Here is a list of all documented struct and union fields with links to the struct/union documentation for each field:

### - o -

- o : ResolverObject
- obj_len : SaveLoadParams
- Object() : Object
- object_height : BuildObjectWindow
- OBJECT_MARGIN : BuildObjectWindow
- ObjectToBool() : Squirrel
- ObjectToInteger() : Squirrel
- ObjectToString() : Squirrel
- OC_AGE : AIOrder
- OC_INVALID : AIOrder
- OC_LOAD_PERCENTAGE : AIOrder
- OC_MAX_SPEED : AIOrder
- OC_RELIABILITY : AIOrder
- OC_REQUIRES_SERVICE : AIOrder
- OC_UNCONDITIONALLY : AIOrder
- occupied : RoadStop::Entry
- offs : TileHighlightData
- offset : Blitter_32bppOptimized::SpriteData , Blitter_8bppOptimized::SpriteData , BmpInfo , CompanyManagerFaceBitsInfo , LoggedChange , NIProperty , NICallback , UnmappedChoiceList , OldChunks , StringParameters
- offsets : LanguagePackHeader
- oil_refinery : ExtraPaletteValues
- oil_refinery_limit : GameCreationSettings
- ok_btn : OskWindow
- okay : PBSTileInfo
- old : Vehicle
- old_d : UnmappedChoiceList
- old_economy : CompanyProperties
- old_max_loan_unround : Economy
- old_max_loan_unround_fract : Economy
- old_new_hash : Vehicle
- old_owner : AIEventCompanyMerger
- old_refittable : ShipVehicleInfo
- old_tile : GetNewVehiclePosResult
- oldval : LoggedChange
- OnboardCount() : VehicleCargoList
- OnCleanPool() : CargoList< Tinst, Tcont > , VehicleCargoList
- OnClick() : DepotWindow , VehicleListWindow , VehicleDetailsWindow , BuildDocksToolbarWindow , VehicleViewWindow , ExtraViewportWindow , BuildDocksStationWindow , WatchCompany , WaypointWindow , BuildDocksDepotWindow , DropdownWindow , Window , EnginePreviewWindow , CreateScenarioWindow , GenerateProgressWindow , GraphLegendWindow , BaseGraphWindow , PerformanceHistoryGraphWindow , PaymentRatesGraphWindow , PerformanceRatingDetailWindow , VehicleGroupWindow , EndGameHighScoreBaseWindow , BuildIndustryWindow , IndustryViewWindow , IndustryDirectoryWindow , IndustryCargoesWindow , SelectGameWindow , QueryWindow , MusicTrackSelectionWindow , MusicWindow , NetworkLobbyWindow , NetworkClientListWindow , NetworkJoinStatusWindow , SpriteAlignerWindow , NewGRFParametersWindow , NewsWindow , AIListWindow , MessageHistoryWindow , MessageOptionsWindow , AISettingsWindow , BuildObjectWindow , OrdersWindow , AIConfigWindow , OskWindow , ProgramWindow , BuildAirToolbarWindow , SpeedWindow , BuildRailToolbarWindow , BuildAirportWindow , BuildRailStationWindow , BuildSignalWindow , ReplaceVehicleWindow , BuildRailDepotWindow , BuildRailWaypointWindow , BuildBridgeWindow , BuildRoadToolbarWindow , BuildRoadDepotWindow , BuildVehicleWindow , BuildRoadStationWindow , GameOptionsWindow , CheatWindow , GameDifficultyWindow , GameSettingsWindow , CompanyFinancesWindow , CustomCurrencyWindow , SmallMapWindow , SelectCompanyLiveryWindow , CompanyStationsWindow , StationViewWindow , SelectCompanyManagerFaceWindow , SelectStationWindow< T > , StatusBarWindow , CompanyWindow , SubsidyListWindow , TerraformToolbarWindow , BuyCompanyWindow , ScenarioEditorLandscapeGenerationWindow , TimetableWindow , CopyPasteWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , SetDateWindow , TownAuthorityWindow , TownViewWindow , SetMinutesWindow , TownDirectoryWindow , TransparenciesWindow , DeparturesWindow< Twaypoint > , BuildTreesWindow , RefitWindow
