Add a Lua call to do damages / heals

doc/lua_api.txt

@@ -2336,6 +2336,7 @@ This is basically a reference to a C++ `ServerActiveObject`
 * `right_click(clicker)`; `clicker` is another `ObjectRef`
 * `get_hp()`: returns number of hitpoints (2 * number of hearts)
 * `set_hp(hp)`: set number of hitpoints (2 * number of hearts)
+* `apply_damage(damage)`: set amount of damage to object. If damage < 0, heal the target
 * `get_inventory()`: returns an `InvRef`
 * `get_wield_list()`: returns the name of the inventory list the wielded item is in
 * `get_wield_index()`: returns the index of the wielded item

src/script/lua_api/l_object.cpp

@@ -29,6 +29,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "content_sao.h"
 #include "server.h"
 #include "hud.h"
+#include "settings.h"
+#include "main.h"
 
 
 struct EnumString es_HudElementType[] =
@@ -255,10 +257,10 @@ int ObjectRef::l_set_hp(lua_State *L)
 	ObjectRef *ref = checkobject(L, 1);
 	luaL_checknumber(L, 2);
 	ServerActiveObject *co = getobject(ref);
-	if(co == NULL) return 0;
+	if(co == NULL)
+		return 0;
 	int hp = lua_tonumber(L, 2);
-	/*infostream<<"ObjectRef::l_set_hp(): id="<<co->getId()
-			<<" hp="<<hp<<std::endl;*/
+
 	// Do it
 	co->setHP(hp);
 	if (co->getType() == ACTIVEOBJECT_TYPE_PLAYER) {
@@ -289,6 +291,38 @@ int ObjectRef::l_get_hp(lua_State *L)
 	return 1;
 }
 
+// apply_damage(self, damage)
+// damage = amount of damage to apply
+// if damage is negative, heal the player
+// returns: nil
+int ObjectRef::l_apply_damage(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	ObjectRef *ref = checkobject(L, 1);
+	luaL_checknumber(L, 2);
+	ServerActiveObject *co = getobject(ref);
+	if(co == NULL)
+		return 0;
+
+	int damage = lua_tonumber(L, 2);
+
+	// No damage, no heal => do nothing
+	if (damage == 0)
+		return 0;
+
+	// If damage is positive (not healing) and damage is disabled, ignore
+	if (damage > 0 && g_settings->getBool("enable_damage") == false)
+		return 0;
+
+	// Do damage/heal
+	co->setHP(co->getHP() - damage);
+	if (co->getType() == ACTIVEOBJECT_TYPE_PLAYER) {
+		getServer(L)->SendPlayerHPOrDie(((PlayerSAO*)co)->getPeerID(), co->getHP() == 0);
+	}
+
+	return 0;
+}
+
 // get_inventory(self)
 int ObjectRef::l_get_inventory(lua_State *L)
 {
@@ -1345,6 +1379,7 @@ const luaL_reg ObjectRef::methods[] = {
 	luamethod(ObjectRef, right_click),
 	luamethod(ObjectRef, set_hp),
 	luamethod(ObjectRef, get_hp),
+	luamethod(ObjectRef, apply_damage),
 	luamethod(ObjectRef, get_inventory),
 	luamethod(ObjectRef, get_wield_list),
 	luamethod(ObjectRef, get_wield_index),

src/script/lua_api/l_object.h

@@ -83,6 +83,12 @@ private:
 	// 0 if not applicable to this type of object
 	static int l_get_hp(lua_State *L);
 
+	// apply_damage(self, damage)
+	// damage = amount of damage to apply
+	// if damage is negative, heal the player
+	// returns: nil
+	static int l_apply_damage(lua_State *L);
+
 	// get_inventory(self)
 	static int l_get_inventory(lua_State *L);