unit Unit6;
{
This software has been designed and it is
CopyLefted by Han de Bruijn:

                          (===)
                         @-O^O-@
                          #/_\#
                           ###
Just ONE Voronoi region
-----------------------
}
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;
    c : TColor;
  end;
  vlak = array of punt;

function Kleur : TColor;
{
  Generates random color
}
var
  even,k : byte;
  effe : Tcolor;
begin
  effe := 0;
  for k := 1 to 3 do
  begin
    even := Round(255*(Random));
    effe := (effe shl 8) or even;
  end;
  Kleur := $00000000 or effe;
end;

procedure tekenen(N : integer);
{
  Draw Image
}
const
  d : integer = 3;
var
  i,j,k,L : integer;
  rij : vlak;
  xm,ym,t,x,y,x1,x2,y1,y2,f : double;
  OK : boolean;
begin
{ Random Sites }
  SetLength(rij,N);
  Random; Random; Random; Random;
  Form1.Image1.Canvas.Brush.Color := clBlack;
  for k := 0 to N-1 do
  begin
    rij[k].x := Random;
    rij[k].y := Random;
    i := x2i(rij[k].x);
    j := y2j(rij[k].y);
    if k > 0 then
    Form1.Image1.Canvas.Ellipse(i-d,j-d,i+d,j+d);
  end;
{ Site has random color }
  for k := 0 to N-1 do
  begin
    rij[k].c := Kleur;
  end;
{ Consider region at site (0) }
  i := x2i(rij[0].x);
  j := y2j(rij[0].y);
  Form1.Image1.Canvas.Ellipse(i-5,j-5,i+5,j+5);
  t := sqrt(sqr(xmax-xmin)+sqr(ymax-ymin));
  for i := 0 to 0 do
  begin
  { Draw Perpendicular Bisectors }
    for j := i+1 to N-1 do
    begin
      xm := (rij[i].x+rij[j].x)/2;
      ym := (rij[i].y+rij[j].y)/2;
      k := x2i(xm-t*(rij[j].y-rij[i].y));
      L := y2j(ym+t*(rij[j].x-rij[i].x));
      Form1.Image1.Canvas.MoveTo(k,L);
      k := x2i(xm+t*(rij[j].y-rij[i].y));
      L := y2j(ym-t*(rij[j].x-rij[i].x));
    { with color belonging to site (j) }
      Form1.Image1.Canvas.Pen.Color := rij[j].c;
      Form1.Image1.Canvas.LineTo(k,L);
    end;
  end;
{ Loop through all pixels }
  for j := 0 to Hoog-1 do
  begin
    y := j2y(j);
    for i := 0 to Wijd-1 do
    begin
      x := i2x(i);
      OK := true;
    { Voronoi region (0) definition }
      for k := 0 to 0 do
      begin
        for L := k+1 to N-1 do
        begin
          x1 := rij[k].x; y1 := rij[k].y;
          x2 := rij[L].x; y2 := rij[L].y;
        { with Perpendicular Bisectors }
          xm := (x1+x2)/2; ym := (y1+y2)/2;
          f := (x-xm)*(x2-x1)+(y-ym)*(y2-y1);
          OK := OK and (f < 0);
        end;
      end;
      if OK then Form1.Image1.Canvas.Pixels[i,j] := clRed;
    end;
  end;
  i := x2i(rij[0].x);
  j := y2j(rij[0].y);
  Form1.Image1.Canvas.Pen.Color := clBlack;
  Form1.Image1.Canvas.Ellipse(i-5,j-5,i+5,j+5);
  for i := 0 to 0 do
  begin
  { Draw radii from (i) to (j) }
    for j := i+1 to N-1 do
    begin
      k := x2i(rij[i].x);
      L := y2j(rij[i].y);
      Form1.Image1.Canvas.MoveTo(k,L);
      k := x2i(rij[j].x);
      L := y2j(rij[j].y);
    { with color belonging to site (j) }
      Form1.Image1.Canvas.Pen.Color := rij[j].c;
      Form1.Image1.Canvas.LineTo(k,L);
    end;
  end;
end;

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

procedure TForm1.Scheppen(Sender: TObject);
{
  At moment of creation
}
begin
  xmin := 0; xmax := 1;
  ymin := 0; ymax := 1;
  TV(Form1.Image1);
  ClearDevice;
  Tekenen(25);
  Form1.Image1.Picture.SaveToFile('voronoi.bmp');
end;

END.