tron@2186: /* $Id$ */
tron@2186: 
hackykid@2008: #include "stdafx.h"
hackykid@2008: #include "openttd.h"
tron@2163: #include "functions.h"
hackykid@2008: #include "pbs.h"
hackykid@2008: #include "debug.h"
hackykid@2008: #include "map.h"
hackykid@2008: #include "tile.h"
hackykid@2008: #include "npf.h"
hackykid@2008: #include "pathfind.h"
hackykid@2008: #include "depot.h"
hackykid@2008: 
hackykid@2008: /** @file pbs.c Path-Based-Signalling implementation file
hackykid@2008:  *  @see pbs.h */
hackykid@2008: 
hackykid@2008: /* reserved track encoding:
hackykid@2008:  normal railway tracks:
hackykid@2017:    map3hi bits 4..6 = 'Track'number of reserved track + 1, if this is zero it means nothing is reserved on this tile
hackykid@2017:    map3hi bit  7    = if this is set, then the opposite track ('Track'number^1) is also reserved
hackykid@2008:  waypoints/stations:
hackykid@2008:    map3lo bit 6 set = track is reserved
hackykid@2008:  tunnels/bridges:
hackykid@2008:    map3hi bit 0 set = track with 'Track'number 0 is reserved
hackykid@2008:    map3hi bit 1 set = track with 'Track'number 1 is reserved
hackykid@2008:  level crossings:
hackykid@2008:    map5 bit 0 set = the rail track is reserved
hackykid@2008: */
hackykid@2008: 
hackykid@2008: /**
hackykid@2008:  * maps an encoded reserved track (from map3lo bits 4..7)
hackykid@2008:  * to the tracks that are reserved.
hackykid@2008:  * 0xFF are invalid entries and should never be accessed.
hackykid@2008:  */
hackykid@2008: static const byte encrt_to_reserved[16] = {
hackykid@2008: 	0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0xFF,
hackykid@2008: 	0xFF, 0xFF, 0xFF, 0x0C, 0x0C, 0x30, 0x30, 0xFF
hackykid@2008: };
hackykid@2008: 
hackykid@2008: /**
hackykid@2008:  * maps an encoded reserved track (from map3lo bits 4..7)
hackykid@2008:  * to the track(dir)s that are unavailable due to reservations.
hackykid@2008:  * 0xFFFF are invalid entries and should never be accessed.
hackykid@2008:  */
tron@2182: static const uint16 encrt_to_unavail[16] = {
hackykid@2008: 	0x0000, 0x3F3F, 0x3F3F, 0x3737, 0x3B3B, 0x1F1F, 0x2F2F, 0xFFFF,
hackykid@2008: 	0xFFFF, 0xFFFF, 0xFFFF, 0x3F3F, 0x3F3F, 0x3F3F, 0x3F3F, 0xFFFF
hackykid@2008: };
hackykid@2008: 
hackykid@2008: void PBSReserveTrack(TileIndex tile, Track track) {
hackykid@2008: 	assert(IsValidTile(tile));
hackykid@2008: 	assert(track <= 5);
hackykid@2008: 	switch (GetTileType(tile)) {
hackykid@2008: 		case MP_RAILWAY:
tron@2049: 			if ((_m[tile].m5 & ~1) == 0xC4) {
hackykid@2008: 				// waypoint
tron@2049: 				SETBIT(_m[tile].m3, 6);
hackykid@2008: 			} else {
hackykid@2008: 				// normal rail track
tron@2493: 				byte encrt = GB(_m[tile].m4, 4, 4); // get current encoded info (see comments at top of file)
hackykid@2008: 
hackykid@2008: 				if (encrt == 0) // nothing reserved before
hackykid@2008: 					encrt = track + 1;
hackykid@2008: 				else if (encrt == (track^1) + 1) // opposite track reserved before
hackykid@2008: 					encrt |= 8;
hackykid@2008: 
tron@2493: 				SB(_m[tile].m4, 4, 4, encrt);
