(svn r18364) -Codechange: move the pathfinders and their related files into a separate directory

src/pathfinder/npf/aystar.cpp

@@ -0,0 +1,306 @@
+/* $Id$ */
+
+/*
+ * 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 aystar.cpp Implementation of A*. */
+
+/*
+ * This file has the core function for AyStar
+ *  AyStar is a fast pathfinding routine and is used for things like
+ *  AI_pathfinding and Train_pathfinding.
+ *  For more information about AyStar (A* Algorithm), you can look at
+ *    http://en.wikipedia.org/wiki/A-star_search_algorithm
+ */
+
+/*
+ * Friendly reminder:
+ *  Call (AyStar).free() when you are done with Aystar. It reserves a lot of memory
+ *  And when not free'd, it can cause system-crashes.
+ * Also remember that when you stop an algorithm before it is finished, your
+ * should call clear() yourself!
+ */
+
+#include "../../stdafx.h"
+#include "../../core/alloc_func.hpp"
+#include "aystar.h"
+
+int _aystar_stats_open_size;
+int _aystar_stats_closed_size;
+
+/* This looks in the Hash if a node exists in ClosedList
+ *  If so, it returns the PathNode, else NULL */
+static PathNode *AyStarMain_ClosedList_IsInList(AyStar *aystar, const AyStarNode *node)
+{
+	return (PathNode*)Hash_Get(&aystar->ClosedListHash, node->tile, node->direction);
+}
+
+/* This adds a node to the ClosedList
+ *  It makes a copy of the data */
+static void AyStarMain_ClosedList_Add(AyStar *aystar, const PathNode *node)
+{
+	/* Add a node to the ClosedList */
+	PathNode *new_node = MallocT<PathNode>(1);
+	*new_node = *node;
+	Hash_Set(&aystar->ClosedListHash, node->node.tile, node->node.direction, new_node);
+}
+
+/* Checks if a node is in the OpenList
+ *   If so, it returns the OpenListNode, else NULL */
+static OpenListNode *AyStarMain_OpenList_IsInList(AyStar *aystar, const AyStarNode *node)
+{
+	return (OpenListNode*)Hash_Get(&aystar->OpenListHash, node->tile, node->direction);
+}
+
+/* Gets the best node from OpenList
+ *  returns the best node, or NULL of none is found
+ * Also it deletes the node from the OpenList */
+static OpenListNode *AyStarMain_OpenList_Pop(AyStar *aystar)
+{
+	/* Return the item the Queue returns.. the best next OpenList item. */
+	OpenListNode *res = (OpenListNode*)aystar->OpenListQueue.pop(&aystar->OpenListQueue);
+	if (res != NULL) {
+		Hash_Delete(&aystar->OpenListHash, res->path.node.tile, res->path.node.direction);
+	}
+
+	return res;
+}
+
+/* Adds a node to the OpenList
+ *  It makes a copy of node, and puts the pointer of parent in the struct */
+static void AyStarMain_OpenList_Add(AyStar *aystar, PathNode *parent, const AyStarNode *node, int f, int g)
+{
+	/* Add a new Node to the OpenList */
+	OpenListNode *new_node = MallocT<OpenListNode>(1);
+	new_node->g = g;
+	new_node->path.parent = parent;
+	new_node->path.node = *node;
+	Hash_Set(&aystar->OpenListHash, node->tile, node->direction, new_node);
+
+	/* Add it to the queue */
+	aystar->OpenListQueue.push(&aystar->OpenListQueue, new_node, f);
+}
+
+/*
+ * Checks one tile and calculate his f-value
+ *  return values:
+ * AYSTAR_DONE : indicates we are done
+ */
+static int AyStarMain_CheckTile(AyStar *aystar, AyStarNode *current, OpenListNode *parent)
+{
+	int new_f, new_g, new_h;
+	PathNode *closedlist_parent;
+	OpenListNode *check;
+
+	/* Check the new node against the ClosedList */
+	if (AyStarMain_ClosedList_IsInList(aystar, current) != NULL) return AYSTAR_DONE;
+
+	/* Calculate the G-value for this node */
+	new_g = aystar->CalculateG(aystar, current, parent);
+	/* If the value was INVALID_NODE, we don't do anything with this node */
+	if (new_g == AYSTAR_INVALID_NODE) return AYSTAR_DONE;
+
+	/* There should not be given any other error-code.. */
+	assert(new_g >= 0);
+	/* Add the parent g-value to the new g-value */
+	new_g += parent->g;
+	if (aystar->max_path_cost != 0 && (uint)new_g > aystar->max_path_cost) return AYSTAR_DONE;
+
+	/* Calculate the h-value */
+	new_h = aystar->CalculateH(aystar, current, parent);
+	/* There should not be given any error-code.. */
+	assert(new_h >= 0);
+
+	/* The f-value if g + h */
+	new_f = new_g + new_h;
+
+	/* Get the pointer to the parent in the ClosedList (the currentone is to a copy of the one in the OpenList) */
+	closedlist_parent = AyStarMain_ClosedList_IsInList(aystar, &parent->path.node);
+
+	/* Check if this item is already in the OpenList */
+	check = AyStarMain_OpenList_IsInList(aystar, current);
+	if (check != NULL) {
+		uint i;
+		/* Yes, check if this g value is lower.. */
+		if (new_g > check->g) return AYSTAR_DONE;
+		aystar->OpenListQueue.del(&aystar->OpenListQueue, check, 0);
+		/* It is lower, so change it to this item */
+		check->g = new_g;
+		check->path.parent = closedlist_parent;
+		/* Copy user data, will probably have changed */
+		for (i = 0; i < lengthof(current->user_data); i++) {
+			check->path.node.user_data[i] = current->user_data[i];
+		}
+		/* Readd him in the OpenListQueue */
+		aystar->OpenListQueue.push(&aystar->OpenListQueue, check, new_f);
+	} else {
+		/* A new node, add him to the OpenList */
+		AyStarMain_OpenList_Add(aystar, closedlist_parent, current, new_f, new_g);
+	}
+
+	return AYSTAR_DONE;
+}
+
+/*
+ * This function is the core of AyStar. It handles one item and checks
+ *  his neighbour items. If they are valid, they are added to be checked too.
+ *  return values:
+ *   AYSTAR_EMPTY_OPENLIST : indicates all items are tested, and no path
+ *    has been found.
+ *   AYSTAR_LIMIT_REACHED : Indicates that the max_nodes limit has been
+ *    reached.
+ *   AYSTAR_FOUND_END_NODE : indicates we found the end. Path_found now is true, and in path is the path found.
+ *   AYSTAR_STILL_BUSY : indicates we have done this tile, did not found the path yet, and have items left to try.
+ */
+static int AyStarMain_Loop(AyStar *aystar)
+{
+	int i, r;
+
+	/* Get the best node from OpenList */
+	OpenListNode *current = AyStarMain_OpenList_Pop(aystar);
+	/* If empty, drop an error */
+	if (current == NULL) return AYSTAR_EMPTY_OPENLIST;
+
+	/* Check for end node and if found, return that code */
+	if (aystar->EndNodeCheck(aystar, current) == AYSTAR_FOUND_END_NODE) {
+		if (aystar->FoundEndNode != NULL)
+			aystar->FoundEndNode(aystar, current);
+		free(current);
+		return AYSTAR_FOUND_END_NODE;
+	}
+
+	/* Add the node to the ClosedList */
+	AyStarMain_ClosedList_Add(aystar, &current->path);
+
+	/* Load the neighbours */
+	aystar->GetNeighbours(aystar, current);
+
+	/* Go through all neighbours */
+	for (i = 0; i < aystar->num_neighbours; i++) {
+		/* Check and add them to the OpenList if needed */
+		r = aystar->checktile(aystar, &aystar->neighbours[i], current);
+	}
+
+	/* Free the node */
+	free(current);
+
+	if (aystar->max_search_nodes != 0 && Hash_Size(&aystar->ClosedListHash) >= aystar->max_search_nodes) {
+		/* We've expanded enough nodes */
+		return AYSTAR_LIMIT_REACHED;
+	} else {
+		/* Return that we are still busy */
+		return AYSTAR_STILL_BUSY;
+	}
+}
+
+/*
+ * This function frees the memory it allocated
+ */
+static void AyStarMain_Free(AyStar *aystar)
+{
+	aystar->OpenListQueue.free(&aystar->OpenListQueue, false);
+	/* 2nd argument above is false, below is true, to free the values only
+	 * once */
+	delete_Hash(&aystar->OpenListHash, true);
+	delete_Hash(&aystar->ClosedListHash, true);
+#ifdef AYSTAR_DEBUG
+	printf("[AyStar] Memory free'd\n");
+#endif
+}
+
+/*
+ * This function make the memory go back to zero
+ *  This function should be called when you are using the same instance again.
+ */
+void AyStarMain_Clear(AyStar *aystar)
+{
+	/* Clean the Queue, but not the elements within. That will be done by
+	 * the hash. */
+	aystar->OpenListQueue.clear(&aystar->OpenListQueue, false);
+	/* Clean the hashes */
+	clear_Hash(&aystar->OpenListHash, true);
+	clear_Hash(&aystar->ClosedListHash, true);
+
+#ifdef AYSTAR_DEBUG
+	printf("[AyStar] Cleared AyStar\n");
+#endif
+}
+
+/*
+ * This is the function you call to run AyStar.
+ *  return values:
+ *   AYSTAR_FOUND_END_NODE : indicates we found an end node.
+ *   AYSTAR_NO_PATH : indicates that there was no path found.
+ *   AYSTAR_STILL_BUSY : indicates we have done some checked, that we did not found the path yet, and that we still have items left to try.
+ * When the algorithm is done (when the return value is not AYSTAR_STILL_BUSY)
+ * aystar->clear() is called. Note that when you stop the algorithm halfway,
+ * you should still call clear() yourself!
+ */
+int AyStarMain_Main(AyStar *aystar)
+{
+	int r, i = 0;
+	/* Loop through the OpenList
+	 *  Quit if result is no AYSTAR_STILL_BUSY or is more than loops_per_tick */
+	while ((r = aystar->loop(aystar)) == AYSTAR_STILL_BUSY && (aystar->loops_per_tick == 0 || ++i < aystar->loops_per_tick)) { }
+#ifdef AYSTAR_DEBUG
+	switch (r) {
+		case AYSTAR_FOUND_END_NODE: printf("[AyStar] Found path!\n"); break;
+		case AYSTAR_EMPTY_OPENLIST: printf("[AyStar] OpenList run dry, no path found\n"); break;
+		case AYSTAR_LIMIT_REACHED:  printf("[AyStar] Exceeded search_nodes, no path found\n"); break;
+		default: break;
+	}
+#endif
+	if (r != AYSTAR_STILL_BUSY) {
+		/* We're done, clean up */
+		_aystar_stats_open_size = aystar->OpenListHash.size;
+		_aystar_stats_closed_size = aystar->ClosedListHash.size;
+		aystar->clear(aystar);
+	}
+
+	switch (r) {
+		case AYSTAR_FOUND_END_NODE: return AYSTAR_FOUND_END_NODE;
+		case AYSTAR_EMPTY_OPENLIST:
+		case AYSTAR_LIMIT_REACHED:  return AYSTAR_NO_PATH;
+		default:                    return AYSTAR_STILL_BUSY;
+	}
+}
+
+/*
+ * Adds a node from where to start an algorithm. Multiple nodes can be added
+ * if wanted. You should make sure that clear() is called before adding nodes
+ * if the AyStar has been used before (though the normal main loop calls
+ * clear() automatically when the algorithm finishes
+ * g is the cost for starting with this node.
+ */
+static void AyStarMain_AddStartNode(AyStar *aystar, AyStarNode *start_node, uint g)
+{
+#ifdef AYSTAR_DEBUG
+	printf("[AyStar] Starting A* Algorithm from node (%d, %d, %d)\n",
+		TileX(start_node->tile), TileY(start_node->tile), start_node->direction);
+#endif
+	AyStarMain_OpenList_Add(aystar, NULL, start_node, 0, g);
+}
+
+void init_AyStar(AyStar *aystar, Hash_HashProc hash, uint num_buckets)
+{
+	/* Allocated the Hash for the OpenList and ClosedList */
+	init_Hash(&aystar->OpenListHash, hash, num_buckets);
+	init_Hash(&aystar->ClosedListHash, hash, num_buckets);
+
+	/* Set up our sorting queue
+	 *  BinaryHeap allocates a block of 1024 nodes
+	 *  When thatone gets full it reserves an otherone, till this number
+	 *  That is why it can stay this high */
+	init_BinaryHeap(&aystar->OpenListQueue, 102400);
+
+	aystar->addstart  = AyStarMain_AddStartNode;
+	aystar->main      = AyStarMain_Main;
+	aystar->loop      = AyStarMain_Loop;
+	aystar->free      = AyStarMain_Free;
+	aystar->clear     = AyStarMain_Clear;
+	aystar->checktile = AyStarMain_CheckTile;
+}

src/pathfinder/npf/aystar.h

@@ -0,0 +1,181 @@
+/* $Id$ */
+
+/*
+ * 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 aystar.h
+ * This file has the header for AyStar
+ *  AyStar is a fast pathfinding routine and is used for things like
+ *  AI_pathfinding and Train_pathfinding.
+ *  For more information about AyStar (A* Algorithm), you can look at
+ *   http://en.wikipedia.org/wiki/A-star_search_algorithm
+ */
+
+#ifndef AYSTAR_H
+#define AYSTAR_H
+
+#include "queue.h"
+#include "../../tile_type.h"
+#include "../../track_type.h"
+
+//#define AYSTAR_DEBUG
+enum {
+	AYSTAR_FOUND_END_NODE,
+	AYSTAR_EMPTY_OPENLIST,
+	AYSTAR_STILL_BUSY,
+	AYSTAR_NO_PATH,
+	AYSTAR_LIMIT_REACHED,
+	AYSTAR_DONE
+};
+
+enum{
+	AYSTAR_INVALID_NODE = -1,
+};
+
+struct AyStarNode {
+	TileIndex tile;
+	Trackdir direction;
+	uint user_data[2];
+};
+
+/* The resulting path has nodes looking like this. */
+struct PathNode {
+	AyStarNode node;
+	/* The parent of this item */
+	PathNode *parent;
+};
+
+/* For internal use only
+ * We do not save the h-value, because it is only needed to calculate the f-value.
+ *  h-value should _always_ be the distance left to the end-tile. */
+struct OpenListNode {
+	int g;
+	PathNode path;
+};
+
+struct AyStar;
+/*
+ * This function is called to check if the end-tile is found
+ *  return values can be:
+ *   AYSTAR_FOUND_END_NODE : indicates this is the end tile
+ *   AYSTAR_DONE : indicates this is not the end tile (or direction was wrong)
+ */
+/*
+ * The 2nd parameter should be OpenListNode, and NOT AyStarNode. AyStarNode is
+ * part of OpenListNode and so it could be accessed without any problems.
+ * The good part about OpenListNode is, and how AIs use it, that you can
+ * access the parent of the current node, and so check if you, for example
+ * don't try to enter the file tile with a 90-degree curve. So please, leave
+ * this an OpenListNode, it works just fine -- TrueLight
+ */
+typedef int32 AyStar_EndNodeCheck(AyStar *aystar, OpenListNode *current);
+
+/*
+ * This function is called to calculate the G-value for AyStar Algorithm.
+ *  return values can be:
+ *   AYSTAR_INVALID_NODE : indicates an item is not valid (e.g.: unwalkable)
+ *   Any value >= 0 : the g-value for this tile
+ */
+typedef int32 AyStar_CalculateG(AyStar *aystar, AyStarNode *current, OpenListNode *parent);
+
+/*
+ * This function is called to calculate the H-value for AyStar Algorithm.
+ *  Mostly, this must result the distance (Manhattan way) between the
+ *   current point and the end point
+ *  return values can be:
+ *   Any value >= 0 : the h-value for this tile
+ */
+typedef int32 AyStar_CalculateH(AyStar *aystar, AyStarNode *current, OpenListNode *parent);
+
+/*
+ * This function request the tiles around the current tile and put them in tiles_around
+ *  tiles_around is never resetted, so if you are not using directions, just leave it alone.
+ * Warning: never add more tiles_around than memory allocated for it.
+ */
+typedef void AyStar_GetNeighbours(AyStar *aystar, OpenListNode *current);
+
+/*
+ * If the End Node is found, this function is called.
+ *  It can do, for example, calculate the route and put that in an array
+ */
+typedef void AyStar_FoundEndNode(AyStar *aystar, OpenListNode *current);
+
+/* For internal use, see aystar.cpp */
+typedef void AyStar_AddStartNode(AyStar *aystar, AyStarNode *start_node, uint g);
+typedef int AyStar_Main(AyStar *aystar);
+typedef int AyStar_Loop(AyStar *aystar);
+typedef int AyStar_CheckTile(AyStar *aystar, AyStarNode *current, OpenListNode *parent);
+typedef void AyStar_Free(AyStar *aystar);
+typedef void AyStar_Clear(AyStar *aystar);
+
+struct AyStar {
+/* These fields should be filled before initting the AyStar, but not changed
+ * afterwards (except for user_data and user_path)! (free and init again to change them) */
+
+	/* These should point to the application specific routines that do the
+	 * actual work */
+	AyStar_CalculateG *CalculateG;
+	AyStar_CalculateH *CalculateH;
+	AyStar_GetNeighbours *GetNeighbours;
+	AyStar_EndNodeCheck *EndNodeCheck;
+	AyStar_FoundEndNode *FoundEndNode;
+
+	/* These are completely untouched by AyStar, they can be accesed by
+	 * the application specific routines to input and output data.
+	 * user_path should typically contain data about the resulting path
+	 * afterwards, user_target should typically contain information about
+	 * what where looking for, and user_data can contain just about
+	 * everything */
+	void *user_path;
+	void *user_target;
+	uint user_data[10];
+
+	/* How many loops are there called before AyStarMain_Main gives
+	 * control back to the caller. 0 = until done */
+	byte loops_per_tick;
+	/* If the g-value goes over this number, it stops searching
+	 *  0 = infinite */
+	uint max_path_cost;
+	/* The maximum amount of nodes that will be expanded, 0 = infinite */
+	uint max_search_nodes;
+
+	/* These should be filled with the neighbours of a tile by
+	 * GetNeighbours */
+	AyStarNode neighbours[12];
+	byte num_neighbours;
+
+	/* These will contain the methods for manipulating the AyStar. Only
+	 * main() should be called externally */
+	AyStar_AddStartNode *addstart;
+	AyStar_Main *main;
+	AyStar_Loop *loop;
+	AyStar_Free *free;
+	AyStar_Clear *clear;
+	AyStar_CheckTile *checktile;
+
+	/* These will contain the open and closed lists */
+
+	/* The actual closed list */
+	Hash ClosedListHash;
+	/* The open queue */
+	Queue OpenListQueue;
+	/* An extra hash to speed up the process of looking up an element in
+	 * the open list */
+	Hash OpenListHash;
+};
+
+
+int AyStarMain_Main(AyStar *aystar);
+void AyStarMain_Clear(AyStar *aystar);
+
+/* Initialize an AyStar. You should fill all appropriate fields before
+ * callling init_AyStar (see the declaration of AyStar for which fields are
+ * internal */
+void init_AyStar(AyStar *aystar, Hash_HashProc hash, uint num_buckets);
+
+
+#endif /* AYSTAR_H */

src/pathfinder/npf/npf.h

@@ -0,0 +1,151 @@
+/* $Id$ */
+
+/*
+ * 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 npf.h New A* pathfinder. */
+
+#ifndef NPF_H
+#define NPF_H
+
+#include "aystar.h"
+#include "../../station_type.h"
+#include "../../rail_type.h"
+#include "../../company_type.h"
+#include "../../vehicle_type.h"
+#include "../../tile_type.h"
+#include "../../track_type.h"
+#include "../../core/bitmath_func.hpp"
+#include "../../transport_type.h"
+
+/* mowing grass */
+enum {
+	NPF_HASH_BITS = 12, ///< The size of the hash used in pathfinding. Just changing this value should be sufficient to change the hash size. Should be an even value.
+	/* Do no change below values */
+	NPF_HASH_SIZE = 1 << NPF_HASH_BITS,
+	NPF_HASH_HALFBITS = NPF_HASH_BITS / 2,
+	NPF_HASH_HALFMASK = (1 << NPF_HASH_HALFBITS) - 1
+};
+
+/* For new pathfinding. Define here so it is globally available without having
+ * to include npf.h */
+enum {
+	NPF_TILE_LENGTH = 100
+};
+
+enum {
+	/** This penalty is the equivalent of "inifite", which means that paths that
+	 * get this penalty will be chosen, but only if there is no other route
+	 * without it. Be careful with not applying this penalty to often, or the
+	 * total path cost might overflow..
+	 * For now, this is just a Very Big Penalty, we might actually implement
+	 * this in a nicer way :-)
+	 */
+	NPF_INFINITE_PENALTY = 1000 * NPF_TILE_LENGTH
+};
+
+/* Meant to be stored in AyStar.targetdata */
+struct NPFFindStationOrTileData {
+	TileIndex dest_coords;   ///< An indication of where the station is, for heuristic purposes, or the target tile
+	StationID station_index; ///< station index we're heading for, or INVALID_STATION when we're heading for a tile
+	bool      reserve_path;  ///< Indicates whether the found path should be reserved
+	const Vehicle *v;        ///< The vehicle we are pathfinding for
+};
+
+/* Indices into AyStar.userdata[] */
+enum {
+	NPF_TYPE = 0,  ///< Contains a TransportTypes value
+	NPF_SUB_TYPE,  ///< Contains the sub transport type
+	NPF_OWNER,     ///< Contains an Owner value
+	NPF_RAILTYPES, ///< Contains a bitmask the compatible RailTypes of the engine when NPF_TYPE == TRANSPORT_RAIL. Unused otherwise.
+};
+
+/* Indices into AyStarNode.userdata[] */
+enum {
+	NPF_TRACKDIR_CHOICE = 0, ///< The trackdir chosen to get here
+	NPF_NODE_FLAGS,
+};
+
+/* Flags for AyStarNode.userdata[NPF_NODE_FLAGS]. Use NPFGetBit() and NPFGetBit() to use them. */
+enum NPFNodeFlag {
+	NPF_FLAG_SEEN_SIGNAL,       ///< Used to mark that a signal was seen on the way, for rail only
+	NPF_FLAG_2ND_SIGNAL,        ///< Used to mark that two signals were seen, rail only
+	NPF_FLAG_3RD_SIGNAL,        ///< Used to mark that three signals were seen, rail only
+	NPF_FLAG_REVERSE,           ///< Used to mark that this node was reached from the second start node, if applicable
+	NPF_FLAG_LAST_SIGNAL_RED,   ///< Used to mark that the last signal on this path was red
+	NPF_FLAG_IGNORE_START_TILE, ///< Used to mark that the start tile is invalid, and searching should start from the second tile on
+	NPF_FLAG_TARGET_RESERVED,   ///< Used to mark that the possible reservation target is already reserved
+	NPF_FLAG_IGNORE_RESERVED,   ///< Used to mark that reserved tiles should be considered impassable
+};
+
+/* Meant to be stored in AyStar.userpath */
+struct NPFFoundTargetData {
+	uint best_bird_dist;    ///< The best heuristic found. Is 0 if the target was found
+	uint best_path_dist;    ///< The shortest path. Is UINT_MAX if no path is found
+	Trackdir best_trackdir; ///< The trackdir that leads to the shortest path/closest birds dist
+	AyStarNode node;        ///< The node within the target the search led us to
+	bool res_okay;          ///< True if a path reservation could be made
+};
+
+/* These functions below are _not_ re-entrant, in favor of speed! */
+
+/* Will search from the given tile and direction, for a route to the given
+ * station for the given transport type. See the declaration of
+ * NPFFoundTargetData above for the meaning of the result. */
+NPFFoundTargetData NPFRouteToStationOrTile(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes);
+
+/* Will search as above, but with two start nodes, the second being the
+ * reverse. Look at the NPF_FLAG_REVERSE flag in the result node to see which
+ * direction was taken (NPFGetBit(result.node, NPF_FLAG_REVERSE)) */
+NPFFoundTargetData NPFRouteToStationOrTileTwoWay(TileIndex tile1, Trackdir trackdir1, bool ignore_start_tile1, TileIndex tile2, Trackdir trackdir2, bool ignore_start_tile2, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes);
+
+/* Will search a route to the closest depot. */
+
+/* Search using breadth first. Good for little track choice and inaccurate
+ * heuristic, such as railway/road.*/
+NPFFoundTargetData NPFRouteToDepotBreadthFirst(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, TransportType type, uint sub_type, Owner owner, RailTypes railtypes);
+/* Same as above but with two start nodes, the second being the reverse. Call
+ * NPFGetBit(result.node, NPF_FLAG_REVERSE) to see from which node the path
+ * orginated. All pathfs from the second node will have the given
+ * reverse_penalty applied (NPF_TILE_LENGTH is the equivalent of one full
+ * tile).
+ */
+NPFFoundTargetData NPFRouteToDepotBreadthFirstTwoWay(TileIndex tile1, Trackdir trackdir1, bool ignore_start_tile1, TileIndex tile2, Trackdir trackdir2, bool ignore_start_tile2, TransportType type, uint sub_type, Owner owner, RailTypes railtypes, uint reverse_penalty);
+/* Search by trying each depot in order of Manhattan Distance. Good for lots
+ * of choices and accurate heuristics, such as water. */
+NPFFoundTargetData NPFRouteToDepotTrialError(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, TransportType type, uint sub_type, Owner owner, RailTypes railtypes);
+
+/**
+ * Search for any safe tile using a breadth first search and try to reserve a path.
+ */
+NPFFoundTargetData NPFRouteToSafeTile(const struct Train *v, TileIndex tile, Trackdir trackdir, bool override_railtype);
+
+
+void NPFFillWithOrderData(NPFFindStationOrTileData *fstd, Vehicle *v, bool reserve_path = false);
+
+
+/*
+ * Functions to manipulate the various NPF related flags on an AyStarNode.
+ */
+
+/**
+ * Returns the current value of the given flag on the given AyStarNode.
+ */
+static inline bool NPFGetFlag(const AyStarNode *node, NPFNodeFlag flag)
+{
+	return HasBit(node->user_data[NPF_NODE_FLAGS], flag);
+}
+
+/**
+ * Sets the given flag on the given AyStarNode to the given value.
+ */
+static inline void NPFSetFlag(AyStarNode *node, NPFNodeFlag flag, bool value)
+{
+	SB(node->user_data[NPF_NODE_FLAGS], flag, 1, value);
+}
+
+#endif /* NPF_H */

