src/pathfind.cpp
branchcpp_gui
changeset 6303 84c215fc8eb8
parent 6298 c30fe89622df
child 6307 f40e88cff863
child 6719 4cc327ad39d5
--- a/src/pathfind.cpp	Mon Mar 26 21:31:37 2007 +0000
+++ b/src/pathfind.cpp	Mon Mar 26 22:15:38 2007 +0000
@@ -1,5 +1,7 @@
 /* $Id$ */
 
+/** @file pathfind.cpp */
+
 #include "stdafx.h"
 #include "openttd.h"
 #include "bridge_map.h"
@@ -15,7 +17,7 @@
 #include "variables.h"
 #include "depot.h"
 
-// remember which tiles we have already visited so we don't visit them again.
+/* remember which tiles we have already visited so we don't visit them again. */
 static bool TPFSetTileBit(TrackPathFinder *tpf, TileIndex tile, int dir)
 {
 	uint hash, val, offs;
@@ -65,7 +67,7 @@
 			tpf->hash_tile[hash] = PATHFIND_GET_LINK_OFFS(tpf, link);
 
 			link->flags = tpf->hash_head[hash];
-			tpf->hash_head[hash] = 0xFFFF; /* multi link */
+			tpf->hash_head[hash] = 0xFFFF; // multi link
 
 			link->next = 0xFFFF;
 		}
@@ -142,9 +144,9 @@
 
 	assert(tpf->tracktype == TRANSPORT_WATER);
 
-	// This addition will sometimes overflow by a single tile.
-	// The use of TILE_MASK here makes sure that we still point at a valid
-	// tile, and then this tile will be in the sentinel row/col, so GetTileTrackStatus will fail.
+	/* This addition will sometimes overflow by a single tile.
+	 * The use of TILE_MASK here makes sure that we still point at a valid
+	 * tile, and then this tile will be in the sentinel row/col, so GetTileTrackStatus will fail. */
 	tile = TILE_MASK(tile + TileOffsByDiagDir(direction));
 
 	if (++tpf->rd.cur_length > 50)
@@ -160,8 +162,8 @@
 	if ( (bits & (bits - 1)) == 0 ) {
 		/* only one direction */
 		i = 0;
-		while (!(bits&1))
-			i++, bits>>=1;
+		while (!(bits & 1))
+			i++, bits >>= 1;
 
 		rd = tpf->rd;
 		goto continue_here;
@@ -172,7 +174,7 @@
 		if (!(bits & 1)) continue;
 		rd = tpf->rd;
 
-		// Change direction 4 times only
+		/* Change direction 4 times only */
 		if ((byte)i != tpf->rd.pft_var6) {
 			if (++tpf->rd.depth > 4) {
 				tpf->rd = rd;
@@ -189,7 +191,7 @@
 		}
 
 		tpf->rd = rd;
-	} while (++i, bits>>=1);
+	} while (++i, bits >>= 1);
 
 }
 
@@ -284,7 +286,7 @@
 
 	/* Check in case of rail if the owner is the same */
 	if (tpf->tracktype == TRANSPORT_RAIL) {
-		// don't enter train depot from the back
+		/* don't enter train depot from the back */
 		if (IsTileDepotType(tile, TRANSPORT_RAIL) && GetRailDepotDirection(tile) == direction) return;
 
 		if (IsTileType(tile_org, MP_RAILWAY) || IsTileType(tile_org, MP_STATION) || IsTileType(tile_org, MP_TUNNELBRIDGE))
@@ -292,12 +294,12 @@
 				if (GetTileOwner(tile_org) != GetTileOwner(tile)) return;
 	}
 
-	// check if the new tile can be entered from that direction
+	/* check if the new tile can be entered from that direction */
 	if (tpf->tracktype == TRANSPORT_ROAD) {
-		// road stops and depots now have a track (r4419)
-		// don't enter road stop from the back
+		/* road stops and depots now have a track (r4419)
+		 * don't enter road stop from the back */
 		if (IsStandardRoadStopTile(tile) && ReverseDiagDir(GetRoadStopDir(tile)) != direction) return;
-		// don't enter road depot from the back
+		/* don't enter road depot from the back */
 		if (IsTileDepotType(tile, TRANSPORT_ROAD) && ReverseDiagDir(GetRoadDepotDirection(tile)) != direction) return;
 	}
 