hackykid@2008: 			}
hackykid@2008: 			break;
hackykid@2008: 		case MP_TUNNELBRIDGE:
tron@2049: 			_m[tile].m4 |= (1 << track) & 3;
hackykid@2008: 			break;
hackykid@2008: 		case MP_STATION:
tron@2049: 			SETBIT(_m[tile].m3, 6);
hackykid@2008: 			break;
hackykid@2008: 		case MP_STREET:
hackykid@2008: 			// make sure it is a railroad crossing
hackykid@2008: 			if (!IsLevelCrossing(tile)) return;
tron@2049: 			SETBIT(_m[tile].m5, 0);
hackykid@2008: 			break;
hackykid@2008: 		default:
hackykid@2008: 			return;
tron@2182: 	}
hackykid@2008: 	// if debugging, mark tile dirty to show reserved status
hackykid@2008: 	if (_debug_pbs_level >= 1)
hackykid@2008: 		MarkTileDirtyByTile(tile);
hackykid@2008: }
hackykid@2008: 
hackykid@2008: byte PBSTileReserved(TileIndex tile) {
hackykid@2008: 	assert(IsValidTile(tile));
hackykid@2008: 	switch (GetTileType(tile)) {
hackykid@2008: 		case MP_RAILWAY:
tron@2049: 			if ((_m[tile].m5 & ~1) == 0xC4) {
hackykid@2008: 				// waypoint
hackykid@2008: 				// check if its reserved
tron@2049: 				if (!HASBIT(_m[tile].m3, 6)) return 0;
hackykid@2008: 				// return the track for the correct direction
tron@2049: 				return HASBIT(_m[tile].m5, 0) ? 2 : 1;
hackykid@2008: 			} else {
hackykid@2008: 				// normal track
tron@2493: 				byte res = encrt_to_reserved[GB(_m[tile].m4, 4, 4)];
hackykid@2008: 				assert(res != 0xFF);
hackykid@2008: 				return res;
tron@2182: 			}
hackykid@2008: 		case MP_TUNNELBRIDGE:
tron@2493: 			return GB(_m[tile].m4, 0, 2);
hackykid@2008: 		case MP_STATION:
hackykid@2008: 			// check if its reserved
tron@2049: 			if (!HASBIT(_m[tile].m3, 6)) return 0;
hackykid@2008: 			// return the track for the correct direction
tron@2049: 			return HASBIT(_m[tile].m5, 0) ? 2 : 1;
hackykid@2008: 		case MP_STREET:
hackykid@2008: 			// make sure its a railroad crossing
hackykid@2008: 			if (!IsLevelCrossing(tile)) return 0;
hackykid@2008: 			// check if its reserved
tron@2049: 			if (!HASBIT(_m[tile].m5, 0)) return 0;
hackykid@2008: 			// return the track for the correct direction
tron@2049: 			return HASBIT(_m[tile].m5, 3) ? 1 : 2;
hackykid@2008: 		default:
hackykid@2008: 			return 0;
tron@2182: 	}
tron@2182: }
hackykid@2008: 
hackykid@2008: uint16 PBSTileUnavail(TileIndex tile) {
hackykid@2008: 	assert(IsValidTile(tile));
hackykid@2008: 	switch (GetTileType(tile)) {
hackykid@2008: 		case MP_RAILWAY:
tron@2049: 			if ((_m[tile].m5 & ~1) == 0xC4) {
hackykid@2008: 				// waypoint
tron@2049: 				return HASBIT(_m[tile].m3, 6) ? TRACKDIR_BIT_MASK : 0;
hackykid@2008: 			} else {
hackykid@2008: 				// normal track
tron@2493: 				uint16 res = encrt_to_unavail[GB(_m[tile].m4, 4, 4)];
hackykid@2008: 				assert(res != 0xFFFF);
hackykid@2008: 				return res;
tron@2182: 			}
hackykid@2008: 		case MP_TUNNELBRIDGE:
tron@2493: 			return GB(_m[tile].m4, 0, 2) | (GB(_m[tile].m4, 0, 2) << 8);
hackykid@2008: 		case MP_STATION:
tron@2049: 			return HASBIT(_m[tile].m3, 6) ? TRACKDIR_BIT_MASK : 0;
hackykid@2008: 		case MP_STREET:
hackykid@2008: 			// make sure its a railroad crossing
