Сoordinates of a tile on an isometric map

How do i know coordinates of a tile on an isometric map? Size map 30*30, width of tile 64, height of tile 32.
Stopped here:

bool HelloWorld::init()
{

m_pCTiledMap = TMXTiledMap::create(“map.tmx”);
m_pCTiledMap->setAnchorPoint(Vec2(0, 0));
m_pCTiledMap->setPosition(Vec2(origin.x, origin.y));
auto listener = EventListenerMouse::create();
listener->onMouseDown = [this](Event * event)
{
EventMouse * eventMouse = dynamic_cast<EventMouse*>(event);
auto pMap = this->GetTiledMap();
auto floor_layer = pMap->getLayer(“floor”);
auto world_pos = floor_layer->convertToNodeSpace(eventMouse->getLocation());
}
_eventDispatcher->addEventListenerWithFixedPriority(listener,1);
return true;
}