@@ -323,7 +325,7 @@
 
 	if ((byte)bits != tpf->var2) {
 		bits &= _tpfmode1_and[direction];
-		bits = bits | (bits>>8);
+		bits = bits | (bits >> 8);
 	}
 	bits &= 0xBF;
 
@@ -333,7 +335,7 @@
 				i = FIND_FIRST_BIT(bits);
 				bits = KILL_FIRST_BIT(bits);
 
-				tpf->the_dir = (Trackdir)((_otherdir_mask[direction] & (byte)(1 << i)) ? (i+8) : i);
+				tpf->the_dir = (Trackdir)((_otherdir_mask[direction] & (byte)(1 << i)) ? (i + 8) : i);
 				rd = tpf->rd;
 
 				if (TPFSetTileBit(tpf, tile, tpf->the_dir) &&
@@ -375,7 +377,7 @@
 		i = FIND_FIRST_BIT(bits);
 		bits = KILL_FIRST_BIT(bits);
 
-		tpf->the_dir = (Trackdir)((_otherdir_mask[direction] & (byte)(1 << i)) ? (i+8) : i);
+		tpf->the_dir = (Trackdir)((_otherdir_mask[direction] & (byte)(1 << i)) ? (i + 8) : i);
 		rd = tpf->rd;
 		if (TPFSetTileBit(tpf, tile, tpf->the_dir) &&
 				!tpf->enum_proc(tile, tpf->userdata, tpf->the_dir, tpf->rd.cur_length, &tpf->rd.pft_var6) ) {
@@ -401,10 +403,10 @@
 	tpf.rd.depth = 0;
 	tpf.rd.pft_var6 = 0;
 
-	tpf.var2 = HASBIT(flags, 15) ? 0x43 : 0xFF; /* 0x8000 */
+	tpf.var2 = HASBIT(flags, 15) ? 0x43 : 0xFF; // 0x8000
 
-	tpf.disable_tile_hash = HASBIT(flags, 12);  /* 0x1000 */
-	tpf.hasbit_13         = HASBIT(flags, 13);  /* 0x2000 */
+	tpf.disable_tile_hash = HASBIT(flags, 12);  // 0x1000
+	tpf.hasbit_13         = HASBIT(flags, 13);  // 0x2000
 
 
 	tpf.tracktype = (TransportType)(flags & 0xFF);
@@ -425,8 +427,8 @@
 
 struct StackedItem {
 	TileIndex tile;
-	uint16 cur_length; // This is the current length to this tile.
-	uint16 priority; // This is the current length + estimated length to the goal.
+	uint16 cur_length; ///< This is the current length to this tile.
+	uint16 priority;   ///< This is the current length + estimated length to the goal.
 	TrackdirByte track;
 	byte depth;
 	byte state;
@@ -461,12 +463,12 @@
 	uint num_links_left;
 
 	uint nstack;
-	StackedItem stack[256]; // priority queue of stacked items
+	StackedItem stack[256];     ///< priority queue of stacked items
 
-	uint16 hash_head[0x400]; // hash heads. 0 means unused. 0xFFFC = length, 0x3 = dir
-	TileIndex hash_tile[0x400]; // tiles. or links.
+	uint16 hash_head[0x400];    ///< hash heads. 0 means unused. 0xFFFC = length, 0x3 = dir
+	TileIndex hash_tile[0x400]; ///< tiles. or links.
 
