Castle Game Engine: CastleWindow

# Unit CastleWindow
Description | Uses | Classes, Interfaces, Objects and Records | Functions and Procedures | Types | Constants | Variables
4. ## Description Window with OpenGL context suitable for 2D and 3D rendering of "Castle Game Engine". The base TCastleWindowBase provides a simple window with OpenGL context, and is suitable for any OpenGL program. More advanced TCastleWindow extends it to comfortably render 2D controls and 3D objects defined by our engine. Application object (instance of class TCastleApplication) is a central manager of all open TCastleWindowBase windows. Using this unit: Declare and create TCastleWindowBase instance. (Or a descendant like TCastleWindow.) Assign Glw properties and callbacks like OnDraw, OnResize, Width, Height, Caption. Call Window.Open, this will actually show the window and it's associated OpenGL context. It also calls EventOpen (OnOpen callback) and EventResize (OnResize callback). Call Application.Run. This will enter message loop that will call appropriate windows' callbacks at appropriate times (OnDraw, OnPress, OnRelease, OnResize, OnUpdate and many more). There are also some Application callbacks, like Application.OnUpdate. For more advanced needs you can use something like
         while Application.ProcessMessage do <something>;
instead of Application.Run. You can also call Window.OpenAndRun, this is just a shortcut for Window.Open + Application.Run. Application.Run ends when you call Application.Quit or when you close last visible window using Close(true). User is also allowed to close a window using WindowManager facilities (clicking on "X" button in the frame corner, pressing Alt+F4 or something like that). By default, such user action will make window close (but you can freely customize what your program does when user tries to close the window using callback OnCloseQuery). So the simplest example of using this unit can look like this:
      uses CastleWindow;

      var
        Window: TCastleWindowCustom;

      procedure Draw(Window: TCastleWindowBase);
      begin  ...  end;

      procedure Resize(Window: TCastleWindowBase);
      begin  ...  end;

      begin
        Window := TCastleWindowCustom.Create(Application);
        Window.OnResize := @Resize;
        Window.OnDraw := @Draw;
        Window.Caption := 'Simplest CastleWindow example';
        Window.OpenAndRun;
      end.
More object-oriented approach: Instead of assigning callbacks (OnDraw, OnResize etc.) you can also derive a new class from TCastleWindowBase and override some of virtual methods, like EventDraw, EventResize etc. Every callback OnXxx has a corresponding EventXxx method. In TCastleWindowBase class, all EventXxx methods simply call appropriate OnXxx callbacks (this way you can use whatever approach you like – OOP or not-OOP). This is a second version of the "simplest example" program above, this time using OOP approach:
      uses CastleWindow;

      type
        TMyWindow = class(TCastleWindowCustom)
          procedure EventDraw; override;
          procedure EventResize; override;
        end;

      procedure TMyWindow.EventDraw;
      begin  ...  end;

      procedure TMyWindow.EventResize;
      begin  ...  end;

