Unit VirCircle;


interface


uses Graphics, Graph, VirPoint;


type
//******************************************************************************
//odvozena trida od Point, definuje kruznici
//******************************************************************************
  TVirCircle = class (TVirPoint)
  protected
    R: Integer;
  public
    constructor Create(Xi, Yi, Ri : Integer);
    procedure Grow(E: Integer); virtual;
    procedure Move; override;
    procedure Draw; override;
  end;

implementation


//******************************************************************************
//
//******************************************************************************
constructor TVirCircle.Create(Xi, Yi, Ri: Integer);
begin
  inherited Create(Xi, Yi);
  R := Ri;
end;

//******************************************************************************
//
//******************************************************************************
procedure TVirCircle.Grow(E: Integer);
begin
  R := R + E;
  if R > 50 then R := 0;
end;

//******************************************************************************
//
//******************************************************************************
procedure TVirCircle.Move;
begin
  inherited Move;
  Grow(random(3));
end;

//******************************************************************************
//
//******************************************************************************
procedure TVirCircle.Draw;
begin
  Graph.Canvas.Pen.Color:=$ff0000;
  Graph.Canvas.Ellipse(X-R, Y-R, X+R, Y+R);
end;

end.