unit Unit4;
{
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}

type
  punt = record
    x,y : double;
  end;

function pad(x,y : double) : punt;
{
  Point
}
var
  p : punt;
begin
  p.x := x; p.y := y;
  pad := p;
end;

procedure naar(p : punt);
{
  MoveTo
}
begin
  with Form1.Image1.Canvas do
  begin
    MoveTo(x2i(p.x),y2j(p.y));
  end;
end;

procedure lijn(p : punt);
{
  LineTo
}
begin
  with Form1.Image1.Canvas do
  begin
    LineTo(x2i(p.x),y2j(p.y));
  end;
end;

procedure just_doit;
{
  Make Picture
  & Calculation
}
var
  k,veel : integer;
  L : double;
begin
  ClearDevice;
  with Form1.Image1.Canvas do
  begin
    Pen.Width := 2;
    Pen.Color := clBlack;
  end;
  naar(pad(0,0));
  lijn(pad(1,0));
  lijn(pad(1,1));
  lijn(pad(0,1));
  lijn(pad(0,0));
  with Form1.Image1.Canvas do
    Pen.Color := clRed;
  naar(pad(1,0));
  lijn(pad(1/2,1));
  lijn(pad(0,0));
  with Form1.Image1.Canvas do
    Pen.Color := clGreen;
  veel := Round(arctan(3/4)*180);
  naar(pad(1,0));
  for k := 0 to veel do
  begin
    lijn(pad(cos(k/180),sin(k/180)));
  end;
  naar(pad(0,0));
  for k := 0 to veel do
  begin
    lijn(pad(1-cos(k/180),sin(k/180)));
  end;
  naar(pad(4/5,3/5));
  lijn(pad(1/2,1));
  naar(pad(1-4/5,3/5));
  lijn(pad(1/2,1));
  L := arctan(3/4) + 1/2;
  Writeln('Minimum =',2*L,' >',sqrt(5));
  Form1.Image1.Picture.SaveToFile('einde.bmp');
end;

procedure TForm1.Toetsdruk(Sender: TObject; var Key: Char);
{
  On KeyPress
}
begin
  Exit;
end;

procedure TForm1.Scheppen(Sender: TObject);
{
  At Creation
}
begin
  xmin := -0.1; xmax := 1.1;
  ymin := -0.1; ymax := 1.1;
  TV(Form1.Image1);
  just_doit;
end;

END.