      var
        Window: TMyWindow;
      begin
        Window := TMyWindow.Create(Application);
        Window.Caption := 'Simplest CastleWindow example using more OOP';
        Window.OpenAndRun;
      end.
The non-OOP approach has one advantage: you can easily switch all callbacks to some other set of callbacks. This allows you to implement modal behaviors, where a function suspends normal callbacks to display some dialog. See CastleWindowModes unit and, build on top of it, dialog boxes in CastleMessages and progress bar in CastleWindowProgress. These units give you some typical GUI capabilities, and they are in pure OpenGL. Using OOP approach (overriding EventXxx methods instead of registering OnXxx callbacks) you can not do such things so easily – in general, you have to define something to turn off special EventXxx functionality (like SetDemoOptions in TCastleWindowDemo and UseControls in TCastleWindowCustom) and you have to turn them off/on when using CastleWindowModes (mentioned TCastleWindowDemo and TCastleWindowCustom are already handled in CastleWindowModes). TODO: I shall do some virtual methods in TCastleWindowBase to make this easy. Random features list: TCastleApplication.ProcessMessage method. This allows you to reimplement event loop handling, which is crucial for implementing things like MessageInputQuery function that does modal GUI dialog box. TCastleWindowBase.Pressed to easily and reliably check which keys are pressed. Frames per second measuring, see TCastleWindowBase.Fps, A menu bar under WinAPI and GTK backends. You can attach a menu to a window. Menu structure is constructed using various descendants of TMenuEntry class. Then you have to assign such menu structure to TCastleWindowBase.MainMenu property. When `CastleWindow` is implemented on top of GTK_2 or WINAPI or LCL we will show this menu and call TCastleWindowBase.EventMenuClick (TCastleWindowBase.OnMenuClick) when user clicks some menu item. Other backends (XLIB for now) ignore MainMenu. See `castle_game_engine/examples/window/window_menu.lpr` for an example how to use the menu. Changing screen resolution and bit depth, see TCastleApplication.VideoChange. You can request OpenGL context properties: color buffer with alpha channel (AlphaBits), stencil buffer (StencilBits), double buffer (DoubleBuffer), multisampling (full-screen antialiasing) buffers (by MultiSampling or higher-level AntiAliasing) You can use native modal dialogs for things such as file selection. GTK backend will use GTK dialogs, WinAPI backend will use Windows dialog boxes, XLib backend will fall back on CastleMessages text input. See TCastleWindowBase.FileDialog (for opening and saving files) and TCastleWindowBase.ColorDialog (for choosing RGB colors). TCastleWindowBase.ParseParameters method allows you to easily initialize TCastleWindowBase properties like initial size and position using command-line parameters like `--geometry WIDTHxHEIGHT`, `--display` etc. ## Uses SysUtils Classes CastleVectors GL GLU GLExt CastleUtils CastleClassUtils CastleGLUtils CastleImages CastleGLImages CastleKeysMouse CastleStringUtils CastleFilesUtils CastleTimeUtils CastleFileFilters CastleUIControls FGL pk3DConnexion Glib2 Gdk2 Gtk2 GdkGLExt GtkGLExt CastleDynLib Gdk2X X Xlib X3DNodes CastleScene CastleSceneManager CastleLevels ## Overview ### Classes, Interfaces, Objects and Records
Name | Description
--- | ---
Class `TMenuEntry` | A basic class representing basic menu building block.
Class `TMenuEntryWithCaption` |
Class `TMenu` | TMenuEntry that contains a list of menu entries.
Class `TMenuItem` | TMenuEntry that is a simple, clickable menu item.
Class `TMenuSeparator` | TMenuEntry that acts as a visual separator (horizontal line or something like that) between menu items.
Class `TMenuItemChecked` | TMenuItem that should visualize Checked state somehow to the user.
Class `TMenuItemRadio` | Menu radio item.
