Reference TScene

  TScene = class
  protected
    { Resize sets the viewport but you might use it to change the perspective
      matrix }
    procedure Resize; virtual;
  public
    { Create a scene of a size using the scene host of the calling thread }
    constructor Create(Width, Height: Integer); virtual;
    destructor Destroy; override;
    { Name of the scene }
    function Name: string; virtual;
    { KeyEvent is fired when a keyboard action occurs }
    procedure KeyEvent(KeyCode: Integer; Shift: TShiftKeys); virtual;
    { MouseEvent is fired when a mouse action occurs }
    procedure MouseEvent(X, Y: Integer; Action: TMouseAction); virtual;
    { Input events sent by the host. By default key up calls KeyEvent and the
      mouse button and move events call MouseEvent. }
    procedure DoKeyDown(var Args: TSceneKeyArgs); virtual;
    procedure DoKeyUp(var Args: TSceneKeyArgs); virtual;
    procedure DoMouseDown(var Args: TSceneMouseArgs); virtual;
    procedure DoMouseMove(var Args: TSceneMouseArgs); virtual;
    procedure DoMouseUp(var Args: TSceneMouseArgs); virtual;
    procedure DoMouseWheel(var Args: TSceneWheelArgs); virtual;
    procedure DoTextInput(var Args: TSceneTextArgs); virtual;
    { Update causes a and Logic, Resize, and Render methods to be invoked in
      that order }
    procedure Update(Width, Height: Integer; Time: Double);
    { Initialize has an active context and is called during Create }
    procedure Initialize; virtual;
    { Finalize has an active context and is called during Destroy }
    procedure Finalize; virtual;
    { Logic phase allows you to calculate logic and has no current context }
    procedure Logic; virtual;
    { Render phase allows you render and has a current context }
    procedure Render; virtual;
    { StepInterval is the time in seconds between calls to Step made by a step
      thread the host runs for the scene, or 0 when the scene does not need a
      step thread. It is read once after the scene is created. }
    function StepInterval: Double; virtual;
    { Step is called on the step thread at a fixed rate when StepInterval is
      greater than 0. It runs at the same time as Logic and Render, so data they
      share must be protected. It has no current context. }
    procedure Step(DeltaTime: Double); virtual;
    { When Animated is True update is called continously }
    property Animated: Boolean read FAnimated write FAnimated;
    { Context associated with the scene }
    property Context: TRenderContext read FContext;
    { The host running the scene, or nil if the scene was created without one }
    property Host: TSceneHost read FHost;
    { The canvas and default font of the host }
    property Canvas: ICanvas read GetCanvas;
    property Font: IFont read GetFont;
    { Time that can be used during Logic or Render }
    property Time: Double read GetTime;
    { Width is updated immediately before Render }
    property Width: Integer read FWidth;
    { Height is updated immediately before Render }
    property Height: Integer read FHeight;
  end;