- OnConnect() : ConsoleContentCallback , TCPConnecter , NetworkHTTPContentConnecter , TCPQueryConnecter , TCPClientConnecter , NetworkContentConnecter , ContentCallback , NetworkContentListWindow
- OnCTRLStateChange() : DepotWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , Window
- OnDisconnect() : ConsoleContentCallback , ContentCallback
- OnDoCommand() : WatchCompany
- OnDownloadComplete() : ConsoleContentCallback , ContentCallback , NetworkContentListWindow
- OnDownloadProgress() : ContentCallback , NetworkContentDownloadStatusWindow
- OnDragDrop() : DepotWindow , VehicleGroupWindow , OrdersWindow , RefitWindow , Window
- OnDropdownSelect() : BuildAirportWindow , ReplaceVehicleWindow , BuildBridgeWindow , BuildVehicleWindow , SelectCompanyLiveryWindow , SetDateWindow , SetMinutesWindow , CreateScenarioWindow , VehicleGroupWindow , IndustryDirectoryWindow , MessageOptionsWindow , OrdersWindow , ProgramWindow , GameOptionsWindow , CompanyStationsWindow , StationViewWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , VehicleListWindow , Window
- OneTileCost() : CYapfCostRailT< Types > , CYapfCostRoadT< Types >
- OnFailure() : TCPConnecter , HTTPCallback , NetworkHTTPContentConnecter , TCPQueryConnecter , TCPClientConnecter , NetworkContentConnecter , ClientNetworkContentSocketHandler
- OnFocus() : Window
- OnFocusLost() : Window
- OnHover() : IndustryCargoesWindow , Window
- OnHundredthTick() : CompanyFinancesWindow , CompanyWindow , IConsoleWindow , PaymentRatesGraphWindow , IndustryDirectoryWindow , ErrmsgWindow , TownAuthorityWindow , TownDirectoryWindow , Window
- OnInit() : BuildVehicleWindow , SelectCompanyManagerFaceWindow , PaymentRatesGraphWindow , BuildIndustryWindow , IndustryCargoesWindow , LandInfoWindow , MessageOptionsWindow , SmallMapWindow , TerraformToolbarWindow , RefitWindow , Window
- OnInitialPosition() : BuildBridgeWindow , SetDateWindow , ErrmsgWindow , TooltipsWindow , NetworkClientListPopupWindow , NewsWindow , StatusBarWindow , TerraformToolbarWindow , TransparenciesWindow , DropdownWindow , Window
- OnInvalidateData() : SpriteAlignerWindow , NewGRFParametersWindow , NewGRFWindow , NewsWindow , MessageHistoryWindow , MessageOptionsWindow , OrdersWindow , OskWindow , ProgramWindow , SpeedWindow , BuildSignalWindow , BuildRoadToolbarWindow , GameOptionsWindow , GameDifficultyWindow , SignListWindow , SmallMapWindow , CompanyStationsWindow , StationViewWindow , SelectStationWindow< T > , StatusBarWindow , SubsidyListWindow , TimetableWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , TownViewWindow , TownDirectoryWindow , FoundTownWindow , TransparenciesWindow , BuildTreesWindow , RefitWindow , VehicleListWindow , VehicleDetailsWindow , VehicleViewWindow , ExtraViewportWindow , WatchCompany , WaypointWindow , Window , AIListWindow , AISettingsWindow , AIConfigWindow , AIDebugWindow , ReplaceVehicleWindow , BuildVehicleWindow , SelectCompanyLiveryWindow , CompanyInfrastructureWindow , DepotWindow , BuildDocksToolbarWindow , SaveLoadWindow , GenerateLandscapeWindow , GraphLegendWindow , BaseGraphWindow , PaymentRatesGraphWindow , CompanyLeagueWindow , PerformanceRatingDetailWindow , VehicleGroupWindow , BuildIndustryWindow , IndustryViewWindow , IndustryDirectoryWindow , IndustryCargoesWindow , SelectGameWindow , MainWindow , LandInfoWindow , ErrmsgWindow , MusicTrackSelectionWindow , MusicWindow , NetworkChatWindow , NetworkContentListWindow , NetworkGameWindow
