Function CanConnectToRoad

src/road_cmd.cpp:937–949

* Checks whether a road or tram connection can be found when building a new road or tram. * @param tile Tile at which the road being built will end. * @param rt Roadtype of the road being built. * @param dir Direction that the road is following. * @return True if the next tile at dir direction is suitable for being connected directly by a second roadbit at the end of the road being built. */

 * @return True if the next tile at dir direction is suitable for being connected directly by a second roadbit at the end of the road being built.
 */
static bool CanConnectToRoad(TileIndex tile, RoadType rt, DiagDirection dir)
{
	tile += TileOffsByDiagDir(dir);
	if (!IsValidTile(tile) || !MayHaveRoad(tile)) return false;

	RoadTramType rtt = GetRoadTramType(rt);
	RoadType existing = GetRoadType(tile, rtt);
	if (existing == INVALID_ROADTYPE) return false;
	if (!HasPowerOnRoad(existing, rt) && !HasPowerOnRoad(rt, existing)) return false;

	RoadBits bits = GetAnyRoadBits(tile, rtt, false);
	return (bits & DiagDirToRoadBits(ReverseDiagDir(dir))) != 0;
}

/**
 * Build a long piece of road.