src/pathfinder/npf/queue.cpp

@@ -0,0 +1,577 @@
+/* $Id$ */
+
+/*
+ * 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 queue.cpp Implementation of the Queue/Hash. */
+
+#include "../../stdafx.h"
+#include "../../core/alloc_func.hpp"
+#include "queue.h"
+
+
+/*
+ * Insertion Sorter
+ */
+
+static void InsSort_Clear(Queue *q, bool free_values)
+{
+	InsSortNode *node = q->data.inssort.first;
+	InsSortNode *prev;
+
+	while (node != NULL) {
+		if (free_values) free(node->item);
+		prev = node;
+		node = node->next;
+		free(prev);
+	}
+	q->data.inssort.first = NULL;
+}
+
+static void InsSort_Free(Queue *q, bool free_values)
+{
+	q->clear(q, free_values);
+}
+
+static bool InsSort_Push(Queue *q, void *item, int priority)
+{
+	InsSortNode *newnode = MallocT<InsSortNode>(1);
+
+	newnode->item = item;
+	newnode->priority = priority;
+	if (q->data.inssort.first == NULL ||
+			q->data.inssort.first->priority >= priority) {
+		newnode->next = q->data.inssort.first;
+		q->data.inssort.first = newnode;
+	} else {
+		InsSortNode *node = q->data.inssort.first;
+		while (node != NULL) {
+			if (node->next == NULL || node->next->priority >= priority) {
+				newnode->next = node->next;
+				node->next = newnode;
+				break;
+			}
+			node = node->next;
+		}
+	}
+	return true;
+}
+
+static void *InsSort_Pop(Queue *q)
+{
+	InsSortNode *node = q->data.inssort.first;
+	void *result;
+
+	if (node == NULL) return NULL;
+	result = node->item;
+	q->data.inssort.first = q->data.inssort.first->next;
+	assert(q->data.inssort.first == NULL || q->data.inssort.first->priority >= node->priority);
+	free(node);
+	return result;
+}
+
+static bool InsSort_Delete(Queue *q, void *item, int priority)
+{
+	return false;
+}
+
+void init_InsSort(Queue *q)
+{
+	q->push = InsSort_Push;
+	q->pop = InsSort_Pop;
+	q->del = InsSort_Delete;
+	q->clear = InsSort_Clear;
+	q->free = InsSort_Free;
+	q->data.inssort.first = NULL;
+}
+
+
+/*
+ * Binary Heap
+ * For information, see: http://www.policyalmanac.org/games/binaryHeaps.htm
+ */
+
+#define BINARY_HEAP_BLOCKSIZE (1 << BINARY_HEAP_BLOCKSIZE_BITS)
+#define BINARY_HEAP_BLOCKSIZE_MASK (BINARY_HEAP_BLOCKSIZE - 1)
+
+/* To make our life easy, we make the next define
+ *  Because Binary Heaps works with array from 1 to n,
+ *  and C with array from 0 to n-1, and we don't like typing
+ *  q->data.binaryheap.elements[i - 1] every time, we use this define. */
+#define BIN_HEAP_ARR(i) q->data.binaryheap.elements[((i) - 1) >> BINARY_HEAP_BLOCKSIZE_BITS][((i) - 1) & BINARY_HEAP_BLOCKSIZE_MASK]
+
+static void BinaryHeap_Clear(Queue *q, bool free_values)
+{
+	/* Free all items if needed and free all but the first blocks of memory */
+	uint i;
+	uint j;
+
+	for (i = 0; i < q->data.binaryheap.blocks; i++) {
+		if (q->data.binaryheap.elements[i] == NULL) {
+			/* No more allocated blocks */
+			break;
+		}
+		/* For every allocated block */
+		if (free_values) {
+			for (j = 0; j < (1 << BINARY_HEAP_BLOCKSIZE_BITS); j++) {
+				/* For every element in the block */
+				if ((q->data.binaryheap.size >> BINARY_HEAP_BLOCKSIZE_BITS) == i &&
+						(q->data.binaryheap.size & BINARY_HEAP_BLOCKSIZE_MASK) == j) {
+					break; // We're past the last element
+				}
+				free(q->data.binaryheap.elements[i][j].item);
+			}
+		}
+		if (i != 0) {
+			/* Leave the first block of memory alone */
+			free(q->data.binaryheap.elements[i]);
+			q->data.binaryheap.elements[i] = NULL;
+		}
+	}
+	q->data.binaryheap.size = 0;
+	q->data.binaryheap.blocks = 1;
+}
+
+static void BinaryHeap_Free(Queue *q, bool free_values)
+{
+	uint i;
+
+	q->clear(q, free_values);
+	for (i = 0; i < q->data.binaryheap.blocks; i++) {
+		if (q->data.binaryheap.elements[i] == NULL) break;
+		free(q->data.binaryheap.elements[i]);
+	}
+	free(q->data.binaryheap.elements);
+}
+
+static bool BinaryHeap_Push(Queue *q, void *item, int priority)
+{
+#ifdef QUEUE_DEBUG
+	printf("[BinaryHeap] Pushing an element. There are %d elements left\n", q->data.binaryheap.size);
+#endif
+
+	if (q->data.binaryheap.size == q->data.binaryheap.max_size) return false;
+	assert(q->data.binaryheap.size < q->data.binaryheap.max_size);
+
+	if (q->data.binaryheap.elements[q->data.binaryheap.size >> BINARY_HEAP_BLOCKSIZE_BITS] == NULL) {
+		/* The currently allocated blocks are full, allocate a new one */
+		assert((q->data.binaryheap.size & BINARY_HEAP_BLOCKSIZE_MASK) == 0);
+		q->data.binaryheap.elements[q->data.binaryheap.size >> BINARY_HEAP_BLOCKSIZE_BITS] = MallocT<BinaryHeapNode>(BINARY_HEAP_BLOCKSIZE);
+		q->data.binaryheap.blocks++;
+#ifdef QUEUE_DEBUG
+		printf("[BinaryHeap] Increasing size of elements to %d nodes\n", q->data.binaryheap.blocks *  BINARY_HEAP_BLOCKSIZE);
+#endif
+	}
+
+	/* Add the item at the end of the array */
+	BIN_HEAP_ARR(q->data.binaryheap.size + 1).priority = priority;
+	BIN_HEAP_ARR(q->data.binaryheap.size + 1).item = item;
+	q->data.binaryheap.size++;
+
+	/* Now we are going to check where it belongs. As long as the parent is
+	 * bigger, we switch with the parent */
+	{
+		BinaryHeapNode temp;
+		int i;
+		int j;
+
+		i = q->data.binaryheap.size;
+		while (i > 1) {
+			/* Get the parent of this object (divide by 2) */
+			j = i / 2;
+			/* Is the parent bigger then the current, switch them */
+			if (BIN_HEAP_ARR(i).priority <= BIN_HEAP_ARR(j).priority) {
+				temp = BIN_HEAP_ARR(j);
+				BIN_HEAP_ARR(j) = BIN_HEAP_ARR(i);
+				BIN_HEAP_ARR(i) = temp;
+				i = j;
+			} else {
+				/* It is not, we're done! */
+				break;
+			}
+		}
+	}
+
+	return true;
+}
+
+static bool BinaryHeap_Delete(Queue *q, void *item, int priority)
+{
+	uint i = 0;
+
+#ifdef QUEUE_DEBUG
+	printf("[BinaryHeap] Deleting an element. There are %d elements left\n", q->data.binaryheap.size);
+#endif
+
+	/* First, we try to find the item.. */
+	do {
+		if (BIN_HEAP_ARR(i + 1).item == item) break;
+		i++;
+	} while (i < q->data.binaryheap.size);
+	/* We did not find the item, so we return false */
+	if (i == q->data.binaryheap.size) return false;
+
+	/* Now we put the last item over the current item while decreasing the size of the elements */
+	q->data.binaryheap.size--;
+	BIN_HEAP_ARR(i + 1) = BIN_HEAP_ARR(q->data.binaryheap.size + 1);
+
+	/* Now the only thing we have to do, is resort it..
+	 * On place i there is the item to be sorted.. let's start there */
+	{
+		uint j;
+		BinaryHeapNode temp;
+		/* Because of the fact that Binary Heap uses array from 1 to n, we need to
+		 * increase i by 1
+		 */
+		i++;
+
+		for (;;) {
+			j = i;
+			/* Check if we have 2 childs */
+			if (2 * j + 1 <= q->data.binaryheap.size) {
+				/* Is this child smaller than the parent? */
+				if (BIN_HEAP_ARR(j).priority >= BIN_HEAP_ARR(2 * j).priority) i = 2 * j;
+				/* Yes, we _need_ to use i here, not j, because we want to have the smallest child
+				 *  This way we get that straight away! */
+				if (BIN_HEAP_ARR(i).priority >= BIN_HEAP_ARR(2 * j + 1).priority) i = 2 * j + 1;
+			/* Do we have one child? */
+			} else if (2 * j <= q->data.binaryheap.size) {
+				if (BIN_HEAP_ARR(j).priority >= BIN_HEAP_ARR(2 * j).priority) i = 2 * j;
+			}
+
+			/* One of our childs is smaller than we are, switch */
+			if (i != j) {
+				temp = BIN_HEAP_ARR(j);
+				BIN_HEAP_ARR(j) = BIN_HEAP_ARR(i);
+				BIN_HEAP_ARR(i) = temp;
+			} else {
+				/* None of our childs is smaller, so we stay here.. stop :) */
+				break;
+			}
+		}
+	}
+
+	return true;
+}
+
+static void *BinaryHeap_Pop(Queue *q)
+{
+	void *result;
+
+#ifdef QUEUE_DEBUG
+	printf("[BinaryHeap] Popping an element. There are %d elements left\n", q->data.binaryheap.size);
+#endif
+
+	if (q->data.binaryheap.size == 0) return NULL;
+
+	/* The best item is always on top, so give that as result */
+	result = BIN_HEAP_ARR(1).item;
+	/* And now we should get rid of this item... */
+	BinaryHeap_Delete(q, BIN_HEAP_ARR(1).item, BIN_HEAP_ARR(1).priority);
+
+	return result;
+}
+
+void init_BinaryHeap(Queue *q, uint max_size)
+{
+	assert(q != NULL);
+	q->push = BinaryHeap_Push;
+	q->pop = BinaryHeap_Pop;
+	q->del = BinaryHeap_Delete;
+	q->clear = BinaryHeap_Clear;
+	q->free = BinaryHeap_Free;
+	q->data.binaryheap.max_size = max_size;
+	q->data.binaryheap.size = 0;
+	/* We malloc memory in block of BINARY_HEAP_BLOCKSIZE
+	 *   It autosizes when it runs out of memory */
+	q->data.binaryheap.elements = CallocT<BinaryHeapNode*>((max_size - 1) / BINARY_HEAP_BLOCKSIZE + 1);
+	q->data.binaryheap.elements[0] = MallocT<BinaryHeapNode>(BINARY_HEAP_BLOCKSIZE);
+	q->data.binaryheap.blocks = 1;
+#ifdef QUEUE_DEBUG
+	printf("[BinaryHeap] Initial size of elements is %d nodes\n", BINARY_HEAP_BLOCKSIZE);
+#endif
+}
+
+/* Because we don't want anyone else to bother with our defines */
+#undef BIN_HEAP_ARR
+
+/*
+ * Hash
+ */
+
+void init_Hash(Hash *h, Hash_HashProc *hash, uint num_buckets)
+{
+	/* Allocate space for the Hash, the buckets and the bucket flags */
+	uint i;
+
+	assert(h != NULL);
+#ifdef HASH_DEBUG
+	debug("Allocated hash: %p", h);
+#endif
+	h->hash = hash;
+	h->size = 0;
+	h->num_buckets = num_buckets;
+	h->buckets = (HashNode*)MallocT<byte>(num_buckets * (sizeof(*h->buckets) + sizeof(*h->buckets_in_use)));
+#ifdef HASH_DEBUG
+	debug("Buckets = %p", h->buckets);
+#endif
+	h->buckets_in_use = (bool*)(h->buckets + num_buckets);
+	for (i = 0; i < num_buckets; i++) h->buckets_in_use[i] = false;
+}
+
+
+void delete_Hash(Hash *h, bool free_values)
+{
+	uint i;
+
+	/* Iterate all buckets */
+	for (i = 0; i < h->num_buckets; i++) {
+		if (h->buckets_in_use[i]) {
+			HashNode *node;
+
+			/* Free the first value */
+			if (free_values) free(h->buckets[i].value);
+			node = h->buckets[i].next;
+			while (node != NULL) {
+				HashNode *prev = node;
+
+				node = node->next;
+				/* Free the value */
+				if (free_values) free(prev->value);
+				/* Free the node */
+				free(prev);
+			}
+		}
+	}
+	free(h->buckets);
+	/* No need to free buckets_in_use, it is always allocated in one
+	 * malloc with buckets */
+#ifdef HASH_DEBUG
+	debug("Freeing Hash: %p", h);
+#endif
+}
+
+#ifdef HASH_STATS
+static void stat_Hash(const Hash *h)
+{
+	uint used_buckets = 0;
+	uint max_collision = 0;
+	uint max_usage = 0;
+	uint usage[200];
+	uint i;
+
+	for (i = 0; i < lengthof(usage); i++) usage[i] = 0;
+	for (i = 0; i < h->num_buckets; i++) {
+		uint collision = 0;
+		if (h->buckets_in_use[i]) {
+			const HashNode *node;
+
+			used_buckets++;
+			for (node = &h->buckets[i]; node != NULL; node = node->next) collision++;
+			if (collision > max_collision) max_collision = collision;
+		}
+		if (collision >= lengthof(usage)) collision = lengthof(usage) - 1;
+		usage[collision]++;
+		if (collision > 0 && usage[collision] >= max_usage) {
+			max_usage = usage[collision];
+		}
+	}
+	printf(
+		"---\n"
+		"Hash size: %d\n"
+		"Nodes used: %d\n"
+		"Non empty buckets: %d\n"
+		"Max collision: %d\n",
+		h->num_buckets, h->size, used_buckets, max_collision
+	);
+	printf("{ ");
+	for (i = 0; i <= max_collision; i++) {
+		if (usage[i] > 0) {
+			printf("%d:%d ", i, usage[i]);
+#if 0
+			if (i > 0) {
+				uint j;
+
+				for (j = 0; j < usage[i] * 160 / 800; j++) putchar('#');
+			}
+			printf("\n");
+#endif
+		}
+	}
+	printf ("}\n");
+}
+#endif
+
+void clear_Hash(Hash *h, bool free_values)
+{
+	uint i;
+
+#ifdef HASH_STATS
+	if (h->size > 2000) stat_Hash(h);
+#endif
+
+	/* Iterate all buckets */
+	for (i = 0; i < h->num_buckets; i++) {
+		if (h->buckets_in_use[i]) {
+			HashNode *node;
+
+			h->buckets_in_use[i] = false;
+			/* Free the first value */
+			if (free_values) free(h->buckets[i].value);
+			node = h->buckets[i].next;
+			while (node != NULL) {
+				HashNode *prev = node;
+
+				node = node->next;
+				if (free_values) free(prev->value);
+				free(prev);
+			}
+		}
+	}
+	h->size = 0;
+}
+
+/** Finds the node that that saves this key pair. If it is not
+ * found, returns NULL. If it is found, *prev is set to the
+ * node before the one found, or if the node found was the first in the bucket
+ * to NULL. If it is not found, *prev is set to the last HashNode in the
+ * bucket, or NULL if it is empty. prev can also be NULL, in which case it is
+ * not used for output.
+ */
+static HashNode *Hash_FindNode(const Hash *h, uint key1, uint key2, HashNode** prev_out)
+{
+	uint hash = h->hash(key1, key2);
+	HashNode *result = NULL;
+
+#ifdef HASH_DEBUG
+	debug("Looking for %u, %u", key1, key2);
+#endif
+	/* Check if the bucket is empty */
+	if (!h->buckets_in_use[hash]) {
+		if (prev_out != NULL) *prev_out = NULL;
+		result = NULL;
+	/* Check the first node specially */
+	} else if (h->buckets[hash].key1 == key1 && h->buckets[hash].key2 == key2) {
+		/* Save the value */
+		result = h->buckets + hash;
+		if (prev_out != NULL) *prev_out = NULL;
+#ifdef HASH_DEBUG
+		debug("Found in first node: %p", result);
+#endif
+	/* Check all other nodes */
+	} else {
+		HashNode *prev = h->buckets + hash;
+		HashNode *node;
+
+		for (node = prev->next; node != NULL; node = node->next) {
+			if (node->key1 == key1 && node->key2 == key2) {
+				/* Found it */
+				result = node;
+#ifdef HASH_DEBUG
+				debug("Found in other node: %p", result);
+#endif
+				break;
+			}
+			prev = node;
+		}
+		if (prev_out != NULL) *prev_out = prev;
+	}
+#ifdef HASH_DEBUG
+	if (result == NULL) debug("Not found");
+#endif
+	return result;
+}
+
+void *Hash_Delete(Hash *h, uint key1, uint key2)
+{
+	void *result;
+	HashNode *prev; // Used as output var for below function call
+	HashNode *node = Hash_FindNode(h, key1, key2, &prev);
+
+	if (node == NULL) {
+		/* not found */
+		result = NULL;
+	} else if (prev == NULL) {
+		/* It is in the first node, we can't free that one, so we free
+		 * the next one instead (if there is any)*/
+		/* Save the value */
+		result = node->value;
+		if (node->next != NULL) {
+			HashNode *next = node->next;
+			/* Copy the second to the first */
+			*node = *next;
+			/* Free the second */
+#ifndef NOFREE
+			free(next);
+#endif
+		} else {
+			/* This was the last in this bucket
+			 * Mark it as empty */
+			uint hash = h->hash(key1, key2);
+			h->buckets_in_use[hash] = false;
+		}
+	} else {
+		/* It is in another node
+		 * Save the value */
+		result = node->value;
+		/* Link previous and next nodes */
+		prev->next = node->next;
+		/* Free the node */
+#ifndef NOFREE
+		free(node);
+#endif
+	}
+	if (result != NULL) h->size--;
+	return result;
+}
+
+
+void *Hash_Set(Hash *h, uint key1, uint key2, void *value)
+{
+	HashNode *prev;
+	HashNode *node = Hash_FindNode(h, key1, key2, &prev);
+
+	if (node != NULL) {
+		/* Found it */
+		void *result = node->value;
+
+		node->value = value;
+		return result;
+	}
+	/* It is not yet present, let's add it */
+	if (prev == NULL) {
+		/* The bucket is still empty */
+		uint hash = h->hash(key1, key2);
+		h->buckets_in_use[hash] = true;
+		node = h->buckets + hash;
+	} else {
+		/* Add it after prev */
+		node = MallocT<HashNode>(1);
+		prev->next = node;
+	}
+	node->next = NULL;
+	node->key1 = key1;
+	node->key2 = key2;
+	node->value = value;
+	h->size++;
+	return NULL;
+}
+
+void *Hash_Get(const Hash *h, uint key1, uint key2)
+{
+	HashNode *node = Hash_FindNode(h, key1, key2, NULL);
+
+#ifdef HASH_DEBUG
+	debug("Found node: %p", node);
+#endif
+	return (node != NULL) ? node->value : NULL;
+}
+
+uint Hash_Size(const Hash *h)
+{
+	return h->size;
+}

src/pathfinder/npf/queue.h

@@ -0,0 +1,167 @@
+/* $Id$ */
+
+/*
+ * 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 queue.h Simple Queue/Hash implementations. */
+
+#ifndef QUEUE_H
+#define QUEUE_H
+
+//#define NOFREE
+//#define QUEUE_DEBUG
+//#define HASH_DEBUG
+//#define HASH_STATS
+
+
+struct Queue;
+typedef bool Queue_PushProc(Queue *q, void *item, int priority);
+typedef void *Queue_PopProc(Queue *q);
+typedef bool Queue_DeleteProc(Queue *q, void *item, int priority);
+typedef void Queue_ClearProc(Queue *q, bool free_values);
+typedef void Queue_FreeProc(Queue *q, bool free_values);
+
+struct InsSortNode {
+	void *item;
+	int priority;
+	InsSortNode *next;
+};
+
+struct BinaryHeapNode {
+	void *item;
+	int priority;
+};
+
+
+struct Queue{
+	/*
+	 * Pushes an element into the queue, at the appropriate place for the queue.
+	 * Requires the queue pointer to be of an appropriate type, of course.
+	 */
+	Queue_PushProc *push;
+	/*
+	 * Pops the first element from the queue. What exactly is the first element,
+	 * is defined by the exact type of queue.
+	 */
+	Queue_PopProc *pop;
+	/*
+	 * Deletes the item from the queue. priority should be specified if
+	 * known, which speeds up the deleting for some queue's. Should be -1
+	 * if not known.
+	 */
+	Queue_DeleteProc *del;
+
+	/* Clears the queue, by removing all values from it. It's state is
+	 * effectively reset. If free_items is true, each of the items cleared
+	 * in this way are free()'d.
+	 */
+	Queue_ClearProc *clear;
+	/* Frees the queue, by reclaiming all memory allocated by it. After
+	 * this it is no longer usable. If free_items is true, any remaining
+	 * items are free()'d too.
+	 */
+	Queue_FreeProc *free;
+
+	union {
+		struct {
+			InsSortNode *first;
+		} inssort;
+		struct {
+			uint max_size;
+			uint size;
+			uint blocks; ///< The amount of blocks for which space is reserved in elements
+			BinaryHeapNode **elements;
+		} binaryheap;
+	} data;
+};
+
+
+/**
+ * Insertion Sorter
+ */
+
+/* Initializes a inssort and allocates internal memory. There is no maximum
+ * size */
+void init_InsSort(Queue *q);
+
+
+/*
+ *  Binary Heap
+ *  For information, see:
+ *   http://www.policyalmanac.org/games/binaryHeaps.htm
+ */
+
+/* The amount of elements that will be malloc'd at a time */
+#define BINARY_HEAP_BLOCKSIZE_BITS 10
+
+/** Initializes a binary heap and allocates internal memory for maximum of
+ * max_size elements */
+void init_BinaryHeap(Queue *q, uint max_size);
+
+
+/*
+ * Hash
+ */
+struct HashNode {
+	uint key1;
+	uint key2;
+	void *value;
+	HashNode *next;
+};
+/**
+ * Generates a hash code from the given key pair. You should make sure that
+ * the resulting range is clearly defined.
+ */
+typedef uint Hash_HashProc(uint key1, uint key2);
+struct Hash {
+	/* The hash function used */
+	Hash_HashProc *hash;
+	/* The amount of items in the hash */
+	uint size;
+	/* The number of buckets allocated */
+	uint num_buckets;
+	/* A pointer to an array of num_buckets buckets. */
+	HashNode *buckets;
+	/* A pointer to an array of numbuckets booleans, which will be true if
+	 * there are any Nodes in the bucket */
+	bool *buckets_in_use;
+};
+
+/* Call these function to manipulate a hash */
+
+/** Deletes the value with the specified key pair from the hash and returns
+ * that value. Returns NULL when the value was not present. The value returned
+ * is _not_ free()'d! */
+void *Hash_Delete(Hash *h, uint key1, uint key2);
+/** Sets the value associated with the given key pair to the given value.
+ * Returns the old value if the value was replaced, NULL when it was not yet present. */
+void *Hash_Set(Hash *h, uint key1, uint key2, void *value);
+/** Gets the value associated with the given key pair, or NULL when it is not
+ * present. */
+void *Hash_Get(const Hash *h, uint key1, uint key2);
+
+/* Call these function to create/destroy a hash */
+
+/** Builds a new hash in an existing struct. Make sure that hash() always
+ * returns a hash less than num_buckets! Call delete_hash after use */
+void init_Hash(Hash *h, Hash_HashProc *hash, uint num_buckets);
+/**
+ * Deletes the hash and cleans up. Only cleans up memory allocated by new_Hash
+ * & friends. If free is true, it will call free() on all the values that
+ * are left in the hash.
+ */
+void delete_Hash(Hash *h, bool free_values);
+/**
+ * Cleans the hash, but keeps the memory allocated
+ */
+void clear_Hash(Hash *h, bool free_values);
+/**
+ * Gets the current size of the Hash
+ */
+uint Hash_Size(const Hash *h);
+
+#endif /* QUEUE_H */