- OnKeyPress() : BuildAirToolbarWindow , BuildBridgeWindow , IConsoleWindow , BuildDocksToolbarWindow , EndGameHighScoreBaseWindow , MainWindow , ErrmsgWindow , QueryWindow , NewsWindow , OrdersWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , Window
- online : NetworkGameList
- OnMouseDrag() : DepotWindow , OrdersWindow , RefitWindow , Window
- OnMouseLoop() : IConsoleWindow , ErrmsgWindow , TooltipsWindow , NetworkClientListPopupWindow , OskWindow , DropdownWindow , Window
- OnMouseOver() : NetworkClientListWindow , SmallMapWindow , Window
- OnMouseWheel() : IConsoleWindow , MainWindow , SmallMapWindow , ExtraViewportWindow , WatchCompany , Window
- OnNewDay() : Aircraft , RoadVehicle , Ship , Train , Vehicle
- OnOpenOSKWindow() : QueryStringWindow , NetworkChatWindow , NetworkCompanyPasswordWindow , QueryStringBaseWindow
- OnOSKInput() : NewGRFWindow , QueryStringBaseWindow
- OnPaint() : OrdersWindow , TimeWindow , BuildTreesWindow , StationViewWindow , ScenarioEditorToolbarWindow , HighScoreWindow , BuildAirportWindow , ReplaceVehicleWindow , BuildVehicleWindow , CompanyFinancesWindow , SelectCompanyLiveryWindow , SelectCompanyManagerFaceWindow , CompanyWindow , IConsoleWindow , CopyPasteWindow , DeparturesWindow< Twaypoint > , DepotWindow , BuildDocksStationWindow , BuildDocksDepotWindow , CreateScenarioWindow , CompanyLeagueWindow , VehicleGroupWindow , EndGameWindow , IndustryViewWindow , IndustryDirectoryWindow , MainWindow , NetworkLobbyWindow , NetworkClientListWindow , MessageHistoryWindow , OskWindow , ProgramWindow , SpeedWindow , BuildRailStationWindow , BuildRoadStationWindow , SmallMapWindow , CompanyStationsWindow , ScenarioEditorLandscapeGenerationWindow , TimetableWindow , MainToolbarWindow , TownAuthorityWindow , TownDirectoryWindow , TransparenciesWindow , RefitWindow , VehicleListWindow , VehicleDetailsWindow , VehicleViewWindow , Window
- OnPlaceDrag() : BuildDocksToolbarWindow , ScenarioEditorLandscapeGenerationWindow , BuildAirToolbarWindow , CopyPasteWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , BuildTreesWindow , Window
- OnPlaceMouseUp() : CopyPasteWindow , BuildAirToolbarWindow , BuildDocksToolbarWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , BuildTreesWindow , Window
- OnPlaceObject() : BuildAirToolbarWindow , BuildIndustryWindow , CompanyWindow , CopyPasteWindow , BuildDocksToolbarWindow , OrdersWindow , ProgramWindow , BuildRailToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , BuildTreesWindow , Window , BuildRoadToolbarWindow
- OnPlaceObjectAbort() : BuildAirToolbarWindow , CopyPasteWindow , DepotWindow , BuildDocksToolbarWindow , BuildIndustryWindow , OrdersWindow , BuildRailToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , BuildTreesWindow , Window , BuildRoadToolbarWindow , VehicleGroupWindow , CompanyWindow
- OnPlacePresize() : BuildDocksToolbarWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , Window
