before move
Trackdir m_old_td; ///< the trackdir (the vehicle was on) before move
TileIndex m_new_tile; ///< the new tile (the vehicle has entered)
TrackdirBits m_new_td_bits; ///< the new set of available trackdirs
DiagDirection m_exitdir; ///< exit direction (leaving the old tile)
bool m_is_tunnel; ///< last turn passed tunnel
bool m_is_bridge; ///< last turn passed bridge ramp
bool m_is_station; ///< last turn passed station
int m_tiles_skipped; ///< number of skipped tunnel or station tiles
ErrorCode m_err;
CPerformanceTimer *m_pPerf;
RailTypes m_railtypes;
inline CFollowTrackT(const VehicleType *v = NULL, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
{
Init(v, railtype_override, pPerf);
}
inline CFollowTrackT(Owner o, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
{
m_veh = NULL;
Init(o, railtype_override, pPerf);
}
inline void Init(const VehicleType *v, RailTypes railtype_override, CPerformanceTimer *pPerf)
{
assert(!IsRailTT() || (v != NULL && v->type == VEH_TRAIN));
m_veh = v;
Init(v != NULL ? v->owner : INVALID_OWNER, IsRailTT() && railtype_override == INVALID_RAILTYPES ? Train::From(v)->compatible_railtypes : railtype_override, pPerf);
}
inline void Init(Owner o, RailTypes railtype_override, CPerformanceTimer *pPerf)
{
assert((!IsRoadTT() || m_veh != NULL) && (!IsRailTT() || railtype_override != INVALID_RAILTYPES));
m_veh_owner = o;
m_pPerf = pPerf;
/* don't worry, all is inlined so compiler should remove unnecessary initializations */
m_new_tile = INVALID_TILE;
m_new_td_bits = TRACKDIR_BIT_NONE;
m_exitdir = INVALID_DIAGDIR;
m_is_station = m_is_bridge = m_is_tunnel = false;
m_tiles_skipped = 0;
m_err = EC_NONE;
m_railtypes = railtype_override;
}
inline static TransportType TT() { return Ttr_type_; }
inline static bool IsWaterTT() { return TT() == TRANSPORT_WATER; }
inline static bool IsRailTT() { return TT() == TRANSPORT_RAIL; }
inline bool IsTram() { return IsRoadTT() && HasBit(RoadVehicle::From(m_veh)->compatible_roadtypes, ROADTYPE_TRAM); }
inline static bool IsRoadTT() { return TT() == TRANSPORT_ROAD; }
inline static bool Allow90degTurns() { return T90deg_turns_allowed_; }
inline static bool DoTrackMasking() { return IsRailTT() && Tmask_reserved_tracks; }
/** Tests if a tile is a road tile with a single tramtrack (tram can reverse) */
inline DiagDirection GetSingleTramBit(TileIndex tile)
{
assert(IsTram()); // this function shouldn't be called in other cases
if (IsNormalRoadTile(tile)) {
RoadBits rb = GetRoadBits(tile, ROADTYPE_TRAM);
switch (rb) {
case ROAD_NW: return DIAGDIR_NW;
case ROAD_SW: return DIAGDIR_SW;
case ROAD_SE: return DIAGDIR_SE;
case ROAD_NE: return DIAGDIR_NE;
default: break;
}
}
return INVALID_DIAGDIR;
}
/**
* main follower routine. Fills all members and return true on success.
* Otherwise returns false if track can't be followed.
*/
inline bool Follow(TileIndex old_tile, Trackdir old_td)
{
m_old_tile = old_tile;
m_old_td = old_td;
m_err = EC_NONE;
assert(((TrackStatusToTrackdirBits(GetTileTrackStatus(m_old_tile, TT(), IsRoadTT() && m_veh != NULL ? RoadVehicle::From(m_veh)->compatible_roadtypes : 0)) & TrackdirToTrackdirBits(m_old_td)) != 0) ||
(IsTram() && GetSingleTramBit(m_old_tile) != INVALID_DIAGDIR)); // Disable the assertion for single tram bits
m_exitdir = TrackdirToExitdir(m_old_td);
if (ForcedReverse()) return true;
if (!CanExitOldTile()) return false;
FollowTileExit();
if (!QueryNewTileTrackStatus()) return TryReverse();
if (!CanEnterNewTile()) return false;
m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
if (m_new_td_bits == TRACKDIR_BIT_NONE) {
/* In case we can't enter the next tile, but are
* a normal road vehicle, then we can actually
* try to reverse as this is the end of the road.
