summaryrefslogtreecommitdiff
path: root/src/yapf/follow_track.hpp
blob: 6987c24a4e9188e7ec2bc03263eba3ceb8075c6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
/* $Id$ */

/** @file follow_track.hpp Template function for track followers */

#ifndef  FOLLOW_TRACK_HPP
#define  FOLLOW_TRACK_HPP

#include "yapf.hpp"

/** Track follower helper template class (can serve pathfinders and vehicle
 *  controllers). See 6 different typedefs below for 3 different transport
 *  types w/ of w/o 90-deg turns allowed */
template <TransportType Ttr_type_, bool T90deg_turns_allowed_ = true>
struct CFollowTrackT : public FollowTrack_t
{
	CPerformanceTimer* m_pPerf;

	FORCEINLINE CFollowTrackT(const Vehicle* v = NULL, CPerformanceTimer* pPerf = NULL)
	{
		Init(v, pPerf);
	}

	FORCEINLINE void Init(const Vehicle* v, CPerformanceTimer* pPerf)
	{
		assert(!IsRailTT() || (v != NULL && v->type == VEH_TRAIN));
		m_veh = v;
		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;
	}

	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_;}

	/** Tests if a tile is a road tile with a single tramtrack (tram can reverse) */
	FORCEINLINE DiagDirection GetSingleTramBit(TileIndex tile)
	{
		if (IsTram() && 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. */
	FORCEINLINE 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->u.road.compatible_roadtypes)) & TrackdirToTrackdirBits(m_old_td)) != 0) ||
		       (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;
	}

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->u.road.compatible_roadtypes));

			if (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 */
		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() && IsTileDepotType(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 */
		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() && IsTileDepotType(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 player's depots
			if (GetTileOwner(m_new_tile) != m_veh->owner) {
				m_err = EC_OWNER;
				return false;
			}
		}
		if (IsRailTT() && IsTileDepotType(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_veh->u.rail.compatible_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 (!IsWaterTT() && 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() && IsTileDepotType(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 (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;

#endif /* FOLLOW_TRACK_HPP */