Function ReverseTrainSwapVeh

src/train_cmd.cpp:1649–1684

* Swap vehicles \a l and \a r in consist \a v, and reverse their direction. * @param v Consist to change. * @param l %Vehicle index in the consist of the first vehicle. * @param r %Vehicle index in the consist of the second vehicle. */

 * @param r %Vehicle index in the consist of the second vehicle.
 */
void ReverseTrainSwapVeh(Train *v, int l, int r)
{
	Train *a, *b;

	/* locate vehicles to swap */
	for (a = v; l != 0; l--) a = a->Next();
	for (b = v; r != 0; r--) b = b->Next();

	if (a != b) {
		/* swap the hidden bits */
		{
			bool a_hidden = a->vehstatus.Test(VehState::Hidden);
			bool b_hidden = b->vehstatus.Test(VehState::Hidden);
			b->vehstatus.Set(VehState::Hidden, a_hidden);
			a->vehstatus.Set(VehState::Hidden, b_hidden);
		}

		std::swap(a->track, b->track);
		std::swap(a->direction, b->direction);
		std::swap(a->x_pos, b->x_pos);
		std::swap(a->y_pos, b->y_pos);
		std::swap(a->tile,  b->tile);
		std::swap(a->z_pos, b->z_pos);

		SwapTrainFlags(&a->gv_flags, &b->gv_flags);

		UpdateStatusAfterSwap(a);
		UpdateStatusAfterSwap(b);
	} else {
		/* Swap GVF_GOINGUP_BIT/GVF_GOINGDOWN_BIT.
		 * This is a little bit redundant way, a->gv_flags will
		 * be (re)set twice, but it reduces code duplication */
		SwapTrainFlags(&a->gv_flags, &a->gv_flags);
		UpdateStatusAfterSwap(a);
	}
}

/**
 * Check if the vehicle is a train