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

6 files changed, 2502 insertions, 0 deletions

diff --git a/src/pathfinder/npf/aystar.cpp b/src/pathfinder/npf/aystar.cpp
new file mode 100644
index 000000000..8c0a65706
--- /dev/null
+++ b/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;
+}
diff --git a/src/pathfinder/npf/aystar.h b/src/pathfinder/npf/aystar.h
new file mode 100644
index 000000000..56c1804e0
--- /dev/null
+++ b/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 */
diff --git a/src/pathfinder/npf/npf.cpp b/src/pathfinder/npf/npf.cpp
new file mode 100644
index 000000000..f4211c298
--- /dev/null
+++ b/src/pathfinder/npf/npf.cpp
@@ -0,0 +1,1120 @@
+/* $Id$ */
+
+/*
+ * 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.cpp Implementation of the NPF pathfinder. */
+
+#include "../../stdafx.h"
+#include "../../debug.h"
+#include "../../landscape.h"
+#include "../../depot_base.h"
+#include "../../network/network.h"
+#include "../../tunnelbridge_map.h"
+#include "../../functions.h"
+#include "../../tunnelbridge.h"
+#include "../../pbs.h"
+#include "../../train.h"
+#include "../pathfinder_func.h"
+#include "npf.h"
+
+static AyStar _npf_aystar;
+
+/* The cost of each trackdir. A diagonal piece is the full NPF_TILE_LENGTH,
+ * the shorter piece is sqrt(2)/2*NPF_TILE_LENGTH =~ 0.7071
+ */
+#define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)
+static const uint _trackdir_length[TRACKDIR_END] = {
+	NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH,
+	0, 0,
+	NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH
+};
+
+/**
+ * Calculates the minimum distance traveled to get from t0 to t1 when only
+ * using tracks (ie, only making 45 degree turns). Returns the distance in the
+ * NPF scale, ie the number of full tiles multiplied by NPF_TILE_LENGTH to
+ * prevent rounding.
+ */
+static uint NPFDistanceTrack(TileIndex t0, TileIndex t1)
+{
+	const uint dx = Delta(TileX(t0), TileX(t1));
+	const uint dy = Delta(TileY(t0), TileY(t1));
+
+	const uint straightTracks = 2 * min(dx, dy); // The number of straight (not full length) tracks
+	/* OPTIMISATION:
+	 * Original: diagTracks = max(dx, dy) - min(dx,dy);
+	 * Proof:
+	 * (dx+dy) - straightTracks  == (min + max) - straightTracks = min + max - 2 * min = max - min */
+	const uint diagTracks = dx + dy - straightTracks; // The number of diagonal (full tile length) tracks.
+
+	/* Don't factor out NPF_TILE_LENGTH below, this will round values and lose
+	 * precision */
+	return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;
+}
+
+
+#if 0
+static uint NTPHash(uint key1, uint key2)
+{
+	/* This function uses the old hash, which is fixed on 10 bits (1024 buckets) */
+	return PATHFIND_HASH_TILE(key1);
+}
+#endif
+
+/**
+ * Calculates a hash value for use in the NPF.
+ * @param key1 The TileIndex of the tile to hash
+ * @param key2 The Trackdir of the track on the tile.
+ *
+ * @todo Think of a better hash.
+ */
+static uint NPFHash(uint key1, uint key2)
+{
+	/* TODO: think of a better hash? */
+	uint part1 = TileX(key1) & NPF_HASH_HALFMASK;
+	uint part2 = TileY(key1) & NPF_HASH_HALFMASK;
+
+	assert(IsValidTrackdir((Trackdir)key2));
+	assert(IsValidTile(key1));
+	return ((part1 << NPF_HASH_HALFBITS | part2) + (NPF_HASH_SIZE * key2 / TRACKDIR_END)) % NPF_HASH_SIZE;
+}
+
+static int32 NPFCalcZero(AyStar *as, AyStarNode *current, OpenListNode *parent)
+{
+	return 0;
+}
+
+/* Calcs the heuristic to the target station or tile. For train stations, it
+ * takes into account the direction of approach.
+ */
+static int32 NPFCalcStationOrTileHeuristic(AyStar *as, AyStarNode *current, OpenListNode *parent)
+{
+	NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
+	NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
+	TileIndex from = current->tile;
+	TileIndex to = fstd->dest_coords;
+	uint dist;
+
+	/* for train-stations, we are going to aim for the closest station tile */
+	if (as->user_data[NPF_TYPE] == TRANSPORT_RAIL && fstd->station_index != INVALID_STATION)
+		to = CalcClosestStationTile(fstd->station_index, from);
+
+	if (as->user_data[NPF_TYPE] == TRANSPORT_ROAD) {
+		/* Since roads only have diagonal pieces, we use manhattan distance here */
+		dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;
+	} else {
+		/* Ships and trains can also go diagonal, so the minimum distance is shorter */
+		dist = NPFDistanceTrack(from, to);
+	}
+
+	DEBUG(npf, 4, "Calculating H for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), dist);
+
+	if (dist < ftd->best_bird_dist) {
+		ftd->best_bird_dist = dist;
+		ftd->best_trackdir = (Trackdir)current->user_data[NPF_TRACKDIR_CHOICE];
+	}
+	return dist;
+}
+
+
+/* Fills AyStarNode.user_data[NPF_TRACKDIRCHOICE] with the chosen direction to
+ * get here, either getting it from the current choice or from the parent's
+ * choice */
+static void NPFFillTrackdirChoice(AyStarNode *current, OpenListNode *parent)
+{
+	if (parent->path.parent == NULL) {
+		Trackdir trackdir = current->direction;
+		/* This is a first order decision, so we'd better save the
+		 * direction we chose */
+		current->user_data[NPF_TRACKDIR_CHOICE] = trackdir;
+		DEBUG(npf, 6, "Saving trackdir: 0x%X", trackdir);
+	} else {
+		/* We've already made the decision, so just save our parent's decision */
+		current->user_data[NPF_TRACKDIR_CHOICE] = parent->path.node.user_data[NPF_TRACKDIR_CHOICE];
+	}
+}
+
+/* Will return the cost of the tunnel. If it is an entry, it will return the
+ * cost of that tile. If the tile is an exit, it will return the tunnel length
+ * including the exit tile. Requires that this is a Tunnel tile */
+static uint NPFTunnelCost(AyStarNode *current)
+{
+	DiagDirection exitdir = TrackdirToExitdir(current->direction);
+	TileIndex tile = current->tile;
+	if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
+		/* We just popped out if this tunnel, since were
+		 * facing the tunnel exit */
+		return NPF_TILE_LENGTH * (GetTunnelBridgeLength(current->tile, GetOtherTunnelEnd(current->tile)) + 1);
+		/* @todo: Penalty for tunnels? */
+	} else {
+		/* We are entering the tunnel, the enter tile is just a
+		 * straight track */
+		return NPF_TILE_LENGTH;
+	}
+}
+
+static inline uint NPFBridgeCost(AyStarNode *current)
+{
+	return NPF_TILE_LENGTH * GetTunnelBridgeLength(current->tile, GetOtherBridgeEnd(current->tile));
+}
+
+static uint NPFSlopeCost(AyStarNode *current)
+{
+	TileIndex next = current->tile + TileOffsByDiagDir(TrackdirToExitdir(current->direction));
+
+	/* Get center of tiles */
+	int x1 = TileX(current->tile) * TILE_SIZE + TILE_SIZE / 2;
+	int y1 = TileY(current->tile) * TILE_SIZE + TILE_SIZE / 2;
+	int x2 = TileX(next) * TILE_SIZE + TILE_SIZE / 2;
+	int y2 = TileY(next) * TILE_SIZE + TILE_SIZE / 2;
+
+	int dx4 = (x2 - x1) / 4;
+	int dy4 = (y2 - y1) / 4;
+
+	/* Get the height on both sides of the tile edge.