-	HashLink links[0x400]; // hash links
+	HashLink links[0x400];      ///< hash links
 
 };
 #define NTP_GET_LINK_OFFS(tpf, link) ((byte*)(link) - (byte*)tpf->links)
@@ -474,22 +476,22 @@
 
 #define ARR(i) tpf->stack[(i)-1]
 
-// called after a new element was added in the queue at the last index.
-// move it down to the proper position
+/** called after a new element was added in the queue at the last index.
+ * move it down to the proper position */
 static inline void HeapifyUp(NewTrackPathFinder *tpf)
 {
 	StackedItem si;
 	int i = ++tpf->nstack;
 
 	while (i != 1 && ARR(i).priority < ARR(i>>1).priority) {
-		// the child element is larger than the parent item.
-		// swap the child item and the parent item.
-		si = ARR(i); ARR(i) = ARR(i>>1); ARR(i>>1) = si;
-		i>>=1;
+		/* the child element is larger than the parent item.
+		 * swap the child item and the parent item. */
+		si = ARR(i); ARR(i) = ARR(i >> 1); ARR(i >> 1) = si;
+		i >>= 1;
 	}
 }
 
-// called after the element 0 was eaten. fill it with a new element
+/** called after the element 0 was eaten. fill it with a new element */
 static inline void HeapifyDown(NewTrackPathFinder *tpf)
 {
 	StackedItem si;
@@ -501,27 +503,27 @@
 
 	if (n == 0) return; // heap is empty so nothing to do?
 
-	// copy the last item to index 0. we use it as base for heapify.
-	ARR(1) = ARR(n+1);
+	/* copy the last item to index 0. we use it as base for heapify. */
+	ARR(1) = ARR(n + 1);
 
-	while ((j=i*2) <= n) {
-		// figure out which is smaller of the children.
-		if (j != n && ARR(j).priority > ARR(j+1).priority)
+	while ((j = i * 2) <= n) {
+		/* figure out which is smaller of the children. */
+		if (j != n && ARR(j).priority > ARR(j + 1).priority)
 			j++; // right item is smaller
 
 		assert(i <= n && j <= n);
 		if (ARR(i).priority <= ARR(j).priority)
 			break; // base elem smaller than smallest, done!
 
-		// swap parent with the child
+		/* swap parent with the child */
 		si = ARR(i); ARR(i) = ARR(j); ARR(j) = si;
 		i = j;
 	}
 }
 
-// mark a tile as visited and store the length of the path.
-// if we already had a better path to this tile, return false.
-// otherwise return true.
+/** mark a tile as visited and store the length of the path.
+ * if we already had a better path to this tile, return false.
+ * otherwise return true. */
 static bool NtpVisit(NewTrackPathFinder* tpf, TileIndex tile, DiagDirection dir, uint length)
 {
 	uint hash,head;
@@ -531,7 +533,7 @@
 
 	hash = PATHFIND_HASH_TILE(tile);
 
-	// never visited before?
+	/* never visited before? */
 	if ((head=tpf->hash_head[hash]) == 0) {
 		tpf->hash_tile[hash] = tile;
 		tpf->hash_head[hash] = dir | (length << 2);
@@ -541,15 +543,15 @@
 	if (head != 0xffff) {
 		if (tile == tpf->hash_tile[hash] && (head & 0x3) == (uint)dir) {
 
-			// longer length
+			/* longer length */
 			if (length >= (head >> 2)) return false;
 
 			tpf->hash_head[hash] = dir | (length << 2);
 			return true;
 		}
-		// two tiles with the same hash, need to make a link
-		// allocate a link. if out of links, handle this by returning
-		// that a tile was already visisted.
+		/* two tiles with the same hash, need to make a link
+		 * allocate a link. if out of links, handle this by returning
+		 * that a tile was already visisted. */
 		if (tpf->num_links_left == 0) {
 			DEBUG(ntp, 1, "No links left");
 			return false;
@@ -564,12 +566,12 @@
 		tpf->hash_tile[hash] = NTP_GET_LINK_OFFS(tpf, link);
 
 		link->typelength = tpf->hash_head[hash];
-		tpf->hash_head[hash] = 0xFFFF; /* multi link */
+		tpf->hash_head[hash] = 0xFFFF; // multi link
 		link->next = 0xFFFF;
 	} else {
-		// a linked list of many tiles,
-		// find the one corresponding to the tile, if it exists.
-		// otherwise make a new link
+		/* a linked list of many tiles,
+		 * find the one corresponding to the tile, if it exists.
+		 * otherwise make a new link */
 
 		uint offs = tpf->hash_tile[hash];
 		do {
@@ -623,7 +625,7 @@
 		return length == (head >> 2);
 	}
 