* Trams can only turn on the appropriate bits in
* which case reaching this would mean a dead end
* near a building and in that case there would
* a "false" QueryNewTileTrackStatus result and
* as such reversing is already tried. The fact
* that function failed can have to do with a
* missing road bit, or inability to connect the
* different bits due to slopes. */
if (IsRoadTT() && !IsTram() && TryReverse()) return true;
m_err = EC_NO_WAY;
return false;
}
if (!Allow90degTurns()) {
m_new_td_bits &= (TrackdirBits)~(int)TrackdirCrossesTrackdirs(m_old_td);
if (m_new_td_bits == TRACKDIR_BIT_NONE) {
m_err = EC_90DEG;
return false;
}
}
return true;
}
inline bool MaskReservedTracks()
{
if (!DoTrackMasking()) return true;
if (m_is_station) {
/* Check skipped station tiles as well. */
TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
for (TileIndex tile = m_new_tile - diff * m_tiles_skipped; tile != m_new_tile; tile += diff) {
if (HasStationReservation(tile)) {
m_new_td_bits = TRACKDIR_BIT_NONE;
m_err = EC_RESERVED;
return false;
}
}
}
TrackBits reserved = GetReservedTrackbits(m_new_tile);
/* Mask already reserved trackdirs. */
m_new_td_bits &= ~TrackBitsToTrackdirBits(reserved);
/* Mask out all trackdirs that conflict with the reservation. */
Track t;
FOR_EACH_SET_TRACK(t, TrackdirBitsToTrackBits(m_new_td_bits)) {
if (TracksOverlap(reserved | TrackToTrackBits(t))) m_new_td_bits &= ~TrackToTrackdirBits(t);
}
if (m_new_td_bits == TRACKDIR_BIT_NONE) {
m_err = EC_RESERVED;
return false;
}
return true;
}
protected:
/** Follow the m_exitdir from m_old_tile and fill m_new_tile and m_tiles_skipped */
inline void FollowTileExit()
{
m_is_station = m_is_bridge = m_is_tunnel = false;
m_tiles_skipped = 0;
/* extra handling for tunnels and bridges in our direction */
if (IsTileType(m_old_tile, MP_TUNNELBRIDGE)) {
DiagDirection enterdir = GetTunnelBridgeDirection(m_old_tile);
if (enterdir == m_exitdir) {
/* we are entering the tunnel / bridge */
if (IsTunnel(m_old_tile)) {
m_is_tunnel = true;
m_new_tile = GetOtherTunnelEnd(m_old_tile);
} else { // IsBridge(m_old_tile)
m_is_bridge = true;
m_new_tile = GetOtherBridgeEnd(m_old_tile);
}
m_tiles_skipped = GetTunnelBridgeLength(m_new_tile, m_old_tile);
return;
}
assert(ReverseDiagDir(enterdir) == m_exitdir);
}
/* normal or station tile, do one step */
TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
m_new_tile = TILE_ADD(m_old_tile, diff);
/* special handling for stations */
if (IsRailTT() && HasStationTileRail(m_new_tile)) {
m_is_station = true;
} else if (IsRoadTT() && IsRoadStopTile(m_new_tile)) {
m_is_station = true;
} else {
m_is_station = false;
}
}
/** stores track status (available trackdirs) for the new tile into m_new_td_bits */
inline bool QueryNewTileTrackStatus()
{
CPerfStart perf(*m_pPerf);
if (IsRailTT() && IsPlainRailTile(m_new_tile)) {
m_new_td_bits = (TrackdirBits)(GetTrackBits(m_new_tile) * 0x101);
} else {
m_new_td_bits = TrackStatusToTrackdirBits(GetTileTrackStatus(m_new_tile, TT(), IsRoadTT() && m_veh != NULL ? RoadVehicle::From(m_veh)->compatible_roadtypes : 0));
if (IsTram() && m_new_td_bits == 0) {
/* GetTileTrackStatus() returns 0 for single tram bits.
