Wie kann ich einen viereckigen Bereich auf GLSceneViewer markieren?

[Boyington]

Folgende ist der Quelltext:

Code:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, GLScene, GLMisc, GLVectorFileObjects, GLWin32Viewer, GLFileSTL,
  Menus, ComCtrls, StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    GLScene1: TGLScene;
    GLSceneViewer1: TGLSceneViewer;
    GLFreeForm1: TGLFreeForm;
    GLLightSource1: TGLLightSource;
    GLCamera1: TGLCamera;
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    Laden1: TMenuItem;
    Beenden1: TMenuItem;
    TrackBar1: TTrackBar;
    TrackBar2: TTrackBar;
    TrackBar3: TTrackBar;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    OpenDialog1: TOpenDialog;
    procedure Beenden1Click(Sender: TObject);
    procedure Laden1Click(Sender: TObject);
    procedure TrackBar1Change(Sender: TObject);
    procedure TrackBar2Change(Sender: TObject);
    procedure TrackBar3Change(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure GLSceneViewer1MouseDown(Sender: TObject;
      Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
    procedure GLSceneViewer1MouseMove(Sender: TObject; Shift: TShiftState;
      X, Y: Integer);
    procedure GLSceneViewer1MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
        
  private
    { Private declarations }

  Massstab: Integer;
  Roll: Integer;
  Turn: Integer;
  sx,sy,ex,ey: Integer;
  Markieren:boolean;

  public
    { Public declarations }
  end;

Var
  Form1: TForm1;
  
implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Massstab:=TrackBar1.Position;
  Roll:=TrackBar2.Position;
  Turn:=TrackBar3.Position;
end;

procedure TForm1.Beenden1Click(Sender: TObject);
begin
Close;
end;

procedure TForm1.Laden1Click(Sender: TObject);
begin
   Form1.OpenDialog1.Title:='Waehlen Sie bitte eine STL-Datei';
   Form1.OpenDialog1.InitialDir:='C:\';
   Form1.OpenDialog1.Filter:='STL Files in ASCII Format(*.stl)|*.stl';
   Form1.OpenDialog1.Execute;

   GLFreeForm1.LoadFromFile(OpenDialog1.FileName);
   GLFreeForm1.Scale.Scale(0.5) ;
   GLFreeForm1.Roll(0);
   GLFreeForm1.Turn(0);
  
end;

procedure TForm1.TrackBar1Change(Sender: TObject);
begin
   Massstab:=TrackBar1.Position;
   GLFreeForm1.Scale.Normalize;
   GLFreeForm1.Scale.Scale(Massstab/10);

end;


procedure TForm1.TrackBar2Change(Sender: TObject);
begin
   Roll:=TrackBar2.Position;
   GLFreeForm1.Rotation.Normalize;
   GLFreeForm1.Roll(Roll);
   GLFreeForm1.Turn(Turn);
end;


procedure TForm1.TrackBar3Change(Sender: TObject);
begin
   Turn:=TrackBar3.Position;
   GLFreeForm1.Rotation.Normalize;
   GLFreeForm1.Roll(Roll);
   GLFreeForm1.Turn(Turn);
end;



procedure TForm1.GLSceneViewer1MouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  //bitte euren Text hier einfügen!!!
end;

procedure TForm1.GLSceneViewer1MouseMove(Sender: TObject;
  Shift: TShiftState; X, Y: Integer);
begin
   //bitte euren Text hier einfügen!!!
end;

procedure TForm1.GLSceneViewer1MouseUp(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
   //bitte euren Text hier einfügen!!!
end;
end.