- OnQueryTextFinished() : WaypointWindow , Window , ScenarioEditorToolbarWindow , VehicleDetailsWindow , GameSettingsWindow , NewGRFParametersWindow , VehicleGroupWindow , AISettingsWindow , BuildVehicleWindow , CheatWindow , CompanyWindow , DepotWindow , CreateScenarioWindow , IndustryViewWindow , NetworkJoinStatusWindow , SpriteAlignerWindow , OrdersWindow , ProgramWindow , SpeedWindow , CustomCurrencyWindow , StationViewWindow , TimetableWindow , SelectCompanyManagerFaceWindow , TownViewWindow
- OnReceiveContentInfo() : ContentCallback , NetworkContentListWindow
- OnReceiveData() : ClientNetworkContentSocketHandler , HTTPCallback
- OnResize() : AISettingsWindow , IndustryDirectoryWindow , IndustryCargoesWindow , ReplaceVehicleWindow , VehicleGroupWindow , IndustryViewWindow , BuildBridgeWindow , DeparturesWindow< Twaypoint > , GameSettingsWindow , WatchCompany , ExtraViewportWindow , WaypointWindow , VehicleDetailsWindow , BuildObjectWindow , TownViewWindow , StationViewWindow , ProgramWindow , NewGRFParametersWindow , OrdersWindow , SubsidyListWindow , AIListWindow , BuildVehicleWindow , DepotWindow , BuildIndustryWindow , MainWindow , NetworkLobbyWindow , SpriteAlignerWindow , MessageHistoryWindow , BuildRailStationWindow , CompanyStationsWindow , SelectStationWindow< T > , TownDirectoryWindow , RefitWindow , VehicleListWindow , VehicleViewWindow , Window , TimetableWindow
- OnRightClick() : DepotWindow , Window , SmallMapWindow
- OnScroll() : Window , SmallMapWindow , ExtraViewportWindow , WatchCompany , MainWindow
- OnTick() : CompanyLeagueWindow , AISettingsWindow , DeparturesWindow< Twaypoint > , VehicleGroupWindow , CopyPasteWindow , AboutWindow , BuildRailStationWindow , VehicleListWindow , BuildRoadStationWindow , SmallMapWindow , SelectStationWindow< T > , TimeWindow , StatusBarWindow , PerformanceRatingDetailWindow , DropdownWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , VehicleViewWindow , CompanyStationsWindow , NewGRFParametersWindow , NewsWindow , BuildIndustryWindow , PaymentRatesGraphWindow , BuildAirportWindow , BuildDocksStationWindow , Window , BaseGraphWindow , WatchCompany
- OnTimeout() : CreateScenarioWindow , BuildIndustryWindow , GameSettingsWindow , ScenarioEditorLandscapeGenerationWindow , ScenarioEditorToolbarWindow , Window , CustomCurrencyWindow , BuildTreesWindow , TerraformToolbarWindow , MainToolbarWindow , OrdersWindow , CopyPasteWindow , DepotWindow , CheatWindow , CompanyStationsWindow , IndustryViewWindow
- OnVehicleSelect() : Window , DepotWindow
- OpenCount() : CNodeList_HashTableT< Titem_, Thash_bits_open_, Thash_bits_closed_ >
- openlist_hash : AyStar
- openlist_queue : AyStar
- OpenListAdd() : AyStar
- OpenListIsInList() : AyStar
- OpenListPop() : AyStar
- openttd_id : LanguageMap::Mapping
- operator const T &() : AdaptT< T >
- operator const Tcls *() : CCountedPtr< Tcls_ >
- operator delete() : ZeroedMemoryAllocator , Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tpool_type, Tcache, Tzero >::PoolItem< Tpool > , GRFText , Window
- operator delete[]() : ZeroedMemoryAllocator
- operator enum_type() : TinyEnumT< Tenum_t > , SimpleTinyEnumT< enum_type, storage_type >
- operator new() : Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tpool_type, Tcache, Tzero >::PoolItem< Tpool > , ZeroedMemoryAllocator , Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tpool_type, Tcache, Tzero >::PoolItem< Tpool > , GRFText , Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tpool_type, Tcache, Tzero >::PoolItem< Tpool > , GRFText