+	 * Avoid testing the height on the tile-center. This will fail for halftile-foundations.
+	 */
+	int z1 = GetSlopeZ(x1 + dx4, y1 + dy4);
+	int z2 = GetSlopeZ(x2 - dx4, y2 - dy4);
+
+	if (z2 - z1 > 1) {
+		/* Slope up */
+		return _settings_game.pf.npf.npf_rail_slope_penalty;
+	}
+	return 0;
+	/* Should we give a bonus for slope down? Probably not, we
+	 * could just substract that bonus from the penalty, because
+	 * there is only one level of steepness... */
+}
+
+static uint NPFReservedTrackCost(AyStarNode *current)
+{
+	TileIndex tile = current->tile;
+	TrackBits track = TrackToTrackBits(TrackdirToTrack(current->direction));
+	TrackBits res = GetReservedTrackbits(tile);
+
+	if (NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL) || ((res & track) == TRACK_BIT_NONE && !TracksOverlap(res | track))) return 0;
+
+	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
+		DiagDirection exitdir = TrackdirToExitdir(current->direction);
+		if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {
+			return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty * (GetTunnelBridgeLength(tile, GetOtherTunnelBridgeEnd(tile)) + 1);
+		}
+	}
+	return  _settings_game.pf.npf.npf_rail_pbs_cross_penalty;
+}
+
+/**
+ * Mark tiles by mowing the grass when npf debug level >= 1.
+ * Will not work for multiplayer games, since it can (will) cause desyncs.
+ */
+static void NPFMarkTile(TileIndex tile)
+{
+#ifndef NO_DEBUG_MESSAGES
+	if (_debug_npf_level < 1 || _networking) return;
+	switch (GetTileType(tile)) {
+		case MP_RAILWAY:
+			/* DEBUG: mark visited tiles by mowing the grass under them ;-) */
+			if (!IsRailDepot(tile)) {
+				SetRailGroundType(tile, RAIL_GROUND_BARREN);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+
+		case MP_ROAD:
+			if (!IsRoadDepot(tile)) {
+				SetRoadside(tile, ROADSIDE_BARREN);
+				MarkTileDirtyByTile(tile);
+			}
+			break;
+
+		default:
+			break;
+	}
+#endif
+}
+
+static int32 NPFWaterPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
+{
+	/* TileIndex tile = current->tile; */
+	int32 cost = 0;
+	Trackdir trackdir = current->direction;
+
+	cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
+
+	if (IsBuoyTile(current->tile) && IsDiagonalTrackdir(trackdir))
+		cost += _settings_game.pf.npf.npf_buoy_penalty; // A small penalty for going over buoys
+
+	if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction))
+		cost += _settings_game.pf.npf.npf_water_curve_penalty;
+
+	/* @todo More penalties? */
+
+	return cost;
+}
+
+/* Determine the cost of this node, for road tracks */
+static int32 NPFRoadPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
+{
+	TileIndex tile = current->tile;
+	int32 cost = 0;
+
+	/* Determine base length */
+	switch (GetTileType(tile)) {
+		case MP_TUNNELBRIDGE:
+			cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
+			break;
+
+		case MP_ROAD:
+			cost = NPF_TILE_LENGTH;
+			/* Increase the cost for level crossings */
+			if (IsLevelCrossing(tile)) cost += _settings_game.pf.npf.npf_crossing_penalty;
+			break;
+
+		case MP_STATION:
+			cost = NPF_TILE_LENGTH;
+			/* Increase the cost for drive-through road stops */
+			if (IsDriveThroughStopTile(tile)) cost += _settings_game.pf.npf.npf_road_drive_through_penalty;
+			break;
+
+		default:
+			break;
+	}
+
+	/* Determine extra costs */
+
+	/* Check for slope */
+	cost += NPFSlopeCost(current);
+
+	/* Check for turns. Road vehicles only really drive diagonal, turns are
+	 * represented by non-diagonal tracks */
+	if (!IsDiagonalTrackdir(current->direction))
+		cost += _settings_game.pf.npf.npf_road_curve_penalty;
+
+	NPFMarkTile(tile);
+	DEBUG(npf, 4, "Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);
+	return cost;
+}
+
+
+/* Determine the cost of this node, for railway tracks */
+static int32 NPFRailPathCost(AyStar *as, AyStarNode *current, OpenListNode *parent)
+{
+	TileIndex tile = current->tile;
+	Trackdir trackdir = current->direction;
+	int32 cost = 0;
+	/* HACK: We create a OpenListNode manually, so we can call EndNodeCheck */
+	OpenListNode new_node;
+
+	/* Determine base length */
+	switch (GetTileType(tile)) {
+		case MP_TUNNELBRIDGE:
+			cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
+			break;
+
+		case MP_RAILWAY:
+			cost = _trackdir_length[trackdir]; // Should be different for diagonal tracks
+			break;
+
+		case MP_ROAD: // Railway crossing
+			cost = NPF_TILE_LENGTH;
+			break;
+
+		case MP_STATION:
+			/* We give a station tile a penalty. Logically we would only want to give
+			 * station tiles that are not our destination this penalty. This would
+			 * discourage trains to drive through busy stations. But, we can just
+			 * give any station tile a penalty, because every possible route will get
+			 * this penalty exactly once, on its end tile (if it's a station) and it
