Here is a list of all documented functions, variables, defines, enums, and typedefs with links to the documentation:

### - r -

- RAIL_GROUND_BARREN : rail_map.h
- RAIL_GROUND_FENCE_HORIZ1 : rail_map.h
- RAIL_GROUND_FENCE_HORIZ2 : rail_map.h
- RAIL_GROUND_FENCE_NE : rail_map.h
- RAIL_GROUND_FENCE_NESW : rail_map.h
- RAIL_GROUND_FENCE_NW : rail_map.h
- RAIL_GROUND_FENCE_SE : rail_map.h
- RAIL_GROUND_FENCE_SENW : rail_map.h
- RAIL_GROUND_FENCE_SW : rail_map.h
- RAIL_GROUND_FENCE_VERT1 : rail_map.h
- RAIL_GROUND_FENCE_VERT2 : rail_map.h
- RAIL_GROUND_GRASS : rail_map.h
- RAIL_GROUND_HALF_SNOW : rail_map.h
- RAIL_GROUND_ICE_DESERT : rail_map.h
- RAIL_GROUND_WATER : rail_map.h
- RAIL_TILE_DEPOT : rail_map.h
- RAIL_TILE_NORMAL : rail_map.h
- RAIL_TILE_SIGNALS : rail_map.h
- RAIL_TILE_WAYPOINT : rail_map.h
- RailBuildCost() : rail.h
- RailConvertCost() : rail.h
- RailGroundType : rail_map.h
- RailTileType : rail_map.h
- RailToolbar_CtrlChanged() : rail_gui.cpp
- RailToolbarWidgets : rail_gui.cpp
- RailType : rail_type.h
- RAILTYPE_BEGIN : rail_type.h
- RAILTYPE_ELECTRIC : rail_type.h
- RAILTYPE_END : rail_type.h
- RAILTYPE_MAGLEV : rail_type.h
- RAILTYPE_MONO : rail_type.h
- RAILTYPE_RAIL : rail_type.h
- RailTypes : rail_type.h
- RAILTYPES_ALL : rail_type.h
- RAILTYPES_ELECTRIC : rail_type.h
- RAILTYPES_END : rail_type.h
- RAILTYPES_MAGLEV : rail_type.h
- RAILTYPES_MONO : rail_type.h
- RAILTYPES_NONE : rail_type.h
- RAILTYPES_RAIL : rail_type.h
- RAILVEH_MULTIHEAD : engine.h
- RAILVEH_SINGLEHEAD : engine.h
- RAILVEH_WAGON : engine.h
- RailVehicleChangeInfo() : newgrf.cpp
- RailVehicleLengthChanged() : train_cmd.cpp
- RailVehicleTypes : engine.h
- RandomDiagDir() : town_cmd.cpp
- RandomHeight() : tgp.cpp
- RandomPlayerFaceBits() : player_face.h
- RandomTile : map_func.h
- RandomTileSeed() : map_func.h
- RATING_OUTSTANDING : town_type.h
- RC_D : engines.h
- RC_E : engines.h
- RC_R : engines.h
- RC_S : engines.h
- RC_W : engines.h
- read_bytes : saveload.cpp
- ReadByte() : oldloader.cpp
- ReadByteFromFile() : oldloader.cpp
- ReadHeightMap() : heightmap.cpp
- ReadHeightmapBMP() : heightmap.cpp
- ReadHeightmapBMPImageData() : heightmap.cpp
- ReadSpriteHeaderSkipData() : spritecache.cpp
- ReadValue() : saveload.cpp , saveload.h
- ReadyForNextItem() : news_gui.cpp
- ReallocError() : alloc_func.cpp , alloc_func.hpp
- ReallocT() : alloc_func.hpp
- RebuildStationLists() : station_gui.cpp , station_gui.h
- RECOLOR_BIT : sprites.h
- RedrawWaypointSign() : waypoint.cpp
- ReferenceToInt() : saveload.cpp
- ReloadNewGRFData() : newgrf.h , openttd.cpp
- RemapNewGRFStringControlCode() : newgrf_text.cpp , newgrf_text.h
- RemapOldStringID() : functions.h , strings.cpp
- RemoveAllEngineReplacement() : autoreplace_func.h , engine.cpp
- RemoveAllEngineReplacementForPlayer() : autoreplace_func.h
- RemoveDuplicatesFromGRFConfigList() : newgrf_config.cpp
- RemoveEngineReplacement() : autoreplace_func.h , engine.cpp
- RemoveEngineReplacementForPlayer() : autoreplace_func.h
- RemoveFirstTrack() : track_func.h
- RemoveFirstTrackdir() : track_func.h
- RemoveHalftileSlope() : slope_func.h
- RemoveOrderFromAllVehicles() : order.h , order_cmd.cpp
- RemoveRoad() : road_cmd.cpp
