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_8bppOptimized::SpriteData , BmpInfo , CompanyManagerFaceBitsInfo , LoggedChange , NIProperty , NICallback , UnmappedChoiceList , OldChunks
- 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_refittable : ShipVehicleInfo
- old_tile : GetNewVehiclePosResult
- oldval : LoggedChange
- OnClick() : GenerateProgressWindow , TransparenciesWindow , BuildTreesWindow , GraphLegendWindow , RefitWindow , VehicleListWindow , BaseGraphWindow , VehicleDetailsWindow , VehicleViewWindow , PerformanceHistoryGraphWindow , ExtraViewportWindow , WaypointWindow , PaymentRatesGraphWindow , DropdownWindow , Window , PerformanceRatingDetailWindow , VehicleGroupWindow , EndGameHighScoreBaseWindow , BuildIndustryWindow , IndustryViewWindow , IndustryDirectoryWindow , IndustryCargoesWindow , SelectGameWindow , QueryStringWindow , QueryWindow , MusicTrackSelectionWindow , AIListWindow , MusicWindow , NetworkChatWindow , AISettingsWindow , NetworkContentDownloadStatusWindow , NetworkContentListWindow , AIConfigWindow , NetworkGameWindow , NetworkStartServerWindow , AIDebugWindow , NetworkLobbyWindow , NetworkClientListWindow , BuildAirToolbarWindow , NetworkJoinStatusWindow , NetworkCompanyPasswordWindow , BuildAirportWindow , SpriteAlignerWindow , NewGRFParametersWindow , ReplaceVehicleWindow , NewGRFWindow , NewsWindow , BuildBridgeWindow , MessageHistoryWindow , MessageOptionsWindow , BuildVehicleWindow , BuildObjectWindow , OrdersWindow , CheatWindow , OskWindow , BuildRailToolbarWindow , CompanyFinancesWindow , BuildRailStationWindow , BuildSignalWindow , SelectCompanyLiveryWindow , BuildRailDepotWindow , BuildRailWaypointWindow , SelectCompanyManagerFaceWindow , BuildRoadToolbarWindow , BuildRoadDepotWindow , CompanyWindow , BuildRoadStationWindow , GameOptionsWindow , BuyCompanyWindow , GameDifficultyWindow , GameSettingsWindow , SetDateWindow , CustomCurrencyWindow , SignListWindow , DepotWindow , SignWindow , SmallMapWindow , BuildDocksToolbarWindow , CompanyStationsWindow , StationViewWindow , BuildDocksStationWindow , SelectStationWindow< T > , StatusBarWindow , BuildDocksDepotWindow , SubsidyListWindow , TerraformToolbarWindow , EnginePreviewWindow , ScenarioEditorLandscapeGenerationWindow , TimetableWindow , SaveLoadWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , GenerateLandscapeWindow , TownAuthorityWindow , TownViewWindow , CreateScenarioWindow , TownDirectoryWindow , FoundTownWindow
- OnConnect() : ConsoleContentCallback , TCPConnecter , NetworkHTTPContentConnecter , TCPQueryConnecter , TCPClientConnecter , NetworkContentConnecter , ContentCallback , ClientNetworkContentSocketHandler , NetworkContentListWindow
- OnCTRLStateChange() : DepotWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , Window
- OnDisconnect() : ConsoleContentCallback , ContentCallback , ClientNetworkContentSocketHandler
- OnDownloadComplete() : ConsoleContentCallback , ContentCallback , ClientNetworkContentSocketHandler , NetworkContentListWindow
- OnDownloadProgress() : ContentCallback , ClientNetworkContentSocketHandler , NetworkContentDownloadStatusWindow
- OnDragDrop() : DepotWindow , VehicleGroupWindow , OrdersWindow , RefitWindow , Window
- OnDropdownSelect() : BuildAirportWindow , ReplaceVehicleWindow , BuildBridgeWindow , BuildVehicleWindow , SelectCompanyLiveryWindow , SetDateWindow , GenerateLandscapeWindow , CreateScenarioWindow , VehicleGroupWindow , IndustryDirectoryWindow , NetworkGameWindow , NetworkStartServerWindow , NewGRFWindow , MessageOptionsWindow , OrdersWindow , GameOptionsWindow , CompanyStationsWindow , 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 , NetworkChatWindow , NetworkClientListPopupWindow , NewsWindow , StatusBarWindow , TerraformToolbarWindow , TransparenciesWindow , DropdownWindow , Window
- OnInvalidateData() : ErrmsgWindow , MusicTrackSelectionWindow , MusicWindow , NetworkChatWindow , NetworkContentListWindow , NetworkGameWindow , SpriteAlignerWindow , NewGRFParametersWindow , NewGRFWindow , NewsWindow , MessageHistoryWindow , MessageOptionsWindow , OrdersWindow , OskWindow , BuildSignalWindow , BuildRoadToolbarWindow , GameOptionsWindow , GameDifficultyWindow , SignListWindow , SmallMapWindow , CompanyStationsWindow , SelectStationWindow< T > , StatusBarWindow , SubsidyListWindow , TimetableWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , TownViewWindow , TownDirectoryWindow , FoundTownWindow , TransparenciesWindow , BuildTreesWindow , RefitWindow , VehicleListWindow , VehicleDetailsWindow , ExtraViewportWindow , 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