+			 * will therefore not make a difference. */
+			cost = NPF_TILE_LENGTH + _settings_game.pf.npf.npf_rail_station_penalty;
+			break;
+
+		default:
+			break;
+	}
+
+	/* Determine extra costs */
+
+	/* Check for signals */
+	if (IsTileType(tile, MP_RAILWAY)) {
+		if (HasSignalOnTrackdir(tile, trackdir)) {
+			/* Ordinary track with signals */
+			if (GetSignalStateByTrackdir(tile, trackdir) == SIGNAL_STATE_RED) {
+				/* Signal facing us is red */
+				if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
+					/* Penalize the first signal we
+					 * encounter, if it is red */
+
+					/* Is this a presignal exit or combo? */
+					SignalType sigtype = GetSignalType(tile, TrackdirToTrack(trackdir));
+					if (!IsPbsSignal(sigtype)) {
+						if (sigtype == SIGTYPE_EXIT || sigtype == SIGTYPE_COMBO) {
+							/* Penalise exit and combo signals differently (heavier) */
+							cost += _settings_game.pf.npf.npf_rail_firstred_exit_penalty;
+						} else {
+							cost += _settings_game.pf.npf.npf_rail_firstred_penalty;
+						}
+					}
+				}
+				/* Record the state of this signal */
+				NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, true);
+			} else {
+				/* Record the state of this signal */
+				NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, false);
+			}
+			if (NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
+				if (NPFGetFlag(current, NPF_FLAG_2ND_SIGNAL)) {
+					NPFSetFlag(current, NPF_FLAG_3RD_SIGNAL, true);
+				} else {
+					NPFSetFlag(current, NPF_FLAG_2ND_SIGNAL, true);
+				}
+			} else {
+				NPFSetFlag(current, NPF_FLAG_SEEN_SIGNAL, true);
+			}
+		}
+
+		if (HasPbsSignalOnTrackdir(tile, ReverseTrackdir(trackdir)) && !NPFGetFlag(current, NPF_FLAG_3RD_SIGNAL)) {
+			cost += _settings_game.pf.npf.npf_rail_pbs_signal_back_penalty;
+		}
+	}
+
+	/* Penalise the tile if it is a target tile and the last signal was
+	 * red */
+	/* HACK: We create a new_node here so we can call EndNodeCheck. Ugly as hell
+	 * of course... */
+	new_node.path.node = *current;
+	if (as->EndNodeCheck(as, &new_node) == AYSTAR_FOUND_END_NODE && NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_RED))
+		cost += _settings_game.pf.npf.npf_rail_lastred_penalty;
+
+	/* Check for slope */
+	cost += NPFSlopeCost(current);
+
+	/* Check for turns */
+	if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction))
+		cost += _settings_game.pf.npf.npf_rail_curve_penalty;
+	/* TODO, with realistic acceleration, also the amount of straight track between
+	 *      curves should be taken into account, as this affects the speed limit. */
+
+	/* Check for reverse in depot */
+	if (IsRailDepotTile(tile) && as->EndNodeCheck(as, &new_node) != AYSTAR_FOUND_END_NODE) {
+		/* Penalise any depot tile that is not the last tile in the path. This
+		 * _should_ penalise every occurence of reversing in a depot (and only
+		 * that) */
+		cost += _settings_game.pf.npf.npf_rail_depot_reverse_penalty;
+	}
+
+	/* Check for occupied track */
+	cost += NPFReservedTrackCost(current);
+
+	NPFMarkTile(tile);
+	DEBUG(npf, 4, "Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);
+	return cost;
+}
+
+/* Will find any depot */
+static int32 NPFFindDepot(AyStar *as, OpenListNode *current)
+{
+	/* It's not worth caching the result with NPF_FLAG_IS_TARGET here as below,
+	 * since checking the cache not that much faster than the actual check */
+	return IsDepotTypeTile(current->path.node.tile, (TransportType)as->user_data[NPF_TYPE]) ?
+		AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
+}
+
+/** Find any safe and free tile. */
+static int32 NPFFindSafeTile(AyStar *as, OpenListNode *current)
+{
+	const Train *v = Train::From(((NPFFindStationOrTileData *)as->user_target)->v);
+
+	return
+		IsSafeWaitingPosition(v, current->path.node.tile, current->path.node.direction, true, _settings_game.pf.forbid_90_deg) &&
+		IsWaitingPositionFree(v, current->path.node.tile, current->path.node.direction, _settings_game.pf.forbid_90_deg) ?
+			AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
+}
+
+/* Will find a station identified using the NPFFindStationOrTileData */
+static int32 NPFFindStationOrTile(AyStar *as, OpenListNode *current)
+{
+	NPFFindStationOrTileData *fstd = (NPFFindStationOrTileData*)as->user_target;
+	AyStarNode *node = &current->path.node;
+	TileIndex tile = node->tile;
+
+	/* If GetNeighbours said we could get here, we assume the station type
+	 * is correct */
+	if (
+		(fstd->station_index == INVALID_STATION && tile == fstd->dest_coords) || // We've found the tile, or
+		(IsTileType(tile, MP_STATION) && GetStationIndex(tile) == fstd->station_index) // the station
+	) {
+		return AYSTAR_FOUND_END_NODE;
+	} else {
+		return AYSTAR_DONE;
+	}
+}
+
+/**
+ * Find the node containing the first signal on the path.
