1 files changed, 69 insertions, 0 deletions
diff --git a/crawl-ref/source/mon-pathfind.h b/crawl-ref/source/mon-pathfind.h
new file mode 100644
index 0000000000..590fb3f777
--- /dev/null
+++ b/crawl-ref/source/mon-pathfind.h
@@ -0,0 +1,69 @@
+#ifndef MON_PATHFIND_H
+#define MON_PATHFIND_H
+
+class monsters;
+
+int mons_tracking_range(const monsters *mon);
+
+class monster_pathfind
+{
+public:
+    monster_pathfind();
+    virtual ~monster_pathfind();
+    
+    // public methods  
+    void set_range(int r);
+    coord_def next_pos(const coord_def &p) const;
+    bool init_pathfind(const monsters *mon, coord_def dest,
+                       bool diag = true, bool msg = false,
+                       bool pass_unmapped = false);
+    bool init_pathfind(coord_def src, coord_def dest,
+                       bool diag = true, bool msg = false);
+    bool start_pathfind(bool msg = false);
+    std::vector<coord_def> backtrack(void);
+    std::vector<coord_def> calc_waypoints(void);
+
+protected:
+    // protected methods
+    bool calc_path_to_neighbours(void);
+    bool traversable(coord_def p);
+    int  travel_cost(coord_def npos);
+    bool mons_traversable(coord_def p);
+    int  mons_travel_cost(coord_def npos);
+    int  estimated_cost(coord_def npos);
+    void add_new_pos(coord_def pos, int total);
+    void update_pos(coord_def pos, int total);
+    bool get_best_position(void);
+
+
+    // The monster trying to find a path.
+    const monsters *mons;
+
+    // Our destination, and the current position we're looking at.
+    coord_def start, target, pos;
+
+    // If false, do not move diagonally along the path.
+    bool allow_diagonals;
+
+    // If true, unmapped terrain is treated as traversable no matter the
+    // monster involved.
+    // (Used for player estimates of whether a monster can travel somewhere.)
+    bool traverse_unmapped;
+
+    // Maximum range to search between start and target. None, if zero.
+    int range;
+
+    // Currently shortest and longest possible total length of the path.
+    int min_length;
+    int max_length;
+
+    // The array of distances from start to any already tried point.
+    int dist[GXM][GYM];
+    // An array to store where we came from on a given shortest path.
+    int prev[GXM][GYM];
+
+    FixedVector<std::vector<coord_def>, GXM * GYM> hash;
+};
+
+#endif
+