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() : NewGRFParametersWindow , NewGRFWindow , NewsWindow , MessageHistoryWindow , MessageOptionsWindow , OrdersWindow , OskWindow , ProgramWindow , 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 , DepotWindow , BuildDocksToolbarWindow , SaveLoadWindow , GenerateLandscapeWindow , GraphLegendWindow , BaseGraphWindow , PaymentRatesGraphWindow , CompanyLeagueWindow , PerformanceRatingDetailWindow , VehicleGroupWindow , BuildIndustryWindow , IndustryViewWindow , IndustryDirectoryWindow , IndustryCargoesWindow , SelectGameWindow , MainWindow , LandInfoWindow , ErrmsgWindow , MusicTrackSelectionWindow , MusicWindow , NetworkChatWindow , NetworkContentListWindow , NetworkGameWindow , SpriteAlignerWindow
- 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() : ProgramWindow , NetworkClientListWindow , VehicleListWindow , TownDirectoryWindow , TimetableWindow , IndustryDirectoryWindow , BuildAirportWindow , ReplaceVehicleWindow , BuildVehicleWindow , CompanyFinancesWindow , SelectCompanyLiveryWindow , SelectCompanyManagerFaceWindow , CompanyWindow , IConsoleWindow , CopyPasteWindow , DeparturesWindow< Twaypoint > , DepotWindow , BuildDocksStationWindow , BuildDocksDepotWindow , CreateScenarioWindow , CompanyLeagueWindow , VehicleGroupWindow , EndGameWindow , HighScoreWindow , IndustryViewWindow , MainWindow , TimeWindow , NetworkLobbyWindow , MessageHistoryWindow , OrdersWindow , OskWindow , SpeedWindow , BuildRailStationWindow , BuildRoadStationWindow , SmallMapWindow , CompanyStationsWindow , StationViewWindow , ScenarioEditorLandscapeGenerationWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , TownAuthorityWindow , TransparenciesWindow , BuildTreesWindow , RefitWindow , VehicleDetailsWindow , VehicleViewWindow , Window
- OnPlaceDrag() : Window , BuildRoadToolbarWindow , BuildAirToolbarWindow , CopyPasteWindow , BuildDocksToolbarWindow , BuildRailToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , BuildTreesWindow
- OnPlaceMouseUp() : BuildRailToolbarWindow , BuildAirToolbarWindow , CopyPasteWindow , BuildDocksToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , BuildTreesWindow , Window
- OnPlaceObject() : ProgramWindow , CopyPasteWindow , BuildAirToolbarWindow , CompanyWindow , BuildDocksToolbarWindow , BuildIndustryWindow , OrdersWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , BuildTreesWindow , Window , ScenarioEditorLandscapeGenerationWindow
- OnPlaceObjectAbort() : BuildAirToolbarWindow , CompanyWindow , CopyPasteWindow , BuildDocksToolbarWindow , VehicleGroupWindow , BuildIndustryWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , BuildTreesWindow , Window , ScenarioEditorLandscapeGenerationWindow , OrdersWindow , DepotWindow
- OnPlacePresize() : BuildDocksToolbarWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , Window
- OnQueryTextFinished() : ProgramWindow , Window , VehicleDetailsWindow , StationViewWindow , NetworkJoinStatusWindow , AISettingsWindow , CheatWindow , SelectCompanyManagerFaceWindow , CompanyWindow , CreateScenarioWindow , VehicleGroupWindow , IndustryViewWindow , SpriteAlignerWindow , NewGRFParametersWindow , OrdersWindow , SpeedWindow , GameSettingsWindow , CustomCurrencyWindow , TimetableWindow , ScenarioEditorToolbarWindow , TownViewWindow , DepotWindow , WaypointWindow , BuildVehicleWindow
- OnReceiveContentInfo() : ContentCallback , NetworkContentListWindow
- OnReceiveData() : HTTPCallback , ClientNetworkContentSocketHandler
