unit Unit1;

interface

uses

  OpenGL,Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, ExtCtrls;

type

  TForm1 = class(TForm)

    Timer1: TTimer;

    procedure FormCreate(Sender: TObject);

    procedure FormPaint(Sender: TObject);

    procedure Timer1Timer(Sender: TObject);

  private

    { Private declarations }

    angle:single;

    procedure Draw; //Draws an OpenGL scene on request

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

function getNormal(p1,p2,p3:TGLArrayf3):TGLArrayf3;

var a,b:TGLArrayf3;

begin

//make two vectors

a[]:=p2[]-p1[]; a[]:=p2[]-p1[]; a[]:=p2[]-p1[];

b[]:=p3[]-p1[]; b[]:=p3[]-p1[]; b[]:=p3[]-p1[];

//calculate cross-product

result[]:=a[]*b[]-a[]*b[];

result[]:=a[]*b[]-a[]*b[];

result[]:=a[]*b[]-a[]*b[];

end; 

procedure setupPixelFormat(DC:HDC);

const

pfd:TPIXELFORMATDESCRIPTOR = (

  nSize:sizeof(TPIXELFORMATDESCRIPTOR); // size

  nVersion:;                           // version

  dwFlags:PFD_SUPPORT_OPENGL or PFD_DRAW_TO_WINDOW or

    PFD_DOUBLEBUFFER;                   // support double-buffering

  iPixelType:PFD_TYPE_RGBA;             // color type

  cColorBits:;                        // preferred color depth

  cRedBits:; cRedShift:;              // color bits (ignored)

  cGreenBits:; cGreenShift:;

  cBlueBits:; cBlueShift:;

  cAlphaBits:; cAlphaShift:;          // no alpha buffer

  cAccumBits: ;

  cAccumRedBits: ;                     // no accumulation buffer,

  cAccumGreenBits: ;                   // accum bits (ignored)

  cAccumBlueBits: ;

  cAccumAlphaBits: ;

  cDepthBits:;                        // depth buffer

  cStencilBits:;                       // no stencil buffer

  cAuxBuffers:;                        // no auxiliary buffers

  iLayerType:PFD_MAIN_PLANE;            // main layer

  bReserved: ;

  dwLayerMask: ;

  dwVisibleMask: ;

  dwDamageMask: ;                      // no layer, visible, damage masks

);

var pixelFormat:integer;

begin

pixelFormat := ChoosePixelFormat(DC, @pfd);

if (pixelFormat = ) then

exit;

if (SetPixelFormat(DC, pixelFormat, @pfd) <> TRUE) then

exit;

end; 

procedure GLInit;

const

light0_position:TGLArrayf4=( -8.0, 8.0, -16.0, 0.0);

ambient: TGLArrayf4=( 0.3, 0.3, 0.3, 0.3);

begin

// set viewing projection

glMatrixMode(GL_PROJECTION);

glFrustum(-0.1, 0.1, -0.1, 0.1, 0.3, 25.0);

// position viewer */

glMatrixMode(GL_MODELVIEW);

glEnable(GL_DEPTH_TEST); 

// set lights

glEnable(GL_LIGHTING);

glLightfv(GL_LIGHT0, GL_POSITION, @light0_position);

glLightfv(GL_LIGHT0, GL_AMBIENT, @ambient);

glEnable(GL_LIGHT0);

end; 

procedure TForm1.Draw;

const D=1.5;

H1=D/1.732;

H2=D*1.732-H1; // D/H = tg() = /sqrt()

HY=3.0;

const //vertexes

a1:TGLArrayf3=(-D, , -H1);

a2:TGLArrayf3=(D, , -H1);

a3:TGLArrayf3=(, , H2);

a4:TGLArrayf3=(, HY, );

var n1, n2, n3, n4: TGLArrayf3; //normals

begin

n1 := getNormal(a1,a3,a2);

n2 := getNormal(a1,a2,a4);

n3 := getNormal(a2,a3,a4);

n4 := getNormal(a3,a1,a4);

glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);

glEnable(GL_NORMALIZE);

glShadeModel(GL_FLAT);

glCullFace(GL_BACK);

glLoadIdentity;

glTranslatef(0.0, 0.0, -12.0);

glBegin(GL_TRIANGLES);

glNormal3fv(@n1);

glVertex3fv(@a1); glVertex3fv(@a2); glVertex3fv(@a3);

glNormal3fv(@n2);

glVertex3fv(@a1); glVertex3fv(@a2); glVertex3fv(@a4);

glNormal3fv(@n3);

glVertex3fv(@a2); glVertex3fv(@a3); glVertex3fv(@a4);

glNormal3fv(@n4);

glVertex3fv(@a3); glVertex3fv(@a1); glVertex3fv(@a4);

glEnd;

SwapBuffers(wglGetCurrentDC);

end; 

procedure TForm1.FormCreate(Sender: TObject);

var DC:HDC;

RC:HGLRC;

i:integer;

begin

DC:=GetDC(Handle); //Actually, you can use any windowed control here

SetupPixelFormat(DC);

RC:=wglCreateContext(DC); //makes OpenGL window out of DC

wglMakeCurrent(DC, RC); //makes OpenGL window active

GLInit; //initialize OpenGL

end; 

procedure TForm1.FormPaint(Sender: TObject);

begin

  Draw;

end;

procedure TForm1.Timer1Timer(Sender: TObject);

begin

angle:=angle+1.0;

Draw;

end;

end.