diff options
| -rw-r--r-- | src/town_cmd.cpp | 48 |
1 files changed, 47 insertions, 1 deletions
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp index 6674c905b..810499d04 100644 --- a/src/town_cmd.cpp +++ b/src/town_cmd.cpp @@ -1297,6 +1297,44 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t } /** + * Checks whether a road can be followed or is a dead end, that can not be extended to the next tile. + * This only checks trivial but often cases. + * @param tile Start tile for road. + * @param dir Direction for road to follow or build. + * @return true If road is or can be connected in the specified direction. + */ +static bool CanFollowRoad(TileIndex tile, DiagDirection dir) +{ + TileIndex target_tile = tile + TileOffsByDiagDir(dir); + if (!IsValidTile(target_tile)) return false; + if (HasTileWaterGround(target_tile)) return false; + + RoadBits target_rb = GetTownRoadBits(target_tile); + if (_settings_game.economy.allow_town_roads) { + /* Check whether a road connection exists or can be build. */ + switch (GetTileType(target_tile)) { + case MP_ROAD: + return target_rb != ROAD_NONE; + + case MP_HOUSE: + case MP_STATION: + case MP_INDUSTRY: + case MP_OBJECT: + return false; + + default: + /* Checked for void and water earlier */ + return true; + } + } else { + /* Check whether a road connection already exists, + * and it leads somewhere else. */ + RoadBits back_rb = DiagDirToRoadBits(ReverseDiagDir(dir)); + return (target_rb & back_rb) != 0 && (target_rb & back_rb) != back_rb; + } +} + +/** * Returns "growth" if a house was built, or no if the build failed. * @param t town to inquiry * @param tile to inquiry @@ -1348,7 +1386,15 @@ static int GrowTownAtRoad(Town *t, TileIndex tile) } else { /* Select a random bit from the blockmask, walk a step * and continue the search from there. */ - do target_dir = RandomDiagDir(); while (!(cur_rb & DiagDirToRoadBits(target_dir))); + do { + if (cur_rb == ROAD_NONE) return GROWTH_SEARCH_STOPPED; + RoadBits target_bits; + do { + target_dir = RandomDiagDir(); + target_bits = DiagDirToRoadBits(target_dir); + } while (!(cur_rb & target_bits)); + cur_rb &= ~target_bits; + } while (!CanFollowRoad(tile, target_dir)); } tile = TileAddByDiagDir(tile, target_dir); |