src/pathfinder/opf/opf_ship.cpp

@@ -0,0 +1,107 @@
+/* $Id$ */
+
+/*
+ * 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 pathfind.cpp Implementation of the oldest supported pathfinder. */
+
+#include "../../stdafx.h"
+#include "../../debug.h"
+#include "../../tunnelbridge_map.h"
+#include "../../core/alloc_type.hpp"
+#include "../../tunnelbridge.h"
+#include "opf_ship.h"
+
+struct RememberData {
+	uint16 cur_length;
+	byte depth;
+	Track last_choosen_track;
+};
+
+struct TrackPathFinder {
+	TPFEnumProc *enum_proc;
+	void *userdata;
+	RememberData rd;
+	TrackdirByte the_dir;
+};
+
+static void TPFModeShip(TrackPathFinder *tpf, TileIndex tile, DiagDirection direction)
+{
+	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
+		/* wrong track type */
+		if (GetTunnelBridgeTransportType(tile) != TRANSPORT_WATER) return;
+
+		DiagDirection dir = GetTunnelBridgeDirection(tile);
+		/* entering tunnel / bridge? */
+		if (dir == direction) {
+			TileIndex endtile = GetOtherTunnelBridgeEnd(tile);
+
+			tpf->rd.cur_length += GetTunnelBridgeLength(tile, endtile) + 1;
+
+			tile = endtile;
+		} else {
+			/* leaving tunnel / bridge? */
+			if (ReverseDiagDir(dir) != direction) return;
+		}
+	}
+
+	/* 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)
+		return;
+
+	TrackBits bits = TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_WATER, 0)) & DiagdirReachesTracks(direction);
+	if (bits == TRACK_BIT_NONE) return;
+
+	assert(TileX(tile) != MapMaxX() && TileY(tile) != MapMaxY());
+
+	bool only_one_track = true;
+	do {
+		Track track = RemoveFirstTrack(&bits);
+		if (bits != TRACK_BIT_NONE) only_one_track = false;
+		RememberData rd = tpf->rd;
+
+		/* Change direction 4 times only */
+		if (!only_one_track && track != tpf->rd.last_choosen_track) {
+			if (++tpf->rd.depth > 4) {
+				tpf->rd = rd;
+				return;
+			}
+			tpf->rd.last_choosen_track = track;
+		}
+
+		tpf->the_dir = TrackEnterdirToTrackdir(track, direction);
+
+		if (!tpf->enum_proc(tile, tpf->userdata, tpf->the_dir, tpf->rd.cur_length)) {
+			TPFModeShip(tpf, tile, TrackdirToExitdir(tpf->the_dir));
+		}
+
+		tpf->rd = rd;
+	} while (bits != TRACK_BIT_NONE);
+
+}
+
+void OPFShipFollowTrack(TileIndex tile, DiagDirection direction, TPFEnumProc *enum_proc, void *data)
+{
+	assert(IsValidDiagDirection(direction));
+
+	SmallStackSafeStackAlloc<TrackPathFinder, 1> tpf;
+
+	/* initialize path finder variables */
+	tpf->userdata = data;
+	tpf->enum_proc = enum_proc;
+
+	tpf->rd.cur_length = 0;
+	tpf->rd.depth = 0;
+	tpf->rd.last_choosen_track = INVALID_TRACK;
+
+	tpf->enum_proc(tile, data, INVALID_TRACKDIR, 0);
+	TPFModeShip(tpf, tile, direction);
+}

src/pathfinder/opf/opf_ship.h

@@ -0,0 +1,21 @@
+/* $Id$ */
+
+/*
+ * 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 opf_ship.h Original pathfinder for ships; very simple. */
+
+#ifndef OPF_SHIP_H
+#define OPF_SHIP_H
+
+#include "../../direction_type.h"
+
+typedef bool TPFEnumProc(TileIndex tile, void *data, Trackdir trackdir, uint length);
+
+void OPFShipFollowTrack(TileIndex tile, DiagDirection direction, TPFEnumProc *enum_proc, void *data);
+
+#endif /* OPF_SHIP_H */

src/pathfinder/pathfinder_func.h

@@ -0,0 +1,49 @@
+/* $Id$ */
+
+/*
+ * 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 pathfinder_func.h General functions related to pathfinders. */
+
+#ifndef PATHFINDER_FUNC_H
+#define PATHFINDER_FUNC_H
+
+#include "../station_base.h"
+#include "../waypoint_base.h"
+
+/**
+ * Calculates the tile of given station that is closest to a given tile
+ * for this we assume the station is a rectangle,
+ * as defined by its tile are (st->train_station)
+ * @param station The station to calculate the distance to
+ * @param tile The tile from where to calculate the distance
+ * @return The closest station tile to the given tile.
+ */
+static inline TileIndex CalcClosestStationTile(StationID station, TileIndex tile)
+{
+	const BaseStation *st = BaseStation::Get(station);
+
+	/* If the rail station is (temporarily) not present, use the station sign to drive near the station */
+	if (st->train_station.tile == INVALID_TILE) return st->xy;
+
+	uint minx = TileX(st->train_station.tile);  // topmost corner of station
+	uint miny = TileY(st->train_station.tile);
+	uint maxx = minx + st->train_station.w - 1; // lowermost corner of station
+	uint maxy = miny + st->train_station.h - 1;
+
+	/* we are going the aim for the x coordinate of the closest corner
+	 * but if we are between those coordinates, we will aim for our own x coordinate */
+	uint x = ClampU(TileX(tile), minx, maxx);
+
+	/* same for y coordinate, see above comment */
+	uint y = ClampU(TileY(tile), miny, maxy);
+
+	/* return the tile of our target coordinates */
+	return TileXY(x, y);
+}
+
+#endif /* PATHFINDER_FUNC_H */

src/pathfinder/yapf/follow_track.hpp

@@ -0,0 +1,451 @@
+/* $Id$ */
+
+/*
+ * 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 "yapf.hpp"
+#include "../../depot_map.h"
+#include "../../roadveh.h"
+#include "../../train.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, IsRailTT() && railtype_override == INVALID_RAILTYPES ? Train::From(v)->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(RoadVehicle::From(m_veh)->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(), 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) {
+			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. */
+		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() && 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 */
+	FORCEINLINE 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 */
+	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 = 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) */
+	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 */

src/pathfinder/yapf/nodelist.hpp

@@ -0,0 +1,164 @@
+/* $Id$ */
+
+/*
+ * 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 nodelist.hpp List of nodes used for the A-star pathfinder. */
+
+#ifndef  NODELIST_HPP
+#define  NODELIST_HPP
+
+#include "../../misc/array.hpp"
+#include "../../misc/hashtable.hpp"
+#include "../../misc/binaryheap.hpp"
+
+/** Hash table based node list multi-container class.
+ *  Implements open list, closed list and priority queue for A-star
+ *  path finder. */
+template <class Titem_, int Thash_bits_open_, int Thash_bits_closed_>
+class CNodeList_HashTableT {
+public:
+	/** make Titem_ visible from outside of class */
+	typedef Titem_ Titem;
+	/** make Titem_::Key a property of HashTable */
+	typedef typename Titem_::Key Key;
+	/** type that we will use as item container */
+	typedef CArrayT<Titem_, 65536, 256> CItemArray;
+	/** how pointers to open nodes will be stored */
+	typedef CHashTableT<Titem_, Thash_bits_open_  > COpenList;
+	/** how pointers to closed nodes will be stored */
+	typedef CHashTableT<Titem_, Thash_bits_closed_> CClosedList;
+	/** how the priority queue will be managed */
+	typedef CBinaryHeapT<Titem_> CPriorityQueue;
+
+protected:
+	/** here we store full item data (Titem_) */
+	CItemArray            m_arr;
+	/** hash table of pointers to open item data */
+	COpenList             m_open;
+	/** hash table of pointers to closed item data */
+	CClosedList           m_closed;
+	/** priority queue of pointers to open item data */
+	CPriorityQueue        m_open_queue;
+	/** new open node under construction */
+	Titem                *m_new_node;
+public:
+	/** default constructor */
+	CNodeList_HashTableT()
+		: m_open_queue(204800)
+	{
+		m_new_node = NULL;
+	}
+
+	/** destructor */
+	~CNodeList_HashTableT()
+	{
+	}
+
+	/** return number of open nodes */
+	FORCEINLINE int OpenCount()
+	{
+		return m_open.Count();
+	}
+
+	/** return number of closed nodes */
+	FORCEINLINE int ClosedCount()
+	{
+		return m_closed.Count();
+	}
+
+	/** allocate new data item from m_arr */
+	FORCEINLINE Titem_ *CreateNewNode()
+	{
+		if (m_new_node == NULL) m_new_node = &m_arr.Add();
+		return m_new_node;
+	}
+
+	/** notify the nodelist, that we don't want to discard the given node */
+	FORCEINLINE void FoundBestNode(Titem_& item)
+	{
+		/* for now it is enough to invalidate m_new_node if it is our given node */
+		if (&item == m_new_node) {
+			m_new_node = NULL;
+		}
+		/* TODO: do we need to store best nodes found in some extra list/array? Probably not now. */
+	}
+
+	/** insert given item as open node (into m_open and m_open_queue) */
+	FORCEINLINE void InsertOpenNode(Titem_& item)
+	{
+		assert(m_closed.Find(item.GetKey()) == NULL);
+		m_open.Push(item);
+		/* TODO: check if m_open_queue is not full */
+		assert(!m_open_queue.IsFull());
+		m_open_queue.Push(item);
+		if (&item == m_new_node) {
+			m_new_node = NULL;
+		}
+	}
+
+	/** return the best open node */
+	FORCEINLINE Titem_ *GetBestOpenNode()
+	{
+		if (!m_open_queue.IsEmpty()) {
+			Titem_& item = m_open_queue.GetHead();
+			return &item;
+		}
+		return NULL;
+	}
+
+	/** remove and return the best open node */
+	FORCEINLINE Titem_ *PopBestOpenNode()
+	{
+		if (!m_open_queue.IsEmpty()) {
+			Titem_& item = m_open_queue.PopHead();
+			m_open.Pop(item);
+			return &item;
+		}
+		return NULL;
+	}
+
+	/** return the open node specified by a key or NULL if not found */
+	FORCEINLINE Titem_ *FindOpenNode(const Key& key)
+	{
+		Titem_ *item = m_open.Find(key);
+		return item;
+	}
+
+	/** remove and return the open node specified by a key */
+	FORCEINLINE Titem_& PopOpenNode(const Key& key)
+	{
+		Titem_& item = m_open.Pop(key);
+		int idxPop = m_open_queue.FindLinear(item);
+		m_open_queue.RemoveByIdx(idxPop);
+		return item;
+	}
+
+	/** close node */
+	FORCEINLINE void InsertClosedNode(Titem_& item)
+	{
+		assert(m_open.Find(item.GetKey()) == NULL);
+		m_closed.Push(item);
+	}
+
+	/** return the closed node specified by a key or NULL if not found */
+	FORCEINLINE Titem_ *FindClosedNode(const Key& key)
+	{
+		Titem_ *item = m_closed.Find(key);
+		return item;
+	}
+
+	FORCEINLINE int TotalCount() {return m_arr.Size();}
+	FORCEINLINE Titem_& ItemAt(int idx) {return m_arr[idx];}
+
+	template <class D> void Dump(D &dmp) const
+	{
+		dmp.WriteStructT("m_arr", &m_arr);
+	}
+};
+
+#endif /* NODELIST_HPP */

src/pathfinder/yapf/yapf.h

@@ -0,0 +1,119 @@
+/* $Id$ */
+
+/*
+ * 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 yapf.h Entry point for OpenTTD to YAPF. */
+
+#ifndef  YAPF_H
+#define  YAPF_H
+
+#include "../../debug.h"
+#include "../../depot_type.h"
+#include "../../direction_type.h"
+#include "../../station_type.h"
+#include "../../pbs.h"
+
+/** Finds the best path for given ship.
+ * @param v        the ship that needs to find a path
+ * @param tile     the tile to find the path from (should be next tile the ship is about to enter)
+ * @param enterdir diagonal direction which the ship will enter this new tile from
+ * @param tracks   available tracks on the new tile (to choose from)
+ * @return         the best trackdir for next turn or INVALID_TRACKDIR if the path could not be found
+ */
+Trackdir YapfChooseShipTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks);
+
+/** Finds the best path for given road vehicle.
+ * @param v        the RV that needs to find a path
+ * @param tile     the tile to find the path from (should be next tile the RV is about to enter)
+ * @param enterdir diagonal direction which the RV will enter this new tile from
+ * @return         the best trackdir for next turn or INVALID_TRACKDIR if the path could not be found
+ */
+Trackdir YapfChooseRoadTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir);
+
+/** Finds the best path for given train.
+ * @param v        the train that needs to find a path
+ * @param tile     the tile to find the path from (should be next tile the train is about to enter)
+ * @param enterdir diagonal direction which the RV will enter this new tile from
+ * @param tracks   available trackdirs on the new tile (to choose from)
+ * @param path_not_found [out] true is returned if no path can be found (returned Trackdir is only a 'guess')
+ * @param reserve_track indicates whether YAPF should try to reserve the found path
+ * @param target   [out] the target tile of the reservation, free is set to true if path was reserved
+ * @return         the best trackdir for next turn or INVALID_TRACKDIR if the path could not be found
+ */
+Trackdir YapfChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target);
+
+/** Used by RV multistop feature to find the nearest road stop that has a free slot.
+ * @param v      RV (its current tile will be the origin)
+ * @param tile   destination tile
+ * @return       distance from origin tile to the destination (number of road tiles) or UINT_MAX if path not found
+ */
+uint YapfRoadVehDistanceToTile(const Vehicle *v, TileIndex tile);
+
+/** Used to determinine the closest reachable compatible road stop for a given vehicle.
+ * @param v            vehicle that needs to go to the road stop
+ * @param station      the station the road stop must belong to
+ * @param stop_tile    receives the stop tile if a stop was found
+ * @return             true if stop was found.
+ */
+bool YapfFindNearestRoadVehicleCompatibleStop(const RoadVehicle *v, StationID station, TileIndex *stop_tile);
+
+/** Used when user sends road vehicle to the nearest depot or if road vehicle needs servicing.
+ * @param v            vehicle that needs to go to some depot
+ * @param max_distance max distance (number of track tiles) from the current vehicle position
+ *                     (used also as optimization - the pathfinder can stop path finding if max_distance
+ *                     was reached and no depot was seen)
+ * @param depot_tile   receives the depot tile if depot was found
+ * @return             true if depot was found.
+ */
+bool YapfFindNearestRoadDepot(const Vehicle *v, int max_distance, TileIndex *depot_tile);
+
+/** Used when user sends train to the nearest depot or if train needs servicing.
+ * @param v            train that needs to go to some depot
+ * @param max_distance max distance (number of track tiles) from the current train position
+ *                     (used also as optimization - the pathfinder can stop path finding if max_distance
+ *                     was reached and no depot was seen)
+ * @param reverse_penalty penalty that should be added for the path that requires reversing the train first
+ * @param depot_tile   receives the depot tile if depot was found
+ * @param reversed     receives true if train needs to reversed first
+ * @return             true if depot was found.
+ */
+bool YapfFindNearestRailDepotTwoWay(const Vehicle *v, int max_distance, int reverse_penalty, TileIndex *depot_tile, bool *reversed);
+
+/** Returns true if it is better to reverse the train before leaving station */
+bool YapfCheckReverseTrain(const Vehicle *v);
+
+/**
+ * Try to extend the reserved path of a train to the nearest safe tile.
+ *
+ * @param v    The train that needs to find a safe tile.
+ * @param tile Last tile of the current reserved path.
+ * @param td   Last trackdir of the current reserved path.
+ * @param override_railtype Should all physically compabtible railtypes be searched, even if the vehicle can't on them on it own?
+ * @return True if the path could be extended to a safe tile.
+ */
+bool YapfRailFindNearestSafeTile(const Vehicle *v, TileIndex tile, Trackdir td, bool override_railtype);
+
+/** Use this function to notify YAPF that track layout (or signal configuration) has change */
+void YapfNotifyTrackLayoutChange(TileIndex tile, Track track);
+
+/** performance measurement helpers */
+void *NpfBeginInterval();
+int NpfEndInterval(void *perf);
+
+
+extern int _aystar_stats_open_size;
+extern int _aystar_stats_closed_size;
+
+
+/** Base tile length units */
+enum {
+	YAPF_TILE_LENGTH = 100,
+	YAPF_TILE_CORNER_LENGTH = 71
+};
+
+#endif /* YAPF_H */

src/pathfinder/yapf/yapf.hpp

@@ -0,0 +1,129 @@
+/* $Id$ */
+
+/*
+ * 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 yapf.hpp Base includes/functions for YAPF. */
+
+#ifndef  YAPF_HPP
+#define  YAPF_HPP
+
+#include "../../openttd.h"
+#include "../../vehicle_base.h"
+#include "../../road_map.h"
+#include "../../tunnel_map.h"
+#include "../../bridge_map.h"
+#include "../../tunnelbridge_map.h"
+#include "../../bridge.h"
+#include "../../station_map.h"
+#include "../../tile_cmd.h"
+#include "../../landscape.h"
+#include "yapf.h"
+#include "../pathfinder_func.h"
+#include "../../waypoint_base.h"
+#include "../../debug.h"
+#include "../../settings_type.h"
+#include "../../tunnelbridge.h"
+
+extern uint64 ottd_rdtsc();
+
+#include <limits.h>
+#include <new>
+
+#if defined(_WIN32) || defined(_WIN64)
+#  include <windows.h>
+#else
+#  include <time.h>
+#endif
+
+struct CPerformanceTimer
+{
+	int64    m_start;
+	int64    m_acc;
+
+	CPerformanceTimer() : m_start(0), m_acc(0) {}
+
+	FORCEINLINE void Start()
+	{
+		m_start = QueryTime();
+	}
+
+	FORCEINLINE void Stop()
+	{
+		m_acc += QueryTime() - m_start;
+	}
+
+	FORCEINLINE int Get(int64 coef)
+	{
+		return (int)(m_acc * coef / QueryFrequency());
+	}
+
+	FORCEINLINE int64 QueryTime()
+	{
+		return ottd_rdtsc();
+	}
+
+	FORCEINLINE int64 QueryFrequency()
+	{
+		return ((int64)2200 * 1000000);
+	}
+};
+
+struct CPerfStartReal
+{
+	CPerformanceTimer *m_pperf;
+
+	FORCEINLINE CPerfStartReal(CPerformanceTimer& perf) : m_pperf(&perf)
+	{
+		if (m_pperf != NULL) m_pperf->Start();
+	}
+
+	FORCEINLINE ~CPerfStartReal()
+	{
+		Stop();
+	}
+
+	FORCEINLINE void Stop()
+	{
+		if (m_pperf != NULL) {
+			m_pperf->Stop();
+			m_pperf = NULL;
+		}
+	}
+};
+
+struct CPerfStartFake
+{
+	FORCEINLINE CPerfStartFake(CPerformanceTimer& perf) {}
+	FORCEINLINE ~CPerfStartFake() {}
+	FORCEINLINE void Stop() {}
+};
+
+typedef CPerfStartFake CPerfStart;
+
+
+//#undef FORCEINLINE
+//#define FORCEINLINE inline
+
+#include "../../misc/crc32.hpp"
+#include "../../misc/blob.hpp"
+#include "../../misc/str.hpp"
+#include "../../misc/fixedsizearray.hpp"
+#include "../../misc/array.hpp"
+#include "../../misc/hashtable.hpp"
+#include "../../misc/binaryheap.hpp"
+#include "../../misc/dbg_helpers.h"
+#include "nodelist.hpp"
+#include "follow_track.hpp"
+#include "yapf_base.hpp"
+#include "yapf_node.hpp"
+#include "yapf_common.hpp"
+#include "yapf_costbase.hpp"
+#include "yapf_costcache.hpp"
+
+
+#endif /* YAPF_HPP */

