OpenGL Grundgerüst

[freq.9]

So ich habe nun ein Koordinatenkreuz gezeichnet. Wenn ich dieses nun aber drehe (0°..360°) dreht sich die X-Achse immer weit über die Anwendung hinaus. Woran kann das liegen?

Mein aktueller Code:

Delphi-Quellcode:

unit main;

interface

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

type
  TglPanel = class(TPanel)
    private
      FOnPaintEvent:TNotifyEvent;
    protected
      procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
      procedure WMEraseBkgnd(var Message: TWmEraseBkgnd); message WM_ERASEBKGND;
    published
      property OnPaint:TNotifyEvent read FOnPaintEvent write FOnPaintEvent;
  end;

  TfrmMain = class(TForm)
    Timer1: TTimer;
    procedure Timer1Timer(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure FormPaint(Sender: TObject);
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormResize(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    myRc, myDc : Cardinal;
    GL_Texture:TglBitmap2D;
    Panel: TglPanel;
    ControlPanel: TPanel;
    procedure InitGl();
    procedure DeInitGl();
    procedure glRender();
  end;

var
  frmMain: TfrmMain;
  e: TWinControl;
  Angle: Integer;

implementation

{$R *.dfm}

procedure TfrmMain.DeInitGl;
begin
  DeactivateRenderingContext();
  DestroyRenderingContext(myRc);
  ReleaseDC(Panel.Handle, myDc);
end; 

procedure TfrmMain.FormCreate(Sender: TObject);
begin
  OnResize := nil;
  Angle := 0;

  Panel := TglPanel.Create(Self);
  with Panel do
  begin
    Caption := '';
    Align   := alClient;
    OnPaint := FormPaint;
    Parent  := frmMain;
  end;

  InitGl();
  Caption := 'OpenGL VCL Template by sniper ([e-mail])';
  KeyPreview := True;

  GL_Texture := TglBitmap2D.Create();
  {//GL_Texture.BuildMipMaps := False;
  GL_Texture.LoadFromFile('../Images/back.bmp');
  GL_Texture.FreeDataAfterGenTexture := True;
  //GL_Texture.GenTexture();}

  OnResize := FormResize;
  Resize();
end;

procedure TfrmMain.FormDestroy(Sender: TObject);
begin
  GL_Texture.Free();
  DeInitGl();
end;

procedure TfrmMain.InitGl;
begin
  InitOpenGL();

  myDc := GetDC(Panel.Handle);
  myRc := CreateRenderingContext(myDc, [opDoubleBuffered], 24, 16, 8, 0, 0, 0);

  ActivateRenderingContext(myDc,myRc);
  glClearColor(0, 0, 0, 0);
  glShadeModel(GL_SMOOTH);
  glClearDepth(1.0);
  glEnable(GL_DEPTH_TEST);
  glDepthFunc (GL_LEQUAL);
  glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
  glEnable(GL_TEXTURE_2D);
end;

procedure TfrmMain.FormPaint(Sender: TObject);
begin
  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
  glRender();
  SwapBuffers(myDc);
end;

procedure TfrmMain.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if Key=27 then Close();
end;

procedure TfrmMain.FormResize(Sender: TObject);
begin//
  if (ClientHeight=0) then
  begin
    ClientHeight := 1;
  end;
  glViewport(0, 0, ClientWidth, ClientHeight);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(120.0, ClientWidth/ClientHeight, 1, 1000);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  FormPaint(nil);
end;

procedure TfrmMain.glRender();
begin
  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
 
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity;
  gluPerspective(120.0, ClientWidth/ClientHeight, 1, 1000);

  glTranslatef(0, 0, -5);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity;
  glRotated(Angle, 0, 1, 0);

  glBegin(GL_LINES);
    glColor3f(255, 0, 0);
    glVertex3f(-8,  0, 0);
    glVertex3f( 8,  0, 0);
    glColor3f(0, 255, 0);
    glVertex3f( 0,  8, 0);
    glVertex3f( 0, -8, 0);
  glEnd;
 
  SwapBuffers(myDC);
end;

{ TglPanel }

procedure TglPanel.WMEraseBkgnd(var Message: TWmEraseBkgnd);
begin
  Message.Result := 1;
end;

procedure TglPanel.WMPaint(var Message: TWMPaint);
var
  PS: TPaintStruct;
begin
  BeginPaint(Handle, PS);
  if Assigned(FOnPaintEvent) then
    FOnPaintEvent(Self);
  EndPaint(Handle, PS);
  Message.Result := 0;
end;

procedure TfrmMain.Timer1Timer(Sender: TObject);
begin
  if Angle >= 360 then
    Angle := 0
  else
  begin
    Inc(Angle);
    Inc(Angle);
    Inc(Angle);
    Inc(Angle);
  end;
  glRender;
end;

end.

Bei der Datei bitte aus foo.wma nen foo.avi machen. Leider habe ich kein Programm, mit dem ich WMA oder so aufnehmen kann. Leider nur AVI