Function RoadFindPathToDest

src/roadveh_cmd.cpp:888–1002

* Returns direction to for a road vehicle to take or * INVALID_TRACKDIR if the direction is currently blocked * @param v the Vehicle to do the pathfinding for * @param tile the where to start the pathfinding * @param enterdir the direction the vehicle enters the tile from * @return the Trackdir to take */

 * @return the Trackdir to take
 */
static Trackdir RoadFindPathToDest(RoadVehicle *v, TileIndex tile, DiagDirection enterdir)
{
#define return_track(x) { best_track = (Trackdir)x; goto found_best_track; }

	TileIndex desttile;
	Trackdir best_track;
	bool path_found = true;

	TrackStatus ts = GetTileTrackStatus(tile, TRANSPORT_ROAD, GetRoadTramType(v->roadtype));
	TrackdirBits red_signals = TrackStatusToRedSignals(ts); // crossing
	TrackdirBits trackdirs = TrackStatusToTrackdirBits(ts);

	if (IsTileType(tile, MP_ROAD)) {
		if (IsRoadDepot(tile) && (!IsTileOwner(tile, v->owner) || GetRoadDepotDirection(tile) == enterdir)) {
			/* Road depot owned by another company or with the wrong orientation */
			trackdirs = TRACKDIR_BIT_NONE;
		}
	} else if (IsTileType(tile, MP_STATION) && IsBayRoadStopTile(tile)) {
		/* Standard road stop (drive-through stops are treated as normal road) */

		if (!IsTileOwner(tile, v->owner) || GetBayRoadStopDir(tile) == enterdir || v->HasArticulatedPart()) {
			/* different station owner or wrong orientation or the vehicle has articulated parts */
			trackdirs = TRACKDIR_BIT_NONE;
		} else {
			/* Our station */
			RoadStopType rstype = v->IsBus() ? RoadStopType::Bus : RoadStopType::Truck;

			if (GetRoadStopType(tile) != rstype) {
				/* Wrong station type */
				trackdirs = TRACKDIR_BIT_NONE;
			} else {
				/* Proper station type, check if there is free loading bay */
				if (!_settings_game.pf.roadveh_queue && IsBayRoadStopTile(tile) &&
						!RoadStop::GetByTile(tile, rstype)->HasFreeBay()) {
					/* Station is full and RV queuing is off */
					trackdirs = TRACKDIR_BIT_NONE;
				}
			}
		}
	}
	/* The above lookups should be moved to GetTileTrackStatus in the
	 * future, but that requires more changes to the pathfinder and other
	 * stuff, probably even more arguments to GTTS.
	 */

	/* Remove tracks unreachable from the enter dir */
	trackdirs &= DiagdirReachesTrackdirs(enterdir);
	if (trackdirs == TRACKDIR_BIT_NONE) {
		/* If vehicle expected a path, it no longer exists, so invalidate it. */
		if (!v->path.empty()) v->path.clear();
		/* No reachable tracks, so we'll reverse */
		return_track(_road_reverse_table[enterdir]);
	}

	if (v->reverse_ctr != 0) {
		bool reverse = true;
		if (RoadTypeIsTram(v->roadtype)) {
			/* Trams may only reverse on a tile if it contains at least the straight