src/pathfinder/yapf/yapf_base.hpp

@@ -0,0 +1,361 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_base.hpp Base classes for YAPF. */
+
+#ifndef  YAPF_BASE_HPP
+#define  YAPF_BASE_HPP
+
+#include "../../debug.h"
+#include "../../settings_type.h"
+
+extern int _total_pf_time_us;
+
+/** CYapfBaseT - A-star type path finder base class.
+ *  Derive your own pathfinder from it. You must provide the following template argument:
+ *    Types      - used as collection of local types used in pathfinder
+ *
+ * Requirements for the Types struct:
+ *  ----------------------------------
+ *  The following types must be defined in the 'Types' argument:
+ *    - Types::Tpf - your pathfinder derived from CYapfBaseT
+ *    - Types::NodeList - open/closed node list (look at CNodeList_HashTableT)
+ *  NodeList needs to have defined local type Titem - defines the pathfinder node type.
+ *  Node needs to define local type Key - the node key in the collection ()
+ *
+ *  For node list you can use template class CNodeList_HashTableT, for which
+ *  you need to declare only your node type. Look at test_yapf.h for an example.
+ *
+ *
+ *  Requrements to your pathfinder class derived from CYapfBaseT:
+ *  -------------------------------------------------------------
+ *  Your pathfinder derived class needs to implement following methods:
+ *    FORCEINLINE void PfSetStartupNodes()
+ *    FORCEINLINE void PfFollowNode(Node& org)
+ *    FORCEINLINE bool PfCalcCost(Node& n)
+ *    FORCEINLINE bool PfCalcEstimate(Node& n)
+ *    FORCEINLINE bool PfDetectDestination(Node& n)
+ *
+ *  For more details about those methods, look at the end of CYapfBaseT
+ *  declaration. There are some examples. For another example look at
+ *  test_yapf.h (part or unittest project).
+ */
+template <class Types>
+class CYapfBaseT {
+public:
+	typedef typename Types::Tpf Tpf;           ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList NodeList; ///< our node list
+	typedef typename NodeList::Titem Node;     ///< this will be our node type
+	typedef typename Node::Key Key;            ///< key to hash tables
+
+
+	NodeList             m_nodes;              ///< node list multi-container
+protected:
+	Node                *m_pBestDestNode;      ///< pointer to the destination node found at last round
+	Node                *m_pBestIntermediateNode; ///< here should be node closest to the destination if path not found
+	const YAPFSettings  *m_settings;           ///< current settings (_settings_game.yapf)
+	int                  m_max_search_nodes;   ///< maximum number of nodes we are allowed to visit before we give up
+	const Vehicle       *m_veh;                ///< vehicle that we are trying to drive
+
+	int                  m_stats_cost_calcs;   ///< stats - how many node's costs were calculated
+	int                  m_stats_cache_hits;   ///< stats - how many node's costs were reused from cache
+
+public:
+	CPerformanceTimer    m_perf_cost;          ///< stats - total CPU time of this run
+	CPerformanceTimer    m_perf_slope_cost;    ///< stats - slope calculation CPU time
+	CPerformanceTimer    m_perf_ts_cost;       ///< stats - GetTrackStatus() CPU time
+	CPerformanceTimer    m_perf_other_cost;    ///< stats - other CPU time
+
+public:
+	int                  m_num_steps;          ///< this is there for debugging purposes (hope it doesn't hurt)
+
+public:
+	/** default constructor */
+	FORCEINLINE CYapfBaseT()
+		: m_pBestDestNode(NULL)
+		, m_pBestIntermediateNode(NULL)
+		, m_settings(&_settings_game.pf.yapf)
+		, m_max_search_nodes(PfGetSettings().max_search_nodes)
+		, m_veh(NULL)
+		, m_stats_cost_calcs(0)
+		, m_stats_cache_hits(0)
+		, m_num_steps(0)
+	{
+	}
+
+	/** default destructor */
+	~CYapfBaseT() {}
+
+protected:
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** return current settings (can be custom - company based - but later) */
+	FORCEINLINE const YAPFSettings& PfGetSettings() const
+	{
+		return *m_settings;
+	}
+
+	/** Main pathfinder routine:
+	 *   - set startup node(s)
+	 *   - main loop that stops if:
+	 *      - the destination was found
+	 *      - or the open list is empty (no route to destination).
+	 *      - or the maximum amount of loops reached - m_max_search_nodes (default = 10000)
+	 * @return true if the path was found */
+	inline bool FindPath(const Vehicle *v)
+	{
+		m_veh = v;
+
+#ifndef NO_DEBUG_MESSAGES
+		CPerformanceTimer perf;
+		perf.Start();
+#endif /* !NO_DEBUG_MESSAGES */
+
+		Yapf().PfSetStartupNodes();
+
+		while (true) {
+			m_num_steps++;
+			Node *n = m_nodes.GetBestOpenNode();
+			if (n == NULL) {
+				break;
+			}
+
+			/* if the best open node was worse than the best path found, we can finish */
+			if (m_pBestDestNode != NULL && m_pBestDestNode->GetCost() < n->GetCostEstimate()) {
+				break;
+			}
+
+			Yapf().PfFollowNode(*n);
+			if (m_max_search_nodes == 0 || m_nodes.ClosedCount() < m_max_search_nodes) {
+				m_nodes.PopOpenNode(n->GetKey());
+				m_nodes.InsertClosedNode(*n);
+			} else {
+				m_pBestDestNode = m_pBestIntermediateNode;
+				break;
+			}
+		}
+
+		bool bDestFound = (m_pBestDestNode != NULL) && (m_pBestDestNode != m_pBestIntermediateNode);
+
+#ifndef NO_DEBUG_MESSAGES
+		perf.Stop();
+		if (_debug_yapf_level >= 2) {
+			int t = perf.Get(1000000);
+			_total_pf_time_us += t;
+
+			if (_debug_yapf_level >= 3) {
+				UnitID veh_idx = (m_veh != NULL) ? m_veh->unitnumber : 0;
+				char ttc = Yapf().TransportTypeChar();
+				float cache_hit_ratio = (m_stats_cache_hits == 0) ? 0.0f : ((float)m_stats_cache_hits / (float)(m_stats_cache_hits + m_stats_cost_calcs) * 100.0f);
+				int cost = bDestFound ? m_pBestDestNode->m_cost : -1;
+				int dist = bDestFound ? m_pBestDestNode->m_estimate - m_pBestDestNode->m_cost : -1;
+
+				DEBUG(yapf, 3, "[YAPF%c]%c%4d- %d us - %d rounds - %d open - %d closed - CHR %4.1f%% - C %d D %d - c%d(sc%d, ts%d, o%d) -- ",
+					ttc, bDestFound ? '-' : '!', veh_idx, t, m_num_steps, m_nodes.OpenCount(), m_nodes.ClosedCount(),
+					cache_hit_ratio, cost, dist, m_perf_cost.Get(1000000), m_perf_slope_cost.Get(1000000),
+					m_perf_ts_cost.Get(1000000), m_perf_other_cost.Get(1000000)
+				);
+			}
+		}
+#endif /* !NO_DEBUG_MESSAGES */
+		return bDestFound;
+	}
+
+	/** If path was found return the best node that has reached the destination. Otherwise
+	 *  return the best visited node (which was nearest to the destination).
+	 */
+	FORCEINLINE Node *GetBestNode()
+	{
+		return (m_pBestDestNode != NULL) ? m_pBestDestNode : m_pBestIntermediateNode;
+	}
+
+	/** Calls NodeList::CreateNewNode() - allocates new node that can be filled and used
+	 *  as argument for AddStartupNode() or AddNewNode()
+	 */
+	FORCEINLINE Node& CreateNewNode()
+	{
+		Node& node = *m_nodes.CreateNewNode();
+		return node;
+	}
+
+	/** Add new node (created by CreateNewNode and filled with data) into open list */
+	FORCEINLINE void AddStartupNode(Node& n)
+	{
+		Yapf().PfNodeCacheFetch(n);
+		/* insert the new node only if it is not there */
+		if (m_nodes.FindOpenNode(n.m_key) == NULL) {
+			m_nodes.InsertOpenNode(n);
+		} else {
+			/* if we are here, it means that node is already there - how it is possible?
+			 *   probably the train is in the position that both its ends point to the same tile/exit-dir
+			 *   very unlikely, but it happened */
+		}
+	}
+
+	/** add multiple nodes - direct children of the given node */
+	FORCEINLINE void AddMultipleNodes(Node *parent, const TrackFollower &tf)
+	{
+		bool is_choice = (KillFirstBit(tf.m_new_td_bits) != TRACKDIR_BIT_NONE);
+		for (TrackdirBits rtds = tf.m_new_td_bits; rtds != TRACKDIR_BIT_NONE; rtds = KillFirstBit(rtds)) {
+			Trackdir td = (Trackdir)FindFirstBit2x64(rtds);
+			Node& n = Yapf().CreateNewNode();
+			n.Set(parent, tf.m_new_tile, td, is_choice);
+			Yapf().AddNewNode(n, tf);
+		}
+	}
+
+	/** AddNewNode() - called by Tderived::PfFollowNode() for each child node.
+	 *  Nodes are evaluated here and added into open list */
+	void AddNewNode(Node &n, const TrackFollower &tf)
+	{
+		/* evaluate the node */
+		bool bCached = Yapf().PfNodeCacheFetch(n);
+		if (!bCached) {
+			m_stats_cost_calcs++;
+		} else {
+			m_stats_cache_hits++;
+		}
+
+		bool bValid = Yapf().PfCalcCost(n, &tf);
+
+		if (bCached) {
+			Yapf().PfNodeCacheFlush(n);
+		}
+
+		if (bValid) bValid = Yapf().PfCalcEstimate(n);
+
+		/* have the cost or estimate callbacks marked this node as invalid? */
+		if (!bValid) return;
+
+		/* detect the destination */
+		bool bDestination = Yapf().PfDetectDestination(n);
+		if (bDestination) {
+			if (m_pBestDestNode == NULL || n < *m_pBestDestNode) {
+				m_pBestDestNode = &n;
+			}
+			m_nodes.FoundBestNode(n);
+			return;
+		}
+
+		if (m_max_search_nodes > 0 && (m_pBestIntermediateNode == NULL || (m_pBestIntermediateNode->GetCostEstimate() - m_pBestIntermediateNode->GetCost()) > (n.GetCostEstimate() - n.GetCost()))) {
+			m_pBestIntermediateNode = &n;
+		}
+
+		/* check new node against open list */
+		Node *openNode = m_nodes.FindOpenNode(n.GetKey());
+		if (openNode != NULL) {
+			/* another node exists with the same key in the open list
+			 * is it better than new one? */
+			if (n.GetCostEstimate() < openNode->GetCostEstimate()) {
+				/* update the old node by value from new one */
+				m_nodes.PopOpenNode(n.GetKey());
+				*openNode = n;
+				/* add the updated old node back to open list */
+				m_nodes.InsertOpenNode(*openNode);
+			}
+			return;
+		}
+
+		/* check new node against closed list */
+		Node *closedNode = m_nodes.FindClosedNode(n.GetKey());
+		if (closedNode != NULL) {
+			/* another node exists with the same key in the closed list
+			 * is it better than new one? */
+			int node_est = n.GetCostEstimate();
+			int closed_est = closedNode->GetCostEstimate();
+			if (node_est < closed_est) {
+				/* If this assert occurs, you have probably problem in
+				 * your Tderived::PfCalcCost() or Tderived::PfCalcEstimate().
+				 * The problem could be:
+				 *  - PfCalcEstimate() gives too large numbers
+				 *  - PfCalcCost() gives too small numbers
+				 *  - You have used negative cost penalty in some cases (cost bonus) */
+				NOT_REACHED();
+			}
+			return;
+		}
+		/* the new node is really new
+		 * add it to the open list */
+		m_nodes.InsertOpenNode(n);
+	}
+
+	const Vehicle * GetVehicle() const
+	{
+		return m_veh;
+	}
+
+	void DumpBase(DumpTarget &dmp) const
+	{
+		dmp.WriteStructT("m_nodes", &m_nodes);
+		dmp.WriteLine("m_num_steps = %d", m_num_steps);
+	}
+
+	/* methods that should be implemented at derived class Types::Tpf (derived from CYapfBaseT) */
+
+#if 0
+	/** Example: PfSetStartupNodes() - set source (origin) nodes */
+	FORCEINLINE void PfSetStartupNodes()
+	{
+		/* example: */
+		Node& n1 = *base::m_nodes.CreateNewNode();
+		.
+		. // setup node members here
+		.
+		base::m_nodes.InsertOpenNode(n1);
+	}
+
+	/** Example: PfFollowNode() - set following (child) nodes of the given node */
+	FORCEINLINE void PfFollowNode(Node& org)
+	{
+		for (each follower of node org) {
+			Node& n = *base::m_nodes.CreateNewNode();
+			.
+			. // setup node members here
+			.
+			n.m_parent   = &org; // set node's parent to allow back tracking
+			AddNewNode(n);
+		}
+	}
+
+	/** Example: PfCalcCost() - set path cost from origin to the given node */
+	FORCEINLINE bool PfCalcCost(Node& n)
+	{
+		/* evaluate last step cost */
+		int cost = ...;
+		/* set the node cost as sum of parent's cost and last step cost */
+		n.m_cost = n.m_parent->m_cost + cost;
+		return true; // true if node is valid follower (i.e. no obstacle was found)
+	}
+
+	/** Example: PfCalcEstimate() - set path cost estimate from origin to the target through given node */
+	FORCEINLINE bool PfCalcEstimate(Node& n)
+	{
+		/* evaluate the distance to our destination */
+		int distance = ...;
+		/* set estimate as sum of cost from origin + distance to the target */
+		n.m_estimate = n.m_cost + distance;
+		return true; // true if node is valid (i.e. not too far away :)
+	}
+
+	/** Example: PfDetectDestination() - return true if the given node is our destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		bool bDest = (n.m_key.m_x == m_x2) && (n.m_key.m_y == m_y2);
+		return bDest;
+	}
+#endif
+};
+
+#endif /* YAPF_BASE_HPP */

src/pathfinder/yapf/yapf_common.hpp

@@ -0,0 +1,194 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_common.hpp Commonly used classes for YAPF. */
+
+#ifndef  YAPF_COMMON_HPP
+#define  YAPF_COMMON_HPP
+
+/** YAPF origin provider base class - used when origin is one tile / multiple trackdirs */
+template <class Types>
+class CYapfOriginTileT
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+
+protected:
+	TileIndex    m_orgTile;                       ///< origin tile
+	TrackdirBits m_orgTrackdirs;                  ///< origin trackdir mask
+
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Set origin tile / trackdir mask */
+	void SetOrigin(TileIndex tile, TrackdirBits trackdirs)
+	{
+		m_orgTile = tile;
+		m_orgTrackdirs = trackdirs;
+	}
+
+	/** Called when YAPF needs to place origin nodes into open list */
+	void PfSetStartupNodes()
+	{
+		bool is_choice = (KillFirstBit(m_orgTrackdirs) != TRACKDIR_BIT_NONE);
+		for (TrackdirBits tdb = m_orgTrackdirs; tdb != TRACKDIR_BIT_NONE; tdb = KillFirstBit(tdb)) {
+			Trackdir td = (Trackdir)FindFirstBit2x64(tdb);
+			Node& n1 = Yapf().CreateNewNode();
+			n1.Set(NULL, m_orgTile, td, is_choice);
+			Yapf().AddStartupNode(n1);
+		}
+	}
+};
+
+/** YAPF origin provider base class - used when there are two tile/trackdir origins */
+template <class Types>
+class CYapfOriginTileTwoWayT
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+
+protected:
+	TileIndex   m_orgTile;                        ///< first origin tile
+	Trackdir    m_orgTd;                          ///< first origin trackdir
+	TileIndex   m_revTile;                        ///< second (reversed) origin tile
+	Trackdir    m_revTd;                          ///< second (reversed) origin trackdir
+	int         m_reverse_penalty;                ///< penalty to be added for using the reversed origin
+	bool        m_treat_first_red_two_way_signal_as_eol; ///< in some cases (leaving station) we need to handle first two-way signal differently
+
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** set origin (tiles, trackdirs, etc.) */
+	void SetOrigin(TileIndex tile, Trackdir td, TileIndex tiler = INVALID_TILE, Trackdir tdr = INVALID_TRACKDIR, int reverse_penalty = 0, bool treat_first_red_two_way_signal_as_eol = true)
+	{
+		m_orgTile = tile;
+		m_orgTd = td;
+		m_revTile = tiler;
+		m_revTd = tdr;
+		m_reverse_penalty = reverse_penalty;
+		m_treat_first_red_two_way_signal_as_eol = treat_first_red_two_way_signal_as_eol;
+	}
+
+	/** Called when YAPF needs to place origin nodes into open list */
+	void PfSetStartupNodes()
+	{
+		if (m_orgTile != INVALID_TILE && m_orgTd != INVALID_TRACKDIR) {
+			Node& n1 = Yapf().CreateNewNode();
+			n1.Set(NULL, m_orgTile, m_orgTd, false);
+			Yapf().AddStartupNode(n1);
+		}
+		if (m_revTile != INVALID_TILE && m_revTd != INVALID_TRACKDIR) {
+			Node& n2 = Yapf().CreateNewNode();
+			n2.Set(NULL, m_revTile, m_revTd, false);
+			n2.m_cost = m_reverse_penalty;
+			Yapf().AddStartupNode(n2);
+		}
+	}
+
+	/** return true if first two-way signal should be treated as dead end */
+	FORCEINLINE bool TreatFirstRedTwoWaySignalAsEOL()
+	{
+		return Yapf().PfGetSettings().rail_firstred_twoway_eol && m_treat_first_red_two_way_signal_as_eol;
+	}
+};
+
+/** YAPF destination provider base class - used when destination is single tile / multiple trackdirs */
+template <class Types>
+class CYapfDestinationTileT
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+
+protected:
+	TileIndex    m_destTile;                      ///< destination tile
+	TrackdirBits m_destTrackdirs;                 ///< destination trackdir mask
+
+public:
+	/** set the destination tile / more trackdirs */
+	void SetDestination(TileIndex tile, TrackdirBits trackdirs)
+	{
+		m_destTile = tile;
+		m_destTrackdirs = trackdirs;
+	}
+
+protected:
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		bool bDest = (n.m_key.m_tile == m_destTile) && ((m_destTrackdirs & TrackdirToTrackdirBits(n.GetTrackdir())) != TRACKDIR_BIT_NONE);
+		return bDest;
+	}
+
+	/** Called by YAPF to calculate cost estimate. Calculates distance to the destination
+	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate */
+	inline bool PfCalcEstimate(Node& n)
+	{
+		static const int dg_dir_to_x_offs[] = {-1, 0, 1, 0};
+		static const int dg_dir_to_y_offs[] = {0, 1, 0, -1};
+		if (PfDetectDestination(n)) {
+			n.m_estimate = n.m_cost;
+			return true;
+		}
+
+		TileIndex tile = n.GetTile();
+		DiagDirection exitdir = TrackdirToExitdir(n.GetTrackdir());
+		int x1 = 2 * TileX(tile) + dg_dir_to_x_offs[(int)exitdir];
+		int y1 = 2 * TileY(tile) + dg_dir_to_y_offs[(int)exitdir];
+		int x2 = 2 * TileX(m_destTile);
+		int y2 = 2 * TileY(m_destTile);
+		int dx = abs(x1 - x2);
+		int dy = abs(y1 - y2);
+		int dmin = min(dx, dy);
+		int dxy = abs(dx - dy);
+		int d = dmin * YAPF_TILE_CORNER_LENGTH + (dxy - 1) * (YAPF_TILE_LENGTH / 2);
+		n.m_estimate = n.m_cost + d;
+		assert(n.m_estimate >= n.m_parent->m_estimate);
+		return true;
+	}
+};
+
+/** YAPF template that uses Ttypes template argument to determine all YAPF
+ *  components (base classes) from which the actual YAPF is composed.
+ *  For example classes consult: CYapfRail_TypesT template and its instantiations:
+ *  CYapfRail1, CYapfRail2, CYapfRail3, CYapfAnyDepotRail1, CYapfAnyDepotRail2, CYapfAnyDepotRail3 */
+template <class Ttypes>
+class CYapfT
+	: public Ttypes::PfBase         ///< Instance of CYapfBaseT - main YAPF loop and support base class
+	, public Ttypes::PfCost         ///< Cost calculation provider base class
+	, public Ttypes::PfCache        ///< Segment cost cache provider
+	, public Ttypes::PfOrigin       ///< Origin (tile or two-tile origin)
+	, public Ttypes::PfDestination  ///< Destination detector and distance (estimate) calculation provider
+	, public Ttypes::PfFollow       ///< Node follower (stepping provider)
+{
+};
+
+
+
+#endif /* YAPF_COMMON_HPP */

src/pathfinder/yapf/yapf_costbase.hpp

@@ -0,0 +1,42 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_costbase.hpp Handling of cost determination. */
+
+#ifndef  YAPF_COSTBASE_HPP
+#define  YAPF_COSTBASE_HPP
+
+struct CYapfCostBase {
+	FORCEINLINE static bool stSlopeCost(TileIndex tile, Trackdir td)
+	{
+		if (IsDiagonalTrackdir(td)) {
+			if (IsBridgeTile(tile)) {
+				/* it is bridge ramp, check if we are entering the bridge */
+				if (GetTunnelBridgeDirection(tile) != TrackdirToExitdir(td)) return false; // no, we are leaving it, no penalty
+				/* we are entering the bridge */
+				Slope tile_slope = GetTileSlope(tile, NULL);
+				Axis axis = DiagDirToAxis(GetTunnelBridgeDirection(tile));
+				return !HasBridgeFlatRamp(tile_slope, axis);
+			} else {
+				/* not bridge ramp */
+				if (IsTunnelTile(tile)) return false; // tunnel entry/exit doesn't slope
+				Slope tile_slope = GetTileSlope(tile, NULL);
+				return IsUphillTrackdir(tile_slope, td); // slopes uphill => apply penalty
+			}
+		}
+		return false;
+	}
+};
+
+struct CostRailSettings {
+	/* look-ahead signal penalty */
+};
+
+
+#endif /* YAPF_COSTBASE_HPP */

src/pathfinder/yapf/yapf_costcache.hpp

@@ -0,0 +1,216 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_costcache.hpp Caching of segment costs. */
+
+#ifndef  YAPF_COSTCACHE_HPP
+#define  YAPF_COSTCACHE_HPP
+
+#include "../../date_func.h"
+
+/** CYapfSegmentCostCacheNoneT - the formal only yapf cost cache provider that implements
+ * PfNodeCacheFetch() and PfNodeCacheFlush() callbacks. Used when nodes don't have CachedData
+ * defined (they don't count with any segment cost caching).
+ */
+template <class Types>
+class CYapfSegmentCostCacheNoneT
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+
+	/** Called by YAPF to attach cached or local segment cost data to the given node.
+	 *  @return true if globally cached data were used or false if local data was used */
+	FORCEINLINE bool PfNodeCacheFetch(Node& n)
+	{
+		return false;
+	}
+
+	/** Called by YAPF to flush the cached segment cost data back into cache storage.
+	 *  Current cache implementation doesn't use that. */
+	FORCEINLINE void PfNodeCacheFlush(Node& n)
+	{
+	}
+};
+
+
+/** CYapfSegmentCostCacheLocalT - the yapf cost cache provider that implements fake segment
+ * cost caching functionality for yapf. Used when node needs caching, but you don't want to
+ * cache the segment costs.
+ */
+template <class Types>
+class CYapfSegmentCostCacheLocalT
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+	typedef typename Node::CachedData CachedData;
+	typedef typename CachedData::Key CacheKey;
+	typedef CArrayT<CachedData> LocalCache;
+
+protected:
+	LocalCache      m_local_cache;
+
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to attach cached or local segment cost data to the given node.
+	 *  @return true if globally cached data were used or false if local data was used */
+	FORCEINLINE bool PfNodeCacheFetch(Node& n)
+	{
+		CacheKey key(n.GetKey());
+		Yapf().ConnectNodeToCachedData(n, *new (&m_local_cache.AddNC()) CachedData(key));
+		return false;
+	}
+
+	/** Called by YAPF to flush the cached segment cost data back into cache storage.
+	 *  Current cache implementation doesn't use that. */
+	FORCEINLINE void PfNodeCacheFlush(Node& n)
+	{
+	}
+};
+
+
+/** Base class for segment cost cache providers. Contains global counter
+ *  of track layout changes and static notification function called whenever
+ *  the track layout changes. It is implemented as base class because it needs
+ *  to be shared between all rail YAPF types (one shared counter, one notification
+ *  function. */
+struct CSegmentCostCacheBase
+{
+	static int   s_rail_change_counter;
+
+	static void NotifyTrackLayoutChange(TileIndex tile, Track track)
+	{
+		s_rail_change_counter++;
+	}
+};
+
+
+/** CSegmentCostCacheT - template class providing hash-map and storage (heap)
+ *  of Tsegment structures. Each rail node contains pointer to the segment
+ *  that contains cached (or non-cached) segment cost information. Nodes can
+ *  differ by key type, but they use the same segment type. Segment key should
+ *  be always the same (TileIndex + DiagDirection) that represent the beginning
+ *  of the segment (origin tile and exit-dir from this tile).
+ *  Different CYapfCachedCostT types can share the same type of CSegmentCostCacheT.
+ *  Look at CYapfRailSegment (yapf_node_rail.hpp) for the segment example */
+template <class Tsegment>
+struct CSegmentCostCacheT
+	: public CSegmentCostCacheBase
+{
+	enum {c_hash_bits = 14};
+
+	typedef CHashTableT<Tsegment, c_hash_bits> HashTable;
+	typedef CArrayT<Tsegment> Heap;
+	typedef typename Tsegment::Key Key;    ///< key to hash table
+
+	HashTable    m_map;
+	Heap         m_heap;
+
+	FORCEINLINE CSegmentCostCacheT() {}
+
+	/** flush (clear) the cache */
+	FORCEINLINE void Flush()
+	{
+		m_map.Clear();
+		m_heap.Clear();
+	}
+
+	FORCEINLINE Tsegment& Get(Key& key, bool *found)
+	{
+		Tsegment *item = m_map.Find(key);
+		if (item == NULL) {
+			*found = false;
+			item = new (&m_heap.AddNC()) Tsegment(key);
+			m_map.Push(*item);
+		} else {
+			*found = true;
+		}
+		return *item;
+	}
+};
+
+/** CYapfSegmentCostCacheGlobalT - the yapf cost cache provider that adds the segment cost
+ *  caching functionality to yapf. Using this class as base of your will provide the global
+ *  segment cost caching services for your Nodes.
+ */
+template <class Types>
+class CYapfSegmentCostCacheGlobalT
+	: public CYapfSegmentCostCacheLocalT<Types>
+{
+public:
+	typedef CYapfSegmentCostCacheLocalT<Types> Tlocal;
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;    ///< key to hash tables
+	typedef typename Node::CachedData CachedData;
+	typedef typename CachedData::Key CacheKey;
+	typedef CSegmentCostCacheT<CachedData> Cache;
+
+protected:
+	Cache&      m_global_cache;
+
+	FORCEINLINE CYapfSegmentCostCacheGlobalT() : m_global_cache(stGetGlobalCache()) {};
+
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+	FORCEINLINE static Cache& stGetGlobalCache()
+	{
+		static int last_rail_change_counter = 0;
+		static Date last_date = 0;
+		static Cache C;
+
+		/* some statistics */
+		if (last_date != _date) {
+			last_date = _date;
+			DEBUG(yapf, 2, "Pf time today: %5d ms", _total_pf_time_us / 1000);
+			_total_pf_time_us = 0;
+		}
+
+		/* delete the cache sometimes... */
+		if (last_rail_change_counter != Cache::s_rail_change_counter) {
+			last_rail_change_counter = Cache::s_rail_change_counter;
+			C.Flush();
+		}
+		return C;
+	}
+
+public:
+	/** Called by YAPF to attach cached or local segment cost data to the given node.
+	 *  @return true if globally cached data were used or false if local data was used */
+	FORCEINLINE bool PfNodeCacheFetch(Node& n)
+	{
+		if (!Yapf().CanUseGlobalCache(n)) {
+			return Tlocal::PfNodeCacheFetch(n);
+		}
+		CacheKey key(n.GetKey());
+		bool found;
+		CachedData& item = m_global_cache.Get(key, &found);
+		Yapf().ConnectNodeToCachedData(n, item);
+		return found;
+	}
+
+	/** Called by YAPF to flush the cached segment cost data back into cache storage.
+	 *  Current cache implementation doesn't use that. */
+	FORCEINLINE void PfNodeCacheFlush(Node& n)
+	{
+	}
+};
+
+#endif /* YAPF_COSTCACHE_HPP */

