static int l_spritesheet_isvisible(lua_State *L) { THSpriteSheet* pSheet = luaT_testuserdata<THSpriteSheet>(L); size_t iSprite = luaL_checkinteger(L, 2); THColour oDummy; lua_pushboolean(L, pSheet->getSpriteAverageColour(iSprite, &oDummy) ? 1:0); return 1; }