* As we cannot change it there (easily) without breaking something, change it here */
switch (GetSingleTramBit(m_new_tile)) {
case DIAGDIR_NE:
case DIAGDIR_SW:
m_new_td_bits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
break;
case DIAGDIR_NW:
case DIAGDIR_SE:
m_new_td_bits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
break;
default: break;
}
}
}
return (m_new_td_bits != TRACKDIR_BIT_NONE);
}
/** return true if we can leave m_old_tile in m_exitdir */
inline bool CanExitOldTile()
{
/* road stop can be left at one direction only unless it's a drive-through stop */
if (IsRoadTT() && IsStandardRoadStopTile(m_old_tile)) {
DiagDirection exitdir = GetRoadStopDir(m_old_tile);
if (exitdir != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
}
/* single tram bits can only be left in one direction */
if (IsTram()) {
DiagDirection single_tram = GetSingleTramBit(m_old_tile);
if (single_tram != INVALID_DIAGDIR && single_tram != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
}
/* road depots can be also left in one direction only */
if (IsRoadTT() && IsDepotTypeTile(m_old_tile, TT())) {
DiagDirection exitdir = GetRoadDepotDirection(m_old_tile);
if (exitdir != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
}
return true;
}
/** return true if we can enter m_new_tile from m_exitdir */
inline bool CanEnterNewTile()
{
if (IsRoadTT() && IsStandardRoadStopTile(m_new_tile)) {
/* road stop can be entered from one direction only unless it's a drive-through stop */
DiagDirection exitdir = GetRoadStopDir(m_new_tile);
if (ReverseDiagDir(exitdir) != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
}
/* single tram bits can only be entered from one direction */
if (IsTram()) {
DiagDirection single_tram = GetSingleTramBit(m_new_tile);
if (single_tram != INVALID_DIAGDIR && single_tram != ReverseDiagDir(m_exitdir)) {
m_err = EC_NO_WAY;
return false;
}
}
/* road and rail depots can also be entered from one direction only */
if (IsRoadTT() && IsDepotTypeTile(m_new_tile, TT())) {
DiagDirection exitdir = GetRoadDepotDirection(m_new_tile);
if (ReverseDiagDir(exitdir) != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
/* don't try to enter other company's depots */
if (GetTileOwner(m_new_tile) != m_veh_owner) {
m_err = EC_OWNER;
return false;
}
}
if (IsRailTT() && IsDepotTypeTile(m_new_tile, TT())) {
DiagDirection exitdir = GetRailDepotDirection(m_new_tile);
if (ReverseDiagDir(exitdir) != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
}
/* rail transport is possible only on tiles with the same owner as vehicle */
if (IsRailTT() && GetTileOwner(m_new_tile) != m_veh_owner) {
/* different owner */
m_err = EC_NO_WAY;
return false;
}
/* rail transport is possible only on compatible rail types */
if (IsRailTT()) {
RailType rail_type = GetTileRailType(m_new_tile);
if (!HasBit(m_railtypes, rail_type)) {
/* incompatible rail type */
m_err = EC_RAIL_TYPE;
return false;
}
}
/* tunnel holes and bridge ramps can be entered only from proper direction */
if (IsTileType(m_new_tile, MP_TUNNELBRIDGE)) {
if (IsTunnel(m_new_tile)) {
if (!m_is_tunnel) {
DiagDirection tunnel_enterdir = GetTunnelBridgeDirection(m_new_tile);
if (tunnel_enterdir != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
}
} else { // IsBridge(m_new_tile)
if (!m_is_bridge) {
DiagDirection ramp_enderdir = GetTunnelBridgeDirection(m_new_tile);
if (ramp_enderdir != m_exitdir) {
m_err = EC_NO_WAY;
return false;
}
}
}
}