hackykid@2008: 			if (!IsLevelCrossing(tile)) return 0;
hackykid@2008: 			// check if its reserved
tron@2049: 			return (HASBIT(_m[tile].m5, 0)) ? TRACKDIR_BIT_MASK : 0;
hackykid@2008: 		default:
hackykid@2008: 			return 0;
tron@2182: 	}
tron@2182: }
hackykid@2008: 
hackykid@2008: void PBSClearTrack(TileIndex tile, Track track) {
hackykid@2008: 	assert(IsValidTile(tile));
hackykid@2008: 	assert(track <= 5);
hackykid@2008: 	switch (GetTileType(tile)) {
hackykid@2008: 		case MP_RAILWAY:
tron@2049: 			if ((_m[tile].m5 & ~1) == 0xC4) {
hackykid@2008: 				// waypoint
tron@2049: 				CLRBIT(_m[tile].m3, 6);
hackykid@2008: 			} else {
hackykid@2008: 				// normal rail track
tron@2493: 				byte encrt = GB(_m[tile].m4, 4, 4);
hackykid@2008: 
hackykid@2008: 				if (encrt == track + 1)
hackykid@2008: 					encrt = 0;
hackykid@2008: 				else if (encrt == track + 1 + 8)
hackykid@2008: 					encrt = (track^1) + 1;
hackykid@2008: 				else if (encrt == (track^1) + 1 + 8)
hackykid@2008: 					encrt &= 7;
hackykid@2008: 
tron@2493: 				SB(_m[tile].m4, 4, 4, encrt);
hackykid@2008: 			}
hackykid@2008: 			break;
hackykid@2008: 		case MP_TUNNELBRIDGE:
tron@2049: 			_m[tile].m4 &= ~((1 << track) & 3);
hackykid@2008: 			break;
hackykid@2008: 		case MP_STATION:
tron@2049: 			CLRBIT(_m[tile].m3, 6);
hackykid@2008: 			break;
hackykid@2008: 		case MP_STREET:
hackykid@2008: 			// make sure it is a railroad crossing
hackykid@2008: 			if (!IsLevelCrossing(tile)) return;
tron@2049: 			CLRBIT(_m[tile].m5, 0);
hackykid@2008: 			break;
hackykid@2008: 		default:
hackykid@2008: 			return;
tron@2182: 	}
hackykid@2008: 	// if debugging, mark tile dirty to show reserved status
hackykid@2008: 	if (_debug_pbs_level >= 1)
hackykid@2008: 		MarkTileDirtyByTile(tile);
tron@2182: }
hackykid@2008: 
hackykid@2115: void PBSClearPath(TileIndex tile, Trackdir trackdir, TileIndex end_tile, Trackdir end_trackdir) {
hackykid@2008: 	uint16 res;
hackykid@2008: 	FindLengthOfTunnelResult flotr;
hackykid@2008: 	assert(IsValidTile(tile));
hackykid@2115: 	assert(IsValidTrackdir(trackdir));
hackykid@2115: 
hackykid@2008: 	do {
hackykid@2115: 		PBSClearTrack(tile, TrackdirToTrack(trackdir));
hackykid@2115: 
hackykid@2115: 		if (tile == end_tile && TrackdirToTrack(trackdir) == TrackdirToTrack(end_trackdir))
hackykid@2115: 			return;
hackykid@2008: 
tron@2493: 		if (IsTileType(tile, MP_TUNNELBRIDGE) &&
tron@2493: 				GB(_m[tile].m5, 4, 4) == 0 &&
tron@2493: 				GB(_m[tile].m5, 0, 2) == TrackdirToExitdir(trackdir)) {
hackykid@2008: 			// this is a tunnel
hackykid@2008: 			flotr = FindLengthOfTunnel(tile, TrackdirToExitdir(trackdir));
hackykid@2008: 
hackykid@2008: 			tile = flotr.tile;
hackykid@2008: 		} else {
hackykid@2008: 			byte exitdir = TrackdirToExitdir(trackdir);
hackykid@2008: 			tile = AddTileIndexDiffCWrap(tile, TileIndexDiffCByDir(exitdir));
tron@2182: 		}
hackykid@2008: 
hackykid@2008: 		res = PBSTileReserved(tile);
hackykid@2008: 		res |= res << 8;
hackykid@2008: 		res &= TrackdirReachesTrackdirs(trackdir);
hackykid@2008: 		trackdir = FindFirstBit2x64(res);
