Made lua binding c++17 compatible

1 files changed, 181 insertions, 0 deletions

diff --git a/src/Script/entityx/entity_lua.cpp b/src/Script/entityx/entity_lua.cpp
new file mode 100644
index 0000000..e62f040
--- /dev/null
+++ b/src/Script/entityx/entity_lua.cpp
@@ -0,0 +1,181 @@
+#include "entityx_lua.h"
+
+using namespace entityx::lua;
+ComponentList entityx::lua::components;
+
+namespace {
+	int ref_EntityManagerSharedPtr = LUA_REFNIL;
+	int ref_EntityId = LUA_REFNIL;
+	const char* TypeName_EntityManagerSharedPtr = "EntityManagerSharedPtr";
+	const char* TypeName_EntityId = "EntityId";
+	const char* setup_lua_create_entity_factory =
+		"function entityx.create_entity_factory(entity_manager_pointer)\n"
+		"	local c = {}\n"
+		"	c.__index = c\n"
+		"	function c:new()\n"
+		"		local ret = {}\n"
+		"		ret.__index = ret\n"
+		"		function ret:init()\n"
+		"			-- Empty\n"
+		"		end\n"
+		"		function ret:instance(param)\n"
+		"			-- Make id const\n"
+		"			local r = {}\n"
+		"			local id = entityx.create_new_entity(entity_manager_pointer, r)\n"
+		"			r.id = id\n"
+		"			function r:component(name, params)\n"
+		"				return entityx.create_new_component(name, entity_manager_pointer, id, params)\n"
+		"			end\n"
+		"			setmetatable(r, self)\n"
+		"			r:init(param)\n"
+		"			return r\n"
+		"		end\n"
+		"		return ret\n"
+		"	end\n"
+		"	function c:get(id)\n"
+		"		return entityx.get_lua_object(entity_manager_pointer, id)\n"
+		"	end\n"
+		"	return c\n"
+		"end\n";
+}
+
+//TODO replace:entityx_lua:: settable->setfield/rawset
+void entityx::lua::setup_entityx_api(lua_State* L)
+{
+	// Create metatables for userdata
+	// metatable for shared_ptr of EntityManager
+	lua_newtable(L);
+	lua_pushstring(L, TypeName_EntityManagerSharedPtr);
+	lua_setfield(L, -2, "type");
+	lua_pushcfunction(L, [](lua_State* L){
+		EntityManagerSharedPtr* ptr = static_cast<EntityManagerSharedPtr*>(lua_touserdata(L, 1));
+		(*ptr).~EntityManagerSharedPtr();
+		return 0;
+	});
+	lua_setfield(L, -2, "__gc");
+	ref_EntityManagerSharedPtr = luaL_ref(L, LUA_REGISTRYINDEX);
+
+	// metatable for Entity::Id
+	lua_newtable(L);
+	lua_pushstring(L, TypeName_EntityId);
+	lua_setfield(L, -2, "type");
+	// We don't need __gc for Entity::Id (with static_assert it is_trivially_destructible)
+	ref_EntityId = luaL_ref(L, LUA_REGISTRYINDEX);
+
+
+	// Create global entityx table
+	lua_newtable(L);
+
+	// create_new_entity
+	lua_pushcfunction(L, [](lua_State* L){
+		// First check the type of the parameter
+		lua_getmetatable(L, 1);
+		lua_pushstring(L, "type");
+		lua_rawget(L, -2);
+		if (!lua_isuserdata(L, 1) || strcmp(lua_tostring(L, -1), TypeName_EntityManagerSharedPtr) != 0 || !lua_istable(L, 2))
+		{
+			lua_pushstring(L, "create_new_entity should be called with pointer of EntityManager and a table.");
+			return lua_error(L);
+		}
+		lua_pop(L, 2);
+
+		lua_pushvalue(L, 2);
+		int ref = luaL_ref(L, LUA_REGISTRYINDEX);
+
+		// Create an new entity