/* special handling for rail stations - get to the end of platform */
if (IsRailTT() && m_is_station) {
/* entered railway station
* get platform length */
uint length = BaseStation::GetByTile(m_new_tile)->GetPlatformLength(m_new_tile, TrackdirToExitdir(m_old_td));
/* how big step we must do to get to the last platform tile; */
m_tiles_skipped = length - 1;
/* move to the platform end */
TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
diff *= m_tiles_skipped;
m_new_tile = TILE_ADD(m_new_tile, diff);
return true;
}
return true;
}
/** return true if we must reverse (in depots and single tram bits) */
inline bool ForcedReverse()
{
/* rail and road depots cause reversing */
if (!IsWaterTT() && IsDepotTypeTile(m_old_tile, TT())) {
DiagDirection exitdir = IsRailTT() ? GetRailDepotDirection(m_old_tile) : GetRoadDepotDirection(m_old_tile);
if (exitdir != m_exitdir) {
/* reverse */
m_new_tile = m_old_tile;
m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
m_exitdir = exitdir;
m_tiles_skipped = 0;
m_is_tunnel = m_is_bridge = m_is_station = false;
return true;
}
}
/* single tram bits cause reversing */
if (IsTram() && GetSingleTramBit(m_old_tile) == ReverseDiagDir(m_exitdir)) {
/* reverse */
m_new_tile = m_old_tile;
m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
m_exitdir = ReverseDiagDir(m_exitdir);
m_tiles_skipped = 0;
m_is_tunnel = m_is_bridge = m_is_station = false;
return true;
}
return false;
}
/** return true if we successfully reversed at end of road/track */
inline bool TryReverse()
{
if (IsRoadTT() && !IsTram()) {
/* if we reached the end of road, we can reverse the RV and continue moving */
m_exitdir = ReverseDiagDir(m_exitdir);
/* new tile will be the same as old one */
m_new_tile = m_old_tile;
/* set new trackdir bits to all reachable trackdirs */
QueryNewTileTrackStatus();
m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
if (m_new_td_bits != TRACKDIR_BIT_NONE) {
/* we have some trackdirs reachable after reversal */
return true;
}
}
m_err = EC_NO_WAY;
return false;
}
public:
/** Helper for pathfinders - get min/max speed on the m_old_tile/m_old_td */
int GetSpeedLimit(int *pmin_speed = NULL) const
{
int min_speed = 0;
int max_speed = INT_MAX; // no limit
/* Check for on-bridge speed limit */
if (!IsWaterTT() && IsBridgeTile(m_old_tile)) {
int spd = GetBridgeSpec(GetBridgeType(m_old_tile))->speed;
if (IsRoadTT()) spd *= 2;
if (max_speed > spd) max_speed = spd;
}
/* Check for speed limit imposed by railtype */
if (IsRailTT()) {
uint16 rail_speed = GetRailTypeInfo(GetRailType(m_old_tile))->max_speed;
if (rail_speed > 0) max_speed = min(max_speed, rail_speed);
}
/* if min speed was requested, return it */
if (pmin_speed != NULL) *pmin_speed = min_speed;
return max_speed;
}
};
typedef CFollowTrackT<TRANSPORT_WATER, Ship, true > CFollowTrackWater;
typedef CFollowTrackT<TRANSPORT_ROAD, RoadVehicle, true > CFollowTrackRoad;
typedef CFollowTrackT<TRANSPORT_RAIL, Train, true > CFollowTrackRail;
typedef CFollowTrackT<TRANSPORT_WATER, Ship, false> CFollowTrackWaterNo90;
typedef CFollowTrackT<TRANSPORT_ROAD, RoadVehicle, false> CFollowTrackRoadNo90;
typedef CFollowTrackT<TRANSPORT_RAIL, Train, false> CFollowTrackRailNo90;
typedef CFollowTrackT<TRANSPORT_RAIL, Train, true, true > CFollowTrackFreeRail;
typedef CFollowTrackT<TRANSPORT_RAIL, Train, false, true > CFollowTrackFreeRailNo90;
#endif /* FOLLOW_TRACK_HPP */
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