-	// else it's a linked list of many tiles
+	/* else it's a linked list of many tiles */
 	offs = tpf->hash_tile[hash];
 	for (;;) {
 		link = NTP_GET_LINK_PTR(tpf, offs);
@@ -638,21 +640,21 @@
 
 
 static const uint16 _is_upwards_slope[15] = {
-	0, // no tileh
-	(1 << TRACKDIR_X_SW) | (1 << TRACKDIR_Y_NW), // 1
-	(1 << TRACKDIR_X_SW) | (1 << TRACKDIR_Y_SE), // 2
-	(1 << TRACKDIR_X_SW), // 3
-	(1 << TRACKDIR_X_NE) | (1 << TRACKDIR_Y_SE), // 4
-	0, // 5
-	(1 << TRACKDIR_Y_SE), // 6
-	0, // 7
-	(1 << TRACKDIR_X_NE) | (1 << TRACKDIR_Y_NW), // 8,
-	(1 << TRACKDIR_Y_NW), // 9
-	0, //10
-	0, //11,
-	(1 << TRACKDIR_X_NE), //12
-	0, //13
-	0, //14
+	0,                                           ///< no tileh
+	(1 << TRACKDIR_X_SW) | (1 << TRACKDIR_Y_NW), ///< 1
+	(1 << TRACKDIR_X_SW) | (1 << TRACKDIR_Y_SE), ///< 2
+	(1 << TRACKDIR_X_SW),                        ///< 3
+	(1 << TRACKDIR_X_NE) | (1 << TRACKDIR_Y_SE), ///< 4
+	0,                                           ///< 5
+	(1 << TRACKDIR_Y_SE),                        ///< 6
+	0,                                           ///< 7
+	(1 << TRACKDIR_X_NE) | (1 << TRACKDIR_Y_NW), ///< 8,
+	(1 << TRACKDIR_Y_NW),                        ///< 9
+	0,                                           ///< 10
+	0,                                           ///< 11,
+	(1 << TRACKDIR_X_NE),                        ///< 12
+	0,                                           ///< 13
+	0,                                           ///< 14
 };
 
 static uint DistanceMoo(TileIndex t0, TileIndex t1)
@@ -660,27 +662,27 @@
 	const uint dx = delta(TileX(t0), TileX(t1));
 	const uint dy = delta(TileY(t0), TileY(t1));
 
-	const uint straightTracks = 2 * min(dx, dy); /* The number of straight (not full length) tracks */
+	const uint straightTracks = 2 * min(dx, dy); // The number of straight (not full length) tracks
 	/* OPTIMISATION:
 	 * Original: diagTracks = max(dx, dy) - min(dx,dy);
 	 * Proof:
 	 * (dx-dy) - straightTracks  == (min + max) - straightTracks = min + // max - 2 * min = max - min */
-	const uint diagTracks = dx + dy - straightTracks; /* The number of diagonal (full tile length) tracks. */
+	const uint diagTracks = dx + dy - straightTracks; // The number of diagonal (full tile length) tracks.
 
 	return diagTracks*DIAG_FACTOR + straightTracks*STR_FACTOR;
 }
 
-// These has to be small cause the max length of a track
-// is currently limited to 16384
+/* These has to be small cause the max length of a track
+ * is currently limited to 16384 */
 
 static const byte _length_of_track[16] = {
 	DIAG_FACTOR, DIAG_FACTOR, STR_FACTOR, STR_FACTOR, STR_FACTOR, STR_FACTOR, 0, 0,
 	DIAG_FACTOR, DIAG_FACTOR, STR_FACTOR, STR_FACTOR, STR_FACTOR, STR_FACTOR, 0, 0
 };
 