+ *
+ * If the first signal is on the very first two tiles of the path,
+ * the second signal is returnd. If no suitable signal is present, the
+ * last node of the path is returned.
+ */
+static const PathNode *FindSafePosition(PathNode *path, const Train *v)
+{
+	/* If there is no signal, reserve the whole path. */
+	PathNode *sig = path;
+
+	for (; path->parent != NULL; path = path->parent) {
+		if (IsSafeWaitingPosition(v, path->node.tile, path->node.direction, true, _settings_game.pf.forbid_90_deg)) {
+			sig = path;
+		}
+	}
+
+	return sig;
+}
+
+/**
+ * Lift the reservation of the tiles from @p start till @p end, excluding @p end itself.
+ */
+static void ClearPathReservation(const PathNode *start, const PathNode *end)
+{
+	bool first_run = true;
+	for (; start != end; start = start->parent) {
+		if (IsRailStationTile(start->node.tile) && first_run) {
+			SetRailStationPlatformReservation(start->node.tile, TrackdirToExitdir(start->node.direction), false);
+		} else {
+			UnreserveRailTrack(start->node.tile, TrackdirToTrack(start->node.direction));
+		}
+		first_run = false;
+	}
+}
+
+/**
+ * To be called when @p current contains the (shortest route to) the target node.
+ * Will fill the contents of the NPFFoundTargetData using
+ * AyStarNode[NPF_TRACKDIR_CHOICE]. If requested, path reservation
+ * is done here.
+ */
+static void NPFSaveTargetData(AyStar *as, OpenListNode *current)
+{
+	NPFFoundTargetData *ftd = (NPFFoundTargetData*)as->user_path;
+	ftd->best_trackdir = (Trackdir)current->path.node.user_data[NPF_TRACKDIR_CHOICE];
+	ftd->best_path_dist = current->g;
+	ftd->best_bird_dist = 0;
+	ftd->node = current->path.node;
+	ftd->res_okay = false;
+
+	if (as->user_target != NULL && ((NPFFindStationOrTileData*)as->user_target)->reserve_path && as->user_data[NPF_TYPE] == TRANSPORT_RAIL) {
+		/* Path reservation is requested. */
+		const Train *v = Train::From(((NPFFindStationOrTileData *)as->user_target)->v);
+
+		const PathNode *target = FindSafePosition(&current->path, v);
+		ftd->node = target->node;
+
+		/* If the target is a station skip to platform end. */
+		if (IsRailStationTile(target->node.tile)) {
+			DiagDirection dir = TrackdirToExitdir(target->node.direction);
+			uint len = Station::GetByTile(target->node.tile)->GetPlatformLength(target->node.tile, dir);
+			TileIndex end_tile = TILE_ADD(target->node.tile, (len - 1) * TileOffsByDiagDir(dir));
+
+			/* Update only end tile, trackdir of a station stays the same. */
+			ftd->node.tile = end_tile;
+			if (!IsWaitingPositionFree(v, end_tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
+			SetRailStationPlatformReservation(target->node.tile, dir, true);
+			SetRailStationReservation(target->node.tile, false);
+		} else {
+			if (!IsWaitingPositionFree(v, target->node.tile, target->node.direction, _settings_game.pf.forbid_90_deg)) return;
+		}
+
+		for (const PathNode *cur = target; cur->parent != NULL; cur = cur->parent) {
+			if (!TryReserveRailTrack(cur->node.tile, TrackdirToTrack(cur->node.direction))) {
+				/* Reservation failed, undo. */
+				ClearPathReservation(target, cur);
+				return;
+			}
+		}
+
+		ftd->res_okay = true;
+	}
+}
+
+/**
+ * Finds out if a given company's vehicles are allowed to enter a given tile.
+ * @param owner    The owner of the vehicle.
+ * @param tile     The tile that is about to be entered.
+ * @param enterdir The direction in which the vehicle wants to enter the tile.
+ * @return         true if the vehicle can enter the tile.
+ * @todo           This function should be used in other places than just NPF,
+ *                 maybe moved to another file too.
+ */
+static bool CanEnterTileOwnerCheck(Owner owner, TileIndex tile, DiagDirection enterdir)
+{
+	if (IsTileType(tile, MP_RAILWAY) || // Rail tile (also rail depot)
+			HasStationTileRail(tile) ||     // Rail station tile/waypoint
+			IsRoadDepotTile(tile) ||        // Road depot tile
+			IsStandardRoadStopTile(tile)) { // Road station tile (but not drive-through stops)
+		return IsTileOwner(tile, owner);  // You need to own these tiles entirely to use them
+	}
+
+	switch (GetTileType(tile)) {
+		case MP_ROAD:
+			/* rail-road crossing : are we looking at the railway part? */
+			if (IsLevelCrossing(tile) &&
+					DiagDirToAxis(enterdir) != GetCrossingRoadAxis(tile)) {
+				return IsTileOwner(tile, owner); // Railway needs owner check, while the street is public
+			}
+			break;
+
+		case MP_TUNNELBRIDGE:
+			if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
+				return IsTileOwner(tile, owner);
+			}
+			break;
+
+		default:
+			break;
+	}
+
+	return true; // no need to check
+}
+
+
+/**
+ * Returns the direction the exit of the depot on the given tile is facing.
+ */
+static DiagDirection GetDepotDirection(TileIndex tile, TransportType type)
+{
+	assert(IsDepotTypeTile(tile, type));
+
+	switch (type) {
+		case TRANSPORT_RAIL:  return GetRailDepotDirection(tile);
+		case TRANSPORT_ROAD:  return GetRoadDepotDirection(tile);
+		case TRANSPORT_WATER: return GetShipDepotDirection(tile);
+		default: return INVALID_DIAGDIR; // Not reached
+	}
+}
+
+/** Tests if a tile is a road tile with a single tramtrack (tram can reverse) */
+static DiagDirection GetSingleTramBit(TileIndex tile)
+{
+	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;
+}
+
+/**
+ * Tests if a tile can be entered or left only from one side.
+ *
+ * Depots, non-drive-through roadstops, and tiles with single trambits are tested.