- OnResize() : OrdersWindow , AISettingsWindow , IndustryCargoesWindow , MainWindow , NetworkLobbyWindow , VehicleGroupWindow , IndustryViewWindow , BuildBridgeWindow , BuildVehicleWindow , Window , GameSettingsWindow , ExtraViewportWindow , WaypointWindow , BuildObjectWindow , TownViewWindow , StationViewWindow , DeparturesWindow< Twaypoint > , ProgramWindow , BuildRailStationWindow , SelectStationWindow< T > , AIListWindow , SubsidyListWindow , ReplaceVehicleWindow , DepotWindow , BuildIndustryWindow , IndustryDirectoryWindow , SpriteAlignerWindow , NewGRFParametersWindow , MessageHistoryWindow , RefitWindow , TownDirectoryWindow , CompanyStationsWindow , TimetableWindow , VehicleListWindow , VehicleDetailsWindow , VehicleViewWindow , WatchCompany
- OnRightClick() : DepotWindow , Window , SmallMapWindow
- OnScroll() : SmallMapWindow , Window , WatchCompany , MainWindow , ExtraViewportWindow
- OnTick() : BuildAirportWindow , CopyPasteWindow , BaseGraphWindow , VehicleGroupWindow , NewGRFParametersWindow , SmallMapWindow , MainToolbarWindow , WatchCompany , SelectStationWindow< T > , CompanyStationsWindow , AISettingsWindow , StatusBarWindow , PerformanceRatingDetailWindow , BuildRailStationWindow , BuildRoadStationWindow , TimeWindow , DropdownWindow , ScenarioEditorToolbarWindow , VehicleListWindow , VehicleViewWindow , BuildDocksStationWindow , NewsWindow , BuildIndustryWindow , DeparturesWindow< Twaypoint > , PaymentRatesGraphWindow , CompanyLeagueWindow , Window , AboutWindow
- OnTimeout() : IndustryViewWindow , OrdersWindow , CompanyStationsWindow , ScenarioEditorToolbarWindow , CustomCurrencyWindow , BuildTreesWindow , TerraformToolbarWindow , MainToolbarWindow , DepotWindow , CreateScenarioWindow , CheatWindow , BuildIndustryWindow , CopyPasteWindow , Window , ScenarioEditorLandscapeGenerationWindow , GameSettingsWindow
- 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() : GRFText , ZeroedMemoryAllocator , Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tpool_type, Tcache, Tzero >::PoolItem< Tpool > , Window
- operator delete[]() : ZeroedMemoryAllocator
- operator enum_type() : TinyEnumT< Tenum_t > , SimpleTinyEnumT< enum_type, storage_type >
- operator new() : 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[]() : ZeroedMemoryAllocator , Window
- operator T &() : AdaptT< T >
- operator T *() : SmallStackSafeStackAlloc< T, length >
- operator Tcls *() : CCountedPtr< Tcls_ >
- operator TileIndex() : TileIterator
- operator!=() : CargoSummaryItem , NetworkAddress , RefitOption
- operator&() : CCountedPtr< Tcls_ >
- operator&=() : SimpleTinyEnumT< enum_type, storage_type >
- operator()() : FlowStat::Comparator , DistanceAnnotation::comp , CapacityAnnotation::comp , StringCompare
- operator*=() : OverflowSafeInt< T, T_MAX, T_MIN >
- operator++() : OrthogonalTileIterator , TinyEnumT< Tenum_t > , DiagonalTileIterator , TinyEnumT< Tenum_t > , TileIterator
- operator+=() : FlowStat , OverflowSafeInt< T, T_MAX, T_MIN >
- operator->() : CCountedPtr< Tcls_ > , SmallStackSafeStackAlloc< T, length >
- operator<() : NetworkAddress , CStrA
- operator=() : TinyEnumT< Tenum_t > , CStrA , AdaptT< T > , CStrA , CCountedPtr< Tcls_ > , SimpleTinyEnumT< enum_type, storage_type > , CCountedPtr< Tcls_ > , SmallVector< T, S > , SimpleTinyEnumT< enum_type, storage_type > , TinyEnumT< Tenum_t >
- operator==() : NetworkAddress , RefitOption , NetworkAddress
- operator[]() : SmallMap< T, U, S > , FixedSizeArray< T, C > , SmallVector< T, S > , CargoArray , SmallArray< T, B, N > , CargoArray , FixedSizeArray< T, C > , SmallVector< T, S >
- operator|=() : SimpleTinyEnumT< enum_type, storage_type >
- opf : PathfinderSettings
- opt : GetOptData
- options : GetOptData
- order : OrderDate
- Order() : Order
- order : GameSettings , RefitWindow , Departure , 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 : Vehicle , OrderBackup
- 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 : Vehicle , TileDesc , Industry , BaseStation , AIEventCompanyInTrouble , AIEventCompanyAskMerger , Group , AIEventCompanyNew , CargoPayment , AIEventCompanyBankrupt , Window
- owner_type : TileDesc