Class `TMenuItemRadioGroup` | A group of radio buttons.
Class `TMenuItemToggleFullScreen` | Menu item that toggles TCastleWindowBase.FullScreen.
Class `EGLContextNotPossible` |
Class `TCastleWindowBase` | Window with an OpenGL context.
Class `TCastleWindowDemo` | Window with OpenGL context and some helper functionality, useful for demo programs.
Class `TCastleWindowCustom` | OpenGL window keeping a Controls list.
Class `TCastleWindow` | Window with an OpenGL context, most comfortable to render 3D worlds with 2D controls above.
Class `TWindowList` |
Class `TCastleApplication` | Application, managing all open TCastleWindowBase (OpenGL windows).
Class `TCastleClipboard` | Clipboard for cut / copy / paste of text.
### Functions and Procedures
`function Application: TCastleApplication;`
`function Clipboard: TCastleClipboard;`
`procedure Resize2D(Window: TCastleWindowBase);`
`function KeyString(const CharKey: char; const Key: TKey; const Modifiers: TModifierKeys; out S: string): boolean;`
`function MenuItemFromSmallId(SearchSmallId: Integer): TMenuItem;`
`function SRemoveMnemonics(const S: string): string;`
`function SQuoteMenuEntryCaption(const S: string): string;`
### Types
`TWindowParseOption = (...);`
`TWindowParseOptions = set of TWindowParseOption;`
`PWindowParseOptions = ˆTWindowParseOptions;`
`TAntiAliasing = (...);`
`TMenuEntryList = specialize TFPGObjectList<TMenuEntry>;`
`TWindowMessageType = (...);`
`TUpdateFunc = procedure;`
`TWindowFunc = procedure (Window: TCastleWindowBase);`
`TDrawFunc = TWindowFunc;`
`TMouseMoveFunc = procedure (Window: TCastleWindowBase; NewX, NewY: Integer);`
`TInputPressReleaseFunc = procedure (Window: TCastleWindowBase; const Event: TInputPressRelease);`
`TMenuClickFunc = procedure (Window: TCastleWindowBase; Item: TMenuItem);`
`TGLContextRetryOpenFunc = function (Window: TCastleWindowBase): boolean;`
`TDropFilesFunc = procedure (Window: TCastleWindowBase; const FileNames: array of string);`
`TResizeAllowed = (...);`
`PGtkGLArea = PGtkWidget;`
`TGLApplication = TCastleApplication deprecated;`
### Constants
`WindowPositionCenter = -1000000;`
`WindowDefaultSize = -1000000;`
`StandardParseOptions = [poGeometry, poScreenGeometry, poDisplay, poMacOsXProcessSerialNumber];`
`DefaultDepthBits = 16;`
`DefaultFpsCaptionUpdateInterval = 5000;`
`DefaultTooltipDelay = 1000;`
`DefaultTooltipDistance = 10;`
`DefaultLimitFPS = 100.0;`
`DefaultAntiAliasing = aaNone;`
`AntiAliasingNames: array [TAntiAliasing] of string = ( 'None', '2 samples (faster)', '2 samples (nicer)', '4 samples (faster)', '4 samples (nicer)', '8 samples (faster) (only latest GPUs)', '8 samples (nicer) (only latest GPUs)', '16 samples (faster) (only latest GPUs)', '16 samples (nicer) (only latest GPUs)' );`
## Description ### Functions and Procedures
`function Application: TCastleApplication;`
Single global instance of TCastleApplication. Automatically created / destroyed by CastleWindow unit.
`function Clipboard: TCastleClipboard;`
Single global instance of TCastleClipboard. Automatically created / destroyed by CastleWindow unit.
`procedure Resize2D(Window: TCastleWindowBase);`
A simple TCastleWindowBase.OnResize callback implementation, that sets 2D projection. You can use it like `Window.OnResize := `Resize2D`;` or just by calling it directly from your OnResize callback. It does
      glViewport(0, 0, Window.Width, Window.Height);
      OrthoProjection(0, Window.Width, 0, Window.Height);
`function KeyString(const CharKey: char; const Key: TKey; const Modifiers: TModifierKeys; out S: string): boolean;`
Describe given key. Key is given as combination of character code (may be #0) and Key code (may be K_None), and additional required `Modifiers` (although some modifiers may be already implied by CharKey). See TMenuItem.Key and TMenuItem.CharKey and TMenuItem.Modifiers. Only when both CharKey = #0 and Key = K_None then this combination doesn't describe any key, and we return `False`. Otherwise we return `True` and set S.
