{: Properties dialog for the GLScene screensaver sample.<p>

	Here is some basic interface and animation stuff showcased in other GLScene
	samples. The selection/hot mechanism is a little different from the approach
	used in other "interface" samples.<br>
	Note that the Cadencer is used in "cmManual" mode. Why doing this ? well, on
	slower systems the PickedObject call in each OnMouseMove may overwhelm the
	message queue, and since the Cadencer uses the message queue, this will result
	in animation "stalls" when the user is constantly and swiftly moving its
	mouse. Using the old "AfterRender" trick sorts this out.<p>

	Beginners may also be interested in the Registry access.
}
unit Unit2;

interface

uses
  Windows, SysUtils, Classes, Graphics, Controls, Forms, GLMisc, GLScene,
  GLObjects, StdCtrls, GLTexture, GLCadencer;

type
  TForm2 = class(TForm)
	 GLSceneViewer1: TGLSceneViewer;
    GLScene1: TGLScene;
    GLCamera1: TGLCamera;
	 GLLightSource1: TGLLightSource;
	 SpaceText4: TSpaceText;
	 Button1: TButton;
    DummyCube1: TDummyCube;
    Torus1: TTorus;
	 Torus2: TTorus;
	 GLCadencer1: TGLCadencer;
    Button2: TButton;
	 procedure FormCreate(Sender: TObject);
	 procedure GLSceneViewer1MouseMove(Sender: TObject; Shift: TShiftState;
		X, Y: Integer);
	 procedure GLSceneViewer1MouseDown(Sender: TObject;
		Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
    procedure Button2Click(Sender: TObject);
  private
	 { Déclarations privées }
	 FLastHotNb : Integer;
	 procedure SetSelected(nb : Integer);
	 procedure SetHot(nb : Integer);
  public
	 { Déclarations publiques }
  end;

var
  Form2: TForm2;

function GetMeshResolutions : Integer;
procedure SetMeshResolutions(MeshResolutions : Integer);

implementation

{$R *.DFM}

uses Registry, ScreenSaver;

const
	cSaverRegistryKey = 'Software\GLScene\Samples\ScreenSaver';
	cSaverRegistryMeshResolutions = 'MeshResolutions';

function GetMeshResolutions : Integer;
var
	reg : TRegistry;
begin
	reg:=TRegistry.Create;
	reg.OpenKey(cSaverRegistryKey, True);
	// If the value cannot be found, we default to hi-resolution
	if reg.ValueExists(cSaverRegistryMeshResolutions) then
		Result:=reg.ReadInteger(cSaverRegistryMeshResolutions)
	else Result:=1;
	reg.Free;
end;

procedure SetMeshResolutions(MeshResolutions : Integer);
var
	reg : TRegistry;
begin
	reg:=TRegistry.Create;
	reg.OpenKey(cSaverRegistryKey, True);
	reg.WriteInteger(cSaverRegistryMeshResolutions, MeshResolutions);
	reg.Free;
end;

procedure TForm2.FormCreate(Sender: TObject);
begin
	// we highlight the current resolution
	SetSelected(GetMeshResolutions);
	SetHot(-1);
end;

procedure TForm2.SetSelected(nb : Integer);
const
	cSelectionColor : array [False..True] of Integer = (clNavy, clBlue);
begin
	Torus1.Material.FrontProperties.Emission.AsWinColor:=(cSelectionColor[nb=0]);
	Torus2.Material.FrontProperties.Emission.AsWinColor:=(cSelectionColor[nb=1]);
end;

procedure TForm2.SetHot(nb : Integer);
const
	cHotColor : array [False..True] of Integer = (clGray, clWhite);
begin
	FLastHotNb:=nb;
	Torus1.Material.FrontProperties.Diffuse.AsWinColor:=(cHotColor[nb=0]);
	Torus2.Material.FrontProperties.Diffuse.AsWinColor:=(cHotColor[nb=1]);
end;

procedure TForm2.GLSceneViewer1MouseMove(Sender: TObject;
  Shift: TShiftState; X, Y: Integer);
var
	bso : TGLBaseSceneObject;
begin
	// Here I used the trick of setting Torus1.Tag=1 and Torus.Tag=2
	// other objects have a Tag of 0
	bso:=GLSceneViewer1.GetPickedObject(X, Y);
	if Assigned(bso) and (bso.Tag>0) then
		SetHot(bso.Tag-1)
	else SetHot(-1);
end;

procedure TForm2.GLSceneViewer1MouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
	if FLastHotNb>=0 then begin
		SetSelected(FLastHotNb);
		SetMeshResolutions(FLastHotNb);
	end;
end;

procedure TForm2.Button2Click(Sender: TObject);
begin
	// a call to "Form1.ScreenSaver1.SetPassword;" would have done the same
	SetScreenSaverPassword;
end;

end.
