Allow damage for attached objects, add attach/detach callbacks (#6786)

* Allow right-clicking on attached LuaEntities

3 files changed, 35 insertions, 51 deletions

diff --git a/src/script/cpp_api/s_entity.cpp b/src/script/cpp_api/s_entity.cpp
index df4b77936..88dbcc620 100644
--- a/src/script/cpp_api/s_entity.cpp
+++ b/src/script/cpp_api/s_entity.cpp
@@ -262,7 +262,9 @@ bool ScriptApiEntity::luaentity_Punch(u16 id,
 	return retval;
 }
 
-bool ScriptApiEntity::luaentity_on_death(u16 id, ServerActiveObject *killer)
+// Calls entity[field](ObjectRef self, ObjectRef sao)
+bool ScriptApiEntity::luaentity_run_simple_callback(u16 id,
+	ServerActiveObject *sao, const char *field)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
@@ -273,14 +275,14 @@ bool ScriptApiEntity::luaentity_on_death(u16 id, ServerActiveObject *killer)
 	int object = lua_gettop(L);
 	// State: object is at top of stack
 	// Get function
-	lua_getfield(L, -1, "on_death");
+	lua_getfield(L, -1, field);
 	if (lua_isnil(L, -1)) {
-		lua_pop(L, 2); // Pop on_death and entity
+		lua_pop(L, 2); // Pop callback field and entity
 		return false;
 	}
 	luaL_checktype(L, -1, LUA_TFUNCTION);
 	lua_pushvalue(L, object);  // self
-	objectrefGetOrCreate(L, killer);  // killer reference
+	objectrefGetOrCreate(L, sao);  // killer reference
 
 	setOriginFromTable(object);
 	PCALL_RES(lua_pcall(L, 2, 1, error_handler));
@@ -290,33 +292,28 @@ bool ScriptApiEntity::luaentity_on_death(u16 id, ServerActiveObject *killer)
 	return retval;
 }
 
-// Calls entity:on_rightclick(ObjectRef clicker)
-void ScriptApiEntity::luaentity_Rightclick(u16 id,
-		ServerActiveObject *clicker)
+bool ScriptApiEntity::luaentity_on_death(u16 id, ServerActiveObject *killer)
 {
-	SCRIPTAPI_PRECHECKHEADER
-
-	//infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
-
-	int error_handler = PUSH_ERROR_HANDLER(L);
+	return luaentity_run_simple_callback(id, killer, "on_death");
+}
 
-	// Get core.luaentities[id]
-	luaentity_get(L, id);
-	int object = lua_gettop(L);
-	// State: object is at top of stack
-	// Get function
-	lua_getfield(L, -1, "on_rightclick");
-	if (lua_isnil(L, -1)) {
-		lua_pop(L, 2); // Pop on_rightclick and entity
-		return;
-	}
-	luaL_checktype(L, -1, LUA_TFUNCTION);
-	lua_pushvalue(L, object); // self
-	objectrefGetOrCreate(L, clicker); // Clicker reference
+// Calls entity:on_rightclick(ObjectRef clicker)
+void ScriptApiEntity::luaentity_Rightclick(u16 id, ServerActiveObject *clicker)
+{
+	luaentity_run_simple_callback(id, clicker, "on_rightclick");
+}
 
-	setOriginFromTable(object);
-	PCALL_RES(lua_pcall(L, 2, 0, error_handler));
+void ScriptApiEntity::luaentity_on_attach_child(u16 id, ServerActiveObject *child)
+{
+	luaentity_run_simple_callback(id, child, "on_attach_child");
+}
 
-	lua_pop(L, 2); // Pop object and error handler
+void ScriptApiEntity::luaentity_on_detach_child(u16 id, ServerActiveObject *child)
+{
+	luaentity_run_simple_callback(id, child, "on_detach_child");
 }
 
+void ScriptApiEntity::luaentity_on_detach(u16 id, ServerActiveObject *parent)
+{
+	luaentity_run_simple_callback(id, parent, "on_detach");
+}
diff --git a/src/script/cpp_api/s_entity.h b/src/script/cpp_api/s_entity.h
index 173e24c30..966c2745e 100644
--- a/src/script/cpp_api/s_entity.h
+++ b/src/script/cpp_api/s_entity.h
@@ -41,6 +41,11 @@ public:
 			ServerActiveObject *puncher, float time_from_last_punch,
 			const ToolCapabilities *toolcap, v3f dir, s16 damage);
 	bool luaentity_on_death(u16 id, ServerActiveObject *killer);
-	void luaentity_Rightclick(u16 id,
-			ServerActiveObject *clicker);
+	void luaentity_Rightclick(u16 id, ServerActiveObject *clicker);
+	void luaentity_on_attach_child(u16 id, ServerActiveObject *child);
+	void luaentity_on_detach_child(u16 id, ServerActiveObject *child);
+	void luaentity_on_detach(u16 id, ServerActiveObject *parent);
+private:
+	bool luaentity_run_simple_callback(u16 id, ServerActiveObject *sao,
+		const char *field);
 };
diff --git a/src/script/lua_api/l_object.cpp b/src/script/lua_api/l_object.cpp
index 0bef23541..b3c3a55bf 100644
--- a/src/script/lua_api/l_object.cpp
+++ b/src/script/lua_api/l_object.cpp
@@ -103,12 +103,8 @@ int ObjectRef::l_remove(lua_State *L)
 	if (co->getType() == ACTIVEOBJECT_TYPE_PLAYER)
 		return 0;
 
-	const std::unordered_set<int> &child_ids = co->getAttachmentChildIds();
-	for (int child_id : child_ids) {
-		// Child can be NULL if it was deleted earlier
-		if (ServerActiveObject *child = env->getActiveObject(child_id))
-			child->setAttachment(0, "", v3f(0, 0, 0), v3f(0, 0, 0));
-	}
+	co->clearChildAttachments();
+	co->clearParentAttachment();
 
 	verbosestream << "ObjectRef::l_remove(): id=" << co->getId() << std::endl;
 	co->m_pending_removal = true;
@@ -721,21 +717,7 @@ int ObjectRef::l_set_detach(lua_State *L)
 	if (co == NULL)
 		return 0;
 
-	int parent_id = 0;
-	std::string bone;
-	v3f position;
-	v3f rotation;
-	co->getAttachment(&parent_id, &bone, &position, &rotation);
-	ServerActiveObject *parent = NULL;
-	if (parent_id) {
-		parent = env->getActiveObject(parent_id);
-		co->setAttachment(0, "", position, rotation);
-	} else {
-		co->setAttachment(0, "", v3f(0, 0, 0), v3f(0, 0, 0));
-	}
-	// Do it
-	if (parent != NULL)
-		parent->removeAttachmentChild(co->getId());
+	co->clearParentAttachment();
 	return 0;
 }