1 files changed, 65 insertions, 0 deletions
diff --git a/pathfind.h b/pathfind.h
new file mode 100644
index 000000000..5f12568b4
--- /dev/null
+++ b/pathfind.h
@@ -0,0 +1,65 @@
+#ifndef PATHFIND_H
+#define PATHFIND_H
+
+typedef struct TrackPathFinder TrackPathFinder;
+typedef bool TPFEnumProc(uint tile, void *data, int track, uint length, byte *state);
+typedef void TPFAfterProc(TrackPathFinder *tpf);
+
+
+#define PATHFIND_GET_LINK_OFFS(tpf, link) ((byte*)(link) - (byte*)tpf->links)
+#define PATHFIND_GET_LINK_PTR(tpf, link_offs) (TrackPathFinderLink*)((byte*)tpf->links + (link_offs))
+
+/* y7 y6 y5 y4 y3 y2 y1 y0 x7 x6 x5 x4 x3 x2 x1 x0
+ * y7 y6 y5 y4 y3 y2 y1 y0 x4 x3 x2 x1 x0  0  0  0
+ *  0  0 y7 y6 y5 y4 y3 y2 y1 y0 x4 x3 x2 x1 x0  0
+ *  0  0  0  0 y5 y4 y3 y2 y1 y0 x4 x3 x2 x1 x0  0
+ */
+#define PATHFIND_HASH_TILE(tile) (GET_TILE_X(tile) & 0x1F) + ((GET_TILE_Y(tile)&0x1F)<<5)
+
+typedef struct TrackPathFinderLink {
+	TileIndex tile;
+	uint16 flags;
+	uint16 next;
+} TrackPathFinderLink;
+
+typedef struct RememberData {
+	uint16 cur_length;
+	byte depth;
+	byte pft_var6;
+} RememberData;
+
+struct TrackPathFinder {
+
+	int num_links_left;
+	TrackPathFinderLink *new_link;
+
+	TPFEnumProc *enum_proc;
+
+	void *userdata;
+	
+	RememberData rd;
+
+	int the_dir;
+
+	byte tracktype;
+	byte var2;
+	bool disable_tile_hash;
+	bool hasbit_13;
+
+	uint16 hash_head[0x400];
+	TileIndex hash_tile[0x400]; /* stores the link index when multi link. */
+
+	TrackPathFinderLink links[0x400]; /* hopefully, this is enough. */
+};
+
+void FollowTrack(uint tile, uint16 flags, byte direction, TPFEnumProc *enum_proc, TPFAfterProc *after_proc, void *data);
+
+typedef struct {
+	uint tile;
+	int length;
+} FindLengthOfTunnelResult;
+FindLengthOfTunnelResult FindLengthOfTunnel(uint tile, int direction, byte type);
+
+void NewTrainPathfind(uint tile, byte direction, TPFEnumProc *enum_proc, void *data, byte *cache);
+
+#endif /* PATHFIND_H */