-// new more optimized pathfinder for trains...
-// Tile is the tile the train is at.
-// direction is the tile the train is moving towards.
+/* new more optimized pathfinder for trains...
+ * Tile is the tile the train is at.
+ * direction is the tile the train is moving towards. */
 
 static void NTPEnum(NewTrackPathFinder* tpf, TileIndex tile, DiagDirection direction)
 {
@@ -692,8 +694,8 @@
 
 
 
-	// Need to have a special case for the start.
-	// We shouldn't call the callback for the current tile.
+	/* Need to have a special case for the start.
+	 * We shouldn't call the callback for the current tile. */
 	si.cur_length = 1; // Need to start at 1 cause 0 is a reserved value.
 	si.depth = 0;
 	si.state = 0;
@@ -701,7 +703,7 @@
 	goto start_at;
 
 	for (;;) {
-		// Get the next item to search from from the priority queue
+		/* Get the next item to search from from the priority queue */
 		do {
 			if (tpf->nstack == 0)
 				return; // nothing left? then we're done!
@@ -709,10 +711,10 @@
 			tile = si.tile;
 
 			HeapifyDown(tpf);
-			// Make sure we havn't already visited this tile.
+			/* Make sure we havn't already visited this tile. */
 		} while (!NtpCheck(tpf, tile, _tpf_prev_direction[si.track], si.cur_length));
 
-		// Add the length of this track.
+		/* Add the length of this track. */
 		si.cur_length += _length_of_track[si.track];
 
 callback_and_continue:
@@ -723,8 +725,8 @@
 		direction = _tpf_new_direction[si.track];
 
 start_at:
-		// If the tile is the entry tile of a tunnel, and we're not going out of the tunnel,
-		//   need to find the exit of the tunnel.
+		/* If the tile is the entry tile of a tunnel, and we're not going out of the tunnel,
+		 *   need to find the exit of the tunnel. */
 		if (IsTileType(tile, MP_TUNNELBRIDGE)) {
 			if (IsTunnel(tile)) {
 				if (GetTunnelDirection(tile) != ReverseDiagDir(direction)) {
@@ -733,7 +735,7 @@
 					/* We are not just driving out of the tunnel */
 					if (GetTunnelDirection(tile) != direction ||
 							GetTunnelTransportType(tile) != tpf->tracktype) {
-						// We are not driving into the tunnel, or it is an invalid tunnel
+						/* We are not driving into the tunnel, or it is an invalid tunnel */
 						continue;
 					}
 					if (!HASBIT(tpf->railtypes, GetRailType(tile))) {
@@ -743,15 +745,15 @@
 					flotr = FindLengthOfTunnel(tile, direction);
 					si.cur_length += flotr.length * DIAG_FACTOR;
 					tile = flotr.tile;
-					// tile now points to the exit tile of the tunnel
+					/* tile now points to the exit tile of the tunnel */
 				}
 			} else {
 				TileIndex tile_end;
 				if (GetBridgeRampDirection(tile) != ReverseDiagDir(direction)) {
-					// We are not just leaving the bridge
+					/* We are not just leaving the bridge */
 					if (GetBridgeRampDirection(tile) != direction ||
 							GetBridgeTransportType(tile) != tpf->tracktype) {
-						// Not entering the bridge or not compatible
+						/* Not entering the bridge or not compatible */
 						continue;
 					}
 				}
@@ -761,29 +763,29 @@
 			}
 		}
 
-		// This is a special loop used to go through
-		// a rail net and find the first intersection
+		/* This is a special loop used to go through
+		 * a rail net and find the first intersection */
 		tile_org = tile;
 		for (;;) {
 			assert(direction <= 3);
 			tile += TileOffsByDiagDir(direction);
 
-			// too long search length? bail out.
+			/* too long search length? bail out. */
 			if (si.cur_length >= tpf->maxlength) {
 				DEBUG(ntp, 1, "Cur_length too big");
 				bits = TRACK_BIT_NONE;
 				break;
 			}
 
