Function TrainApproachingCrossingTile

src/train_cmd.cpp:3869–3886

* Determines whether train is approaching a rail-road crossing * (thus making it barred) * @param v front engine of train * @return TileIndex of crossing the train is approaching, else INVALID_TILE * @pre v in non-crashed front engine */

 * @pre v in non-crashed front engine
 */
static TileIndex TrainApproachingCrossingTile(const Train *v)
{
	assert(v->IsFrontEngine());
	assert(!v->vehstatus.Test(VehState::Crashed));

	if (!TrainCanLeaveTile(v)) return INVALID_TILE;

	DiagDirection dir = VehicleExitDir(v->direction, v->track);
	TileIndex tile = v->tile + TileOffsByDiagDir(dir);

	/* not a crossing || wrong axis || unusable rail (wrong type or owner) */
	if (!IsLevelCrossingTile(tile) || DiagDirToAxis(dir) == GetCrossingRoadAxis(tile) ||
			!CheckCompatibleRail(v, tile)) {
		return INVALID_TILE;
	}

	return tile;
}


/**