src/pathfinder/yapf/yapf_costrail.hpp

@@ -0,0 +1,591 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_costrail.hpp Cost determination for rails. */
+
+#ifndef  YAPF_COSTRAIL_HPP
+#define  YAPF_COSTRAIL_HPP
+
+#include "../../pbs.h"
+
+template <class Types>
+class CYapfCostRailT
+	: public CYapfCostBase
+	, public CostRailSettings
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+	typedef typename Node::CachedData CachedData;
+
+protected:
+
+	/* Structure used inside PfCalcCost() to keep basic tile information. */
+	struct TILE {
+		TileIndex   tile;
+		Trackdir    td;
+		TileType    tile_type;
+		RailType    rail_type;
+
+		TILE()
+		{
+			tile = INVALID_TILE;
+			td = INVALID_TRACKDIR;
+			tile_type = MP_VOID;
+			rail_type = INVALID_RAILTYPE;
+		}
+
+		TILE(TileIndex tile, Trackdir td)
+		{
+			this->tile = tile;
+			this->td = td;
+			this->tile_type = GetTileType(tile);
+			this->rail_type = GetTileRailType(tile);
+		}
+
+		TILE(const TILE &src)
+		{
+			tile = src.tile;
+			td = src.td;
+			tile_type = src.tile_type;
+			rail_type = src.rail_type;
+		}
+	};
+
+protected:
+	/**
+	 * @note maximum cost doesn't work with caching enabled
+	 * @todo fix maximum cost failing with caching (e.g. FS#2900)
+	 */
+	int           m_max_cost;
+	CBlobT<int>   m_sig_look_ahead_costs;
+	bool          m_disable_cache;
+
+public:
+	bool          m_stopped_on_first_two_way_signal;
+protected:
+
+	static const int s_max_segment_cost = 10000;
+
+	CYapfCostRailT()
+		: m_max_cost(0)
+		, m_disable_cache(false)
+		, m_stopped_on_first_two_way_signal(false)
+	{
+		/* pre-compute look-ahead penalties into array */
+		int p0 = Yapf().PfGetSettings().rail_look_ahead_signal_p0;
+		int p1 = Yapf().PfGetSettings().rail_look_ahead_signal_p1;
+		int p2 = Yapf().PfGetSettings().rail_look_ahead_signal_p2;
+		int *pen = m_sig_look_ahead_costs.GrowSizeNC(Yapf().PfGetSettings().rail_look_ahead_max_signals);
+		for (uint i = 0; i < Yapf().PfGetSettings().rail_look_ahead_max_signals; i++) {
+			pen[i] = p0 + i * (p1 + i * p2);
+		}
+	}
+
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	FORCEINLINE int SlopeCost(TileIndex tile, Trackdir td)
+	{
+		CPerfStart perf_cost(Yapf().m_perf_slope_cost);
+		if (!stSlopeCost(tile, td)) return 0;
+		return Yapf().PfGetSettings().rail_slope_penalty;
+	}
+
+	FORCEINLINE int CurveCost(Trackdir td1, Trackdir td2)
+	{
+		assert(IsValidTrackdir(td1));
+		assert(IsValidTrackdir(td2));
+		int cost = 0;
+		if (TrackFollower::Allow90degTurns()
+				&& ((TrackdirToTrackdirBits(td2) & (TrackdirBits)TrackdirCrossesTrackdirs(td1)) != 0)) {
+			/* 90-deg curve penalty */
+			cost += Yapf().PfGetSettings().rail_curve90_penalty;
+		} else if (td2 != NextTrackdir(td1)) {
+			/* 45-deg curve penalty */
+			cost += Yapf().PfGetSettings().rail_curve45_penalty;
+		}
+		return cost;
+	}
+
+	FORCEINLINE int SwitchCost(TileIndex tile1, TileIndex tile2, DiagDirection exitdir)
+	{
+		if (IsPlainRailTile(tile1) && IsPlainRailTile(tile2)) {
+			bool t1 = KillFirstBit(GetTrackBits(tile1) & DiagdirReachesTracks(ReverseDiagDir(exitdir))) != TRACK_BIT_NONE;
+			bool t2 = KillFirstBit(GetTrackBits(tile2) & DiagdirReachesTracks(exitdir)) != TRACK_BIT_NONE;
+			if (t1 && t2) return Yapf().PfGetSettings().rail_doubleslip_penalty;
+		}
+		return 0;
+	}
+
+	/** Return one tile cost (base cost + level crossing penalty). */
+	FORCEINLINE int OneTileCost(TileIndex& tile, Trackdir trackdir)
+	{
+		int cost = 0;
+		/* set base cost */
+		if (IsDiagonalTrackdir(trackdir)) {
+			cost += YAPF_TILE_LENGTH;
+			switch (GetTileType(tile)) {
+				case MP_ROAD:
+					/* Increase the cost for level crossings */
+					if (IsLevelCrossing(tile)) {
+						cost += Yapf().PfGetSettings().rail_crossing_penalty;
+					}
+					break;
+
+				default:
+					break;
+			}
+		} else {
+			/* non-diagonal trackdir */
+			cost = YAPF_TILE_CORNER_LENGTH;
+		}
+		return cost;
+	}
+
+	/** Check for a reserved station platform. */
+	FORCEINLINE bool IsAnyStationTileReserved(TileIndex tile, Trackdir trackdir, int skipped)
+	{
+		TileIndexDiff diff = TileOffsByDiagDir(TrackdirToExitdir(ReverseTrackdir(trackdir)));
+		for (; skipped >= 0; skipped--, tile += diff) {
+			if (HasStationReservation(tile)) return true;
+		}
+		return false;
+	}
+
+	/** The cost for reserved tiles, including skipped ones. */
+	FORCEINLINE int ReservationCost(Node& n, TileIndex tile, Trackdir trackdir, int skipped)
+	{
+		if (n.m_num_signals_passed >= m_sig_look_ahead_costs.Size() / 2) return 0;
+
+		if (IsRailStationTile(tile) && IsAnyStationTileReserved(tile, trackdir, skipped)) {
+			return Yapf().PfGetSettings().rail_pbs_station_penalty * (skipped + 1);
+		} else if (TrackOverlapsTracks(GetReservedTrackbits(tile), TrackdirToTrack(trackdir))) {
+			int cost = Yapf().PfGetSettings().rail_pbs_cross_penalty;
+			if (!IsDiagonalTrackdir(trackdir)) cost = (cost * YAPF_TILE_CORNER_LENGTH) / YAPF_TILE_LENGTH;
+			return cost * (skipped + 1);
+		}
+		return 0;
+	}
+
+	int SignalCost(Node& n, TileIndex tile, Trackdir trackdir)
+	{
+		int cost = 0;
+		/* if there is one-way signal in the opposite direction, then it is not our way */
+		CPerfStart perf_cost(Yapf().m_perf_other_cost);
+		if (IsTileType(tile, MP_RAILWAY)) {
+			bool has_signal_against = HasSignalOnTrackdir(tile, ReverseTrackdir(trackdir));
+			bool has_signal_along = HasSignalOnTrackdir(tile, trackdir);
+			if (has_signal_against && !has_signal_along && IsOnewaySignal(tile, TrackdirToTrack(trackdir))) {
+				/* one-way signal in opposite direction */
+				n.m_segment->m_end_segment_reason |= ESRB_DEAD_END;
+			} else {
+				if (has_signal_along) {
+					SignalState sig_state = GetSignalStateByTrackdir(tile, trackdir);
+					/* cache the look-ahead polynomial constant only if we didn't pass more signals than the look-ahead limit is */
+					int look_ahead_cost = (n.m_num_signals_passed < m_sig_look_ahead_costs.Size()) ? m_sig_look_ahead_costs.Data()[n.m_num_signals_passed] : 0;
+					if (sig_state != SIGNAL_STATE_RED) {
+						/* green signal */
+						n.flags_u.flags_s.m_last_signal_was_red = false;
+						/* negative look-ahead red-signal penalties would cause problems later, so use them as positive penalties for green signal */
+						if (look_ahead_cost < 0) {
+							/* add its negation to the cost */
+							cost -= look_ahead_cost;
+						}
+					} else {
+						SignalType sig_type = GetSignalType(tile, TrackdirToTrack(trackdir));
+						/* we have a red signal in our direction
+						 * was it first signal which is two-way? */
+						if (!IsPbsSignal(sig_type) && Yapf().TreatFirstRedTwoWaySignalAsEOL() && n.flags_u.flags_s.m_choice_seen && has_signal_against && n.m_num_signals_passed == 0) {
+							/* yes, the first signal is two-way red signal => DEAD END */
+							n.m_segment->m_end_segment_reason |= ESRB_DEAD_END;
+							Yapf().m_stopped_on_first_two_way_signal = true;
+							return -1;
+						}
+						n.m_last_red_signal_type = sig_type;
+						n.flags_u.flags_s.m_last_signal_was_red = true;
+
+						/* look-ahead signal penalty */
+						if (!IsPbsSignal(sig_type) && look_ahead_cost > 0) {
+							/* add the look ahead penalty only if it is positive */
+							cost += look_ahead_cost;
+						}
+
+						/* special signal penalties */
+						if (n.m_num_signals_passed == 0) {
+							switch (sig_type) {
+								case SIGTYPE_COMBO:
+								case SIGTYPE_EXIT:   cost += Yapf().PfGetSettings().rail_firstred_exit_penalty; break; // first signal is red pre-signal-exit
+								case SIGTYPE_NORMAL:
+								case SIGTYPE_ENTRY:  cost += Yapf().PfGetSettings().rail_firstred_penalty; break;
+								default: break;
+							}
+						}
+					}
+
+					n.m_num_signals_passed++;
+					n.m_segment->m_last_signal_tile = tile;
+					n.m_segment->m_last_signal_td = trackdir;
+				}
+
+				if (has_signal_against && IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) {
+					cost += n.m_num_signals_passed < Yapf().PfGetSettings().rail_look_ahead_max_signals ? Yapf().PfGetSettings().rail_pbs_signal_back_penalty : 0;
+				}
+			}
+		}
+		return cost;
+	}
+
+	FORCEINLINE int PlatformLengthPenalty(int platform_length)
+	{
+		int cost = 0;
+		const Vehicle *v = Yapf().GetVehicle();
+		assert(v != NULL);
+		assert(v->type == VEH_TRAIN);
+		assert(Train::From(v)->tcache.cached_total_length != 0);
+		int missing_platform_length = (Train::From(v)->tcache.cached_total_length + TILE_SIZE - 1) / TILE_SIZE - platform_length;
+		if (missing_platform_length < 0) {
+			/* apply penalty for longer platform than needed */
+			cost += Yapf().PfGetSettings().rail_longer_platform_penalty + Yapf().PfGetSettings().rail_longer_platform_per_tile_penalty * -missing_platform_length;
+		} else if (missing_platform_length > 0) {
+			/* apply penalty for shorter platform than needed */
+			cost += Yapf().PfGetSettings().rail_shorter_platform_penalty + Yapf().PfGetSettings().rail_shorter_platform_per_tile_penalty * missing_platform_length;
+		}
+		return cost;
+	}
+
+public:
+	FORCEINLINE void SetMaxCost(int max_cost)
+	{
+		m_max_cost = max_cost;
+	}
+
+	/** Called by YAPF to calculate the cost from the origin to the given node.
+	 *  Calculates only the cost of given node, adds it to the parent node cost
+	 *  and stores the result into Node::m_cost member */
+	FORCEINLINE bool PfCalcCost(Node &n, const TrackFollower *tf)
+	{
+		assert(!n.flags_u.flags_s.m_targed_seen);
+		assert(tf->m_new_tile == n.m_key.m_tile);
+		assert((TrackdirToTrackdirBits(n.m_key.m_td) & tf->m_new_td_bits) != TRACKDIR_BIT_NONE);
+
+		CPerfStart perf_cost(Yapf().m_perf_cost);
+
+		/* Does the node have some parent node? */
+		bool has_parent = (n.m_parent != NULL);
+
+		/* Do we already have a cached segment? */
+		CachedData &segment = *n.m_segment;
+		bool is_cached_segment = (segment.m_cost >= 0);
+
+		int parent_cost = has_parent ? n.m_parent->m_cost : 0;
+
+		/* Each node cost contains 2 or 3 main components:
+		 *  1. Transition cost - cost of the move from previous node (tile):
+		 *    - curve cost (or zero for straight move)
+		 *  2. Tile cost:
+		 *    - base tile cost
+		 *      - YAPF_TILE_LENGTH for diagonal tiles
+		 *      - YAPF_TILE_CORNER_LENGTH for non-diagonal tiles
+		 *    - tile penalties
+		 *      - tile slope penalty (upward slopes)
+		 *      - red signal penalty
+		 *      - level crossing penalty
+		 *      - speed-limit penalty (bridges)
+		 *      - station platform penalty
+		 *      - penalty for reversing in the depot
+		 *      - etc.
+		 *  3. Extra cost (applies to the last node only)
+		 *    - last red signal penalty
+		 *    - penalty for too long or too short platform on the destination station
+		 */
+		int transition_cost = 0;
+		int extra_cost = 0;
+
+		/* Segment: one or more tiles connected by contiguous tracks of the same type.
+		 * Each segment cost includes 'Tile cost' for all its tiles (including the first
+		 * and last), and the 'Transition cost' between its tiles. The first transition
+		 * cost of segment entry (move from the 'parent' node) is not included!
+		 */
+		int segment_entry_cost = 0;
+		int segment_cost = 0;
+
+		const Vehicle *v = Yapf().GetVehicle();
+
+		/* start at n.m_key.m_tile / n.m_key.m_td and walk to the end of segment */
+		TILE cur(n.m_key.m_tile, n.m_key.m_td);
+
+		/* the previous tile will be needed for transition cost calculations */
+		TILE prev = !has_parent ? TILE() : TILE(n.m_parent->GetLastTile(), n.m_parent->GetLastTrackdir());
+
+		EndSegmentReasonBits end_segment_reason = ESRB_NONE;
+
+		TrackFollower tf_local(v, Yapf().GetCompatibleRailTypes(), &Yapf().m_perf_ts_cost);
+
+		if (!has_parent) {
+			/* We will jump to the middle of the cost calculator assuming that segment cache is not used. */
+			assert(!is_cached_segment);
+			/* Skip the first transition cost calculation. */
+			goto no_entry_cost;
+		}
+
+		for (;;) {
+			/* Transition cost (cost of the move from previous tile) */
+			transition_cost = Yapf().CurveCost(prev.td, cur.td);
+			transition_cost += Yapf().SwitchCost(prev.tile, cur.tile, TrackdirToExitdir(prev.td));
+
+			/* First transition cost counts against segment entry cost, other transitions
+			 * inside segment will come to segment cost (and will be cached) */
+			if (segment_cost == 0) {
+				/* We just entered the loop. First transition cost goes to segment entry cost)*/
+				segment_entry_cost = transition_cost;
+				transition_cost = 0;
+
+				/* It is the right time now to look if we can reuse the cached segment cost. */
+				if (is_cached_segment) {
+					/* Yes, we already know the segment cost. */
+					segment_cost = segment.m_cost;
+					/* We know also the reason why the segment ends. */
+					end_segment_reason = segment.m_end_segment_reason;
+					/* We will need also some information about the last signal (if it was red). */
+					if (segment.m_last_signal_tile != INVALID_TILE) {
+						assert(HasSignalOnTrackdir(segment.m_last_signal_tile, segment.m_last_signal_td));
+						SignalState sig_state = GetSignalStateByTrackdir(segment.m_last_signal_tile, segment.m_last_signal_td);
+						bool is_red = (sig_state == SIGNAL_STATE_RED);
+						n.flags_u.flags_s.m_last_signal_was_red = is_red;
+						if (is_red) {
+							n.m_last_red_signal_type = GetSignalType(segment.m_last_signal_tile, TrackdirToTrack(segment.m_last_signal_td));
+						}
+					}
+					/* No further calculation needed. */
+					cur = TILE(n.GetLastTile(), n.GetLastTrackdir());
+					break;
+				}
+			} else {
+				/* Other than first transition cost count as the regular segment cost. */
+				segment_cost += transition_cost;
+			}
+
+no_entry_cost: // jump here at the beginning if the node has no parent (it is the first node)
+
+			/* All other tile costs will be calculated here. */
+			segment_cost += Yapf().OneTileCost(cur.tile, cur.td);
+
+			/* If we skipped some tunnel/bridge/station tiles, add their base cost */
+			segment_cost += YAPF_TILE_LENGTH * tf->m_tiles_skipped;
+
+			/* Slope cost. */
+			segment_cost += Yapf().SlopeCost(cur.tile, cur.td);
+
+			/* Reserved tiles. */
+			segment_cost += Yapf().ReservationCost(n, cur.tile, cur.td, tf->m_tiles_skipped);
+
+			/* Signal cost (routine can modify segment data). */
+			segment_cost += Yapf().SignalCost(n, cur.tile, cur.td);
+			end_segment_reason = segment.m_end_segment_reason;
+
+			/* Tests for 'potential target' reasons to close the segment. */
+			if (cur.tile == prev.tile) {
+				/* Penalty for reversing in a depot. */
+				assert(IsRailDepot(cur.tile));
+				segment_cost += Yapf().PfGetSettings().rail_depot_reverse_penalty;
+				/* We will end in this pass (depot is possible target) */
+				end_segment_reason |= ESRB_DEPOT;
+
+			} else if (tf->m_is_station) {
+				/* Station penalties. */
+				uint platform_length = tf->m_tiles_skipped + 1;
+				/* We don't know yet if the station is our target or not. Act like
+				 * if it is pass-through station (not our destination). */
+				segment_cost += Yapf().PfGetSettings().rail_station_penalty * platform_length;
+				/* We will end in this pass (station is possible target) */
+				end_segment_reason |= ESRB_STATION;
+
+			} else if (cur.tile_type == MP_STATION && IsRailWaypoint(cur.tile)) {
+				/* Waypoint is also a good reason to finish. */
+				end_segment_reason |= ESRB_WAYPOINT;
+			} else if (TrackFollower::DoTrackMasking() && cur.tile_type == MP_RAILWAY) {
+				/* Searching for a safe tile? */
+				if (HasSignalOnTrackdir(cur.tile, cur.td) && !IsPbsSignal(GetSignalType(cur.tile, TrackdirToTrack(cur.td)))) {
+					end_segment_reason |= ESRB_SAFE_TILE;
+				}
+			}
+
+			/* Apply min/max speed penalties only when inside the look-ahead radius. Otherwise
+			 * it would cause desync in MP. */
+			if (n.m_num_signals_passed < m_sig_look_ahead_costs.Size())
+			{
+				int min_speed = 0;
+				int max_speed = tf->GetSpeedLimit(&min_speed);
+				if (max_speed < v->max_speed) {
+					extra_cost += YAPF_TILE_LENGTH * (v->max_speed - max_speed) * (4 + tf->m_tiles_skipped) / v->max_speed;
+				}
+				if (min_speed > v->max_speed) {
+					extra_cost += YAPF_TILE_LENGTH * (min_speed - v->max_speed);
+				}
+			}
+
+			/* Finish if we already exceeded the maximum path cost (i.e. when
+			 * searching for the nearest depot). */
+			if (m_max_cost > 0 && (parent_cost + segment_entry_cost + segment_cost) > m_max_cost) {
+				end_segment_reason |= ESRB_PATH_TOO_LONG;
+			}
+
+			/* Move to the next tile/trackdir. */
+			tf = &tf_local;
+			tf_local.Init(v, Yapf().GetCompatibleRailTypes(), &Yapf().m_perf_ts_cost);
+
+			if (!tf_local.Follow(cur.tile, cur.td)) {
+				assert(tf_local.m_err != TrackFollower::EC_NONE);
+				/* Can't move to the next tile (EOL?). */
+				if (tf_local.m_err == TrackFollower::EC_RAIL_TYPE) {
+					end_segment_reason |= ESRB_RAIL_TYPE;
+				} else {
+					end_segment_reason |= ESRB_DEAD_END;
+				}
+
+				if (TrackFollower::DoTrackMasking() && !HasOnewaySignalBlockingTrackdir(cur.tile, cur.td)) {
+					end_segment_reason |= ESRB_SAFE_TILE;
+				}
+				break;
+			}
+
+			/* Check if the next tile is not a choice. */
+			if (KillFirstBit(tf_local.m_new_td_bits) != TRACKDIR_BIT_NONE) {
+				/* More than one segment will follow. Close this one. */
+				end_segment_reason |= ESRB_CHOICE_FOLLOWS;
+				break;
+			}
+
+			/* Gather the next tile/trackdir/tile_type/rail_type. */
+			TILE next(tf_local.m_new_tile, (Trackdir)FindFirstBit2x64(tf_local.m_new_td_bits));
+
+			if (TrackFollower::DoTrackMasking() && HasPbsSignalOnTrackdir(next.tile, next.td)) {
+				/* Possible safe tile. */
+				end_segment_reason |= ESRB_SAFE_TILE;
+			}
+
+			/* Check the next tile for the rail type. */
+			if (next.rail_type != cur.rail_type) {
+				/* Segment must consist from the same rail_type tiles. */
+				end_segment_reason |= ESRB_RAIL_TYPE;
+				break;
+			}
+
+			/* Avoid infinite looping. */
+			if (next.tile == n.m_key.m_tile && next.td == n.m_key.m_td) {
+				end_segment_reason |= ESRB_INFINITE_LOOP;
+				break;
+			}
+
+			if (segment_cost > s_max_segment_cost) {
+				/* Potentially in the infinite loop (or only very long segment?). We should
+				 * not force it to finish prematurely unless we are on a regular tile. */
+				if (IsTileType(tf->m_new_tile, MP_RAILWAY)) {
+					end_segment_reason |= ESRB_SEGMENT_TOO_LONG;
+					break;
+				}
+			}
+
+			/* Any other reason bit set? */
+			if (end_segment_reason != ESRB_NONE) {
+				break;
+			}
+
+			/* For the next loop set new prev and cur tile info. */
+			prev = cur;
+			cur = next;
+
+		} // for (;;)
+
+		bool target_seen = false;
+		if ((end_segment_reason & ESRB_POSSIBLE_TARGET) != ESRB_NONE) {
+			/* Depot, station or waypoint. */
+			if (Yapf().PfDetectDestination(cur.tile, cur.td)) {
+				/* Destination found. */
+				target_seen = true;
+			}
+		}
+
+		/* Update the segment if needed. */
+		if (!is_cached_segment) {
+			/* Write back the segment information so it can be reused the next time. */
+			segment.m_cost = segment_cost;
+			segment.m_end_segment_reason = end_segment_reason & ESRB_CACHED_MASK;
+			/* Save end of segment back to the node. */
+			n.SetLastTileTrackdir(cur.tile, cur.td);
+		}
+
+		/* Do we have an excuse why not to continue pathfinding in this direction? */
+		if (!target_seen && (end_segment_reason & ESRB_ABORT_PF_MASK) != ESRB_NONE) {
+			/* Reason to not continue. Stop this PF branch. */
+			return false;
+		}
+
+		/* Special costs for the case we have reached our target. */
+		if (target_seen) {
+			n.flags_u.flags_s.m_targed_seen = true;
+			/* Last-red and last-red-exit penalties. */
+			if (n.flags_u.flags_s.m_last_signal_was_red) {
+				if (n.m_last_red_signal_type == SIGTYPE_EXIT) {
+					/* last signal was red pre-signal-exit */
+					extra_cost += Yapf().PfGetSettings().rail_lastred_exit_penalty;
+				} else {
+					/* last signal was red, but not exit */
+					extra_cost += Yapf().PfGetSettings().rail_lastred_penalty;
+				}
+			}
+
+			/* Station platform-length penalty. */
+			if ((end_segment_reason & ESRB_STATION) != ESRB_NONE) {
+				const BaseStation *st = BaseStation::GetByTile(n.GetLastTile());
+				assert(st != NULL);
+				uint platform_length = st->GetPlatformLength(n.GetLastTile(), ReverseDiagDir(TrackdirToExitdir(n.GetLastTrackdir())));
+				/* Reduce the extra cost caused by passing-station penalty (each station receives it in the segment cost). */
+				extra_cost -= Yapf().PfGetSettings().rail_station_penalty * platform_length;
+				/* Add penalty for the inappropriate platform length. */
+				extra_cost += PlatformLengthPenalty(platform_length);
+			}
+		}
+
+		/* total node cost */
+		n.m_cost = parent_cost + segment_entry_cost + segment_cost + extra_cost;
+
+		return true;
+	}
+
+	FORCEINLINE bool CanUseGlobalCache(Node& n) const
+	{
+		return !m_disable_cache
+			&& (n.m_parent != NULL)
+			&& (n.m_parent->m_num_signals_passed >= m_sig_look_ahead_costs.Size());
+	}
+
+	FORCEINLINE void ConnectNodeToCachedData(Node& n, CachedData& ci)
+	{
+		n.m_segment = &ci;
+		if (n.m_segment->m_cost < 0) {
+			n.m_segment->m_last_tile = n.m_key.m_tile;
+			n.m_segment->m_last_td = n.m_key.m_td;
+		}
+	}
+
+	void DisableCache(bool disable)
+	{
+		m_disable_cache = disable;
+	}
+};
+
+#endif /* YAPF_COSTRAIL_HPP */

src/pathfinder/yapf/yapf_destrail.hpp

@@ -0,0 +1,203 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_destrail.hpp Determining the destination for rail vehicles. */
+
+#ifndef  YAPF_DESTRAIL_HPP
+#define  YAPF_DESTRAIL_HPP
+
+class CYapfDestinationRailBase
+{
+protected:
+	RailTypes m_compatible_railtypes;
+
+public:
+	void SetDestination(const Vehicle *v, bool override_rail_type = false)
+	{
+		m_compatible_railtypes = Train::From(v)->compatible_railtypes;
+		if (override_rail_type) m_compatible_railtypes |= GetRailTypeInfo(Train::From(v)->railtype)->compatible_railtypes;
+	}
+
+	bool IsCompatibleRailType(RailType rt)
+	{
+		return HasBit(m_compatible_railtypes, rt);
+	}
+
+	RailTypes GetCompatibleRailTypes() const
+	{
+		return m_compatible_railtypes;
+	}
+};
+
+template <class Types>
+class CYapfDestinationAnyDepotRailT
+	: public CYapfDestinationRailBase
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		return PfDetectDestination(n.GetLastTile(), n.GetLastTrackdir());
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(TileIndex tile, Trackdir td)
+	{
+		bool bDest = IsRailDepotTile(tile);
+		return bDest;
+	}
+
+	/** Called by YAPF to calculate cost estimate. Calculates distance to the destination
+	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate */
+	FORCEINLINE bool PfCalcEstimate(Node& n)
+	{
+		n.m_estimate = n.m_cost;
+		return true;
+	}
+};
+
+template <class Types>
+class CYapfDestinationAnySafeTileRailT
+	: public CYapfDestinationRailBase
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+	typedef typename Types::TrackFollower TrackFollower; ///< TrackFollower. Need to typedef for gcc 2.95
+
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		return PfDetectDestination(n.GetLastTile(), n.GetLastTrackdir());
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(TileIndex tile, Trackdir td)
+	{
+		return
+			IsSafeWaitingPosition(Train::From(Yapf().GetVehicle()), tile, td, true, !TrackFollower::Allow90degTurns()) &&
+			IsWaitingPositionFree(Train::From(Yapf().GetVehicle()), tile, td, !TrackFollower::Allow90degTurns());
+	}
+
+	/** Called by YAPF to calculate cost estimate. Calculates distance to the destination
+	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate. */
+	FORCEINLINE bool PfCalcEstimate(Node& n)
+	{
+		n.m_estimate = n.m_cost;
+		return true;
+	}
+};
+
+template <class Types>
+class CYapfDestinationTileOrStationRailT
+	: public CYapfDestinationRailBase
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+
+protected:
+	TileIndex    m_destTile;
+	TrackdirBits m_destTrackdirs;
+	StationID    m_dest_station_id;
+
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	void SetDestination(const Vehicle *v)
+	{
+		switch (v->current_order.GetType()) {
+			case OT_GOTO_STATION:
+			case OT_GOTO_WAYPOINT:
+				m_destTile = CalcClosestStationTile(v->current_order.GetDestination(), v->tile);
+				m_dest_station_id = v->current_order.GetDestination();
+				m_destTrackdirs = INVALID_TRACKDIR_BIT;
+				break;
+
+			default:
+				m_destTile = v->dest_tile;
+				m_dest_station_id = INVALID_STATION;
+				m_destTrackdirs = TrackStatusToTrackdirBits(GetTileTrackStatus(v->dest_tile, TRANSPORT_RAIL, 0));
+				break;
+		}
+		CYapfDestinationRailBase::SetDestination(v);
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		return PfDetectDestination(n.GetLastTile(), n.GetLastTrackdir());
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(TileIndex tile, Trackdir td)
+	{
+		bool bDest;
+		if (m_dest_station_id != INVALID_STATION) {
+			bDest = HasStationTileRail(tile)
+				&& (GetStationIndex(tile) == m_dest_station_id)
+				&& (GetRailStationTrack(tile) == TrackdirToTrack(td));
+		} else {
+			bDest = (tile == m_destTile)
+				&& ((m_destTrackdirs & TrackdirToTrackdirBits(td)) != TRACKDIR_BIT_NONE);
+		}
+		return bDest;
+	}
+
+	/** Called by YAPF to calculate cost estimate. Calculates distance to the destination
+	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate */
+	FORCEINLINE bool PfCalcEstimate(Node& n)
+	{
+		static const int dg_dir_to_x_offs[] = {-1, 0, 1, 0};
+		static const int dg_dir_to_y_offs[] = {0, 1, 0, -1};
+		if (PfDetectDestination(n)) {
+			n.m_estimate = n.m_cost;
+			return true;
+		}
+
+		TileIndex tile = n.GetLastTile();
+		DiagDirection exitdir = TrackdirToExitdir(n.GetLastTrackdir());
+		int x1 = 2 * TileX(tile) + dg_dir_to_x_offs[(int)exitdir];
+		int y1 = 2 * TileY(tile) + dg_dir_to_y_offs[(int)exitdir];
+		int x2 = 2 * TileX(m_destTile);
+		int y2 = 2 * TileY(m_destTile);
+		int dx = abs(x1 - x2);
+		int dy = abs(y1 - y2);
+		int dmin = min(dx, dy);
+		int dxy = abs(dx - dy);
+		int d = dmin * YAPF_TILE_CORNER_LENGTH + (dxy - 1) * (YAPF_TILE_LENGTH / 2);
+		n.m_estimate = n.m_cost + d;
+		assert(n.m_estimate >= n.m_parent->m_estimate);
+		return true;
+	}
+};
+
+#endif /* YAPF_DESTRAIL_HPP */

