unit Unit1;

interface

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

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

type
  TForm1 = class(TForm)
    panOpenGL: TPanel;
    Label1: TLabel;
    Label2: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure IdleHandler(Sender: TObject; var Done: Boolean);
    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
  private
    { Private-Deklarationen }
    StartTime, TimeCount, FrameCount  : Cardinal; //FrameCounter
    Frames, DrawTime                  : Cardinal; //& Timebased Movement
    procedure SetupGL;
    procedure Render;
    procedure ErrorHandler;
    procedure Init;
  public
    { Public-Deklarationen }
    DC                                : HDC;  //Handle auf Zeichenfläche
    RC                                : HGLRC;//Rendering Context
  end;

var
  Form1: TForm1;
  x1,y1,x2,y2,z1:real;

const
  NearClipping = 0.1;
  FarClipping  = 100;

implementation

{$R *.dfm}

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

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

//KeyDown
procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  case key of
    39: x1 := x1 + 0.1;       //Pfeiltaste rechts       -   Objekt nach rechts
    37: x1 := x1 - 0.1;       //Pfeiltaste links        -   Objekt nach links
    40: y1 := y1 - 0.1;       //Pfeiltaste nach unten   -   Objekt nach unten
    38: y1 := y1 + 0.1;       //Pfeiltaste nach oben    -   Objekt nach oben
    87: y2 := y2 + 0.1;       //w                       -   Szenario nach oben
    65: x2 := x2 - 0.1;       //a                       -   Szenario nach links
    83: y2 := y2 - 0.1;       //s                       -   Szenario nach unten
    68: x2 := x2 + 0.1;       //d                       -   Szenario nach rechts
    69: z1 := z1 + 0.01;       //e                       -   Reinzoomen
    81: z1 := z1 - 0.01;       //q                       -   Rauszoomen
  end;
end;

// Setup - OpenGL
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

  glEnable(GL_BLEND) ;
  glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
end;

// Init - OpenGL
procedure TForm1.Init;
begin
// Initsachen wie Texturzuordnung hier rein
end;

// Render - OpenGL
procedure TForm1.Render;
begin
  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity;
  gluPerspective(90.0, panOpenGL.ClientWidth/panOpenGL.ClientHeight, NearClipping, FarClipping);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity;

  glTranslatef(0+x2, 0+y2, -3+z1);

  glBegin(GL_QUADS);
    glTexCoord2f(0,0); glVertex3f(0+x1, 0+y1, 0);
    glTexCoord2f(0,1); glVertex3f(1+x1, 0+y1, 0);
    glTexCoord2f(1,1); glVertex3f(1+x1, 2+y1, 0);
    glTexCoord2f(1,0); glVertex3f(0+x1, 2+y1, 0);
    glColor3f(1, 0, 0); glVertex3f(0, 0, 0);
    glColor3f(0, 1, 0); glVertex3f(0.5, 0, 0);
    glColor3f(0, 0, 1); glVertex3f(0.5, 0.5, 0);
    glColor3f(1, 1, 0); glVertex3f(0, 0.5, 0);
  glEnd;

  SwapBuffers(DC);
end;

// ErrorHandle - OpenGL
procedure TForm1.ErrorHandler;
begin
  Label2.Caption := string(gluErrorString(glGetError));
end;

// IdleHandle - OpenGL
procedure TForm1.IdleHandler(Sender: TObject; var Done: Boolean);
begin
  StartTime:= GetTickCount;
  Render;
  DrawTime:= GetTickCount - StartTime;
  Inc(TimeCount, DrawTime);
  Inc(FrameCount);

  if TimeCount >= 1000 then begin
    Frames:= FrameCount;
    TimeCount:= TimeCount - 1000;
    FrameCount:= 0;
    Label1.Caption:= InttoStr(Frames) + ' FPS';
    ErrorHandler;
  end;

  Done:= false;
end;

end.

// Pfeiltasten oben/unten
acceleration = 0;
if (Pfeiltaste oben gedrückt) then acceleration = acceleration + 1;
if (Pfeiltaste unten gedrückt) then acceleration = acceleration - 1;

// Pfeiltaste links gedrückt
angle = angle + drehenProSekunde * timeElapsed;
if angle > 2*PI then angle = angle - 2*PI;

// Pfeiltaste rechts gedrückt
angle = angle - drehenProSekunde * timeElapsed
if angle < 0 then angle = angle + 2*PI;

// Beschleunigung ausführen
velocity.x = velocity.x + acceleration * timeElapsed * sin(angle)
velocity.y = velocity.y + acceleration * timeElapsed * cos(angle)

// Bewegung ausführen
position = position + velocity * timeElapsed