unit Unit0;
{
  This software has been designed and is CopyLefted
  by Han de Bruijn
                     (===)
                    @-O^O-@
                     #/_\#
                      ###

  All I ask is to be credited when it is appropriate.

  Main unit for Project0
  ======================
}
interface

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

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}

const
  N = 14;
  rij : array[0..N] of integer = { Star positions }
  (  0, 30, 60, 90,120,135,150,165,180,210,240,270,300,330,360);
  hel : array[0..N] of integer = { Star luminosity }
  ( 10, 14, 18, 22, 26, 28, 30, 28, 26, 22, 18, 14, 10,  6, 10);
  {  0, 30, 60, 90,120,135,150,165,180,210,240,270,300,330,360}
var
  x,y : array of double;
  tel : integer;
  beeld : array of array of double;
  max : double;

procedure cirkel;
{
  Coordinates of Circle
}
var
  k : integer;
begin
  SetLength(x,N+1);
  SetLength(y,N+1);
  for k := 0 to N do
  begin
    x[k] := cos(rij[k]*Pi/180);
    y[k] := -sin(rij[k]*Pi/180);
  end;
end;
  
procedure Schetsen;
{
  First picture
}
var
  i,j,k : integer;
begin
  cirkel;
  for k := 0 to N do
  begin
    i := x2i(x[k]); j := y2j(y[k]);
    with Form1.Image1.Canvas do
    begin
      MoveTo(i,j);
      Brush.Color := Grijs(hel[k]/30);
      Pen.Color := Grijs(hel[k]/30);
      Ellipse(i-5,j-5,i+5,j+5);
    end;
  end;
end;

function P(r,d : double) : double;
{
  Fuzzy Optics @
  http://www.alternatievewiskunde.nl/MijnBoek/vaagzien.htm
}
begin
  P := d/(2*Pi*(r*r+d*d)*sqrt(r*r+d*d));
end;

procedure starten(var sigma : double);
{
  Determine Fuzzyness
}
var
  k : integer;
  alpha,hoek,dt : double;
begin
  alpha := sqrt(2*ln(512));
  hoek := 0;
  for k := 0 to N-1 do
  begin
    dt := (rij[k+1]-rij[k])*Pi/180;
    if dt > hoek then hoek := dt;
  end;
  sigma := 2*sin(hoek/2)/(2*Pi)*alpha*1.5;
end;

procedure VaagZien;
{
  Second picture =
  fuzzyfication of first one
}
var
  i,j,k : integer;
  a,b,r,d : double;
begin
  starten(d);
  max := 0;
  for k := 0 to N do
  begin
    for j := 0 to Hoog-1 do
    begin
      for i := 0 to Wijd-1 do
      begin
        a := i2x(i); b := j2y(j);
        r := sqrt((a-x[k])*(a-x[k])+(b-y[k])*(b-y[k]));
        beeld[i,j] := beeld[i,j] + hel[k]*P(r,d);
        if beeld[i,j] > max then max := beeld[i,j];
      end;
    end;
  end;
  for i := 0 to Wijd-1 do
  for j := 0 to Hoog-1 do
    Form1.Image1.Canvas.Pixels[i,j] := Grijs(1-beeld[i,j]/max);
end;

procedure TForm1.Toetsdruk(Sender: TObject; var Key: Char);
{
  On KeyPress
}
begin
  if tel = 0 then
  begin
    ClearDevice;
    Form1.Image1.Canvas.Pen.Width := 2;
    Form1.Image1.Canvas.Pen.Color := clBlack;
    Form1.Image1.Canvas.Brush.Color := clBlack;
    Schetsen;
    Form1.Image1.Picture.SaveToFile('BH1.bmp');
  end;
  if tel = 1 then
  begin
    VaagZien;
    Form1.Image1.Picture.SaveToFile('BH2.bmp');
  end;
  tel := tel+1;
  if tel = 2 then tel := 0;
end;

procedure TForm1.Scheppen(Sender: TObject);
{
  On Create
}
var
  i,j : integer;
begin
  xmin := -1.5; xmax := +1.5;
  ymin := -1.5; ymax := +1.5;
  TV(Form1.Image1);
  ClearDevice;
  tel := 0;
  SetLength(beeld,Wijd,Hoog);
  for i := 0 to Wijd-1 do
  for j := 0 to Hoog-1 do
    beeld[i,j] := 0;
  max := 0;
end;

end.