src/pathfinder/yapf/yapf_node.hpp

@@ -0,0 +1,101 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_node.hpp Node in the pathfinder's graph. */
+
+#ifndef  YAPF_NODE_HPP
+#define  YAPF_NODE_HPP
+
+/** Yapf Node Key that evaluates hash from (and compares) tile & exit dir. */
+struct CYapfNodeKeyExitDir {
+	TileIndex      m_tile;
+	Trackdir       m_td;
+	DiagDirection  m_exitdir;
+
+	FORCEINLINE void Set(TileIndex tile, Trackdir td)
+	{
+		m_tile = tile;
+		m_td = td;
+		m_exitdir = (m_td == INVALID_TRACKDIR) ? INVALID_DIAGDIR : TrackdirToExitdir(m_td);
+	}
+
+	FORCEINLINE int CalcHash() const {return m_exitdir | (m_tile << 2);}
+	FORCEINLINE bool operator == (const CYapfNodeKeyExitDir& other) const {return (m_tile == other.m_tile) && (m_exitdir == other.m_exitdir);}
+
+	void Dump(DumpTarget &dmp) const
+	{
+		dmp.WriteTile("m_tile", m_tile);
+		dmp.WriteEnumT("m_td", m_td);
+		dmp.WriteEnumT("m_exitdir", m_exitdir);
+	}
+};
+
+struct CYapfNodeKeyTrackDir : public CYapfNodeKeyExitDir
+{
+	FORCEINLINE int CalcHash() const {return m_td | (m_tile << 4);}
+	FORCEINLINE bool operator == (const CYapfNodeKeyTrackDir& other) const {return (m_tile == other.m_tile) && (m_td == other.m_td);}
+};
+
+/** Yapf Node base */
+template <class Tkey_, class Tnode>
+struct CYapfNodeT {
+	typedef Tkey_ Key;
+	typedef Tnode Node;
+
+	Tkey_       m_key;
+	Node       *m_hash_next;
+	Node       *m_parent;
+	int         m_cost;
+	int         m_estimate;
+
+	FORCEINLINE void Set(Node *parent, TileIndex tile, Trackdir td, bool is_choice)
+	{
+		m_key.Set(tile, td);
+		m_hash_next = NULL;
+		m_parent = parent;
+		m_cost = 0;
+		m_estimate = 0;
+	}
+
+	FORCEINLINE Node *GetHashNext() {return m_hash_next;}
+	FORCEINLINE void SetHashNext(Node *pNext) {m_hash_next = pNext;}
+	FORCEINLINE TileIndex GetTile() const {return m_key.m_tile;}
+	FORCEINLINE Trackdir GetTrackdir() const {return m_key.m_td;}
+	FORCEINLINE const Tkey_& GetKey() const {return m_key;}
+	FORCEINLINE int GetCost() const {return m_cost;}
+	FORCEINLINE int GetCostEstimate() const {return m_estimate;}
+	FORCEINLINE bool operator < (const Node& other) const {return m_estimate < other.m_estimate;}
+
+	void Dump(DumpTarget &dmp) const
+	{
+		dmp.WriteStructT("m_key", &m_key);
+		dmp.WriteStructT("m_parent", m_parent);
+		dmp.WriteLine("m_cost = %d", m_cost);
+		dmp.WriteLine("m_estimate = %d", m_estimate);
+	}
+};
+
+/** Yapf Node for ships */
+template <class Tkey_>
+struct CYapfShipNodeT
+	: CYapfNodeT<Tkey_, CYapfShipNodeT<Tkey_> >
+{
+
+};
+
+/* now define two major node types (that differ by key type) */
+typedef CYapfShipNodeT<CYapfNodeKeyExitDir>  CYapfShipNodeExitDir;
+typedef CYapfShipNodeT<CYapfNodeKeyTrackDir> CYapfShipNodeTrackDir;
+
+/* Default NodeList types */
+typedef CNodeList_HashTableT<CYapfShipNodeExitDir , 14, 16> CShipNodeListExitDir;
+typedef CNodeList_HashTableT<CYapfShipNodeTrackDir, 16, 20> CShipNodeListTrackDir;
+
+
+#endif /* YAPF_NODE_HPP */

src/pathfinder/yapf/yapf_node_rail.hpp

@@ -0,0 +1,284 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_node_rail.hpp Node tailored for rail pathfinding. */
+
+#ifndef  YAPF_NODE_RAIL_HPP
+#define  YAPF_NODE_RAIL_HPP
+
+/** key for cached segment cost for rail YAPF */
+struct CYapfRailSegmentKey
+{
+	uint32    m_value;
+
+	FORCEINLINE CYapfRailSegmentKey(const CYapfRailSegmentKey& src) : m_value(src.m_value) {}
+
+	FORCEINLINE CYapfRailSegmentKey(const CYapfNodeKeyTrackDir& node_key)
+	{
+		Set(node_key);
+	}
+
+	FORCEINLINE void Set(const CYapfRailSegmentKey& src)
+	{
+		m_value = src.m_value;
+	}
+
+	FORCEINLINE void Set(const CYapfNodeKeyTrackDir& node_key)
+	{
+		m_value = (((int)node_key.m_tile) << 4) | node_key.m_td;
+	}
+
+	FORCEINLINE int32 CalcHash() const
+	{
+		return m_value;
+	}
+
+	FORCEINLINE TileIndex GetTile() const
+	{
+		return (TileIndex)(m_value >> 4);
+	}
+
+	FORCEINLINE Trackdir GetTrackdir() const
+	{
+		return (Trackdir)(m_value & 0x0F);
+	}
+
+	FORCEINLINE bool operator == (const CYapfRailSegmentKey& other) const
+	{
+		return m_value == other.m_value;
+	}
+
+	void Dump(DumpTarget &dmp) const
+	{
+		dmp.WriteTile("tile", GetTile());
+		dmp.WriteEnumT("td", GetTrackdir());
+	}
+};
+
+/* Enum used in PfCalcCost() to see why was the segment closed. */
+enum EndSegmentReason {
+	/* The following reasons can be saved into cached segment */
+	ESR_DEAD_END = 0,      ///< track ends here
+	ESR_RAIL_TYPE,         ///< the next tile has a different rail type than our tiles
+	ESR_INFINITE_LOOP,     ///< infinite loop detected
+	ESR_SEGMENT_TOO_LONG,  ///< the segment is too long (possible infinite loop)
+	ESR_CHOICE_FOLLOWS,    ///< the next tile contains a choice (the track splits to more than one segments)
+	ESR_DEPOT,             ///< stop in the depot (could be a target next time)
+	ESR_WAYPOINT,          ///< waypoint encountered (could be a target next time)
+	ESR_STATION,           ///< station encountered (could be a target next time)
+	ESR_SAFE_TILE,         ///< safe waiting position found (could be a target)
+
+	/* The following reasons are used only internally by PfCalcCost().
+	 *  They should not be found in the cached segment. */
+	ESR_PATH_TOO_LONG,     ///< the path is too long (searching for the nearest depot in the given radius)
+	ESR_FIRST_TWO_WAY_RED, ///< first signal was 2-way and it was red
+	ESR_LOOK_AHEAD_END,    ///< we have just passed the last look-ahead signal
+	ESR_TARGET_REACHED,    ///< we have just reached the destination
+
+	/* Special values */
+	ESR_NONE = 0xFF,          ///< no reason to end the segment here
+};
+
+enum EndSegmentReasonBits {
+	ESRB_NONE = 0,
+
+	ESRB_DEAD_END          = 1 << ESR_DEAD_END,
+	ESRB_RAIL_TYPE         = 1 << ESR_RAIL_TYPE,
+	ESRB_INFINITE_LOOP     = 1 << ESR_INFINITE_LOOP,
+	ESRB_SEGMENT_TOO_LONG  = 1 << ESR_SEGMENT_TOO_LONG,
+	ESRB_CHOICE_FOLLOWS    = 1 << ESR_CHOICE_FOLLOWS,
+	ESRB_DEPOT             = 1 << ESR_DEPOT,
+	ESRB_WAYPOINT          = 1 << ESR_WAYPOINT,
+	ESRB_STATION           = 1 << ESR_STATION,
+	ESRB_SAFE_TILE         = 1 << ESR_SAFE_TILE,
+
+	ESRB_PATH_TOO_LONG     = 1 << ESR_PATH_TOO_LONG,
+	ESRB_FIRST_TWO_WAY_RED = 1 << ESR_FIRST_TWO_WAY_RED,
+	ESRB_LOOK_AHEAD_END    = 1 << ESR_LOOK_AHEAD_END,
+	ESRB_TARGET_REACHED    = 1 << ESR_TARGET_REACHED,
+
+	/* Additional (composite) values. */
+
+	/* What reasons mean that the target can be found and needs to be detected. */
+	ESRB_POSSIBLE_TARGET = ESRB_DEPOT | ESRB_WAYPOINT | ESRB_STATION | ESRB_SAFE_TILE,
+
+	/* What reasons can be stored back into cached segment. */
+	ESRB_CACHED_MASK = ESRB_DEAD_END | ESRB_RAIL_TYPE | ESRB_INFINITE_LOOP | ESRB_SEGMENT_TOO_LONG | ESRB_CHOICE_FOLLOWS | ESRB_DEPOT | ESRB_WAYPOINT | ESRB_STATION | ESRB_SAFE_TILE,
+
+	/* Reasons to abort pathfinding in this direction. */
+	ESRB_ABORT_PF_MASK = ESRB_DEAD_END | ESRB_PATH_TOO_LONG | ESRB_INFINITE_LOOP | ESRB_FIRST_TWO_WAY_RED,
+};
+
+DECLARE_ENUM_AS_BIT_SET(EndSegmentReasonBits);
+
+inline CStrA ValueStr(EndSegmentReasonBits bits)
+{
+	static const char * const end_segment_reason_names[] = {
+		"DEAD_END", "RAIL_TYPE", "INFINITE_LOOP", "SEGMENT_TOO_LONG", "CHOICE_FOLLOWS",
+		"DEPOT", "WAYPOINT", "STATION", "SAFE_TILE",
+		"PATH_TOO_LONG", "FIRST_TWO_WAY_RED", "LOOK_AHEAD_END", "TARGET_REACHED"
+	};
+
+	CStrA out;
+	out.Format("0x%04X (%s)", bits, ComposeNameT(bits, end_segment_reason_names, "UNK", ESRB_NONE, "NONE").Data());
+	return out.Transfer();
+}
+
+/** cached segment cost for rail YAPF */
+struct CYapfRailSegment
+{
+	typedef CYapfRailSegmentKey Key;
+
+	CYapfRailSegmentKey    m_key;
+	TileIndex              m_last_tile;
+	Trackdir               m_last_td;
+	int                    m_cost;
+	TileIndex              m_last_signal_tile;
+	Trackdir               m_last_signal_td;
+	EndSegmentReasonBits   m_end_segment_reason;
+	CYapfRailSegment      *m_hash_next;
+
+	FORCEINLINE CYapfRailSegment(const CYapfRailSegmentKey& key)
+		: m_key(key)
+		, m_last_tile(INVALID_TILE)
+		, m_last_td(INVALID_TRACKDIR)
+		, m_cost(-1)
+		, m_last_signal_tile(INVALID_TILE)
+		, m_last_signal_td(INVALID_TRACKDIR)
+		, m_end_segment_reason(ESRB_NONE)
+		, m_hash_next(NULL)
+	{}
+
+	FORCEINLINE const Key& GetKey() const
+	{
+		return m_key;
+	}
+
+	FORCEINLINE TileIndex GetTile() const
+	{
+		return m_key.GetTile();
+	}
+
+	FORCEINLINE CYapfRailSegment *GetHashNext()
+	{
+		return m_hash_next;
+	}
+
+	FORCEINLINE void SetHashNext(CYapfRailSegment *next)
+	{
+		m_hash_next = next;
+	}
+
+	void Dump(DumpTarget &dmp) const
+	{
+		dmp.WriteStructT("m_key", &m_key);
+		dmp.WriteTile("m_last_tile", m_last_tile);
+		dmp.WriteEnumT("m_last_td", m_last_td);
+		dmp.WriteLine("m_cost = %d", m_cost);
+		dmp.WriteTile("m_last_signal_tile", m_last_signal_tile);
+		dmp.WriteEnumT("m_last_signal_td", m_last_signal_td);
+		dmp.WriteEnumT("m_end_segment_reason", m_end_segment_reason);
+	}
+};
+
+/** Yapf Node for rail YAPF */
+template <class Tkey_>
+struct CYapfRailNodeT
+	: CYapfNodeT<Tkey_, CYapfRailNodeT<Tkey_> >
+{
+	typedef CYapfNodeT<Tkey_, CYapfRailNodeT<Tkey_> > base;
+	typedef CYapfRailSegment CachedData;
+
+	CYapfRailSegment *m_segment;
+	uint16            m_num_signals_passed;
+	union {
+		uint32          m_inherited_flags;
+		struct {
+			bool          m_targed_seen : 1;
+			bool          m_choice_seen : 1;
+			bool          m_last_signal_was_red : 1;
+		} flags_s;
+	} flags_u;
+	SignalType        m_last_red_signal_type;
+
+	FORCEINLINE void Set(CYapfRailNodeT *parent, TileIndex tile, Trackdir td, bool is_choice)
+	{
+		base::Set(parent, tile, td, is_choice);
+		m_segment = NULL;
+		if (parent == NULL) {
+			m_num_signals_passed      = 0;
+			flags_u.m_inherited_flags = 0;
+			m_last_red_signal_type    = SIGTYPE_NORMAL;
+		} else {
+			m_num_signals_passed      = parent->m_num_signals_passed;
+			flags_u.m_inherited_flags = parent->flags_u.m_inherited_flags;
+			m_last_red_signal_type    = parent->m_last_red_signal_type;
+		}
+		flags_u.flags_s.m_choice_seen |= is_choice;
+	}
+
+	FORCEINLINE TileIndex GetLastTile() const
+	{
+		assert(m_segment != NULL);
+		return m_segment->m_last_tile;
+	}
+
+	FORCEINLINE Trackdir GetLastTrackdir() const
+	{
+		assert(m_segment != NULL);
+		return m_segment->m_last_td;
+	}
+
+	FORCEINLINE void SetLastTileTrackdir(TileIndex tile, Trackdir td)
+	{
+		assert(m_segment != NULL);
+		m_segment->m_last_tile = tile;
+		m_segment->m_last_td = td;
+	}
+
+	template <class Tbase, class Tfunc, class Tpf>
+	bool IterateTiles(const Vehicle *v, Tpf &yapf, Tbase &obj, bool (Tfunc::*func)(TileIndex, Trackdir)) const
+	{
+		typename Tbase::TrackFollower ft(v, yapf.GetCompatibleRailTypes());
+		TileIndex cur = base::GetTile();
+		Trackdir  cur_td = base::GetTrackdir();
+
+		while (cur != GetLastTile() || cur_td != GetLastTrackdir()) {
+			if (!((obj.*func)(cur, cur_td))) return false;
+
+			ft.Follow(cur, cur_td);
+			cur = ft.m_new_tile;
+			assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
+			cur_td = FindFirstTrackdir(ft.m_new_td_bits);
+		}
+
+		return (obj.*func)(cur, cur_td);
+	}
+
+	void Dump(DumpTarget &dmp) const
+	{
+		base::Dump(dmp);
+		dmp.WriteStructT("m_segment", m_segment);
+		dmp.WriteLine("m_num_signals_passed = %d", m_num_signals_passed);
+		dmp.WriteLine("m_targed_seen = %s", flags_u.flags_s.m_targed_seen ? "Yes" : "No");
+		dmp.WriteLine("m_choice_seen = %s", flags_u.flags_s.m_choice_seen ? "Yes" : "No");
+		dmp.WriteLine("m_last_signal_was_red = %s", flags_u.flags_s.m_last_signal_was_red ? "Yes" : "No");
+		dmp.WriteEnumT("m_last_red_signal_type", m_last_red_signal_type);
+	}
+};
+
+/* now define two major node types (that differ by key type) */
+typedef CYapfRailNodeT<CYapfNodeKeyExitDir>  CYapfRailNodeExitDir;
+typedef CYapfRailNodeT<CYapfNodeKeyTrackDir> CYapfRailNodeTrackDir;
+
+/* Default NodeList types */
+typedef CNodeList_HashTableT<CYapfRailNodeExitDir , 10, 12> CRailNodeListExitDir;
+typedef CNodeList_HashTableT<CYapfRailNodeTrackDir, 12, 16> CRailNodeListTrackDir;
+
+#endif /* YAPF_NODE_RAIL_HPP */

src/pathfinder/yapf/yapf_node_road.hpp

@@ -0,0 +1,41 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_node_road.hpp Node tailored for road pathfinding. */
+
+#ifndef  YAPF_NODE_ROAD_HPP
+#define  YAPF_NODE_ROAD_HPP
+
+/** Yapf Node for road YAPF */
+template <class Tkey_>
+struct CYapfRoadNodeT
+	: CYapfNodeT<Tkey_, CYapfRoadNodeT<Tkey_> >
+{
+	typedef CYapfNodeT<Tkey_, CYapfRoadNodeT<Tkey_> > base;
+
+	TileIndex       m_segment_last_tile;
+	Trackdir        m_segment_last_td;
+
+	void Set(CYapfRoadNodeT *parent, TileIndex tile, Trackdir td, bool is_choice)
+	{
+		base::Set(parent, tile, td, is_choice);
+		m_segment_last_tile = tile;
+		m_segment_last_td = td;
+	}
+};
+
+/* now define two major node types (that differ by key type) */
+typedef CYapfRoadNodeT<CYapfNodeKeyExitDir>  CYapfRoadNodeExitDir;
+typedef CYapfRoadNodeT<CYapfNodeKeyTrackDir> CYapfRoadNodeTrackDir;
+
+/* Default NodeList types */
+typedef CNodeList_HashTableT<CYapfRoadNodeExitDir , 8, 12> CRoadNodeListExitDir;
+typedef CNodeList_HashTableT<CYapfRoadNodeTrackDir, 10, 14> CRoadNodeListTrackDir;
+
+#endif /* YAPF_NODE_ROAD_HPP */