- OnKeyPress() : AIDebugWindow , BuildAirToolbarWindow , BuildBridgeWindow , IConsoleWindow , BuildDocksToolbarWindow , SaveLoadWindow , GenerateLandscapeWindow , EndGameHighScoreBaseWindow , MainWindow , ErrmsgWindow , QueryStringWindow , QueryWindow , NetworkChatWindow , NetworkContentListWindow , NetworkGameWindow , NetworkStartServerWindow , NetworkCompanyPasswordWindow , NewGRFWindow , NewsWindow , OrdersWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , SignListWindow , SignWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , FoundTownWindow , Window
- online : NetworkGameList
- OnMouseDrag() : DepotWindow , OrdersWindow , RefitWindow , Window
- OnMouseLoop() : AIDebugWindow , IConsoleWindow , SaveLoadWindow , GenerateLandscapeWindow , ErrmsgWindow , TooltipsWindow , QueryStringWindow , NetworkChatWindow , NetworkContentListWindow , NetworkGameWindow , NetworkStartServerWindow , NetworkClientListPopupWindow , NetworkCompanyPasswordWindow , NewGRFWindow , OskWindow , SignListWindow , SignWindow , FoundTownWindow , DropdownWindow , Window
- OnMouseOver() : NetworkClientListWindow , Window
- OnMouseWheel() : IConsoleWindow , MainWindow , SmallMapWindow , ExtraViewportWindow , Window
- OnNewDay() : Aircraft , RoadVehicle , Ship , Train , Vehicle
- OnPaint() : VehicleDetailsWindow , TransparenciesWindow , CompanyStationsWindow , BuildRoadStationWindow , MessageHistoryWindow , NetworkChatWindow , HighScoreWindow , CreateScenarioWindow , SelectCompanyManagerFaceWindow , ReplaceVehicleWindow , AIDebugWindow , BuildAirportWindow , BuildVehicleWindow , CompanyFinancesWindow , SelectCompanyLiveryWindow , CompanyWindow , IConsoleWindow , DepotWindow , BuildDocksStationWindow , BuildDocksDepotWindow , SaveLoadWindow , GenerateLandscapeWindow , CompanyLeagueWindow , VehicleGroupWindow , EndGameWindow , IndustryViewWindow , MainWindow , QueryStringWindow , NetworkContentListWindow , NetworkGameWindow , NetworkStartServerWindow , NetworkLobbyWindow , NetworkClientListWindow , NetworkCompanyPasswordWindow , NewGRFWindow , OrdersWindow , OskWindow , BuildRailStationWindow , SignListWindow , SignWindow , SmallMapWindow , StationViewWindow , ScenarioEditorLandscapeGenerationWindow , TimetableWindow , MainToolbarWindow , ScenarioEditorToolbarWindow , TownAuthorityWindow , FoundTownWindow , BuildTreesWindow , RefitWindow , VehicleListWindow , VehicleViewWindow , Window
- OnPlaceDrag() : BuildDocksToolbarWindow , BuildAirToolbarWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , BuildTreesWindow , Window
- OnPlaceMouseUp() : BuildDocksToolbarWindow , BuildAirToolbarWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , BuildTreesWindow , Window , ScenarioEditorLandscapeGenerationWindow
- OnPlaceObject() : BuildAirToolbarWindow , BuildDocksToolbarWindow , BuildIndustryWindow , OrdersWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , ScenarioEditorToolbarWindow , FoundTownWindow , BuildTreesWindow , Window , MainToolbarWindow , CompanyWindow
- OnPlaceObjectAbort() : FoundTownWindow , BuildAirToolbarWindow , CompanyWindow , DepotWindow , VehicleGroupWindow , BuildIndustryWindow , OrdersWindow , BuildRailToolbarWindow , BuildRoadToolbarWindow , TerraformToolbarWindow , ScenarioEditorLandscapeGenerationWindow , BuildTreesWindow , Window , BuildDocksToolbarWindow
- OnPlacePresize() : BuildRailToolbarWindow , BuildDocksToolbarWindow , BuildRoadToolbarWindow , Window
- OnQueryTextFinished() : SpriteAlignerWindow , VehicleDetailsWindow , Window , ScenarioEditorToolbarWindow , NewGRFWindow , OrdersWindow , NetworkStartServerWindow , IndustryViewWindow , DepotWindow , BuildVehicleWindow , GameSettingsWindow , AISettingsWindow , CheatWindow , SelectCompanyManagerFaceWindow , WaypointWindow , CompanyWindow , GenerateLandscapeWindow , CreateScenarioWindow , VehicleGroupWindow , NetworkGameWindow , NetworkJoinStatusWindow , NewGRFParametersWindow , CustomCurrencyWindow , StationViewWindow , TimetableWindow , TownViewWindow
- OnReceiveContentInfo() : ClientNetworkContentSocketHandler , ContentCallback , NetworkContentListWindow