- RemoveRoadStop() : station_cmd.cpp
- RemoveSharedOrderVehicleList() : order_cmd.cpp
- RemoveTrainWaypoint() : waypoint.cpp , waypoint.h
- RemoveVehicleFromGroup() : group.h , group_cmd.cpp
- ReportNewsProductionChangeIndustry() : industry_cmd.cpp
- ResetBridges() : tunnelbridge_cmd.cpp , bridge.h
- ResetCurrencies() : currency.cpp , currency.h
- ResetIndustries() : industry_cmd.cpp , industry.h
- ResetIndustryConstructionStage() : industry_map.h
- ResetIndustryCounts() : industry.h
- ResetLandscapeConfirmationCallback() : terraform_gui.cpp
- ResetNewGRFData() : newgrf.cpp
- ResetPlayerLivery() : livery.h , players.cpp
- ResetPriceBaseMultipliers() : economy.cpp , economy_func.h
- ResetRestoreAllTransparency() : transparency.h
- ResetSets() : signal.cpp
- ResetStationClasses() : newgrf_station.h , newgrf_station.cpp
- RESIZE_BOTTOM : window_gui.h
- RESIZE_LEFT : window_gui.h
- RESIZE_LR : window_gui.h
- RESIZE_LRB : window_gui.h
- RESIZE_LRTB : window_gui.h
- RESIZE_NONE : window_gui.h
- RESIZE_RB : window_gui.h
- RESIZE_RIGHT : window_gui.h
- RESIZE_RTB : window_gui.h
- RESIZE_TB : window_gui.h
- RESIZE_TOP : window_gui.h
- ResizeButtons() : window_gui.h , widget.cpp
- ResizeFlag : window_gui.h
- ResizeWindow() : window_func.h , window.cpp , window_gui.h
- ResizeWindowForWidget() : window_gui.h , widget.cpp
- ResortStationLists() : station_gui.h , station_gui.cpp
- RestoreVehicleOrders() : order_cmd.cpp , order.h
- return_cmd_error : command_func.h
- ReverseDiagDir() : direction_func.h
- ReverseDir() : direction_func.h
- ReverseTrackdir() : track_func.h
- ReverseTrainDirection() : train_cmd.cpp
- RGBToGrayscale() : heightmap.cpp
- ROAD_ALL : road_type.h
- ROAD_NE : road_type.h
- ROAD_NONE : road_type.h
- ROAD_NW : road_type.h
- ROAD_SE : road_type.h
- ROAD_SW : road_type.h
- ROAD_X : road_type.h
- ROAD_Y : road_type.h
- RoadBits : road_type.h
- RoadFindPathToDest() : roadveh_cmd.cpp
- RoadFlags : road_gui.cpp
- RoadToolbar_CtrlChanged() : road_gui.cpp
- RoadToolbarWidgets : road_gui.cpp
- RoadType : road_type.h
- ROADTYPE_END : road_type.h
- ROADTYPE_HWAY : road_type.h
- ROADTYPE_ROAD : road_type.h
- ROADTYPE_TRAM : road_type.h
- RoadTypes : road_type.h
- ROADTYPES_ALL : road_type.h
- ROADTYPES_END : road_type.h
- ROADTYPES_HWAY : road_type.h
- ROADTYPES_NONE : road_type.h
- ROADTYPES_ROAD : road_type.h
- ROADTYPES_ROADHWAY : road_type.h
- ROADTYPES_ROADTRAM : road_type.h
- ROADTYPES_TRAM : road_type.h
- ROADTYPES_TRAMHWAY : road_type.h
- RoadTypeToRoadTypes() : road_func.h
- RoadVehicleChangeInfo() : newgrf.cpp
- RoadVehicleStates : vehicle_base.h
- ROL() : bitmath_func.hpp
- ROR() : bitmath_func.hpp
- RotateRight() : newgrf_spritegroup.cpp
- RotateRoadBits() : road_func.h
- ROV : engines.h
- RunVehicleDayProc() : date.cpp
- RVI : engines.h
- RVS_DRIVE_SIDE : vehicle_base.h
- RVS_IN_DT_ROAD_STOP : vehicle_base.h
- RVS_IN_ROAD_STOP : vehicle_base.h
- RVS_IS_STOPPING : vehicle_base.h
- RVS_USING_SECOND_BAY : vehicle_base.h
- RVSB_IN_DEPOT : vehicle_base.h
- RVSB_IN_DT_ROAD_STOP : vehicle_base.h
- RVSB_IN_ROAD_STOP : vehicle_base.h
- RVSB_ROAD_STOP_TRACKDIR_MASK : vehicle_base.h
- RVSB_TRACKDIR_MASK : vehicle_base.h
- RVSB_WORMHOLE : vehicle_base.h