src/pathfinder/yapf/yapf_rail.cpp

@@ -0,0 +1,645 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_rail.cpp The rail pathfinding. */
+
+#include "../../stdafx.h"
+
+#include "yapf.hpp"
+#include "yapf_node_rail.hpp"
+#include "yapf_costrail.hpp"
+#include "yapf_destrail.hpp"
+#include "../../functions.h"
+
+#define DEBUG_YAPF_CACHE 0
+
+#if DEBUG_YAPF_CACHE
+template <typename Tpf> void DumpState(Tpf &pf1, Tpf &pf2)
+{
+	DumpTarget dmp1, dmp2;
+	pf1.DumpBase(dmp1);
+	pf2.DumpBase(dmp2);
+	FILE *f1 = fopen("yapf1.txt", "wt");
+	FILE *f2 = fopen("yapf2.txt", "wt");
+	fwrite(dmp1.m_out.Data(), 1, dmp1.m_out.Size(), f1);
+	fwrite(dmp2.m_out.Data(), 1, dmp2.m_out.Size(), f2);
+	fclose(f1);
+	fclose(f2);
+}
+#endif
+
+int _total_pf_time_us = 0;
+
+template <class Types>
+class CYapfReserveTrack
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+
+protected:
+	/** to access inherited pathfinder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+private:
+	TileIndex m_res_dest;         ///< The reservation target tile
+	Trackdir  m_res_dest_td;      ///< The reservation target trackdir
+	Node      *m_res_node;        ///< The reservation target node
+	TileIndex m_res_fail_tile;    ///< The tile where the reservation failed
+	Trackdir  m_res_fail_td;      ///< The trackdir where the reservation failed
+
+	bool FindSafePositionProc(TileIndex tile, Trackdir td)
+	{
+		if (IsSafeWaitingPosition(Train::From(Yapf().GetVehicle()), tile, td, true, !TrackFollower::Allow90degTurns())) {
+			m_res_dest = tile;
+			m_res_dest_td = td;
+			return false;   // Stop iterating segment
+		}
+		return true;
+	}
+
+	/** Reserve a railway platform. Tile contains the failed tile on abort. */
+	bool ReserveRailStationPlatform(TileIndex &tile, DiagDirection dir)
+	{
+		TileIndex     start = tile;
+		TileIndexDiff diff = TileOffsByDiagDir(dir);
+
+		do {
+			if (HasStationReservation(tile)) return false;
+			SetRailStationReservation(tile, true);
+			MarkTileDirtyByTile(tile);
+			tile = TILE_ADD(tile, diff);
+		} while (IsCompatibleTrainStationTile(tile, start));
+
+		return true;
+	}
+
+	/** Try to reserve a single track/platform. */
+	bool ReserveSingleTrack(TileIndex tile, Trackdir td)
+	{
+		if (IsRailStationTile(tile)) {
+			if (!ReserveRailStationPlatform(tile, TrackdirToExitdir(ReverseTrackdir(td)))) {
+				/* Platform could not be reserved, undo. */
+				m_res_fail_tile = tile;
+				m_res_fail_td = td;
+			}
+		} else {
+			if (!TryReserveRailTrack(tile, TrackdirToTrack(td))) {
+				/* Tile couldn't be reserved, undo. */
+				m_res_fail_tile = tile;
+				m_res_fail_td = td;
+				return false;
+			}
+		}
+
+		return tile != m_res_dest || td != m_res_dest_td;
+	}
+
+	/** Unreserve a single track/platform. Stops when the previous failer is reached. */
+	bool UnreserveSingleTrack(TileIndex tile, Trackdir td)
+	{
+		if (IsRailStationTile(tile)) {
+			TileIndex     start = tile;
+			TileIndexDiff diff = TileOffsByDiagDir(TrackdirToExitdir(ReverseTrackdir(td)));
+			while ((tile != m_res_fail_tile || td != m_res_fail_td) && IsCompatibleTrainStationTile(tile, start)) {
+				SetRailStationReservation(tile, false);
+				tile = TILE_ADD(tile, diff);
+			}
+		} else if (tile != m_res_fail_tile || td != m_res_fail_td) {
+			UnreserveRailTrack(tile, TrackdirToTrack(td));
+		}
+		return (tile != m_res_dest || td != m_res_dest_td) && (tile != m_res_fail_tile || td != m_res_fail_td);
+	}
+
+public:
+	/** Set the target to where the reservation should be extended. */
+	inline void SetReservationTarget(Node *node, TileIndex tile, Trackdir td)
+	{
+		m_res_node = node;
+		m_res_dest = tile;
+		m_res_dest_td = td;
+	}
+
+	/** Check the node for a possible reservation target. */
+	inline void FindSafePositionOnNode(Node *node)
+	{
+		assert(node->m_parent != NULL);
+
+		/* We will never pass more than two signals, no need to check for a safe tile. */
+		if (node->m_parent->m_num_signals_passed >= 2) return;
+
+		if (!node->IterateTiles(Yapf().GetVehicle(), Yapf(), *this, &CYapfReserveTrack<Types>::FindSafePositionProc)) {
+			m_res_node = node;
+		}
+	}
+
+	/** Try to reserve the path till the reservation target. */
+	bool TryReservePath(PBSTileInfo *target)
+	{
+		m_res_fail_tile = INVALID_TILE;
+
+		if (target != NULL) {
+			target->tile = m_res_dest;
+			target->trackdir = m_res_dest_td;
+			target->okay = false;
+		}
+
+		/* Don't bother if the target is reserved. */
+		if (!IsWaitingPositionFree(Train::From(Yapf().GetVehicle()), m_res_dest, m_res_dest_td)) return false;
+
+		for (Node *node = m_res_node; node->m_parent != NULL; node = node->m_parent) {
+			node->IterateTiles(Yapf().GetVehicle(), Yapf(), *this, &CYapfReserveTrack<Types>::ReserveSingleTrack);
+			if (m_res_fail_tile != INVALID_TILE) {
+				/* Reservation failed, undo. */
+				Node *fail_node = m_res_node;
+				TileIndex stop_tile = m_res_fail_tile;
+				do {
+					/* If this is the node that failed, stop at the failed tile. */
+					m_res_fail_tile = fail_node == node ? stop_tile : INVALID_TILE;
+					fail_node->IterateTiles(Yapf().GetVehicle(), Yapf(), *this, &CYapfReserveTrack<Types>::UnreserveSingleTrack);
+				} while (fail_node != node && (fail_node = fail_node->m_parent) != NULL);
+
+				return false;
+			}
+		}
+
+		if (target != NULL) target->okay = true;
+
+		if (Yapf().CanUseGlobalCache(*m_res_node))
+			YapfNotifyTrackLayoutChange(INVALID_TILE, INVALID_TRACK);
+
+		return true;
+	}
+};
+
+template <class Types>
+class CYapfFollowAnyDepotRailT
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+protected:
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to move from the given node to the next tile. For each
+	 *  reachable trackdir on the new tile creates new node, initializes it
+	 *  and adds it to the open list by calling Yapf().AddNewNode(n) */
+	inline void PfFollowNode(Node& old_node)
+	{
+		TrackFollower F(Yapf().GetVehicle());
+		if (F.Follow(old_node.GetLastTile(), old_node.GetLastTrackdir())) {
+			Yapf().AddMultipleNodes(&old_node, F);
+		}
+	}
+
+	/** return debug report character to identify the transportation type */
+	FORCEINLINE char TransportTypeChar() const
+	{
+		return 't';
+	}
+
+	static bool stFindNearestDepotTwoWay(const Vehicle *v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int max_distance, int reverse_penalty, TileIndex *depot_tile, bool *reversed)
+	{
+		Tpf pf1;
+		/*
+		 * With caching enabled it simply cannot get a reliable result when you
+		 * have limited the distance a train may travel. This means that the
+		 * cached result does not match uncached result in all cases and that
+		 * causes desyncs. So disable caching when finding for a depot that is
+		 * nearby. This only happens with automatic servicing of vehicles,
+		 * so it will only impact performance when you do not manually set
+		 * depot orders and you do not disable automatic servicing.
+		 */
+		if (max_distance != 0) pf1.DisableCache(true);
+		bool result1 = pf1.FindNearestDepotTwoWay(v, t1, td1, t2, td2, max_distance, reverse_penalty, depot_tile, reversed);
+
+#if DEBUG_YAPF_CACHE
+		Tpf pf2;
+		TileIndex depot_tile2 = INVALID_TILE;
+		bool reversed2 = false;
+		pf2.DisableCache(true);
+		bool result2 = pf2.FindNearestDepotTwoWay(v, t1, td1, t2, td2, max_distance, reverse_penalty, &depot_tile2, &reversed2);
+		if (result1 != result2 || (result1 && (*depot_tile != depot_tile2 || *reversed != reversed2))) {
+			DEBUG(yapf, 0, "CACHE ERROR: FindNearestDepotTwoWay() = [%s, %s]", result1 ? "T" : "F", result2 ? "T" : "F");
+			DumpState(pf1, pf2);
+		}
+#endif
+
+		return result1;
+	}
+
+	FORCEINLINE bool FindNearestDepotTwoWay(const Vehicle *v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int max_distance, int reverse_penalty, TileIndex *depot_tile, bool *reversed)
+	{
+		/* set origin and destination nodes */
+		Yapf().SetOrigin(t1, td1, t2, td2, reverse_penalty, true);
+		Yapf().SetDestination(v);
+		Yapf().SetMaxCost(YAPF_TILE_LENGTH * max_distance);
+
+		/* find the best path */
+		bool bFound = Yapf().FindPath(v);
+		if (!bFound) return false;
+
+		/* some path found
+		 * get found depot tile */
+		Node *n = Yapf().GetBestNode();
+		*depot_tile = n->GetLastTile();
+
+		/* walk through the path back to the origin */
+		Node *pNode = n;
+		while (pNode->m_parent != NULL) {
+			pNode = pNode->m_parent;
+		}
+
+		/* if the origin node is our front vehicle tile/Trackdir then we didn't reverse
+		 * but we can also look at the cost (== 0 -> not reversed, == reverse_penalty -> reversed) */
+		*reversed = (pNode->m_cost != 0);
+
+		return true;
+	}
+};
+
+template <class Types>
+class CYapfFollowAnySafeTileRailT : public CYapfReserveTrack<Types>
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+protected:
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to move from the given node to the next tile. For each
+	 *  reachable trackdir on the new tile creates new node, initializes it
+	 *  and adds it to the open list by calling Yapf().AddNewNode(n) */
+	inline void PfFollowNode(Node& old_node)
+	{
+		TrackFollower F(Yapf().GetVehicle(), Yapf().GetCompatibleRailTypes());
+		if (F.Follow(old_node.GetLastTile(), old_node.GetLastTrackdir()) && F.MaskReservedTracks()) {
+			Yapf().AddMultipleNodes(&old_node, F);
+		}
+	}
+
+	/** Return debug report character to identify the transportation type */
+	FORCEINLINE char TransportTypeChar() const
+	{
+		return 't';
+	}
+
+	static bool stFindNearestSafeTile(const Vehicle *v, TileIndex t1, Trackdir td, bool override_railtype)
+	{
+		/* Create pathfinder instance */
+		Tpf pf1;
+#if !DEBUG_YAPF_CACHE
+		bool result1 = pf1.FindNearestSafeTile(v, t1, td, override_railtype, false);
+
+#else
+		bool result2 = pf1.FindNearestSafeTile(v, t1, td, override_railtype, true);
+		Tpf pf2;
+		pf2.DisableCache(true);
+		bool result1 = pf2.FindNearestSafeTile(v, t1, td, override_railtype, false);
+		if (result1 != result2) {
+			DEBUG(yapf, 0, "CACHE ERROR: FindSafeTile() = [%s, %s]", result2 ? "T" : "F", result1 ? "T" : "F");
+			DumpState(pf1, pf2);
+		}
+#endif
+
+		return result1;
+	}
+
+	bool FindNearestSafeTile(const Vehicle *v, TileIndex t1, Trackdir td, bool override_railtype, bool dont_reserve)
+	{
+		/* Set origin and destination. */
+		Yapf().SetOrigin(t1, td);
+		Yapf().SetDestination(v, override_railtype);
+
+		bool bFound = Yapf().FindPath(v);
+		if (!bFound) return false;
+
+		/* Found a destination, set as reservation target. */
+		Node *pNode = Yapf().GetBestNode();
+		this->SetReservationTarget(pNode, pNode->GetLastTile(), pNode->GetLastTrackdir());
+
+		/* Walk through the path back to the origin. */
+		Node *pPrev = NULL;
+		while (pNode->m_parent != NULL) {
+			pPrev = pNode;
+			pNode = pNode->m_parent;
+
+			this->FindSafePositionOnNode(pPrev);
+		}
+
+		return dont_reserve || this->TryReservePath(NULL);
+	}
+};
+
+template <class Types>
+class CYapfFollowRailT : public CYapfReserveTrack<Types>
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+protected:
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to move from the given node to the next tile. For each
+	 *  reachable trackdir on the new tile creates new node, initializes it
+	 *  and adds it to the open list by calling Yapf().AddNewNode(n) */
+	inline void PfFollowNode(Node& old_node)
+	{
+		TrackFollower F(Yapf().GetVehicle());
+		if (F.Follow(old_node.GetLastTile(), old_node.GetLastTrackdir())) {
+			Yapf().AddMultipleNodes(&old_node, F);
+		}
+	}
+
+	/** return debug report character to identify the transportation type */
+	FORCEINLINE char TransportTypeChar() const
+	{
+		return 't';
+	}
+
+	static Trackdir stChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target)
+	{
+		/* create pathfinder instance */
+		Tpf pf1;
+#if !DEBUG_YAPF_CACHE
+		Trackdir result1 = pf1.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found, reserve_track, target);
+
+#else
+		Trackdir result1 = pf1.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found, false, NULL);
+		Tpf pf2;
+		pf2.DisableCache(true);
+		Trackdir result2 = pf2.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found, reserve_track, target);
+		if (result1 != result2) {
+			DEBUG(yapf, 0, "CACHE ERROR: ChooseRailTrack() = [%d, %d]", result1, result2);
+			DumpState(pf1, pf2);
+		}
+#endif
+
+		return result1;
+	}
+
+	FORCEINLINE Trackdir ChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target)
+	{
+		if (target != NULL) target->tile = INVALID_TILE;
+
+		/* set origin and destination nodes */
+		PBSTileInfo origin = FollowTrainReservation(Train::From(v));
+		Yapf().SetOrigin(origin.tile, origin.trackdir, INVALID_TILE, INVALID_TRACKDIR, 1, true);
+		Yapf().SetDestination(v);
+
+		/* find the best path */
+		bool path_found = Yapf().FindPath(v);
+		if (path_not_found != NULL) {
+			/* tell controller that the path was only 'guessed'
+			 * treat the path as found if stopped on the first two way signal(s) */
+			*path_not_found = !(path_found || Yapf().m_stopped_on_first_two_way_signal);
+		}
+
+		/* if path not found - return INVALID_TRACKDIR */
+		Trackdir next_trackdir = INVALID_TRACKDIR;
+		Node *pNode = Yapf().GetBestNode();
+		if (pNode != NULL) {
+			/* reserve till end of path */
+			this->SetReservationTarget(pNode, pNode->GetLastTile(), pNode->GetLastTrackdir());
+
+			/* path was found or at least suggested
+			 * walk through the path back to the origin */
+			Node *pPrev = NULL;
+			while (pNode->m_parent != NULL) {
+				pPrev = pNode;
+				pNode = pNode->m_parent;
+
+				this->FindSafePositionOnNode(pPrev);
+			}
+			/* return trackdir from the best origin node (one of start nodes) */
+			Node& best_next_node = *pPrev;
+			next_trackdir = best_next_node.GetTrackdir();
+
+			if (reserve_track && path_found) this->TryReservePath(target);
+		}
+		return next_trackdir;
+	}
+
+	static bool stCheckReverseTrain(const Vehicle *v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int reverse_penalty)
+	{
+		Tpf pf1;
+		bool result1 = pf1.CheckReverseTrain(v, t1, td1, t2, td2, reverse_penalty);
+
+#if DEBUG_YAPF_CACHE
+		Tpf pf2;
+		pf2.DisableCache(true);
+		bool result2 = pf2.CheckReverseTrain(v, t1, td1, t2, td2, reverse_penalty);
+		if (result1 != result2) {
+			DEBUG(yapf, 0, "CACHE ERROR: CheckReverseTrain() = [%s, %s]", result1 ? "T" : "F", result2 ? "T" : "F");
+			DumpState(pf1, pf2);
+		}
+#endif
+
+		return result1;
+	}
+
+	FORCEINLINE bool CheckReverseTrain(const Vehicle *v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int reverse_penalty)
+	{
+		/* create pathfinder instance
+		 * set origin and destination nodes */
+		Yapf().SetOrigin(t1, td1, t2, td2, reverse_penalty, false);
+		Yapf().SetDestination(v);
+
+		/* find the best path */
+		bool bFound = Yapf().FindPath(v);
+
+		if (!bFound) return false;
+
+		/* path was found
+		 * walk through the path back to the origin */
+		Node *pNode = Yapf().GetBestNode();
+		while (pNode->m_parent != NULL) {
+			pNode = pNode->m_parent;
+		}
+
+		/* check if it was reversed origin */
+		Node& best_org_node = *pNode;
+		bool reversed = (best_org_node.m_cost != 0);
+		return reversed;
+	}
+};
+
+template <class Tpf_, class Ttrack_follower, class Tnode_list, template <class Types> class TdestinationT, template <class Types> class TfollowT>
+struct CYapfRail_TypesT
+{
+	typedef CYapfRail_TypesT<Tpf_, Ttrack_follower, Tnode_list, TdestinationT, TfollowT>  Types;
+
+	typedef Tpf_                                Tpf;
+	typedef Ttrack_follower                     TrackFollower;
+	typedef Tnode_list                          NodeList;
+	typedef CYapfBaseT<Types>                   PfBase;
+	typedef TfollowT<Types>                     PfFollow;
+	typedef CYapfOriginTileTwoWayT<Types>       PfOrigin;
+	typedef TdestinationT<Types>                PfDestination;
+	typedef CYapfSegmentCostCacheGlobalT<Types> PfCache;
+	typedef CYapfCostRailT<Types>               PfCost;
+};
+
+struct CYapfRail1         : CYapfT<CYapfRail_TypesT<CYapfRail1        , CFollowTrackRail    , CRailNodeListTrackDir, CYapfDestinationTileOrStationRailT, CYapfFollowRailT> > {};
+struct CYapfRail2         : CYapfT<CYapfRail_TypesT<CYapfRail2        , CFollowTrackRailNo90, CRailNodeListTrackDir, CYapfDestinationTileOrStationRailT, CYapfFollowRailT> > {};
+
+struct CYapfAnyDepotRail1 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail1, CFollowTrackRail    , CRailNodeListTrackDir, CYapfDestinationAnyDepotRailT     , CYapfFollowAnyDepotRailT> > {};
+struct CYapfAnyDepotRail2 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail2, CFollowTrackRailNo90, CRailNodeListTrackDir, CYapfDestinationAnyDepotRailT     , CYapfFollowAnyDepotRailT> > {};
+
+struct CYapfAnySafeTileRail1 : CYapfT<CYapfRail_TypesT<CYapfAnySafeTileRail1, CFollowTrackFreeRail    , CRailNodeListTrackDir, CYapfDestinationAnySafeTileRailT , CYapfFollowAnySafeTileRailT> > {};
+struct CYapfAnySafeTileRail2 : CYapfT<CYapfRail_TypesT<CYapfAnySafeTileRail2, CFollowTrackFreeRailNo90, CRailNodeListTrackDir, CYapfDestinationAnySafeTileRailT , CYapfFollowAnySafeTileRailT> > {};
+
+
+Trackdir YapfChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target)
+{
+	/* default is YAPF type 2 */
+	typedef Trackdir (*PfnChooseRailTrack)(const Vehicle*, TileIndex, DiagDirection, TrackBits, bool*, bool, PBSTileInfo*);
+	PfnChooseRailTrack pfnChooseRailTrack = &CYapfRail1::stChooseRailTrack;
+
+	/* check if non-default YAPF type needed */
+	if (_settings_game.pf.forbid_90_deg) {
+		pfnChooseRailTrack = &CYapfRail2::stChooseRailTrack; // Trackdir, forbid 90-deg
+	}
+
+	Trackdir td_ret = pfnChooseRailTrack(v, tile, enterdir, tracks, path_not_found, reserve_track, target);
+
+	return td_ret;
+}
+
+bool YapfCheckReverseTrain(const Vehicle *vt)
+{
+	const Train *v = Train::From(vt);
+	const Train *last_veh = v->Last();
+
+	/* get trackdirs of both ends */
+	Trackdir td = v->GetVehicleTrackdir();
+	Trackdir td_rev = ReverseTrackdir(last_veh->GetVehicleTrackdir());
+
+	/* tiles where front and back are */
+	TileIndex tile = v->tile;
+	TileIndex tile_rev = last_veh->tile;
+
+	int reverse_penalty = 0;
+
+	if (v->track == TRACK_BIT_WORMHOLE) {
+		/* front in tunnel / on bridge */
+		DiagDirection dir_into_wormhole = GetTunnelBridgeDirection(tile);
+
+		if (TrackdirToExitdir(td) == dir_into_wormhole) tile = GetOtherTunnelBridgeEnd(tile);
+		/* Now 'tile' is the tunnel entry/bridge ramp the train will reach when driving forward */
+
+		/* Current position of the train in the wormhole */
+		TileIndex cur_tile = TileVirtXY(v->x_pos, v->y_pos);
+
+		/* Add distance to drive in the wormhole as penalty for the forward path, i.e. bonus for the reverse path
+		 * Note: Negative penalties are ok for the start tile. */
+		reverse_penalty -= DistanceManhattan(cur_tile, tile) * YAPF_TILE_LENGTH;
+	}
+
+	if (last_veh->track == TRACK_BIT_WORMHOLE) {
+		/* back in tunnel / on bridge */
+		DiagDirection dir_into_wormhole = GetTunnelBridgeDirection(tile_rev);
+
+		if (TrackdirToExitdir(td_rev) == dir_into_wormhole) tile_rev = GetOtherTunnelBridgeEnd(tile_rev);
+		/* Now 'tile_rev' is the tunnel entry/bridge ramp the train will reach when reversing */
+
+		/* Current position of the last wagon in the wormhole */
+		TileIndex cur_tile = TileVirtXY(last_veh->x_pos, last_veh->y_pos);
+
+		/* Add distance to drive in the wormhole as penalty for the revere path. */
+		reverse_penalty += DistanceManhattan(cur_tile, tile_rev) * YAPF_TILE_LENGTH;
+	}
+
+	typedef bool (*PfnCheckReverseTrain)(const Vehicle*, TileIndex, Trackdir, TileIndex, Trackdir, int);
+	PfnCheckReverseTrain pfnCheckReverseTrain = CYapfRail1::stCheckReverseTrain;
+
+	/* check if non-default YAPF type needed */
+	if (_settings_game.pf.forbid_90_deg) {
+		pfnCheckReverseTrain = &CYapfRail2::stCheckReverseTrain; // Trackdir, forbid 90-deg
+	}
+
+	/* slightly hackish: If the pathfinders finds a path, the cost of the first node is tested to distinguish between forward- and reverse-path. */
+	if (reverse_penalty == 0) reverse_penalty = 1;
+
+	bool reverse = pfnCheckReverseTrain(v, tile, td, tile_rev, td_rev, reverse_penalty);
+
+	return reverse;
+}
+
+bool YapfFindNearestRailDepotTwoWay(const Vehicle *v, int max_distance, int reverse_penalty, TileIndex *depot_tile, bool *reversed)
+{
+	*depot_tile = INVALID_TILE;
+	*reversed = false;
+
+	const Vehicle *last_veh = v->Last();
+
+	PBSTileInfo origin = FollowTrainReservation(Train::From(v));
+	TileIndex last_tile = last_veh->tile;
+	Trackdir td_rev = ReverseTrackdir(last_veh->GetVehicleTrackdir());
+
+	typedef bool (*PfnFindNearestDepotTwoWay)(const Vehicle*, TileIndex, Trackdir, TileIndex, Trackdir, int, int, TileIndex*, bool*);
+	PfnFindNearestDepotTwoWay pfnFindNearestDepotTwoWay = &CYapfAnyDepotRail1::stFindNearestDepotTwoWay;
+
+	/* check if non-default YAPF type needed */
+	if (_settings_game.pf.forbid_90_deg) {
+		pfnFindNearestDepotTwoWay = &CYapfAnyDepotRail2::stFindNearestDepotTwoWay; // Trackdir, forbid 90-deg
+	}
+
+	bool ret = pfnFindNearestDepotTwoWay(v, origin.tile, origin.trackdir, last_tile, td_rev, max_distance, reverse_penalty, depot_tile, reversed);
+	return ret;
+}
+
+bool YapfRailFindNearestSafeTile(const Vehicle *v, TileIndex tile, Trackdir td, bool override_railtype)
+{
+	typedef bool (*PfnFindNearestSafeTile)(const Vehicle*, TileIndex, Trackdir, bool);
+	PfnFindNearestSafeTile pfnFindNearestSafeTile = CYapfAnySafeTileRail1::stFindNearestSafeTile;
+
+	/* check if non-default YAPF type needed */
+	if (_settings_game.pf.forbid_90_deg) {
+		pfnFindNearestSafeTile = &CYapfAnySafeTileRail2::stFindNearestSafeTile;
+	}
+
+	return pfnFindNearestSafeTile(v, tile, td, override_railtype);
+}
+
+/** if any track changes, this counter is incremented - that will invalidate segment cost cache */
+int CSegmentCostCacheBase::s_rail_change_counter = 0;
+
+void YapfNotifyTrackLayoutChange(TileIndex tile, Track track)
+{
+	CSegmentCostCacheBase::NotifyTrackLayoutChange(tile, track);
+}

