unit Unit13;
{
This software has been designed and it is
CopyLefted by Han de Bruijn:

                          (===)
                         @-O^O-@
                          #/_\#
                           ###
}
INTERFACE

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

type
  TForm1 = class(TForm)
    Image1: TImage;
    procedure Toetsdruk(Sender: TObject; var Key: Char);
    procedure Scheppen(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

IMPLEMENTATION

{$R *.dfm}

var
  veel : integer;
  r : double;

procedure proef;
const
  dik : integer = 3;
var
  a,l2,l3,lr : double;
  m,n : integer;
begin
  with Form1.Image1.Canvas do
  begin
    Brush.Color := clBlack;
    Pen.Width := 1;
    Pen.Color := clBlack;
  end;
  l2 := ln(2); l3 := ln(3);
  lr := ln(r);
  m := 0; n := 0;
  while true do
  begin
    with Form1.Image1.Canvas do
      Ellipse(x2i(m)-dik,y2j(n)-dik,x2i(m)+dik,y2j(n)+dik);
    if (m > veel) or (n > veel) then Break;
    a := m*l2 - n*l3 - lr;
    if a < 0 then m := m + 1 else n := n + 1;
  end;
end;

procedure tekenen;
var
  i,j : integer;
  x,y : double;
begin
  with Form1.Image1.Canvas do
  begin
    Brush.Color := clWhite;
    Pen.Width := 1;
    Pen.Color := clBlack;
  end;
  for i := 0 to veel do
  begin
    for j := -10 to veel-10 do
    begin
      with Form1.Image1.Canvas do
      Ellipse(x2i(i)-2,y2j(j)-2,x2i(i)+2,y2j(j)+2);
    end;
  end;
  with Form1.Image1.Canvas do
  begin
    Pen.Width := 2;
    Pen.Color := clYellow;
    MoveTo(x2i(0),y2j(ymin));
    LineTo(x2i(0),y2j(ymax));
    MoveTo(x2i(xmin),y2j(0));
    LineTo(x2i(xmax),y2j(0));
    Pen.Color := clRed;
    y := -ln(r)/ln(3);
    MoveTo(x2i(0),y2j(y));
    x := xmax;
    y := ln(2)/ln(3)*x - ln(r)/ln(3);
    LineTo(x2i(x),y2j(y));
  end;
  proef;
end;

procedure TForm1.Toetsdruk(Sender: TObject; var Key: Char);
{
  Inactive
}
var
  x,y : double;
begin
  with Form1.Image1.Canvas do
  begin
    Pen.Color := clBlue;
    y := -ln(r)/ln(3)+1;
    MoveTo(x2i(0),y2j(y));
    x := xmax;
    y := ln(2)/ln(3)*x - ln(r)/ln(3)+1;
    LineTo(x2i(x),y2j(y));
    y := -ln(r)/ln(3)-ln(2)/ln(3);
    MoveTo(x2i(0),y2j(y));
    x := xmax;
    y := ln(2)/ln(3)*x - ln(r)/ln(3)-ln(2)/ln(3);
    LineTo(x2i(x),y2j(y));
  end;
  Form1.Image1.Picture.SaveToFile('unit13a.bmp');
end;

procedure TForm1.Scheppen(Sender: TObject);
{
  At moment of creation
}
begin
  veel := 50; r := 100;
  xmin := 0; xmax := veel;
  ymin := -10 ; ymax := veel-10;
  TV(Form1.Image1);
  ClearDevice;
  tekenen;
  Form1.Image1.Picture.SaveToFile('unit13.bmp');
end;

END.