-			// Not a regular rail tile?
-			// Then we can't use the code below, but revert to more general code.
+			/* Not a regular rail tile?
+			 * Then we can't use the code below, but revert to more general code. */
 			if (!IsTileType(tile, MP_RAILWAY) || !IsPlainRailTile(tile)) {
-				// We found a tile which is not a normal railway tile.
-				// Determine which tracks that exist on this tile.
+				/* We found a tile which is not a normal railway tile.
+				 * Determine which tracks that exist on this tile. */
 				uint32 ts = GetTileTrackStatus(tile, TRANSPORT_RAIL) & _tpfmode1_and[direction];
 				bits = TrackdirBitsToTrackBits((TrackdirBits)(ts & TRACKDIR_BIT_MASK));
 
-				// Check that the tile contains exactly one track
+				/* Check that the tile contains exactly one track */
 				if (bits == 0 || KILL_FIRST_BIT(bits) != 0) break;
 
 				if (!HASBIT(tpf->railtypes, GetRailType(tile))) {
@@ -791,12 +793,12 @@
 					break;
 				}
 
-				///////////////////
-				// If we reach here, the tile has exactly one track.
-				//   tile - index to a tile that is not rail tile, but still straight (with optional signals)
-				//   bits - bitmask of which track that exist on the tile (exactly one bit is set)
-				//   direction - which direction are we moving in?
-				///////////////////
+				/*******************
+				 * If we reach here, the tile has exactly one track.
+				 *   tile - index to a tile that is not rail tile, but still straight (with optional signals)
+				 *   bits - bitmask of which track that exist on the tile (exactly one bit is set)
+				 *   direction - which direction are we moving in?
+				 *******************/
 				si.track = _new_trackdir[FIND_FIRST_BIT(bits)][direction];
 				si.cur_length += _length_of_track[si.track];
 				goto callback_and_continue;
@@ -825,89 +827,89 @@
 
 			si.cur_length += _length_of_track[track];
 
-			// Check if this rail is an upwards slope. If it is, then add a penalty.
-			// Small optimization here.. if (track&7)>1 then it can't be a slope so we avoid calling GetTileSlope
+			/* Check if this rail is an upwards slope. If it is, then add a penalty.
+			 * Small optimization here.. if (track&7)>1 then it can't be a slope so we avoid calling GetTileSlope */
 			if ((track & 7) <= 1 && (_is_upwards_slope[GetTileSlope(tile, NULL)] & (1 << track)) ) {
 				// upwards slope. add some penalty.
-				si.cur_length += 4*DIAG_FACTOR;
+				si.cur_length += 4 * DIAG_FACTOR;
 			}
 
-			// railway tile with signals..?
+			/* railway tile with signals..? */
 			if (HasSignals(tile)) {
 				if (!HasSignalOnTrackdir(tile, track)) {
-					// if one way signal not pointing towards us, stop going in this direction => End of rail segment.
+					/* if one way signal not pointing towards us, stop going in this direction => End of rail segment. */
 					if (HasSignalOnTrackdir(tile, ReverseTrackdir(track))) {
 						bits = TRACK_BIT_NONE;
 						break;
 					}
 				} else if (GetSignalStateByTrackdir(tile, track) == SIGNAL_STATE_GREEN) {
-					// green signal in our direction. either one way or two way.
+					/* green signal in our direction. either one way or two way. */
 					si.state |= 3;
 				} else {
-					// reached a red signal.
+					/* reached a red signal. */
 					if (HasSignalOnTrackdir(tile, ReverseTrackdir(track))) {
-						// two way red signal. unless we passed another green signal on the way,
-						// stop going in this direction => End of rail segment.
-						// this is to prevent us from going into a full platform.
-						if (!(si.state&1)) {
+						/* two way red signal. unless we passed another green signal on the way,
+						 * stop going in this direction => End of rail segment.
+						 * this is to prevent us from going into a full platform. */
+						if (!(si.state & 1)) {
 							bits = TRACK_BIT_NONE;
 							break;
 						}
 					}
 					if (!(si.state & 2)) {
-						// Is this the first signal we see? And it's red... add penalty
-						si.cur_length += 10*DIAG_FACTOR;
+						/* Is this the first signal we see? And it's red... add penalty */
+						si.cur_length += 10 * DIAG_FACTOR;
 						si.state += 2; // remember that we added penalty.
-						// Because we added a penalty, we can't just continue as usual.
-						// Need to get out and let A* do it's job with
-						// possibly finding an even shorter path.
+						/* Because we added a penalty, we can't just continue as usual.
+						 * Need to get out and let A* do it's job with
+						 * possibly finding an even shorter path. */
 						break;
 					}
 				}
 
 				if (tpf->enum_proc(tile, tpf->userdata, si.first_track, si.cur_length))
-					return; /* Don't process this tile any further */
+					return; // Don't process this tile any further
 			}
 
