Moved attribute (re)calculation to the scripts

This introduces two callbacks:
 - on_update_derived_attribute   -> Called to recalculate other derived
                                    attributes.
 - on_recalculate_base_attribute -> Called to recalculate a base attribute
                                    (only called for characters. However the
                                    function passed as callback can be useful
                                    for recalculating the derived attributes
                                    as well)

Monsters no longer block recalculation of attributes except HP and Speed.
I saw no sense to keep this.

Fixed constant value in libmana-constants.lua

Dropped bool type of the recalculation functions. It would be difficult to
keep it while pushing all to the script engine and it was unused anyway.

All in all this adds a LOT more flexibillity to projects since they can now
adapt all attributes in the way they want.

1 files changed, 26 insertions, 0 deletions

diff --git a/src/scripting/lua.cpp b/src/scripting/lua.cpp
index 880216d..4e2cd28 100644
--- a/src/scripting/lua.cpp
+++ b/src/scripting/lua.cpp
@@ -69,6 +69,30 @@ extern "C" {
 
 
 /**
+ * on_update_derived_attribute( function(Being*) ): void
+ * Sets a listener function to handle
+ * recalculation of derived attributes event.
+ */
+static int on_update_derived_attribute(lua_State *s)
+{
+    luaL_checktype(s, 1, LUA_TFUNCTION);
+    Being::setUpdateDerivedAttributesCallback(getScript(s));
+    return 0;
+}
+
+
+/**
+ * on_recalculateBaseAttributeCallback( function(Being*) ): void
+ * Sets a listener function to the attribute recalculation event.
+ */
+static int on_recalculate_base_attribute(lua_State *s)
+{
+    luaL_checktype(s, 1, LUA_TFUNCTION);
+    Being::setRecalculateBaseAttributeCallback(getScript(s));
+    return 0;
+}
+
+/**
  * on_character_death( function(Character*) ): void
  * Sets a listener function to the character death event.
  */
@@ -2582,6 +2606,8 @@ LuaScript::LuaScript():
 
     // Put the callback functions in the scripting environment.
     static luaL_Reg const callbacks[] = {
+        { "on_update_derived_attribute",     &on_update_derived_attribute     },
+        { "on_recalculate_base_attribute",   &on_recalculate_base_attribute   },
         { "on_character_death",              &on_character_death              },
         { "on_character_death_accept",       &on_character_death_accept       },
         { "on_character_login",              &on_character_login              },