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

### - d -

- DATA_DIR : fileio.h
- DAY_TICKS : date_type.h
- DAYS_TILL_ORIGINAL_BASE_YEAR : date_type.h
- DC_AI_BUILDING : command_type.h
- DC_AUTO : command_type.h
- DC_AUTOREPLACE : command_type.h
- DC_BANKRUPT : command_type.h
- DC_EXEC : command_type.h
- DC_NO_RAIL_OVERLAP : command_type.h
- DC_NO_TOWN_RATING : command_type.h
- DC_NO_WATER : command_type.h
- DC_QUERY_COST : command_type.h
- DeallocateSpecFromStation() : newgrf_station.cpp , newgrf_station.h
- DecHouseProcessingTime() : town_map.h
- DecIndustryTypeCount() : industry.h
- DECLARE_ENUM_AS_BIT_SET : enum_type.hpp , player_face.h
- DECLARE_POSTFIX_INCREMENT : enum_type.hpp , direction_type.h , newgrf_station.h , rail_type.h , track_type.h
- DecloneOrder() : order_cmd.cpp
- DecreaseBuildingCount() : newgrf_house.cpp , newgrf_house.h
- decreaseIndex() : news_gui.cpp
- DedicatedFork() : dedicated.cpp
- DEF_COMMAND : command.cpp
- DEFAULT_GROUP : group.h
- delete_Hash() : queue.cpp , queue.h
- DeleteAllNonVitalWindows() : window.cpp , window_func.h , window_gui.h
- DeleteAnimatedTile() : functions.h , texteff.cpp
- DeleteDepotHighlightOfVehicle() : depot.h , depot_gui.cpp
- DeleteLastWagon() : train_cmd.cpp
- DeleteOrderWarnings() : order_cmd.cpp
- DeletePlayerWindows() : player_gui.h , window.cpp , window_gui.h
- DeleteStationIfEmpty() : station_cmd.cpp
- DeleteTextBufferAll() : misc_gui.cpp , textbuf_gui.h
- DeleteTextBufferChar() : misc_gui.cpp , textbuf_gui.h
- DeleteVehicleChain() : vehicle.cpp
- DeleteVehicleNews() : news.h , news_gui.cpp
- DeleteVehicleOrders() : order.h , order_cmd.cpp
- DeliverGoodsToIndustry() : economy.cpp
- Delta() : math_func.hpp
- DEPOT_WIDGET_H_SCROLL : depot_gui.cpp
- DEPOT_WIDGET_V_SCROLL : depot_gui.cpp
- DepotWindowWidgets : depot_gui.cpp
- DestroyCompanyHQ() : unmovable_cmd.cpp
- DetermineBasePaths() : fileio.cpp
- DeterminePalette() : gfxinit.cpp
- DeterminePaths() : fileio.cpp , fileio.h
- DeterministicSpriteGroupAdjustOperation : newgrf_spritegroup.h
- DIAGDIR_BEGIN : direction_type.h
- DIAGDIR_END : direction_type.h
- diagdir_names : dbg_helpers.cpp
- DIAGDIR_NE : direction_type.h
- DIAGDIR_NW : direction_type.h
- DIAGDIR_SE : direction_type.h
- DIAGDIR_SW : direction_type.h
- DiagDirDiff : direction_type.h
- DIAGDIRDIFF_90LEFT : direction_type.h
- DIAGDIRDIFF_90RIGHT : direction_type.h
- DIAGDIRDIFF_REVERSE : direction_type.h
- DIAGDIRDIFF_SAME : direction_type.h
- DiagDirection : direction_type.h
- DiagdirReachesTrackdirs() : track_func.h
- DiagdirReachesTracks() : track_func.h
- DiagDirToAxis() : direction_func.h
- DiagdirToDiagTrackdir() : track_func.h
- DiagDirToDir() : direction_func.h
