/* $Id$ */
/** @file follow_track.hpp Template function for track followers */
#ifndef FOLLOW_TRACK_HPP
#define FOLLOW_TRACK_HPP
#include "yapf.hpp"
#include "../depot_map.h"
/** 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_, 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 Vehicle *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;
FORCEINLINE CFollowTrackT(const Vehicle *v = NULL, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
{
Init(v, railtype_override, pPerf);
}
FORCEINLINE CFollowTrackT(Owner o, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
{
m_veh = NULL;
Init(o, railtype_override, pPerf);
}
FORCEINLINE void Init(const Vehicle *v, RailTypes railtype_override, CPerformanceTimer *pPerf)
{
assert(!IsRailTT() || (v != NULL && v->type == VEH_TRAIN));
m_veh = v;
Init(v != NULL ? v->owner : INVALID_OWNER, railtype_override == INVALID_RAILTYPES ? v->u.rail.compatible_railtypes : railtype_override, pPerf);
}
FORCEINLINE 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;
}
FORCEINLINE static TransportType TT() {return Ttr_type_;}
FORCEINLINE static bool IsWaterTT() {return TT() == TRANSPORT_WATER;}
FORCEINLINE static bool IsRailTT() {return TT() == TRANSPORT_RAIL;}
FORCEINLINE bool IsTram() {return IsRoadTT() && HasBit(m_veh->u.road.compatible_roadtypes, ROADTYPE_TRAM);}
FORCEINLINE static bool IsRoadTT() {return TT() == TRANSPORT_ROAD;}
FORCEINLINE static bool Allow90degTurns() {return T90deg_turns_allowed_;}
FORCEINLINE static bool DoTrackMasking() {return IsRailTT() && Tmask_reserved_tracks;}
/** Tests if a tile is a road tile with a single tramtrack (tram can reverse) */
FORCEINLINE 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(), m_veh ? m_veh->u.road.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) {
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 (GetRailwayStationReservation(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. */
uint bits = (uint)TrackdirBitsToTrackBits(m_new_td_bits);
int i;
FOR_EACH_SET_BIT(i, bits) {
if (TracksOverlap(reserved | TrackToTrackBits((Track)i))) m_new_td_bits &= ~TrackToTrackdirBits((Track)i);
}
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 */
FORCEINLINE 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() && IsRailwayStationTile(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 */
FORCEINLINE bool QueryNewTileTrackStatus()
{
CPerfStart perf(*m_pPerf);
if (IsRailTT() && GetTileType(m_new_tile) == MP_RAILWAY && 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(), m_veh != NULL ? m_veh->u.road.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 */
FORCEINLINE 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 */
FORCEINLINE 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 = GetStationByTile(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) */
FORCEINLINE 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 */
FORCEINLINE 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
// for now we handle only 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;
}
// if min speed was requested, return it
if (pmin_speed) *pmin_speed = min_speed;
return max_speed;
}
};
typedef CFollowTrackT<TRANSPORT_WATER, true > CFollowTrackWater;
typedef CFollowTrackT<TRANSPORT_ROAD , true > CFollowTrackRoad;
typedef CFollowTrackT<TRANSPORT_RAIL , true > CFollowTrackRail;
typedef CFollowTrackT<TRANSPORT_WATER, false> CFollowTrackWaterNo90;
typedef CFollowTrackT<TRANSPORT_ROAD , false> CFollowTrackRoadNo90;
typedef CFollowTrackT<TRANSPORT_RAIL , false> CFollowTrackRailNo90;
typedef CFollowTrackT<TRANSPORT_RAIL , true , true> CFollowTrackFreeRail;
typedef CFollowTrackT<TRANSPORT_RAIL , false, true> CFollowTrackFreeRailNo90;
#endif /* FOLLOW_TRACK_HPP */