hackykid@2008: 
hackykid@2008: 	} while (res != 0);
tron@2182: }
hackykid@2008: 
hackykid@2008: bool PBSIsPbsSignal(TileIndex tile, Trackdir trackdir)
hackykid@2008: {
hackykid@2008: 	assert(IsValidTile(tile));
hackykid@2008: 	assert(IsValidTrackdir(trackdir));
hackykid@2008: 
hackykid@2008: 	if (!_patches.new_pathfinding_all)
hackykid@2008: 		return false;
hackykid@2008: 
hackykid@2008: 	if (!IsTileType(tile, MP_RAILWAY))
hackykid@2008: 		return false;
hackykid@2008: 
hackykid@2008: 	if (GetRailTileType(tile) != RAIL_TYPE_SIGNALS)
hackykid@2008: 		return false;
hackykid@2008: 
hackykid@2008: 	if (!HasSignalOnTrackdir(tile, trackdir))
hackykid@2008: 		return false;
hackykid@2008: 
hackykid@2008: 	if (GetSignalType(tile, TrackdirToTrack(trackdir)) == 4)
hackykid@2008: 		return true;
hackykid@2008: 	else
hackykid@2008: 		return false;
tron@2182: }
hackykid@2008: 
hackykid@2008: typedef struct SetSignalsDataPbs {
hackykid@2008: 	int cur;
hackykid@2008: 
hackykid@2008: 	// these are used to keep track of the signals.
hackykid@2008: 	byte bit[NUM_SSD_ENTRY];
hackykid@2008: 	TileIndex tile[NUM_SSD_ENTRY];
hackykid@2008: } SetSignalsDataPbs;
hackykid@2008: 
hackykid@2008: // This function stores the signals inside the SetSignalsDataPbs struct, passed as callback to FollowTrack() in the PBSIsPbsSegment() function below
hackykid@2008: static bool SetSignalsEnumProcPBS(uint tile, SetSignalsDataPbs *ssd, int trackdir, uint length, byte *state)
hackykid@2008: {
hackykid@2008: 	// the tile has signals?
hackykid@2008: 	if (IsTileType(tile, MP_RAILWAY)) {
hackykid@2008: 		if (HasSignalOnTrack(tile, TrackdirToTrack(trackdir))) {
hackykid@2008: 
hackykid@2008: 				if (ssd->cur != NUM_SSD_ENTRY) {
hackykid@2008: 					ssd->tile[ssd->cur] = tile; // remember the tile index
hackykid@2008: 					ssd->bit[ssd->cur] = TrackdirToTrack(trackdir); // and the controlling bit number
hackykid@2008: 					ssd->cur++;
hackykid@2008: 				}
hackykid@2008: 				return true;
hackykid@2008: 		} else if (IsTileDepotType(tile, TRANSPORT_RAIL))
hackykid@2008: 			return true; // don't look further if the tile is a depot
hackykid@2008: 	}
hackykid@2008: 	return false;
hackykid@2008: }
hackykid@2008: 
hackykid@2164: bool PBSIsPbsSegment(uint tile, Trackdir trackdir)
hackykid@2008: {
hackykid@2008: 	SetSignalsDataPbs ssd;
hackykid@2164: 	bool result = PBSIsPbsSignal(tile, trackdir);
hackykid@2164: 	DiagDirection direction = TrackdirToExitdir(trackdir);//GetDepotDirection(tile,TRANSPORT_RAIL);
hackykid@2008: 	int i;
hackykid@2008: 
hackykid@2008: 	ssd.cur = 0;
hackykid@2008: 
hackykid@2008: 	FollowTrack(tile, 0xC000 | TRANSPORT_RAIL, direction, (TPFEnumProc*)SetSignalsEnumProcPBS, NULL, &ssd);
hackykid@2008: 	for(i=0; i!=ssd.cur; i++) {
hackykid@2008: 		uint tile = ssd.tile[i];
hackykid@2008: 		byte bit = ssd.bit[i];
hackykid@2008: 		if (!PBSIsPbsSignal(tile, bit) && !PBSIsPbsSignal(tile, bit | 8))
hackykid@2008: 			return false;
hackykid@2008: 		result = true;
tron@2182: 	}
hackykid@2008: 
hackykid@2008: 	return result;
hackykid@2008: }