+		EntityManagerSharedPtr* ptr = static_cast<EntityManagerSharedPtr*>(lua_touserdata(L, 1));
+		entityx::Entity entity = (*ptr)->create();
+
+		// Save the lua object (ref) in the entity
+		entity.assign<LuaComponent>(ref);
+
+		// Return the Id of the entity
+		lua_newuserdata(L, sizeof(entityx::Entity::Id));
+		lua_rawgeti(L, LUA_REGISTRYINDEX, ref_EntityId);
+		lua_setmetatable(L, -2);
+		new (lua_touserdata(L, -1)) entityx::Entity::Id(entity.id());
+
+		return 1;
+	});
+	lua_setfield(L, -2, "create_new_entity");
+
+	// get_lua_object
+	lua_pushcfunction(L, [](lua_State* L){
+		// First check the type of the parameters
+		lua_getmetatable(L, 1);
+		lua_pushstring(L, "type");
+		lua_rawget(L, -2);
+		if (!lua_isuserdata(L, 1) || strcmp(lua_tostring(L, -1), TypeName_EntityManagerSharedPtr) != 0)
+		{
+			lua_pushstring(L, "get_lua_object should be called with pointer of EntityManager and an EntityId.");
+			return lua_error(L);
+		}
+		lua_pop(L, 2);
+
+		lua_getmetatable(L, 2);
+		lua_pushstring(L, "type");
+		lua_rawget(L, -2);
+		if (!lua_isuserdata(L, 2) || strcmp(lua_tostring(L, -1), TypeName_EntityId) != 0)
+		{
+			lua_pushstring(L, "get_lua_object should be called with pointer of EntityManager and an EntityId.");
+			return lua_error(L);
+		}
+		lua_pop(L, 2);
+
+		// Get the object
+		EntityManagerSharedPtr* ptr = static_cast<EntityManagerSharedPtr*>(lua_touserdata(L, 1));
+		entityx::Entity::Id* id = static_cast<entityx::Entity::Id*>(lua_touserdata(L, 2));
+
+		entityx::Entity entity = (*ptr)->get(*id);
+		int ref = entity.component<LuaComponent>()->ref;
+
+		lua_rawgeti(L, LUA_REGISTRYINDEX, ref);
+		return 1;
+	});
+	lua_setfield(L, -2, "get_lua_object");
+
+	// create_new_component
+	lua_pushcfunction(L, [](lua_State* L){
+		ComponentList::iterator i;
+		//return 0;
+		if ((i = components.find(std::string(lua_tostring(L, 1)))) != components.end())
+		{
+			i->second(L);
+		}
+		else
+		{
+			lua_pushstring(L, "Component not found.");
+			return lua_error(L);
+		}
+		return 1;
+	});
+	lua_setfield(L, -2, "create_new_component");
+
+	lua_setglobal(L, "entityx");
+
+	luaL_loadstring(L, setup_lua_create_entity_factory);
+	lua_call(L, 0, 0);
+}
+
+void entityx::lua::push_entity_manager(lua_State* L, const EntityManagerSharedPtr& manager)
+{
+	lua_newuserdata(L, sizeof(EntityManagerSharedPtr));
+	lua_rawgeti(L, LUA_REGISTRYINDEX, ref_EntityManagerSharedPtr);
+	lua_setmetatable(L, -2);
+
+	new (lua_touserdata(L, -1)) EntityManagerSharedPtr(manager);
+}
+
+void entityx::lua::new_entity_manager(lua_State* L, const EntityManagerSharedPtr& manager, const char* name)
+{
+	lua_getglobal(L, "entityx");
+	lua_getfield(L, -1, "create_entity_factory");
+	lua_remove(L, -2); // _G["entityx"]
+	push_entity_manager(L, manager);
+	lua_pcall(L, 1, 1, 1);
+
+	lua_getglobal(L, "entityx");
+	lua_pushvalue(L, -2);
+	lua_setfield(L, -2, name);
+	lua_pop(L, 2); // original return value & entityx
+}