-			// continue with the next track
+			/* continue with the next track */
 			direction = _tpf_new_direction[track];
 
-			// safety check if we're running around chasing our tail... (infinite loop)
+			/* safety check if we're running around chasing our tail... (infinite loop) */
 			if (tile == tile_org) {
 				bits = TRACK_BIT_NONE;
 				break;
 			}
 		}
 
-		// There are no tracks to choose between.
-		// Stop searching in this direction
+		/* There are no tracks to choose between.
+		 * Stop searching in this direction */
 		if (bits == TRACK_BIT_NONE)
 			continue;
 
-		////////////////
-		// We got multiple tracks to choose between (intersection).
-		// Branch the search space into several branches.
-		////////////////
+		/****************
+		 * We got multiple tracks to choose between (intersection).
+		 * Branch the search space into several branches.
+		 ****************/
 
-		// Check if we've already visited this intersection.
-		// If we've already visited it with a better length, then
-		// there's no point in visiting it again.
+		/* Check if we've already visited this intersection.
+		 * If we've already visited it with a better length, then
+		 * there's no point in visiting it again. */
 		if (!NtpVisit(tpf, tile, direction, si.cur_length))
 			continue;
 
-		// Push all possible alternatives that we can reach from here
-		// onto the priority heap.
-		// 'bits' contains the tracks that we can choose between.
+		/* Push all possible alternatives that we can reach from here
+		 * onto the priority heap.
+		 * 'bits' contains the tracks that we can choose between. */
 
-		// First compute the estimated distance to the target.
-		// This is used to implement A*
+		/* First compute the estimated distance to the target.
+		 * This is used to implement A* */
 		estimation = 0;
 		if (tpf->dest != 0)
 			estimation = DistanceMoo(tile, tpf->dest);
 
 		si.depth++;
 		if (si.depth == 0)
-			continue; /* We overflowed our depth. No more searching in this direction. */
+			continue; // We overflowed our depth. No more searching in this direction.
 		si.tile = tile;
 		while (bits != TRACK_BIT_NONE) {
 			Track track = RemoveFirstTrack(&bits);
@@ -915,7 +917,7 @@
 			assert(si.track != 0xFF);
 			si.priority = si.cur_length + estimation;
 
-			// out of stack items, bail out?
+			/* out of stack items, bail out? */
 			if (tpf->nstack >= lengthof(tpf->stack)) {
 				DEBUG(ntp, 1, "Out of stack");
 				break;
@@ -925,9 +927,9 @@
 			HeapifyUp(tpf);
 		};
 
-		// If this is the first intersection, we need to fill the first_track member.
-		// so the code outside knows which path is better.
-		// also randomize the order in which we search through them.
+		/* If this is the first intersection, we need to fill the first_track member.
+		 * so the code outside knows which path is better.
+		 * also randomize the order in which we search through them. */
 		if (si.depth == 1) {
 			assert(tpf->nstack == 1 || tpf->nstack == 2 || tpf->nstack == 3);
 			if (tpf->nstack != 1) {
@@ -944,12 +946,12 @@
 			}
 		}
 
-		// Continue with the next from the queue...
+		/* Continue with the next from the queue... */
 	}
 }
 
 
-// new pathfinder for trains. better and faster.
+/** new pathfinder for trains. better and faster. */
 void NewTrainPathfind(TileIndex tile, TileIndex dest, RailTypeMask railtypes, DiagDirection direction, NTPEnumProc* enum_proc, void* data)
 {
 	NewTrackPathFinder tpf;