--- path_finding1.h	Mon Apr  8 09:06:55 2002
+++ path_finding2.h	Mon Apr  8 10:04:58 2002
@@ -21,9 +21,10 @@
  *  - turn: obvious
  *  - path: a list of steps which leads from the start to the end
  *  - basic movement cost (BMC): the basic movements costs of the step
- *    as returned by map_move_cost
+ *    as returned by map_move_cost. Note that the BMC of a step is 0
+ *    if the target is unknown.
  *  - extra cost (EC): sum of various extra costs (which all have to be >=0)
- *  - final cost (FC): BMC * PF_BMC_FACTOR + FC
+ *  - final cost (FC): FC = BMC * PF_BMC_FACTOR + EC
  *  - best path: a path which has the minimal FC. If two paths have
  *  equal FC, the path with the minimal turns and if these are equal
  *  too the maximum remaining points at the destination is choosen.
@@ -35,6 +36,12 @@
 #define PF_BMC_FACTOR	100
 
 /*
+ * The step is ignored completely if any extra cost or the sum EC is
+ * larger or equal PF_IGNORE_COST.
+ */
+#define PF_IGNORE_COST	FC_INFINITY
+
+/*
  * Maximal number of steps in a path.
  */
 #define MAX_PATH_LENGTH	100
@@ -49,10 +56,10 @@
     struct player *owner;
 
     /*
-     * Callback to query the known state of a tile. tile_get_known can
-     * be used for the client.
+     * Callback to query the known state of a tile for the given
+     * player.
      */
-    enum known_type (*get_known)(int , int);
+    enum known_type (*get_known)(int , int, struct player *);
 
     /*
      * GOTO_MOVE_STRAIGHTEST will set the BMC to constant 1. Even for
@@ -61,50 +68,30 @@
     enum goto_move_restriction restriction;
 
     /*
-     * If EC is above this value the step is ignored completely.
-     */
-    int extra_cost_cutoff;
-
-    /*
-     * If the destination tile of a step is fogged these extra costs
-     * are added to EC.
-     */
-    int fogged_area_extra_cost;
-
-    /*
-     * If the destination tile of a step is unknown these extra costs
-     * are added to EC.
-     *
-     * Note: For an unknown tile the BMC is 0. So it is a good idea to
-     * set unknown_area_extra_cost to something >0.
-     */
-    int unknown_area_extra_cost;
-
-    /*
-     * Passed as third parameter to extra_cost1.
+     * Passed as last parameter to extra_cost1.
      */
     void *user_data1;
 
     /*
      * Callback which can be used to provide extra costs depending on
-     * the tile. Can be NULL. Parameter are x, y and user_data1. It
-     * can be assumed that the implementation of path_finding.h will
-     * cache this value.
+     * the tile. Can be NULL. Parameters are x, y, known and
+     * user_data1. It can be assumed that the implementation of
+     * path_finding.h will cache this value.
      */
-    int (*extra_cost_1)(int, int, void *);
+    int (*extra_cost_1)(int, int, enum known_type, void *);
 
     /*
-     * Passed as fourth parameter to extra_cost2.
+     * Passed as last parameter to extra_cost2.
      */
     void *user_data2;
 
     /*
      * Callback which can be used to provide extra costs depending on
      * the tile and the moves left of the unit. Can be NULL. Parameter
-     * are x, y, moves left and user_data2. An implementation of
-     * path_finding.h may or may not cache this value.
+     * are x, y, known, moves left and user_data2. An implementation
+     * of path_finding.h may or may not cache this value.
      */
-    int (*extra_cost_2)(int, int, int, void *);
+    int (*extra_cost_2)(int, int, enum known_type, int, void *);
 };
 
 struct pf_path {