- DiagDirToRoadBits() : road_func.h
- DIR_BEGIN : direction_type.h
- DIR_E : direction_type.h
- DIR_END : direction_type.h
- DIR_N : direction_type.h
- DIR_NE : direction_type.h
- DIR_NW : direction_type.h
- DIR_S : direction_type.h
- DIR_SE : direction_type.h
- DIR_SW : direction_type.h
- DIR_W : direction_type.h
- DirDiff : direction_type.h
- DIRDIFF_45LEFT : direction_type.h
- DIRDIFF_45RIGHT : direction_type.h
- DIRDIFF_90LEFT : direction_type.h
- DIRDIFF_90RIGHT : direction_type.h
- DIRDIFF_REVERSE : direction_type.h
- DIRDIFF_SAME : direction_type.h
- DirDifference() : direction_func.h
- Direction : direction_type.h
- DirToDiagDir() : direction_func.h
- DisableStaticNewGRFInfluencingNonStaticNewGRFs() : newgrf.cpp
- DisallowedPPPofTrackAtPCP : elrail_data.h
- DisallowedRoadDirections : road_map.h
- Disaster_CoalMine_Init() : disaster_cmd.cpp
- Disaster_Helicopter_Init() : disaster_cmd.cpp
- Disaster_Small_Ufo_Init() : disaster_cmd.cpp
- Disaster_Zeppeliner_Init() : disaster_cmd.cpp
- DisasterTick_Airplane() : disaster_cmd.cpp
- DisasterTick_Big_Ufo() : disaster_cmd.cpp
- DisasterTick_Big_Ufo_Destroyer() : disaster_cmd.cpp
- DisasterTick_Helicopter() : disaster_cmd.cpp
- DisasterTick_Helicopter_Rotors() : disaster_cmd.cpp
- DisasterTick_Submarine() : disaster_cmd.cpp
- DisasterTick_Ufo() : disaster_cmd.cpp
- DisasterTick_Zeppeliner() : disaster_cmd.cpp
- DispatchMouseWheelEvent() : window.cpp
- DistanceFromEdge() : map.cpp , map_func.h
- DistanceManhattan() : map.cpp , map_func.h
- DistanceMax() : map_func.h , map.cpp
- DistanceMaxPlusManhattan() : map.cpp , map_func.h
- DistanceSquare() : map.cpp , map_func.h
- DNC_BANKRUPCY : news.h
- DNC_VEHICLEAVAIL : news.h
- DoAutosave() : openttd.cpp
- DoBuildShiplift() : water_cmd.cpp
- DoCommand() : command.cpp , command_func.h
- DoCommandP() : command_func.h , command.cpp
- DoCreateTown() : town_cmd.cpp
- DoDrawString() : gfx.cpp , gfx_func.h
- DoDryUp() : water_cmd.cpp
- DoExitSave() : saveload.cpp , saveload.h
- DoFloodTile() : water_cmd.cpp
- DoPlaceMoreTrees() : tree_cmd.cpp
- DoSelectPlayerFace() : player_gui.cpp
- DoStartupNewPlayer() : openttd.cpp , players.cpp
- DrawAircraftDetails() : aircraft_gui.cpp , vehicle_gui.cpp
- DrawArrowButtons() : settings_gui.cpp , gui.h
- DrawAutorailSelection() : viewport.cpp
- DrawBox() : gfx.cpp , gfx_func.h
- DrawBridgePillars() : tunnelbridge_cmd.cpp
- DrawBridgeTramBits() : tunnelbridge_cmd.cpp
- DrawCanalWater() : water_cmd.cpp
- DrawCargoIcons() : station_gui.cpp
- DrawCatenary() : elrail.cpp , rail.h
- DrawCatenaryOnTunnel() : elrail.cpp , rail.h
- DrawCatenaryRailway() : elrail.cpp
- DrawChatMessage() : texteff.cpp , gfx_func.h
