unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, dglOpenGL;

Type
  TVector2f = Array [0..1] of Single;
  TVector3f = Array [0..2] of Single;

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Timer1: TTimer;
    Timer2: TTimer;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure Timer2Timer(Sender: TObject);
  private
    { Private-Deklarationen }
    FrameCount  : Cardinal; //FrameCounter
    procedure SetupGL;
    procedure Render;
    procedure ErrorHandler;
    procedure Cube(Color:Integer);
  public
    { Public-Deklarationen }
    DC                                : HDC;  //Handle auf Zeichenfläche
    RC                                : HGLRC;//Rendering Context
  end;

var
  Form1: TForm1;

const
  NearClipping = 1;
  FarClipping  = 1000;

var
  RotateX  : single;                 // Rotation um die X-Achse
  RotateY  : single;                 // Rotation um die Y-Achse
  RotateZ  : single;                 // Rotation um die Z-Achse
  PosVect  : TVector3f;         // Vector mit der Position des Objektes.

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  DC:= GetDC(Panel1.Handle);
  if not InitOpenGL then Application.Terminate;
  RC:= CreateRenderingContext( DC,
                               [opDoubleBuffered],
                               32,
                               24,
                               0,0,0,
                               0);
  ActivateRenderingContext(DC, RC);
  SetupGL;
end;

procedure TForm1.SetupGL;
begin
  glClearColor(0.0, 0.0, 0.0, 0.0); //Hintergrundfarbe:
  glEnable(GL_DEPTH_TEST);          //Tiefentest aktivieren
  glEnable(GL_CULL_FACE);           //Backface Culling aktivieren

  RotateX := 0;
  RotateY := 0;
  RotateZ := 0;
  PosVect[0] := 0;
  PosVect[1] := 0;
  PosVect[2] := -5;
end;

procedure TForm1.Cube(Color:Integer);
begin
    if Color <> 0 then glColor4f(0.5, 0.5, 1.0, 0.8)  // Set The Color
    else glColor4f(0.3, 0.3, 0.3, 0.4);
      glVertex3f( 1.0, 1.0,-1.0);         // Top Right Of The Quad (Top)
      glVertex3f(-1.0, 1.0,-1.0);         // Top Left Of The Quad (Top)
      glVertex3f(-1.0, 1.0, 1.0);         // Bottom Left Of The Quad (Top)
      glVertex3f( 1.0, 1.0, 1.0);         // Bottom Right Of The Quad (Top)

    if Color <> 0 then glColor4f(0.5, 0.5, 1.0, 0.8)  // Set The Color
    else glColor4f(0.3, 0.3, 0.3, 0.4);
      glVertex3f( 1.0,-1.0, 1.0);         // Top Right Of The Quad (Bottom)
      glVertex3f(-1.0,-1.0, 1.0);         // Top Left Of The Quad (Bottom)
      glVertex3f(-1.0,-1.0,-1.0);         // Bottom Left Of The Quad (Bottom)
      glVertex3f( 1.0,-1.0,-1.0);         // Bottom Right Of The Quad (Bottom)

    if Color <> 0 then glColor4f(0.5, 0.5, 1.0, 0.8)  // Set The Color
    else glColor4f(0.3, 0.3, 0.3, 0.4);
      glVertex3f( 1.0, 1.0, 1.0);         // Top Right Of The Quad (Front)
      glVertex3f(-1.0, 1.0, 1.0);         // Top Left Of The Quad (Front)
      glVertex3f(-1.0,-1.0, 1.0);         // Bottom Left Of The Quad (Front)
      glVertex3f( 1.0,-1.0, 1.0);         // Bottom Right Of The Quad (Front)

    if Color <> 0 then glColor4f(0.5, 0.5, 1.0, 0.8)  // Set The Color
    else glColor4f(0.3, 0.3, 0.3, 0.4);
      glVertex3f( 1.0,-1.0,-1.0);         // Bottom Left Of The Quad (Back)
      glVertex3f(-1.0,-1.0,-1.0);         // Bottom Right Of The Quad (Back)
      glVertex3f(-1.0, 1.0,-1.0);         // Top Right Of The Quad (Back)
      glVertex3f( 1.0, 1.0,-1.0);         // Top Left Of The Quad (Back)

    if Color <> 0 then glColor4f(0.5, 0.5, 1.0, 0.8)  // Set The Color
    else glColor4f(0.3, 0.3, 0.3, 0.4);
      glVertex3f(-1.0, 1.0, 1.0);         // Top Right Of The Quad (Left)
      glVertex3f(-1.0, 1.0,-1.0);         // Top Left Of The Quad (Left)
      glVertex3f(-1.0,-1.0,-1.0);         // Bottom Left Of The Quad (Left)
      glVertex3f(-1.0,-1.0, 1.0);         // Bottom Right Of The Quad (Left)

    if Color <> 0 then glColor4f(0.5, 0.5, 1.0, 0.8)  // Set The Color
    else glColor4f(0.3, 0.3, 0.3, 0.4);
      glVertex3f( 1.0, 1.0,-1.0);         // Top Right Of The Quad (Right)
      glVertex3f( 1.0, 1.0, 1.0);         // Top Left Of The Quad (Right)
      glVertex3f( 1.0,-1.0, 1.0);         // Bottom Left Of The Quad (Right)
      glVertex3f( 1.0,-1.0,-1.0);         // Bottom Right Of The Quad (Right)
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  DeactivateRenderingContext;
  DestroyRenderingContext(RC);
  ReleaseDC(Handle, DC);
end;

procedure TForm1.Render;
Const voffset : TVector3f = (0.0, 0.0, 0.0);
      toffset : TVector2f = (0.0, 0.0);
      tscale  : TVector2f = (1.0, 1.0);
begin
  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity;
  gluPerspective(45.0, ClientWidth/ClientHeight, NearClipping, FarClipping);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity;

  glTranslatef(0, 0, 0);

  // Das Objekt auf seine aktuelle Position setzen.
  glTranslatef( PosVect[0],  PosVect[1],  PosVect[2]);

  { Das Objekt noch drehen, damit denn wir haben bis jetzt ja nur den }
  { Vector gedreht.                                                   }
  glRotatef(RotateX, 1, 0, 0);
  glRotatef(RotateY, 0, 1, 0);
  glRotatef(RotateZ, 0, 0, 1);


  glBegin(GL_QUADS);
    Cube(0);
  glEnd;

  SwapBuffers(DC);
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  inc(FrameCount);
  Render;
  If FrameCount = 20 then
  begin
    ErrorHandler;
    FrameCount := 0;
  end;
end;

procedure TForm1.Timer2Timer(Sender: TObject);
begin
  RotateY := RotateY + 0.5;
//  if RotateY <= 0 then RotateY := RotateY + 360;
//  RotateX := RotateX + 0.5;
//  if RotateX <= 0 then RotateX := RotateX + 360;
//  RotateZ := RotateY + 0.5;
end;

procedure TForm1.ErrorHandler;
begin
  Form1.Caption := string(gluErrorString(glGetError));
end;

end.

gluPerspective(45.0, panel1.ClientWidth/panel1.ClientHeight, NearClipping, FarClipping);