Сделать на форме произвольный многоугольник, на вершины которого можно кликнуть и перетащить их, изменив его форму - Delphi - Ответ 13927667

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    procedure FormCreate(Sender: TObject);
    procedure FormPaint(Sender: TObject);
    procedure FormMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure FormMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    pol: array of TPoint;
    cpoint: integer;
    polcol: TColor;
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.FormCreate(Sender: TObject);
var
  i, r, vcnt: integer;
begin
  r := 100;
  vcnt := 5;
  SetLength(pol, vcnt);
  for i := 0 to High(pol) do begin
    pol[i].X := 500 + round(r * cos(i*2*pi/vcnt));
    pol[i].Y := 250 - round(r * sin(i*2*pi/vcnt));
  end;
  cpoint := -1;
  polcol := clBtnFace;
end;
 
procedure TForm1.FormPaint(Sender: TObject);
var
  i: integer;
begin
  Canvas.Brush.Color := polcol;
  Canvas.Polygon(pol);
  Canvas.Brush.Color := clRed;
  for i := 0 to High(pol) do
    Canvas.Rectangle(pol[i].X - 5, pol[i].Y - 5, pol[i].X + 5, pol[i].Y + 5);
end;
 
procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  i: integer;
begin
  for i := 0 to High(pol) do begin
    if (PtInRect(Rect(pol[i].X - 5, pol[i].Y - 5, pol[i].X + 5, pol[i].Y + 5), Point(X, Y))) then
      cpoint := i;
  end;
end;
 
procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if cpoint >= 0 then begin
    pol[cpoint].X := X;
    pol[cpoint].Y := Y;
    Repaint;
  end;
end;
 
procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  cpoint := -1;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
begin
  polcol := clBtnFace;
  Repaint;
end;
 
procedure TForm1.Button2Click(Sender: TObject);
begin
  polcol := clYellow;
  Repaint;
end;
 
procedure TForm1.Button3Click(Sender: TObject);
begin
  polcol := clRed;
  Repaint;
end;
 
procedure TForm1.Button4Click(Sender: TObject);
begin
  polcol := clLime;
  Repaint;
end;
 
procedure TForm1.Button5Click(Sender: TObject);
begin
  polcol := clBlue;
  Repaint;
end;
 
end.