- DrawCompanyOwnerText() : player_gui.cpp
- DrawDirtyBlocks() : gfx_func.h , gfx.cpp
- DrawEngineList() : build_vehicle_gui.cpp , autoreplace_gui.cpp
- DrawFaceStringLabel() : player_gui.cpp , player_face.h
- DrawGraph() : graph_gui.cpp
- DrawGroundSprite() : viewport.cpp , viewport_func.h
- DrawGroundSpriteAt() : viewport_func.h , viewport.cpp
- DrawNewsString() : news_gui.cpp
- DrawPlayerFace() : player_gui.cpp , player_face.h
- DrawPlayerVehiclesAmount() : player_gui.cpp
- DrawRoadBits() : road_cmd.cpp
- DrawRoadDetail() : road_cmd.cpp
- DrawSeaWater() : water_cmd.cpp
- DrawSelectionSprite() : viewport.cpp
- DrawShipDetails() : ship_gui.cpp , vehicle_gui.cpp
- DrawSignalSprite() : rail_gui.cpp
- DrawSmallMap() : smallmap_gui.cpp
- DrawSmallMapStuff() : smallmap_gui.cpp
- DrawSortButtonState() : window_gui.h , widget.cpp
- DrawStationTile() : newgrf_station.cpp , newgrf_station.h
- DrawStationViewWindow() : station_gui.cpp
- DrawStringMultiCenter() : gfx.cpp , gfx_func.h
- DrawTile_Town() : town_cmd.cpp
- DrawTile_TunnelBridge() : tunnelbridge_cmd.cpp
- DrawTileSelection() : viewport.cpp
- DrawTileSelectionRect() : viewport.cpp
- DrawTrackBits() : rail_cmd.cpp
- DrawTrackFence_NS_1() : rail_cmd.cpp
- DrawTrackFence_NS_2() : rail_cmd.cpp
- DrawTrackFence_WE_1() : rail_cmd.cpp
- DrawTrackFence_WE_2() : rail_cmd.cpp
- DrawTramCatenary() : road_internal.h , road_cmd.cpp
- DrawVehicleDetails() : vehicle_gui.cpp
- DrawVehicleDetailsWindow() : vehicle_gui.cpp
- DrawVehicleInDepot() : depot_gui.cpp
- DrawVehicleProfitButton() : vehicle_gui.cpp , vehicle_gui.h
- DrawVehiclePurchaseInfo() : vehicle_gui.h , build_vehicle_gui.cpp
- DrawVehicleRefitWindow() : vehicle_gui.cpp
- DrawVehicleViewWindow() : vehicle_gui.cpp
- DrawWaypointSprite() : waypoint.h , waypoint.cpp
- DRD_BOTH : road_map.h
- DRD_NONE : road_map.h
- DRD_NORTHBOUND : road_map.h
- DRD_SOUTHBOUND : road_map.h
- DSGA_OP_ADD : newgrf_spritegroup.h
- DSGA_OP_AND : newgrf_spritegroup.h
- DSGA_OP_MUL : newgrf_spritegroup.h
- DSGA_OP_OR : newgrf_spritegroup.h
- DSGA_OP_ROR : newgrf_spritegroup.h
- DSGA_OP_RST : newgrf_spritegroup.h
- DSGA_OP_SCMP : newgrf_spritegroup.h
- DSGA_OP_SDIV : newgrf_spritegroup.h
- DSGA_OP_SMAX : newgrf_spritegroup.h
- DSGA_OP_SMIN : newgrf_spritegroup.h
- DSGA_OP_SMOD : newgrf_spritegroup.h
- DSGA_OP_STO : newgrf_spritegroup.h
- DSGA_OP_STOP : newgrf_spritegroup.h
- DSGA_OP_SUB : newgrf_spritegroup.h
- DSGA_OP_UCMP : newgrf_spritegroup.h
- DSGA_OP_UDIV : newgrf_spritegroup.h
- DSGA_OP_UMAX : newgrf_spritegroup.h
- DSGA_OP_UMIN : newgrf_spritegroup.h
- DSGA_OP_UMOD : newgrf_spritegroup.h
- DSGA_OP_XOR : newgrf_spritegroup.h
- DynamicPlaceIndustriesWidgets : industry_gui.cpp