Added a new hook: HOOK_ENCOUNTER

Added procedure and macros for unsigned integer comparison to lib.math.h.

artifacts/scripting/headers/lib.math.h

@@ -5,6 +5,17 @@
   Numbers...
 */
 
+#define above(a, b)        (unsigned_comp(a, b) > 0)
+#define above_equal(a, b)  (unsigned_comp(a, b) >= 0)
+#define below(a, b)        (unsigned_comp(a, b) < 0)
+#define below_equal(a, b)  (unsigned_comp(a, b) <= 0)
+
+procedure unsigned_comp(variable a, variable b) begin
+   if (a bwxor b) then return 0;
+   if (b == 0) then return 1;
+   return 1 if (a / b) else -1;
+end
+
 #define MAX(x, y)    ((x > y) * x + (x <= y) * y)
 #define MIN(x, y)    ((x < y) * x + (x >= y) * y)
 #define in_range(x, from, to)    (x >= from and x <= to)

artifacts/scripting/headers/sfall.h

@@ -65,6 +65,7 @@
 #define HOOK_STDPROCEDURE     (40)
 #define HOOK_STDPROCEDURE_END (41)
 #define HOOK_TARGETOBJECT     (42)
+#define HOOK_ENCOUNTER        (43)
 
 //Valid arguments to list_begin
 #define LIST_CRITTERS    (0)

artifacts/scripting/hookscripts.txt

@@ -669,3 +669,17 @@ int     arg2 - 1 when the target object is valid to attack, 0 otherwise
 Obj     arg3 - the target object
 
 mixed   ret1 - overrides the target object, or pass -1 to prevent the player from attacking the object
+
+-------------------------------------------
+
+HOOK_ENCOUNTER (hs_encounter.int)
+
+Runs whenever a random encounter occurs (except the Horrigan meeting and scripted encounters), or when the player enters a local map from the world map.
+You can override the map for loading or the encounter.
+
+int     arg1 - event type: 0 - when a random encounter occurs, 1 - when the player enters from the world map
+int     arg2 - the map ID that the encounter will load (see MAPS.h or Maps.txt)
+int     arg3 - 1 when the encounter occurs is a special encounter, 0 otherwise
+
+int     ret1 - overrides the map ID, or pass -1 to cancel the encounter and continue traveling (only for event type 0)
+int     ret2 - pass 1 to cancel the encounter and load the specified map from the ret1 (only for event type 0)