+ *
+ * @param tile The tile of interest.
+ * @param type The transporttype of the vehicle.
+ * @param subtype For TRANSPORT_ROAD the compatible RoadTypes of the vehicle.
+ * @return The single entry/exit-direction of the tile, or INVALID_DIAGDIR if there are more or less directions
+ */
+static DiagDirection GetTileSingleEntry(TileIndex tile, TransportType type, uint subtype)
+{
+	if (type != TRANSPORT_WATER && IsDepotTypeTile(tile, type)) return GetDepotDirection(tile, type);
+
+	if (type == TRANSPORT_ROAD) {
+		if (IsStandardRoadStopTile(tile)) return GetRoadStopDir(tile);
+		if (HasBit(subtype, ROADTYPE_TRAM)) return GetSingleTramBit(tile);
+	}
+
+	return INVALID_DIAGDIR;
+}
+
+/**
+ * Tests if a vehicle must reverse on a tile.
+ *
+ * @param tile The tile of interest.
+ * @param dir The direction in which the vehicle drives on a tile.
+ * @param type The transporttype of the vehicle.
+ * @param subtype For TRANSPORT_ROAD the compatible RoadTypes of the vehicle.
+ * @return true iff the vehicle must reverse on the tile.
+ */
+static inline bool ForceReverse(TileIndex tile, DiagDirection dir, TransportType type, uint subtype)
+{
+	DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
+	return single_entry != INVALID_DIAGDIR && single_entry != dir;
+}
+
+/**
+ * Tests if a vehicle can enter a tile.
+ *
+ * @param tile The tile of interest.
+ * @param dir The direction in which the vehicle drives onto a tile.
+ * @param type The transporttype of the vehicle.
+ * @param subtype For TRANSPORT_ROAD the compatible RoadTypes of the vehicle.
+ * @param railtypes For TRANSPORT_RAIL the compatible RailTypes of the vehicle.
+ * @param owner The owner of the vehicle.
+ * @return true iff the vehicle can enter the tile.
+ */
+static bool CanEnterTile(TileIndex tile, DiagDirection dir, TransportType type, uint subtype, RailTypes railtypes, Owner owner)
+{
+	/* Check tunnel entries and bridge ramps */
+	if (IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(tile) != dir) return false;
+
+	/* Test ownership */
+	if (!CanEnterTileOwnerCheck(owner, tile, dir)) return false;
+
+	/* check correct rail type (mono, maglev, etc) */
+	if (type == TRANSPORT_RAIL) {
+		RailType rail_type = GetTileRailType(tile);
+		if (!HasBit(railtypes, rail_type)) return false;
+	}
+
+	/* Depots, standard roadstops and single tram bits can only be entered from one direction */
+	DiagDirection single_entry = GetTileSingleEntry(tile, type, subtype);
+	if (single_entry != INVALID_DIAGDIR && single_entry != ReverseDiagDir(dir)) return false;
+
+	return true;
+}
+
+/**
+ * Returns the driveable Trackdirs on a tile.
+ *
+ * One-way-roads are taken into account. Signals are not tested.
+ *
+ * @param dst_tile The tile of interest.
+ * @param src_trackdir The direction the vehicle is currently moving.
+ * @param type The transporttype of the vehicle.
+ * @param subtype For TRANSPORT_ROAD the compatible RoadTypes of the vehicle.
+ * @return The Trackdirs the vehicle can continue moving on.
+ */
+static TrackdirBits GetDriveableTrackdirBits(TileIndex dst_tile, Trackdir src_trackdir, TransportType type, uint subtype)
+{
+	TrackdirBits trackdirbits = TrackStatusToTrackdirBits(GetTileTrackStatus(dst_tile, type, subtype));
+
+	if (trackdirbits == 0 && type == TRANSPORT_ROAD && HasBit(subtype, ROADTYPE_TRAM)) {
+		/* GetTileTrackStatus() returns 0 for single tram bits.
+		 * As we cannot change it there (easily) without breaking something, change it here */
+		switch (GetSingleTramBit(dst_tile)) {
+			case DIAGDIR_NE:
+			case DIAGDIR_SW:
+				trackdirbits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
+				break;
+
+			case DIAGDIR_NW:
+			case DIAGDIR_SE:
+				trackdirbits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
+				break;
+
+			default: break;
+		}
+	}
+
+	DEBUG(npf, 4, "Next node: (%d, %d) [%d], possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), dst_tile, trackdirbits);
+
+	/* Select only trackdirs we can reach from our current trackdir */
+	trackdirbits &= TrackdirReachesTrackdirs(src_trackdir);
+
+	/* Filter out trackdirs that would make 90 deg turns for trains */
+	if (_settings_game.pf.forbid_90_deg && (type == TRANSPORT_RAIL || type == TRANSPORT_WATER)) trackdirbits &= ~TrackdirCrossesTrackdirs(src_trackdir);
+
+	DEBUG(npf, 6, "After filtering: (%d, %d), possible trackdirs: 0x%X", TileX(dst_tile), TileY(dst_tile), trackdirbits);
+
+	return trackdirbits;
+}
+
+
+/* Will just follow the results of GetTileTrackStatus concerning where we can
+ * go and where not. Uses AyStar.user_data[NPF_TYPE] as the transport type and
+ * an argument to GetTileTrackStatus. Will skip tunnels, meaning that the
+ * entry and exit are neighbours. Will fill
+ * AyStarNode.user_data[NPF_TRACKDIR_CHOICE] with an appropriate value, and
+ * copy AyStarNode.user_data[NPF_NODE_FLAGS] from the parent */
+static void NPFFollowTrack(AyStar *aystar, OpenListNode *current)
+{
+	/* We leave src_tile on track src_trackdir in direction src_exitdir */
+	Trackdir src_trackdir = current->path.node.direction;
+	TileIndex src_tile = current->path.node.tile;
+	DiagDirection src_exitdir = TrackdirToExitdir(src_trackdir);
+
+	/* Is src_tile valid, and can be used?
+	 * When choosing track on a junction src_tile is the tile neighboured to the junction wrt. exitdir.
