unit Unit1;

{$mode objfpc}{$H+}

interface

uses

  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, ExtCtrls,

  Math;

type

  { TForm1 }

  TForm1 = class(TForm)

    Timer1: TTimer;

    procedure FormCreate(Sender: TObject);

    procedure FormPaint(Sender: TObject);

    procedure Timer1Timer(Sender: TObject);

  private

    { private declarations }

  public

    { public declarations }

  end;

const

  starsCount = 200;

var

  Form1: TForm1;

  sx: array [0..starsCount] of integer;

  sy: array [0..starsCount] of integer;

  sz: array [0..starsCount] of integer;

implementation

{$R *.lfm}

procedure TForm1.FormCreate(Sender: TObject);

var

  i : integer;

begin

  for i := 0 to starsCount-1 do begin

    sx[i] := Random(ClientWidth);

    sy[i] := Random(ClientHeight);

    sz[i] := RandomRange(1, 10);

  end;

end;

procedure TForm1.Timer1Timer(Sender: TObject);

var

  i: integer;

begin

  for i := 0 to starsCount-1 do begin

    sx[i] := sx[i] - sz[i];

    if sx[i] < 0 then begin

      sx[i] := ClientWidth;

      sy[i] := Random(ClientHeight);

      sz[i] := RandomRange(1, 10);

    end;

  end;

  Refresh;

end;

procedure TForm1.FormPaint(Sender: TObject);

var

  i: integer;

begin

  for i := 0 to starsCount-1 do begin

    Canvas.Pixels[ sx[i], sy[i] ] := clWhite;

  end;

end;

end.