- OnReceiveData() : HTTPCallback , ClientNetworkContentSocketHandler
- OnResize() : NewGRFWindow , MessageHistoryWindow , BuildObjectWindow , BuildRailStationWindow , StationViewWindow , SelectStationWindow< T > , TownViewWindow , VehicleDetailsWindow , VehicleViewWindow , Window , SubsidyListWindow , SaveLoadWindow , NetworkGameWindow , MainWindow , AIListWindow , OrdersWindow , TownDirectoryWindow , RefitWindow , WaypointWindow , TimetableWindow , VehicleListWindow , CompanyStationsWindow , NetworkContentListWindow , NewGRFParametersWindow , AISettingsWindow , IndustryViewWindow , SignListWindow , AIDebugWindow , GameSettingsWindow , ExtraViewportWindow , VehicleGroupWindow , BuildIndustryWindow , IndustryCargoesWindow , ReplaceVehicleWindow , BuildBridgeWindow , BuildVehicleWindow , DepotWindow , NetworkLobbyWindow , IndustryDirectoryWindow , SpriteAlignerWindow
- OnRightClick() : DepotWindow , SmallMapWindow , Window
- OnScroll() : MainWindow , SmallMapWindow , Window , ExtraViewportWindow
- OnTick() : NewGRFParametersWindow , PaymentRatesGraphWindow , CompanyLeagueWindow , BuildIndustryWindow , BuildRailStationWindow , SelectStationWindow< T > , VehicleListWindow , VehicleViewWindow , Window , CompanyStationsWindow , ScenarioEditorToolbarWindow , StatusBarWindow , MainToolbarWindow , VehicleGroupWindow , BuildRoadStationWindow , NewsWindow , AboutWindow , BuildAirportWindow , BuildDocksStationWindow , BaseGraphWindow , PerformanceRatingDetailWindow , DropdownWindow , SmallMapWindow , AISettingsWindow
- OnTimeout() : MainToolbarWindow , AIDebugWindow , GenerateLandscapeWindow , CompanyStationsWindow , GameSettingsWindow , ScenarioEditorLandscapeGenerationWindow , ScenarioEditorToolbarWindow , IndustryViewWindow , TerraformToolbarWindow , Window , CustomCurrencyWindow , OrdersWindow , CreateScenarioWindow , BuildIndustryWindow , SaveLoadWindow , CheatWindow , DepotWindow , BuildTreesWindow , NetworkStartServerWindow , FoundTownWindow
- OnVehicleSelect() : DepotWindow , Window
- 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 , Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tcache, Tzero >::PoolItem< Tpool > , Window , ZeroedMemoryAllocator
- operator delete[]() : ZeroedMemoryAllocator
- operator enum_type() : SimpleTinyEnumT< enum_type, storage_type > , TinyEnumT< Tenum_t >
- operator new() : ZeroedMemoryAllocator , Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tcache, Tzero >::PoolItem< Tpool > , GRFText , Pool< Titem, Tindex, Tgrowth_step, Tmax_size, Tcache, Tzero >::PoolItem< Tpool >
- operator new[]() : ZeroedMemoryAllocator , Window
- operator T &() : AdaptT< T >
- operator T *() : SmallStackSafeStackAlloc< T, length >
- operator Tcls *() : CCountedPtr< Tcls_ >
- operator TileIndex() : TileIterator
- operator!=() : NetworkAddress , RefitOption , CargoSummaryItem
- operator&() : CCountedPtr< Tcls_ >
- operator&=() : SimpleTinyEnumT< enum_type, storage_type >
- operator()() : StringCompare
- operator*=() : OverflowSafeInt< T, T_MAX, T_MIN >
- operator++() : OrthogonalTileIterator , TinyEnumT< Tenum_t > , TileIterator , DiagonalTileIterator , TinyEnumT< Tenum_t >
- operator+=() : OverflowSafeInt< T, T_MAX, T_MIN >
- operator->() : CCountedPtr< Tcls_ > , SmallStackSafeStackAlloc< T, length > , CCountedPtr< Tcls_ >
- operator<() : CStrA , NetworkAddress
- operator=() : CCountedPtr< Tcls_ > , SimpleTinyEnumT< enum_type, storage_type > , CStrA , SimpleTinyEnumT< enum_type, storage_type > , CCountedPtr< Tcls_ > , AdaptT< T > , CStrA , TinyEnumT< Tenum_t >
- operator==() : NetworkAddress , RefitOption , NetworkAddress
- operator[]() : CargoArray , SmallVector< T, S > , FixedSizeArray< T, C > , CargoArray , SmallVector< T, S > , SmallMap< T, U, S > , SmallArray< T, B, N >
- operator|=() : SimpleTinyEnumT< enum_type, storage_type >
- opf : PathfinderSettings
- order : RefitWindow
- Order() : Order
- order : GameSettings , 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
- OrderWaitingCargo() : StationViewWindow
- ordinal_width : CompanyLeagueWindow
- orientation : RailStationGUISettings
- orig_list : NewGRFWindow
- orig_str_buf : OskWindow
- 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 : Industry , Group , Window , CargoPayment , TileDesc , BaseStation , Vehicle
- owner_type : TileDesc