+	 * But we must not check the validity of this move, as src_tile is totally unrelated to the move, if a roadvehicle reversed on a junction. */
+	bool ignore_src_tile = (current->path.parent == NULL && NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_START_TILE));
+
+	/* Information about the vehicle: TransportType (road/rail/water) and SubType (compatible rail/road types) */
+	TransportType type = (TransportType)aystar->user_data[NPF_TYPE];
+	uint subtype = aystar->user_data[NPF_SUB_TYPE];
+
+	/* Initialize to 0, so we can jump out (return) somewhere an have no neighbours */
+	aystar->num_neighbours = 0;
+	DEBUG(npf, 4, "Expanding: (%d, %d, %d) [%d]", TileX(src_tile), TileY(src_tile), src_trackdir, src_tile);
+
+	/* We want to determine the tile we arrive, and which choices we have there */
+	TileIndex dst_tile;
+	TrackdirBits trackdirbits;
+
+	/* Find dest tile */
+	if (ignore_src_tile) {
+		/* Do not perform any checks that involve src_tile */
+		dst_tile = src_tile + TileOffsByDiagDir(src_exitdir);
+		trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
+	} else if (IsTileType(src_tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(src_tile) == src_exitdir) {
+		/* We drive through the wormhole and arrive on the other side */
+		dst_tile = GetOtherTunnelBridgeEnd(src_tile);
+		trackdirbits = TrackdirToTrackdirBits(src_trackdir);
+	} else if (ForceReverse(src_tile, src_exitdir, type, subtype)) {
+		/* We can only reverse on this tile */
+		dst_tile = src_tile;
+		src_trackdir = ReverseTrackdir(src_trackdir);
+		trackdirbits = TrackdirToTrackdirBits(src_trackdir);
+	} else {
+		/* We leave src_tile in src_exitdir and reach dst_tile */
+		dst_tile = AddTileIndexDiffCWrap(src_tile, TileIndexDiffCByDiagDir(src_exitdir));
+
+		if (dst_tile != INVALID_TILE && !CanEnterTile(dst_tile, src_exitdir, type, subtype, (RailTypes)aystar->user_data[NPF_RAILTYPES], (Owner)aystar->user_data[NPF_OWNER])) dst_tile = INVALID_TILE;
+
+		if (dst_tile == INVALID_TILE) {
+			/* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
+			if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
+
+			dst_tile = src_tile;
+			src_trackdir = ReverseTrackdir(src_trackdir);
+		}
+
+		trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
+
+		if (trackdirbits == 0) {
+			/* We cannot enter the next tile. Road vehicles can reverse, others reach dead end */
+			if (type != TRANSPORT_ROAD || HasBit(subtype, ROADTYPE_TRAM)) return;
+
+			dst_tile = src_tile;
+			src_trackdir = ReverseTrackdir(src_trackdir);
+
+			trackdirbits = GetDriveableTrackdirBits(dst_tile, src_trackdir, type, subtype);
+		}
+	}
+
+	if (NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_RESERVED)) {
+		/* Mask out any reserved tracks. */
+		TrackBits reserved = GetReservedTrackbits(dst_tile);
+		trackdirbits &= ~TrackBitsToTrackdirBits(reserved);
+
+		uint bits = TrackdirBitsToTrackBits(trackdirbits);
+		int i;
+		FOR_EACH_SET_BIT(i, bits) {
+			if (TracksOverlap(reserved | TrackToTrackBits((Track)i))) trackdirbits &= ~TrackToTrackdirBits((Track)i);
+		}
+	}
+
+	/* Enumerate possible track */
+	uint i = 0;
+	while (trackdirbits != 0) {
+		Trackdir dst_trackdir = RemoveFirstTrackdir(&trackdirbits);
+		DEBUG(npf, 5, "Expanded into trackdir: %d, remaining trackdirs: 0x%X", dst_trackdir, trackdirbits);
+
+		/* Tile with signals? */
+		if (IsTileType(dst_tile, MP_RAILWAY) && GetRailTileType(dst_tile) == RAIL_TILE_SIGNALS) {
+			if (HasSignalOnTrackdir(dst_tile, ReverseTrackdir(dst_trackdir)) && !HasSignalOnTrackdir(dst_tile, dst_trackdir) && IsOnewaySignal(dst_tile, TrackdirToTrack(dst_trackdir)))
+				/* If there's a one-way signal not pointing towards us, stop going in this direction. */
+				break;
+		}
+		{
+			/* We've found ourselves a neighbour :-) */
+			AyStarNode *neighbour = &aystar->neighbours[i];
+			neighbour->tile = dst_tile;
+			neighbour->direction = dst_trackdir;
+			/* Save user data */
+			neighbour->user_data[NPF_NODE_FLAGS] = current->path.node.user_data[NPF_NODE_FLAGS];
+			NPFFillTrackdirChoice(neighbour, current);
+		}
+		i++;
+	}
+	aystar->num_neighbours = i;
+}
+
+/*
+ * Plan a route to the specified target (which is checked by target_proc),
+ * from start1 and if not NULL, from start2 as well. The type of transport we
+ * are checking is in type. reverse_penalty is applied to all routes that
+ * originate from the second start node.
+ * When we are looking for one specific target (optionally multiple tiles), we
+ * should use a good heuristic to perform aystar search. When we search for
+ * multiple targets that are spread around, we should perform a breadth first
+ * search by specifiying CalcZero as our heuristic.