`function MenuItemFromSmallId(SearchSmallId: Integer): TMenuItem;`
Search for menu item with given SmallId. SearchSmallId must be a SmallId of some existing (i.e. created and not destroyed yet) TMenuItem. This function returns this TMenuItem.
`function SRemoveMnemonics(const S: string): string;`
Returns S with each '__' replaced with single '_', any other '_' removed. In other words: with mnemonics (as defined by TMenuEntryWithCaption.Caption removed.
`function SQuoteMenuEntryCaption(const S: string): string;`
Returns S with each underscore '_' replaced by two underscores, '__'. In other words: S will not contain any mnemonics. If you will assign S to TMenuEntryWithCaption.Caption, then this menu entry caption will display exactly S, without any mnemonics. Single '_' in S will be displayed exactly as single '_'.
### Types
`TWindowParseOption = (...);`
###### Values poGeometry: poScreenGeometry: poDisplay: poMacOsXProcessSerialNumber:
`TWindowParseOptions = set of TWindowParseOption;`
`PWindowParseOptions = ˆTWindowParseOptions;`
`TAntiAliasing = (...);`
Anti-aliasing values for TCastleWindowBase.AntiAliasing. ###### Values aaNone: aa2SamplesFaster: 2 samples, "don't care" hint. aa2SamplesNicer: 2 samples, "nicest" hint (quincunx (5 taps) for NVidia). aa4SamplesFaster: 4 samples, "don't care" hint. aa4SamplesNicer: 4 samples, "nicest" hint (9 taps for NVidia). aa8SamplesFaster: 8 samples, "don't care" hint. aa8SamplesNicer: 8 samples, "nicest" hint. aa16SamplesFaster: 16 samples, "don't care" hint. aa16SamplesNicer: 16 samples, "nicest" hint.
`TMenuEntryList = specialize TFPGObjectList<TMenuEntry>;`
`TWindowMessageType = (...);`
Type of message box, for TCastleWindowBase.MessageOK and TCastleWindowBase.MessageYesNo. ###### Values mtInfo: mtWarning: mtQuestion: mtError: mtOther:
`TUpdateFunc = procedure;`
`TWindowFunc = procedure (Window: TCastleWindowBase);`
`TDrawFunc = TWindowFunc;`
`TMouseMoveFunc = procedure (Window: TCastleWindowBase; NewX, NewY: Integer);`
`TInputPressReleaseFunc = procedure (Window: TCastleWindowBase; const Event: TInputPressRelease);`
`TMenuClickFunc = procedure (Window: TCastleWindowBase; Item: TMenuItem);`
`TGLContextRetryOpenFunc = function (Window: TCastleWindowBase): boolean;`
`TDropFilesFunc = procedure (Window: TCastleWindowBase; const FileNames: array of string);`
`TResizeAllowed = (...);`
###### Values raNotAllowed: raOnlyAtOpen: raAllowed:
`PGtkGLArea = PGtkWidget;`
For now I use GtkDrawingArea when CASTLE_WINDOW_GTK_2. But, really, GLAreaGtk could be any gtk widget with CASTLE_WINDOW_GTK_2.
`TGLApplication = TCastleApplication deprecated;`
Warning: this symbol is deprecated. Deprecated name for TCastleApplication.
### Constants
`WindowPositionCenter = -1000000;`
`WindowDefaultSize = -1000000;`
`StandardParseOptions = [poGeometry, poScreenGeometry, poDisplay, poMacOsXProcessSerialNumber];`
All "normal" command-line options, that most programs using CastleWindow should be able to handle without any problems. In other words, most programs calling TCastleWindowBase.ParseParameters method can safely pass as the 1st parameter this constant, `StandardParseOptions`. Or they can simply call overloaded version of TCastleWindowBase.ParseParameters that doesn't take any parameters, it is always equivalent to calling TCastleWindowBase.ParseParameters(`StandardParseOptions`).
`DefaultDepthBits = 16;`
`DefaultFpsCaptionUpdateInterval = 5000;`
`DefaultTooltipDelay = 1000;`
`DefaultTooltipDistance = 10;`
`DefaultLimitFPS = 100.0;`
`DefaultAntiAliasing = aaNone;`
`AntiAliasingNames: array [TAntiAliasing] of string = ( 'None', '2 samples (faster)', '2 samples (nicer)', '4 samples (faster)', '4 samples (nicer)', '8 samples (faster) (only latest GPUs)', '8 samples (nicer) (only latest GPUs)', '16 samples (faster) (only latest GPUs)', '16 samples (nicer) (only latest GPUs)' );`
Generated by PasDoc 0.13.0 on 2013-08-17 21:27:15