diff options
| -rw-r--r-- | src/road_cmd.cpp | 41 |
1 files changed, 34 insertions, 7 deletions
diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp index 6f91e20be..57f550765 100644 --- a/src/road_cmd.cpp +++ b/src/road_cmd.cpp @@ -786,17 +786,32 @@ do_clear:; } /** + * 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. + */ +static bool CanConnectToRoad(TileIndex tile, RoadType rt, DiagDirection dir) +{ + RoadBits bits = GetAnyRoadBits(tile + TileOffsByDiagDir(dir), rt, false); + return (bits & DiagDirToRoadBits(ReverseDiagDir(dir))); +} + +/** * Build a long piece of road. * @param start_tile start tile of drag (the building cost will appear over this tile) * @param flags operation to perform * @param p1 end tile of drag * @param p2 various bitstuffed elements - * - p2 = (bit 0) - start tile starts in the 2nd half of tile (p2 & 1) - * - p2 = (bit 1) - end tile starts in the 2nd half of tile (p2 & 2) + * - p2 = (bit 0) - start tile starts in the 2nd half of tile (p2 & 1). Only used if bit 6 is set or if we are building a single tile + * - p2 = (bit 1) - end tile starts in the 2nd half of tile (p2 & 2). Only used if bit 6 is set or if we are building a single tile * - p2 = (bit 2) - direction: 0 = along x-axis, 1 = along y-axis (p2 & 4) * - p2 = (bit 3 + 4) - road type * - p2 = (bit 5) - set road direction - * - p2 = (bit 6) - 0 = build up to an obstacle, 1 = fail if an obstacle is found (used for AIs). + * - p2 = (bit 6) - defines two different behaviors for this command: + * - 0 = Build up to an obstacle. Do not build the first and last roadbits unless they can be connected to something, or if we are building a single tile + * - 1 = Fail if an obstacle is found. Always take into account bit 0 and 1. This behavior is used for scripts * @param text unused * @return the cost of this operation or an error */ @@ -837,19 +852,31 @@ CommandCost CmdBuildLongRoad(TileIndex start_tile, DoCommandFlag flags, uint32 p bool had_bridge = false; bool had_tunnel = false; bool had_success = false; + bool is_ai = HasBit(p2, 6); + /* Start tile is the first tile clicked by the user. */ for (;;) { RoadBits bits = AxisToRoadBits(axis); - /* Road parts only have to be built at the start tile or at the end tile. */ - if (tile == end_tile && !HasBit(p2, 1)) bits &= DiagDirToRoadBits(ReverseDiagDir(dir)); - if (tile == start_tile && HasBit(p2, 0)) bits &= DiagDirToRoadBits(dir); + /* Determine which road parts should be built. */ + if (!is_ai && start_tile != end_tile) { + /* Only build the first and last roadbit if they can connect to something. */ + if (tile == end_tile && !CanConnectToRoad(tile, rt, dir)) { + bits = DiagDirToRoadBits(ReverseDiagDir(dir)); + } else if (tile == start_tile && !CanConnectToRoad(tile, rt, ReverseDiagDir(dir))) { + bits = DiagDirToRoadBits(dir); + } + } else { + /* Road parts only have to be built at the start tile or at the end tile. */ + if (tile == end_tile && !HasBit(p2, 1)) bits &= DiagDirToRoadBits(ReverseDiagDir(dir)); + if (tile == start_tile && HasBit(p2, 0)) bits &= DiagDirToRoadBits(dir); + } CommandCost ret = DoCommand(tile, drd << 6 | rt << 4 | bits, 0, flags, CMD_BUILD_ROAD); if (ret.Failed()) { last_error = ret; if (last_error.GetErrorMessage() != STR_ERROR_ALREADY_BUILT) { - if (HasBit(p2, 6)) return last_error; + if (is_ai) return last_error; break; } } else { |