+ */
+static NPFFoundTargetData NPFRouteInternal(AyStarNode *start1, bool ignore_start_tile1, AyStarNode *start2, bool ignore_start_tile2, NPFFindStationOrTileData *target, AyStar_EndNodeCheck target_proc, AyStar_CalculateH heuristic_proc, TransportType type, uint sub_type, Owner owner, RailTypes railtypes, uint reverse_penalty)
+{
+	int r;
+	NPFFoundTargetData result;
+
+	/* Initialize procs */
+	_npf_aystar.CalculateH = heuristic_proc;
+	_npf_aystar.EndNodeCheck = target_proc;
+	_npf_aystar.FoundEndNode = NPFSaveTargetData;
+	_npf_aystar.GetNeighbours = NPFFollowTrack;
+	switch (type) {
+		default: NOT_REACHED();
+		case TRANSPORT_RAIL:  _npf_aystar.CalculateG = NPFRailPathCost;  break;
+		case TRANSPORT_ROAD:  _npf_aystar.CalculateG = NPFRoadPathCost;  break;
+		case TRANSPORT_WATER: _npf_aystar.CalculateG = NPFWaterPathCost; break;
+	}
+
+	/* Initialize Start Node(s) */
+	start1->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+	start1->user_data[NPF_NODE_FLAGS] = 0;
+	NPFSetFlag(start1, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile1);
+	_npf_aystar.addstart(&_npf_aystar, start1, 0);
+	if (start2) {
+		start2->user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+		start2->user_data[NPF_NODE_FLAGS] = 0;
+		NPFSetFlag(start2, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile2);
+		NPFSetFlag(start2, NPF_FLAG_REVERSE, true);
+		_npf_aystar.addstart(&_npf_aystar, start2, reverse_penalty);
+	}
+
+	/* Initialize result */
+	result.best_bird_dist = UINT_MAX;
+	result.best_path_dist = UINT_MAX;
+	result.best_trackdir  = INVALID_TRACKDIR;
+	result.node.tile      = INVALID_TILE;
+	result.res_okay       = false;
+	_npf_aystar.user_path = &result;
+
+	/* Initialize target */
+	_npf_aystar.user_target = target;
+
+	/* Initialize user_data */
+	_npf_aystar.user_data[NPF_TYPE] = type;
+	_npf_aystar.user_data[NPF_SUB_TYPE] = sub_type;
+	_npf_aystar.user_data[NPF_OWNER] = owner;
+	_npf_aystar.user_data[NPF_RAILTYPES] = railtypes;
+
+	/* GO! */
+	r = AyStarMain_Main(&_npf_aystar);
+	assert(r != AYSTAR_STILL_BUSY);
+
+	if (result.best_bird_dist != 0) {
+		if (target != NULL) {
+			DEBUG(npf, 1, "Could not find route to tile 0x%X from 0x%X.", target->dest_coords, start1->tile);
+		} else {
+			/* Assumption: target == NULL, so we are looking for a depot */
+			DEBUG(npf, 1, "Could not find route to a depot from tile 0x%X.", start1->tile);
+		}
+
+	}
+	return result;
+}
+
+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)
+{
+	AyStarNode start1;
+	AyStarNode start2;
+
+	start1.tile = tile1;
+	start2.tile = tile2;
+	/* We set this in case the target is also the start tile, we will just
+	 * return a not found then */
+	start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+	start1.direction = trackdir1;
+	start2.direction = trackdir2;
+	start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+
+	return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, target, NPFFindStationOrTile, NPFCalcStationOrTileHeuristic, type, sub_type, owner, railtypes, 0);
+}
+
+NPFFoundTargetData NPFRouteToStationOrTile(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, NPFFindStationOrTileData *target, TransportType type, uint sub_type, Owner owner, RailTypes railtypes)
+{
+	return NPFRouteToStationOrTileTwoWay(tile, trackdir, ignore_start_tile, INVALID_TILE, INVALID_TRACKDIR, false, target, type, sub_type, owner, railtypes);
+}
+
+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)
+{
+	AyStarNode start1;
+	AyStarNode start2;
+
+	start1.tile = tile1;
+	start2.tile = tile2;
+	/* We set this in case the target is also the start tile, we will just
+	 * return a not found then */
+	start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+	start1.direction = trackdir1;
+	start2.direction = trackdir2;
+	start2.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+
+	/* perform a breadth first search. Target is NULL,
+	 * since we are just looking for any depot...*/
+	return NPFRouteInternal(&start1, ignore_start_tile1, (IsValidTile(tile2) ? &start2 : NULL), ignore_start_tile2, NULL, NPFFindDepot, NPFCalcZero, type, sub_type, owner, railtypes, reverse_penalty);
+}
+
+NPFFoundTargetData NPFRouteToDepotBreadthFirst(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, TransportType type, uint sub_type, Owner owner, RailTypes railtypes)
+{
+	return NPFRouteToDepotBreadthFirstTwoWay(tile, trackdir, ignore_start_tile, INVALID_TILE, INVALID_TRACKDIR, false, type, sub_type, owner, railtypes, 0);
+}
+
+NPFFoundTargetData NPFRouteToDepotTrialError(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, TransportType type, uint sub_type, Owner owner, RailTypes railtypes)
+{
+	/* Okay, what we're gonna do. First, we look at all depots, calculate
+	 * the manhatten distance to get to each depot. We then sort them by
+	 * distance. We start by trying to plan a route to the closest, then
+	 * the next closest, etc. We stop when the best route we have found so
+	 * far, is shorter than the manhattan distance. This will obviously
+	 * always find the closest depot. It will probably be most efficient
+	 * for ships, since the heuristic will not be to far off then. I hope.