src/pathfinder/yapf/yapf_road.cpp

@@ -0,0 +1,631 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_road.cpp The road pathfinding. */
+
+#include "../../stdafx.h"
+#include "../../roadstop_base.h"
+#include "../../cargotype.h"
+
+#include "yapf.hpp"
+#include "yapf_node_road.hpp"
+
+
+template <class Types>
+class CYapfCostRoadT
+{
+public:
+	typedef typename Types::Tpf Tpf; ///< pathfinder (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower; ///< track follower helper
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;    ///< key to hash tables
+
+protected:
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+	int SlopeCost(TileIndex tile, TileIndex next_tile, Trackdir trackdir)
+	{
+		/* height of the center of the current tile */
+		int x1 = TileX(tile) * TILE_SIZE;
+		int y1 = TileY(tile) * TILE_SIZE;
+		int z1 = GetSlopeZ(x1 + TILE_SIZE / 2, y1 + TILE_SIZE / 2);
+
+		/* height of the center of the next tile */
+		int x2 = TileX(next_tile) * TILE_SIZE;
+		int y2 = TileY(next_tile) * TILE_SIZE;
+		int z2 = GetSlopeZ(x2 + TILE_SIZE / 2, y2 + TILE_SIZE / 2);
+
+		if (z2 - z1 > 1) {
+			/* Slope up */
+			return Yapf().PfGetSettings().road_slope_penalty;
+		}
+		return 0;
+	}
+
+	/** return one tile cost */
+	FORCEINLINE int OneTileCost(TileIndex tile, Trackdir trackdir)
+	{
+		int cost = 0;
+		/* set base cost */
+		if (IsDiagonalTrackdir(trackdir)) {
+			cost += YAPF_TILE_LENGTH;
+			switch (GetTileType(tile)) {
+				case MP_ROAD:
+					/* Increase the cost for level crossings */
+					if (IsLevelCrossing(tile)) {
+						cost += Yapf().PfGetSettings().road_crossing_penalty;
+					}
+					break;
+
+				case MP_STATION:
+					if (IsDriveThroughStopTile(tile)) {
+						cost += Yapf().PfGetSettings().road_stop_penalty;
+					}
+					break;
+
+				default:
+					break;
+			}
+		} else {
+			/* non-diagonal trackdir */
+			cost = YAPF_TILE_CORNER_LENGTH + Yapf().PfGetSettings().road_curve_penalty;
+		}
+		return cost;
+	}
+
+public:
+	/** Called by YAPF to calculate the cost from the origin to the given node.
+	 *  Calculates only the cost of given node, adds it to the parent node cost
+	 *  and stores the result into Node::m_cost member */
+	FORCEINLINE bool PfCalcCost(Node& n, const TrackFollower *tf)
+	{
+		int segment_cost = 0;
+		/* start at n.m_key.m_tile / n.m_key.m_td and walk to the end of segment */
+		TileIndex tile = n.m_key.m_tile;
+		Trackdir trackdir = n.m_key.m_td;
+		while (true) {
+			/* base tile cost depending on distance between edges */
+			segment_cost += Yapf().OneTileCost(tile, trackdir);
+
+			const Vehicle *v = Yapf().GetVehicle();
+			/* we have reached the vehicle's destination - segment should end here to avoid target skipping */
+			if (Yapf().PfDetectDestinationTile(tile, trackdir)) break;
+
+			/* stop if we have just entered the depot */
+			if (IsRoadDepotTile(tile) && trackdir == DiagDirToDiagTrackdir(ReverseDiagDir(GetRoadDepotDirection(tile)))) {
+				/* next time we will reverse and leave the depot */
+				break;
+			}
+
+			/* if there are no reachable trackdirs on new tile, we have end of road */
+			TrackFollower F(Yapf().GetVehicle());
+			if (!F.Follow(tile, trackdir)) break;
+
+			/* if there are more trackdirs available & reachable, we are at the end of segment */
+			if (KillFirstBit(F.m_new_td_bits) != TRACKDIR_BIT_NONE) break;
+
+			Trackdir new_td = (Trackdir)FindFirstBit2x64(F.m_new_td_bits);
+
+			/* stop if RV is on simple loop with no junctions */
+			if (F.m_new_tile == n.m_key.m_tile && new_td == n.m_key.m_td) return false;
+
+			/* if we skipped some tunnel tiles, add their cost */
+			segment_cost += F.m_tiles_skipped * YAPF_TILE_LENGTH;
+
+			/* add hilly terrain penalty */
+			segment_cost += Yapf().SlopeCost(tile, F.m_new_tile, trackdir);
+
+			/* add min/max speed penalties */
+			int min_speed = 0;
+			int max_speed = F.GetSpeedLimit(&min_speed);
+			if (max_speed < v->max_speed) segment_cost += 1 * (v->max_speed - max_speed);
+			if (min_speed > v->max_speed) segment_cost += 10 * (min_speed - v->max_speed);
+
+			/* move to the next tile */
+			tile = F.m_new_tile;
+			trackdir = new_td;
+		};
+
+		/* save end of segment back to the node */
+		n.m_segment_last_tile = tile;
+		n.m_segment_last_td = trackdir;
+
+		/* save also tile cost */
+		int parent_cost = (n.m_parent != NULL) ? n.m_parent->m_cost : 0;
+		n.m_cost = parent_cost + segment_cost;
+		return true;
+	}
+};
+
+
+template <class Types>
+class CYapfDestinationAnyDepotRoadT
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		bool bDest = IsRoadDepotTile(n.m_segment_last_tile);
+		return bDest;
+	}
+
+	FORCEINLINE bool PfDetectDestinationTile(TileIndex tile, Trackdir trackdir)
+	{
+		return IsRoadDepotTile(tile);
+	}
+
+	/** Called by YAPF to calculate cost estimate. Calculates distance to the destination
+	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate */
+	FORCEINLINE bool PfCalcEstimate(Node& n)
+	{
+		n.m_estimate = n.m_cost;
+		return true;
+	}
+};
+
+
+template <class Types>
+class CYapfDestinationAnyRoadVehicleCompatibleStopOfGivenStationT
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+	TileIndex      m_destTile;
+	StationID      m_dest_station;
+	bool           m_bus;
+	bool           m_non_artic;
+
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+	void SetDestination(const RoadVehicle *v, StationID sid, TileIndex destTile)
+	{
+		m_dest_station = sid;
+		m_destTile     = destTile;
+		m_bus          = IsCargoInClass(v->cargo_type, CC_PASSENGERS);
+		m_non_artic    = !v->HasArticulatedPart();
+	}
+
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		return PfDetectDestinationTile(n.m_segment_last_tile, INVALID_TRACKDIR);
+	}
+
+	FORCEINLINE bool PfDetectDestinationTile(TileIndex tile, Trackdir trackdir)
+	{
+		return
+			IsTileType(tile, MP_STATION) &&
+			GetStationIndex(tile) == m_dest_station &&
+			(m_bus ? IsBusStop(tile) : IsTruckStop(tile)) &&
+			(m_non_artic || IsDriveThroughStopTile(tile));
+	}
+
+	/** Called by YAPF to calculate cost estimate. Calculates distance to the destination
+	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate */
+	FORCEINLINE bool PfCalcEstimate(Node& n)
+	{
+		static const int dg_dir_to_x_offs[] = {-1, 0, 1, 0};
+		static const int dg_dir_to_y_offs[] = {0, 1, 0, -1};
+		if (PfDetectDestination(n)) {
+			n.m_estimate = n.m_cost;
+			return true;
+		}
+
+		TileIndex tile = n.m_segment_last_tile;
+		DiagDirection exitdir = TrackdirToExitdir(n.m_segment_last_td);
+		int x1 = 2 * TileX(tile) + dg_dir_to_x_offs[(int)exitdir];
+		int y1 = 2 * TileY(tile) + dg_dir_to_y_offs[(int)exitdir];
+		int x2 = 2 * TileX(m_destTile);
+		int y2 = 2 * TileY(m_destTile);
+		int dx = abs(x1 - x2);
+		int dy = abs(y1 - y2);
+		int dmin = min(dx, dy);
+		int dxy = abs(dx - dy);
+		int d = dmin * YAPF_TILE_CORNER_LENGTH + (dxy - 1) * (YAPF_TILE_LENGTH / 2);
+		n.m_estimate = n.m_cost + d;
+		assert(n.m_estimate >= n.m_parent->m_estimate);
+		return true;
+	}
+};
+
+
+template <class Types>
+class CYapfDestinationTileRoadT
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+protected:
+	TileIndex    m_destTile;
+	TrackdirBits m_destTrackdirs;
+
+public:
+	void SetDestination(TileIndex tile, TrackdirBits trackdirs)
+	{
+		m_destTile = tile;
+		m_destTrackdirs = trackdirs;
+	}
+
+protected:
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to detect if node ends in the desired destination */
+	FORCEINLINE bool PfDetectDestination(Node& n)
+	{
+		bool bDest = (n.m_segment_last_tile == m_destTile) && ((m_destTrackdirs & TrackdirToTrackdirBits(n.m_segment_last_td)) != TRACKDIR_BIT_NONE);
+		return bDest;
+	}
+
+	FORCEINLINE bool PfDetectDestinationTile(TileIndex tile, Trackdir trackdir)
+	{
+		return tile == m_destTile && ((m_destTrackdirs & TrackdirToTrackdirBits(trackdir)) != TRACKDIR_BIT_NONE);
+	}
+
+	/** Called by YAPF to calculate cost estimate. Calculates distance to the destination
+	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate */
+	inline bool PfCalcEstimate(Node& n)
+	{
+		static const int dg_dir_to_x_offs[] = {-1, 0, 1, 0};
+		static const int dg_dir_to_y_offs[] = {0, 1, 0, -1};
+		if (PfDetectDestination(n)) {
+			n.m_estimate = n.m_cost;
+			return true;
+		}
+
+		TileIndex tile = n.m_segment_last_tile;
+		DiagDirection exitdir = TrackdirToExitdir(n.m_segment_last_td);
+		int x1 = 2 * TileX(tile) + dg_dir_to_x_offs[(int)exitdir];
+		int y1 = 2 * TileY(tile) + dg_dir_to_y_offs[(int)exitdir];
+		int x2 = 2 * TileX(m_destTile);
+		int y2 = 2 * TileY(m_destTile);
+		int dx = abs(x1 - x2);
+		int dy = abs(y1 - y2);
+		int dmin = min(dx, dy);
+		int dxy = abs(dx - dy);
+		int d = dmin * YAPF_TILE_CORNER_LENGTH + (dxy - 1) * (YAPF_TILE_LENGTH / 2);
+		n.m_estimate = n.m_cost + d;
+		assert(n.m_estimate >= n.m_parent->m_estimate);
+		return true;
+	}
+};
+
+
+
+template <class Types>
+class CYapfFollowRoadT
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+protected:
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+
+	/** Called by YAPF to move from the given node to the next tile. For each
+	 *  reachable trackdir on the new tile creates new node, initializes it
+	 *  and adds it to the open list by calling Yapf().AddNewNode(n) */
+	inline void PfFollowNode(Node& old_node)
+	{
+		TrackFollower F(Yapf().GetVehicle());
+		if (F.Follow(old_node.m_segment_last_tile, old_node.m_segment_last_td)) {
+			Yapf().AddMultipleNodes(&old_node, F);
+		}
+	}
+
+	/** return debug report character to identify the transportation type */
+	FORCEINLINE char TransportTypeChar() const
+	{
+		return 'r';
+	}
+
+	static Trackdir stChooseRoadTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir)
+	{
+		Tpf pf;
+		return pf.ChooseRoadTrack(v, tile, enterdir);
+	}
+
+	FORCEINLINE Trackdir ChooseRoadTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir)
+	{
+		/* handle special case - when next tile is destination tile */
+		if (tile == v->dest_tile) {
+			/* choose diagonal trackdir reachable from enterdir */
+			return DiagDirToDiagTrackdir(enterdir);
+		}
+		/* our source tile will be the next vehicle tile (should be the given one) */
+		TileIndex src_tile = tile;
+		/* get available trackdirs on the start tile */
+		TrackdirBits src_trackdirs = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_ROAD, RoadVehicle::From(v)->compatible_roadtypes));
+		/* select reachable trackdirs only */
+		src_trackdirs &= DiagdirReachesTrackdirs(enterdir);
+
+		/* get available trackdirs on the destination tile */
+		TileIndex dest_tile = v->dest_tile;
+		TrackdirBits dest_trackdirs = TrackStatusToTrackdirBits(GetTileTrackStatus(dest_tile, TRANSPORT_ROAD, RoadVehicle::From(v)->compatible_roadtypes));
+
+		/* set origin and destination nodes */
+		Yapf().SetOrigin(src_tile, src_trackdirs);
+		Yapf().SetDestination(dest_tile, dest_trackdirs);
+
+		/* find the best path */
+		Yapf().FindPath(v);
+
+		/* if path not found - return INVALID_TRACKDIR */
+		Trackdir next_trackdir = INVALID_TRACKDIR;
+		Node *pNode = Yapf().GetBestNode();
+		if (pNode != NULL) {
+			/* path was found or at least suggested
+			 * walk through the path back to its origin */
+			while (pNode->m_parent != NULL) {
+				pNode = pNode->m_parent;
+			}
+			/* return trackdir from the best origin node (one of start nodes) */
+			Node& best_next_node = *pNode;
+			assert(best_next_node.GetTile() == tile);
+			next_trackdir = best_next_node.GetTrackdir();
+		}
+		return next_trackdir;
+	}
+
+	static uint stDistanceToTile(const Vehicle *v, TileIndex tile)
+	{
+		Tpf pf;
+		return pf.DistanceToTile(v, tile);
+	}
+
+	FORCEINLINE uint DistanceToTile(const Vehicle *v, TileIndex dst_tile)
+	{
+		/* handle special case - when current tile is the destination tile */
+		if (dst_tile == v->tile) {
+			/* distance is zero in this case */
+			return 0;
+		}
+
+		if (!SetOriginFromVehiclePos(v)) return UINT_MAX;
+
+		/* set destination tile, trackdir
+		 *   get available trackdirs on the destination tile */
+		TrackdirBits dst_td_bits = TrackStatusToTrackdirBits(GetTileTrackStatus(dst_tile, TRANSPORT_ROAD, RoadVehicle::From(v)->compatible_roadtypes));
+		Yapf().SetDestination(dst_tile, dst_td_bits);
+
+		/* if path not found - return distance = UINT_MAX */
+		uint dist = UINT_MAX;
+
+		/* find the best path */
+		if (!Yapf().FindPath(v)) return dist;
+
+		Node *pNode = Yapf().GetBestNode();
+		if (pNode != NULL) {
+			/* path was found
+			 * get the path cost estimate */
+			dist = pNode->GetCostEstimate();
+		}
+
+		return dist;
+	}
+
+	/** Return true if the valid origin (tile/trackdir) was set from the current vehicle position. */
+	FORCEINLINE bool SetOriginFromVehiclePos(const Vehicle *v)
+	{
+		/* set origin (tile, trackdir) */
+		TileIndex src_tile = v->tile;
+		Trackdir src_td = v->GetVehicleTrackdir();
+		if ((TrackStatusToTrackdirBits(GetTileTrackStatus(src_tile, TRANSPORT_ROAD, RoadVehicle::From(v)->compatible_roadtypes)) & TrackdirToTrackdirBits(src_td)) == 0) {
+			/* sometimes the roadveh is not on the road (it resides on non-existing track)
+			 * how should we handle that situation? */
+			return false;
+		}
+		Yapf().SetOrigin(src_tile, TrackdirToTrackdirBits(src_td));
+		return true;
+	}
+
+	static bool stFindNearestDepot(const Vehicle *v, TileIndex tile, Trackdir td, int max_distance, TileIndex *depot_tile)
+	{
+		Tpf pf;
+		return pf.FindNearestDepot(v, tile, td, max_distance, depot_tile);
+	}
+
+	FORCEINLINE bool FindNearestDepot(const Vehicle *v, TileIndex tile, Trackdir td, int max_distance, TileIndex *depot_tile)
+	{
+		/* set origin and destination nodes */
+		Yapf().SetOrigin(tile, TrackdirToTrackdirBits(td));
+
+		/* find the best path */
+		bool bFound = Yapf().FindPath(v);
+		if (!bFound) return false;
+
+		/* some path found
+		 * get found depot tile */
+		Node *n = Yapf().GetBestNode();
+
+		if (max_distance > 0 && n->m_cost > max_distance * YAPF_TILE_LENGTH) return false;
+
+		*depot_tile = n->m_segment_last_tile;
+		return true;
+	}
+
+	static bool stFindNearestRoadVehicleCompatibleStop(const RoadVehicle *v, TileIndex tile, TileIndex destTile, Trackdir td, StationID sid, TileIndex *stop_tile)
+	{
+		Tpf pf;
+		return pf.FindNearestRoadVehicleCompatibleStop(v, tile, destTile, td, sid, stop_tile);
+	}
+
+	FORCEINLINE bool FindNearestRoadVehicleCompatibleStop(const RoadVehicle *v, TileIndex tile, TileIndex destTile, Trackdir td, StationID sid, TileIndex *stop_tile)
+	{
+		/* set origin and destination nodes */
+		Yapf().SetOrigin(tile, TrackdirToTrackdirBits(td));
+		Yapf().SetDestination(v, sid, destTile);
+
+		/* find the best path */
+		bool bFound = Yapf().FindPath(v);
+		if (!bFound) return false;
+
+		/* some path found
+		 * get found depot tile */
+		const Node *n = Yapf().GetBestNode();
+
+		*stop_tile = n->m_segment_last_tile;
+		return true;
+	}
+};
+
+template <class Tpf_, class Tnode_list, template <class Types> class Tdestination>
+struct CYapfRoad_TypesT
+{
+	typedef CYapfRoad_TypesT<Tpf_, Tnode_list, Tdestination>  Types;
+
+	typedef Tpf_                              Tpf;
+	typedef CFollowTrackRoad                  TrackFollower;
+	typedef Tnode_list                        NodeList;
+	typedef CYapfBaseT<Types>                 PfBase;
+	typedef CYapfFollowRoadT<Types>           PfFollow;
+	typedef CYapfOriginTileT<Types>           PfOrigin;
+	typedef Tdestination<Types>               PfDestination;
+	typedef CYapfSegmentCostCacheNoneT<Types> PfCache;
+	typedef CYapfCostRoadT<Types>             PfCost;
+};
+
+struct CYapfRoad1         : CYapfT<CYapfRoad_TypesT<CYapfRoad1        , CRoadNodeListTrackDir, CYapfDestinationTileRoadT    > > {};
+struct CYapfRoad2         : CYapfT<CYapfRoad_TypesT<CYapfRoad2        , CRoadNodeListExitDir , CYapfDestinationTileRoadT    > > {};
+
+struct CYapfRoadAnyDepot1 : CYapfT<CYapfRoad_TypesT<CYapfRoadAnyDepot1, CRoadNodeListTrackDir, CYapfDestinationAnyDepotRoadT> > {};
+struct CYapfRoadAnyDepot2 : CYapfT<CYapfRoad_TypesT<CYapfRoadAnyDepot2, CRoadNodeListExitDir , CYapfDestinationAnyDepotRoadT> > {};
+
+struct CYapfRoadAnyRoadVehicleCompatibleStopOfGivenStation1 : CYapfT<CYapfRoad_TypesT<CYapfRoadAnyRoadVehicleCompatibleStopOfGivenStation1, CRoadNodeListTrackDir, CYapfDestinationAnyRoadVehicleCompatibleStopOfGivenStationT> > {};
+struct CYapfRoadAnyRoadVehicleCompatibleStopOfGivenStation2 : CYapfT<CYapfRoad_TypesT<CYapfRoadAnyRoadVehicleCompatibleStopOfGivenStation2, CRoadNodeListExitDir , CYapfDestinationAnyRoadVehicleCompatibleStopOfGivenStationT> > {};
+
+
+Trackdir YapfChooseRoadTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir)
+{
+	/* default is YAPF type 2 */
+	typedef Trackdir (*PfnChooseRoadTrack)(const Vehicle*, TileIndex, DiagDirection);
+	PfnChooseRoadTrack pfnChooseRoadTrack = &CYapfRoad2::stChooseRoadTrack; // default: ExitDir, allow 90-deg
+
+	/* check if non-default YAPF type should be used */
+	if (_settings_game.pf.yapf.disable_node_optimization) {
+		pfnChooseRoadTrack = &CYapfRoad1::stChooseRoadTrack; // Trackdir, allow 90-deg
+	}
+
+	Trackdir td_ret = pfnChooseRoadTrack(v, tile, enterdir);
+	return td_ret;
+}
+
+uint YapfRoadVehDistanceToTile(const Vehicle *v, TileIndex tile)
+{
+	/* default is YAPF type 2 */
+	typedef uint (*PfnDistanceToTile)(const Vehicle*, TileIndex);
+	PfnDistanceToTile pfnDistanceToTile = &CYapfRoad2::stDistanceToTile; // default: ExitDir, allow 90-deg
+
+	/* check if non-default YAPF type should be used */
+	if (_settings_game.pf.yapf.disable_node_optimization) {
+		pfnDistanceToTile = &CYapfRoad1::stDistanceToTile; // Trackdir, allow 90-deg
+	}
+
+	/* measure distance in YAPF units */
+	uint dist = pfnDistanceToTile(v, tile);
+	/* convert distance to tiles */
+	if (dist != UINT_MAX) {
+		dist = (dist + YAPF_TILE_LENGTH - 1) / YAPF_TILE_LENGTH;
+	}
+
+	return dist;
+}
+
+bool YapfFindNearestRoadDepot(const Vehicle *v, int max_distance, TileIndex *depot_tile)
+{
+	*depot_tile = INVALID_TILE;
+
+	TileIndex tile = v->tile;
+	Trackdir trackdir = v->GetVehicleTrackdir();
+	if ((TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_ROAD, RoadVehicle::From(v)->compatible_roadtypes)) & TrackdirToTrackdirBits(trackdir)) == 0) {
+		return false;
+	}
+
+	/* handle the case when our vehicle is already in the depot tile */
+	if (IsRoadDepotTile(tile)) {
+		/* only what we need to return is the Depot* */
+		*depot_tile = tile;
+		return true;
+	}
+
+	/* default is YAPF type 2 */
+	typedef bool (*PfnFindNearestDepot)(const Vehicle*, TileIndex, Trackdir, int, TileIndex*);
+	PfnFindNearestDepot pfnFindNearestDepot = &CYapfRoadAnyDepot2::stFindNearestDepot;
+
+	/* check if non-default YAPF type should be used */
+	if (_settings_game.pf.yapf.disable_node_optimization) {
+		pfnFindNearestDepot = &CYapfRoadAnyDepot1::stFindNearestDepot; // Trackdir, allow 90-deg
+	}
+
+	bool ret = pfnFindNearestDepot(v, tile, trackdir, max_distance, depot_tile);
+	return ret;
+}
+
+bool YapfFindNearestRoadVehicleCompatibleStop(const RoadVehicle *v, StationID station, TileIndex *stop_tile)
+{
+	*stop_tile = INVALID_TILE;
+
+	const RoadStop *rs = Station::Get(station)->GetPrimaryRoadStop(v);
+	if (rs == NULL) return false;
+
+	TileIndex tile = v->tile;
+	Trackdir trackdir = v->GetVehicleTrackdir();
+	if ((TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_ROAD, RoadVehicle::From(v)->compatible_roadtypes)) & TrackdirToTrackdirBits(trackdir)) == 0) {
+		return false;
+	}
+
+	/* default is YAPF type 2 */
+	typedef bool (*PfnFindNearestRoadVehicleCompatibleStop)(const RoadVehicle*, TileIndex, TileIndex, Trackdir, StationID, TileIndex*);
+	PfnFindNearestRoadVehicleCompatibleStop pfnFindNearestRoadVehicleCompatibleStop = &CYapfRoadAnyRoadVehicleCompatibleStopOfGivenStation2::stFindNearestRoadVehicleCompatibleStop;
+
+	/* check if non-default YAPF type should be used */
+	if (_settings_game.pf.yapf.disable_node_optimization) {
+		pfnFindNearestRoadVehicleCompatibleStop = &CYapfRoadAnyRoadVehicleCompatibleStopOfGivenStation1::stFindNearestRoadVehicleCompatibleStop; // Trackdir, allow 90-deg
+	}
+
+	bool ret = pfnFindNearestRoadVehicleCompatibleStop(v, tile, rs->xy, trackdir, station, stop_tile);
+	return ret;
+}

src/pathfinder/yapf/yapf_ship.cpp

@@ -0,0 +1,203 @@
+/* $Id$ */
+
+/*
+ * 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 yapf_ship.cpp Implementation of YAPF for ships. */
+
+#include "../../stdafx.h"
+
+#include "yapf.hpp"
+
+/** Node Follower module of YAPF for ships */
+template <class Types>
+class CYapfFollowShipT
+{
+public:
+	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+	typedef typename Node::Key Key;                      ///< key to hash tables
+
+protected:
+	/** to access inherited path finder */
+	FORCEINLINE Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to move from the given node to the next tile. For each
+	 *  reachable trackdir on the new tile creates new node, initializes it
+	 *  and adds it to the open list by calling Yapf().AddNewNode(n) */
+	inline void PfFollowNode(Node& old_node)
+	{
+		TrackFollower F(Yapf().GetVehicle());
+		if (F.Follow(old_node.m_key.m_tile, old_node.m_key.m_td)) {
+			Yapf().AddMultipleNodes(&old_node, F);
+		}
+	}
+
+	/** return debug report character to identify the transportation type */
+	FORCEINLINE char TransportTypeChar() const
+	{
+		return 'w';
+	}
+
+	static Trackdir ChooseShipTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks)
+	{
+		/* handle special case - when next tile is destination tile */
+		if (tile == v->dest_tile) {
+			/* convert tracks to trackdirs */
+			TrackdirBits trackdirs = (TrackdirBits)(tracks | ((int)tracks << 8));
+			/* choose any trackdir reachable from enterdir */
+			trackdirs &= DiagdirReachesTrackdirs(enterdir);
+			return (Trackdir)FindFirstBit2x64(trackdirs);
+		}
+
+		/* move back to the old tile/trackdir (where ship is coming from) */
+		TileIndex src_tile = TILE_ADD(tile, TileOffsByDiagDir(ReverseDiagDir(enterdir)));
+		Trackdir trackdir = v->GetVehicleTrackdir();
+		assert(IsValidTrackdir(trackdir));
+
+		/* convert origin trackdir to TrackdirBits */
+		TrackdirBits trackdirs = TrackdirToTrackdirBits(trackdir);
+		/* get available trackdirs on the destination tile */
+		TrackdirBits dest_trackdirs = TrackStatusToTrackdirBits(GetTileTrackStatus(v->dest_tile, TRANSPORT_WATER, 0));
+
+		/* create pathfinder instance */
+		Tpf pf;
+		/* set origin and destination nodes */
+		pf.SetOrigin(src_tile, trackdirs);
+		pf.SetDestination(v->dest_tile, dest_trackdirs);
+		/* find best path */
+		pf.FindPath(v);
+
+		Trackdir next_trackdir = INVALID_TRACKDIR; // this would mean "path not found"
+
+		Node *pNode = pf.GetBestNode();
+		if (pNode != NULL) {
+			/* walk through the path back to the origin */
+			Node *pPrevNode = NULL;
+			while (pNode->m_parent != NULL) {
+				pPrevNode = pNode;
+				pNode = pNode->m_parent;
+			}
+			/* return trackdir from the best next node (direct child of origin) */
+			Node& best_next_node = *pPrevNode;
+			assert(best_next_node.GetTile() == tile);
+			next_trackdir = best_next_node.GetTrackdir();
+		}
+		return next_trackdir;
+	}
+};
+
+/** Cost Provider module of YAPF for ships */
+template <class Types>
+class CYapfCostShipT
+{
+public:
+	typedef typename Types::Tpf Tpf;              ///< the pathfinder class (derived from THIS class)
+	typedef typename Types::TrackFollower TrackFollower;
+	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+	typedef typename Node::Key Key;               ///< key to hash tables
+
+protected:
+	/** to access inherited path finder */
+	Tpf& Yapf()
+	{
+		return *static_cast<Tpf*>(this);
+	}
+
+public:
+	/** Called by YAPF to calculate the cost from the origin to the given node.
+	 *  Calculates only the cost of given node, adds it to the parent node cost
+	 *  and stores the result into Node::m_cost member */
+	FORCEINLINE bool PfCalcCost(Node& n, const TrackFollower *tf)
+	{
+		/* base tile cost depending on distance */
+		int c = IsDiagonalTrackdir(n.GetTrackdir()) ? YAPF_TILE_LENGTH : YAPF_TILE_CORNER_LENGTH;
+		/* additional penalty for curves */
+		if (n.m_parent != NULL && n.GetTrackdir() != NextTrackdir(n.m_parent->GetTrackdir())) {
+			/* new trackdir does not match the next one when going straight */
+			c += YAPF_TILE_LENGTH;
+		}
+
+		c += YAPF_TILE_LENGTH * tf->m_tiles_skipped;
+
+		/* apply it */
+		n.m_cost = n.m_parent->m_cost + c;
+		return true;
+	}
+};
+
+/** Config struct of YAPF for ships.
+ *  Defines all 6 base YAPF modules as classes providing services for CYapfBaseT.
+ */
+template <class Tpf_, class Ttrack_follower, class Tnode_list>
+struct CYapfShip_TypesT
+{
+	/** Types - shortcut for this struct type */
+	typedef CYapfShip_TypesT<Tpf_, Ttrack_follower, Tnode_list>  Types;
+
+	/** Tpf - pathfinder type */
+	typedef Tpf_                              Tpf;
+	/** track follower helper class */
+	typedef Ttrack_follower                   TrackFollower;
+	/** node list type */
+	typedef Tnode_list                        NodeList;
+	/** pathfinder components (modules) */
+	typedef CYapfBaseT<Types>                 PfBase;        // base pathfinder class
+	typedef CYapfFollowShipT<Types>           PfFollow;      // node follower
+	typedef CYapfOriginTileT<Types>           PfOrigin;      // origin provider
+	typedef CYapfDestinationTileT<Types>      PfDestination; // destination/distance provider
+	typedef CYapfSegmentCostCacheNoneT<Types> PfCache;       // segment cost cache provider
+	typedef CYapfCostShipT<Types>             PfCost;        // cost provider
+};
+
+/* YAPF type 1 - uses TileIndex/Trackdir as Node key, allows 90-deg turns */
+struct CYapfShip1 : CYapfT<CYapfShip_TypesT<CYapfShip1, CFollowTrackWater    , CShipNodeListTrackDir> > {};
+/* YAPF type 2 - uses TileIndex/DiagDirection as Node key, allows 90-deg turns */
+struct CYapfShip2 : CYapfT<CYapfShip_TypesT<CYapfShip2, CFollowTrackWater    , CShipNodeListExitDir > > {};
+/* YAPF type 3 - uses TileIndex/Trackdir as Node key, forbids 90-deg turns */
+struct CYapfShip3 : CYapfT<CYapfShip_TypesT<CYapfShip3, CFollowTrackWaterNo90, CShipNodeListTrackDir> > {};
+
+/** Ship controller helper - path finder invoker */
+Trackdir YapfChooseShipTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks)
+{
+	/* default is YAPF type 2 */
+	typedef Trackdir (*PfnChooseShipTrack)(const Vehicle*, TileIndex, DiagDirection, TrackBits);
+	PfnChooseShipTrack pfnChooseShipTrack = CYapfShip2::ChooseShipTrack; // default: ExitDir, allow 90-deg
+
+	/* check if non-default YAPF type needed */
+	if (_settings_game.pf.forbid_90_deg) {
+		pfnChooseShipTrack = &CYapfShip3::ChooseShipTrack; // Trackdir, forbid 90-deg
+	} else if (_settings_game.pf.yapf.disable_node_optimization) {
+		pfnChooseShipTrack = &CYapfShip1::ChooseShipTrack; // Trackdir, allow 90-deg
+	}
+
+	Trackdir td_ret = pfnChooseShipTrack(v, tile, enterdir, tracks);
+	return td_ret;
+}
+
+/** performance measurement helper */
+void *NpfBeginInterval()
+{
+	CPerformanceTimer& perf = *new CPerformanceTimer;
+	perf.Start();
+	return &perf;
+}
+
+/** performance measurement helper */
+int NpfEndInterval(void *vperf)
+{
+	CPerformanceTimer& perf = *(CPerformanceTimer*)vperf;
+	perf.Stop();
+	int t = perf.Get(1000000);
+	delete &perf;
+	return t;
+}