- operator new[]() : Window , ZeroedMemoryAllocator
- operator T &() : AdaptT< T >
- operator T *() : SmallStackSafeStackAlloc< T, length >
- operator Tcls *() : CCountedPtr< Tcls_ >
- operator TileIndex() : TileIterator
- operator!=() : CargoSummaryItem , RefitOption , NetworkAddress
- operator&() : CCountedPtr< Tcls_ >
- operator&=() : SimpleTinyEnumT< enum_type, storage_type >
- operator()() : FlowStat::Comparator , StringCompare , DistanceAnnotation::comp , CapacityAnnotation::comp , StringCompare
- operator*=() : OverflowSafeInt< T, T_MAX, T_MIN >
- operator++() : OrthogonalTileIterator , DiagonalTileIterator , TileIterator , TinyEnumT< Tenum_t >
- operator+=() : OverflowSafeInt< T, T_MAX, T_MIN > , FlowStat
- operator->() : CCountedPtr< Tcls_ > , SmallStackSafeStackAlloc< T, length >
- operator<() : CStrA , NetworkAddress
- operator=() : SimpleTinyEnumT< enum_type, storage_type > , CCountedPtr< Tcls_ > , CStrA , SmallVector< T, S > , AdaptT< T > , CCountedPtr< Tcls_ > , TinyEnumT< Tenum_t > , SimpleTinyEnumT< enum_type, storage_type >
- operator==() : NetworkAddress , RefitOption , NetworkAddress
- operator[]() : SmallArray< T, B, N > , FixedSizeArray< T, C > , CargoArray , SmallMap< T, U, S > , SmallVector< T, S > , SmallArray< T, B, N > , CargoArray
- operator|=() : SimpleTinyEnumT< enum_type, storage_type >
- opf : PathfinderSettings
- opt : GetOptData
- options : GetOptData
- order : Departure , RefitWindow , OrderDate , GameSettings
- Order() : Order
- order : Listing
- ORDER_CURRENT : AIOrder
- ORDER_INVALID : AIOrder
- order_over : OrdersWindow
- order_review_system : GUISettings
- OrderBackup() : OrderBackup
- OrderClick_Conditional() : OrdersWindow
- OrderClick_Delete() : OrdersWindow
- OrderClick_FullLoad() : OrdersWindow
- OrderClick_Goto() : OrdersWindow
- OrderClick_NearestDepot() : OrdersWindow
- OrderClick_Nonstop() : OrdersWindow
- OrderClick_Refit() : OrdersWindow
- OrderClick_Service() : OrdersWindow
- OrderClick_Share() : OrdersWindow
- OrderClick_Skip() : OrdersWindow
- OrderClick_StopSharing() : OrdersWindow
- OrderClick_Unload() : OrdersWindow
- OrderCondition : AIOrder
- OrderGetSel() : OrdersWindow
- OrderHotkey_NoLoad() : OrdersWindow
- OrderHotkey_NoUnload() : OrdersWindow
- OrderHotkey_Transfer() : OrdersWindow
- orderindex : OrderBackup
- OrderList() : OrderList
- OrderPlaceObjectState : OrdersWindow
- OrderPosition : AIOrder
- orders : OrderBackup , Vehicle
- ordinal_width : CompanyLeagueWindow
- orientation : RailStationGUISettings
- orig_list : NewGRFWindow
- orig_str_buf : OskWindow
- origin : Path
- original_image_index : Engine
- original_md5sum : GRFConfig
- OrthogonalTileIterator() : OrthogonalTileIterator
- os2_bmp : BmpInfo
- other_accepted : CargoesField
- other_company_name : CompanyNewsInformation
- other_produced : CargoesField
- outersize : TileHighlightData
- outgoing_queue : ServerNetworkGameSocketHandler
- overdrawn_ops : Squirrel
- Overflowed() : SmallSet< Tdir, items >
- override : GRFFileProps
- OverrideManagerBase() : OverrideManagerBase
- overtaking : RoadVehicle
- overtaking_ctr : RoadVehicle
- own_name : LanguagePackHeader
- owner : CargoPayment , AIEventCompanyAskMerger , TileDesc , Industry , AIEventCompanyNew , AIEventCompanyBankrupt , BaseStation , AIEventCompanyInTrouble , Group , Window , Vehicle
- owner_type : TileDesc