+	 */
+	Queue depots;
+	int r;
+	NPFFoundTargetData best_result = {UINT_MAX, UINT_MAX, INVALID_TRACKDIR, {INVALID_TILE, INVALID_TRACKDIR, {0, 0}}, false};
+	NPFFoundTargetData result;
+	NPFFindStationOrTileData target;
+	AyStarNode start;
+	Depot *current;
+	Depot *depot;
+
+	init_InsSort(&depots);
+	/* Okay, let's find all depots that we can use first */
+	FOR_ALL_DEPOTS(depot) {
+		/* Check if this is really a valid depot, it is of the needed type and
+		 * owner */
+		if (IsDepotTypeTile(depot->xy, type) && IsTileOwner(depot->xy, owner))
+			/* If so, let's add it to the queue, sorted by distance */
+			depots.push(&depots, depot, DistanceManhattan(tile, depot->xy));
+	}
+
+	/* Now, let's initialise the aystar */
+
+	/* Initialize procs */
+	_npf_aystar.CalculateH = NPFCalcStationOrTileHeuristic;
+	_npf_aystar.EndNodeCheck = NPFFindStationOrTile;
+	_npf_aystar.FoundEndNode = NPFSaveTargetData;
+	_npf_aystar.GetNeighbours = NPFFollowTrack;
+	switch (type) {
+		default: NOT_REACHED();
+		case TRANSPORT_RAIL:  _npf_aystar.CalculateG = NPFRailPathCost;  break;
+		case TRANSPORT_ROAD:  _npf_aystar.CalculateG = NPFRoadPathCost;  break;
+		case TRANSPORT_WATER: _npf_aystar.CalculateG = NPFWaterPathCost; break;
+	}
+
+	/* Initialize target */
+	target.station_index = INVALID_STATION; // We will initialize dest_coords inside the loop below
+	_npf_aystar.user_target = &target;
+
+	/* Initialize user_data */
+	_npf_aystar.user_data[NPF_TYPE] = type;
+	_npf_aystar.user_data[NPF_SUB_TYPE] = sub_type;
+	_npf_aystar.user_data[NPF_OWNER] = owner;
+
+	/* Initialize Start Node */
+	start.tile = tile;
+	start.direction = trackdir; // We will initialize user_data inside the loop below
+
+	/* Initialize Result */
+	_npf_aystar.user_path = &result;
+	best_result.best_path_dist = UINT_MAX;
+	best_result.best_bird_dist = UINT_MAX;
+
+	/* Just iterate the depots in order of increasing distance */
+	while ((current = (Depot*)depots.pop(&depots))) {
+		/* Check to see if we already have a path shorter than this
+		 * depot's manhattan distance. HACK: We call DistanceManhattan
+		 * again, we should probably modify the queue to give us that
+		 * value... */
+		if ( DistanceManhattan(tile, current->xy * NPF_TILE_LENGTH) > best_result.best_path_dist)
+			break;
+
+		/* Initialize Start Node
+		 * We set this in case the target is also the start tile, we will just
+		 * return a not found then */
+		start.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+		start.user_data[NPF_NODE_FLAGS] = 0;
+		NPFSetFlag(&start, NPF_FLAG_IGNORE_START_TILE, ignore_start_tile);
+		_npf_aystar.addstart(&_npf_aystar, &start, 0);
+
+		/* Initialize result */
+		result.best_bird_dist = UINT_MAX;
+		result.best_path_dist = UINT_MAX;
+		result.best_trackdir = INVALID_TRACKDIR;
+
+		/* Initialize target */
+		target.dest_coords = current->xy;
+
+		/* GO! */
+		r = AyStarMain_Main(&_npf_aystar);
+		assert(r != AYSTAR_STILL_BUSY);
+
+		/* This depot is closer */
+		if (result.best_path_dist < best_result.best_path_dist)
+			best_result = result;
+	}
+	if (result.best_bird_dist != 0) {
+		DEBUG(npf, 1, "Could not find route to any depot from tile 0x%X.", tile);
+	}
+	return best_result;
+}
+
+NPFFoundTargetData NPFRouteToSafeTile(const Train *v, TileIndex tile, Trackdir trackdir, bool override_railtype)
+{
+	assert(v->type == VEH_TRAIN);
+
+	NPFFindStationOrTileData fstd;
+	fstd.v = v;
+	fstd.reserve_path = true;
+
+	AyStarNode start1;
+	start1.tile = tile;
+	/* We set this in case the target is also the start tile, we will just
+	 * return a not found then */
+	start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+	start1.direction = trackdir;
+	NPFSetFlag(&start1, NPF_FLAG_IGNORE_RESERVED, true);
+
+	RailTypes railtypes = v->compatible_railtypes;
+	if (override_railtype) railtypes |= GetRailTypeInfo(v->railtype)->compatible_railtypes;
+
+	/* perform a breadth first search. Target is NULL,
+	 * since we are just looking for any safe tile...*/
+	return NPFRouteInternal(&start1, true, NULL, false, &fstd, NPFFindSafeTile, NPFCalcZero, TRANSPORT_RAIL, 0, v->owner, railtypes, 0);
+}
+
+void InitializeNPF()
+{
+	static bool first_init = true;
+	if (first_init) {
+		first_init = false;
+		init_AyStar(&_npf_aystar, NPFHash, NPF_HASH_SIZE);
+	} else {
+		AyStarMain_Clear(&_npf_aystar);
+	}
+	_npf_aystar.loops_per_tick = 0;
+	_npf_aystar.max_path_cost = 0;
+	//_npf_aystar.max_search_nodes = 0;
+	/* We will limit the number of nodes for now, until we have a better
+	 * solution to really fix performance */
+	_npf_aystar.max_search_nodes = _settings_game.pf.npf.npf_max_search_nodes;
+}
+
+void NPFFillWithOrderData(NPFFindStationOrTileData *fstd, Vehicle *v, bool reserve_path)
+{
+	/* Ships don't really reach their stations, but the tile in front. So don't
+	 * save the station id for ships. For roadvehs we don't store it either,
+	 * because multistop depends on vehicles actually reaching the exact
+	 * dest_tile, not just any stop of that station.
+	 * So only for train orders to stations we fill fstd->station_index, for all
+	 * others only dest_coords */
+	if (v->type == VEH_TRAIN && (v->current_order.IsType(OT_GOTO_STATION) || v->current_order.IsType(OT_GOTO_WAYPOINT))) {
+		fstd->station_index = v->current_order.GetDestination();
+		/* Let's take the closest tile of the station as our target for trains */
+		fstd->dest_coords = CalcClosestStationTile(fstd->station_index, v->tile);
+	} else {
+		fstd->dest_coords = v->dest_tile;
+		fstd->station_index = INVALID_STATION;
+	}
+	fstd->reserve_path = reserve_path;
+	fstd->v = v;
+}
diff --git a/src/pathfinder/npf/npf.h b/src/pathfinder/npf/npf.h
new file mode 100644
index 000000000..3beb09391
--- /dev/null
+++ b/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 */
diff --git a/src/pathfinder/npf/queue.cpp b/src/pathfinder/npf/queue.cpp
new file mode 100644
index 000000000..a954876a6
--- /dev/null
+++ b/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;
+}
diff --git a/src/pathfinder/npf/queue.h b/src/pathfinder/npf/queue.h
new file mode 100644
index 000000000..76421e9ac
--- /dev/null
+++ b/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 */