Function RoadTypesAllowHouseHere

src/town_cmd.cpp:1466–1486

* Checks whether at least one surrounding road allows to build a house here. * * @param t The tile where the house will be built. * @return true if at least one surrounding roadtype allows building houses here. */

 * @return true if at least one surrounding roadtype allows building houses here.
 */
static inline bool RoadTypesAllowHouseHere(TileIndex t)
{
	static const TileIndexDiffC tiles[] = { {-1, -1}, {-1, 0}, {-1, 1}, {0, -1}, {0, 1}, {1, -1}, {1, 0}, {1, 1} };
	bool allow = false;

	for (const auto &ptr : tiles) {
		TileIndex cur_tile = t + ToTileIndexDiff(ptr);
		if (!IsValidTile(cur_tile)) continue;

		if (!(IsTileType(cur_tile, MP_ROAD) || IsAnyRoadStopTile(cur_tile))) continue;
		allow = true;

		RoadType road_rt = GetRoadTypeRoad(cur_tile);
		if (road_rt != INVALID_ROADTYPE && !GetRoadTypeInfo(road_rt)->flags.Test(RoadTypeFlag::NoHouses)) return true;
	}

	/* If no road was found surrounding the tile we can allow building the house since there is
	 * nothing which forbids it, if a road was found but the execution reached this point, then
	 * all the found roads don't allow houses to be built */
	return !allow;
}

/** Test if town can grow road onto a specific tile.
 * @param tile Tile to build upon.