Unit CastleWindow

Description

Window with rendering context suitable for rendering of "Castle Game Engine". Provides a window that can render hierarchy of TCastleUserInterface, which includes a hierarchy of 3D and 2D scenes inside TCastleViewport. Use the TCastleWindow as your window class.

Application object (instance of class TCastleApplication) is a central manager of all open TCastleWindow windows.

Using this unit:

1. Declare and create TCastleWindow instance. (Or a descendant like TCastleWindow.)

2. Assign Window properties and callbacks like OnRender, OnResize, Width, Height, Caption.

3. To initialize your game, you usually want to use Application.OnInitialize.

   If you only care about standalone programs (for normal OSes like Linux, Windows, MacOSX, but not Android) you may also just initialize your game in the main program block, although using Application.OnInitialize is still often comfortable.

4. Call Window.Open, this will actually show the window and it's associated OpenGL context.

   The first window open calls Application.OnInitialize. It also calls OnOpen and OnResize callbacks.

5. Call Application.Run. This will enter message loop that will call appropriate windows' callbacks at appropriate times (OnRender, 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.

6. 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: TCastleWindow;

procedure Render(Sender: TCastleContainer);
begin
  // ... e.g. DrawRectangle or TDrawableImage.Draw calls inside
end;

begin
  Window := TCastleWindow.Create(Application);
  Window.OnResize := @Resize;
  Window.Caption := 'Simplest CastleWindow example';
  Window.OpenAndRun;
end.

More component-like approach: For larger programs, it makes more sense to divide functionality into controls, which are classes descending from TCastleUserInterface. You can override TCastleUserInterface methods to render, capture input and so on (see e.g. TCastleUserInterface.Render, TCastleUserInterface.Press, TCastleUserInterface.Update.) You can then add your control to the TCastleWindow.Controls list.

Some 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.

• TCastleWindow.Pressed to easily and reliably check which keys are pressed.

• Application speed, see TCastleWindow.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 TCastleWindow.MainMenu property. When CastleWindow is implemented on top of GTK_2 or WINAPI or LCL we will show this menu and call TCastleWindow.OnMenuClick when user clicks some menu item. Other backends (XLIB for now) ignore MainMenu.

  See examples/window/window_menu/ 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 TCastleWindow.FileDialog (for opening and saving files) and TCastleWindow.ColorDialog (for choosing RGB colors).

• TCastleWindow.ParseParameters method allows you to easily initialize TCastleWindow properties like initial size and position using command-line parameters like --geometry WIDTHxHEIGHT, --display etc.

Uses

• Glx
• Glib2
• Gdk2
• Gtk2
• CastleDynLib
• Gdk2X
• X
• Xlib
• XUtil
• SysUtils
• Classes
• Generics.Collections
• CustApp
• GL
• GLExt
• CastleVectors
• CastleRectangles
• CastleColors
• CastleUtils
• CastleClassUtils
• CastleGLUtils
• CastleImages
• CastleGLImages
• CastleKeysMouse
• CastleStringUtils
• CastleFilesUtils
• CastleTimeUtils
• CastleFileFilters
• CastleUIControls
• CastleInternalPk3DConnexion
• CastleParameters
• CastleSoundEngine
• CastleApplicationProperties

Overview

Classes, Interfaces, Objects and Records

Functions and Procedures

Types

Constants

Description

Functions and Procedures

RenderContext.Viewport := Window.Rect;
OrthoProjection(0, Window.Width, 0, Window.Height);

Types

Constants