procedure TForm1.Demo_TgtPDFPolygonAnnot;
var
  gtPDFPolygonAnnot1: TgtPDFPolygonAnnot;
  arrVertices: Array [0 .. 4] of TgtPoint;
  i: Integer;
  gtPDFEngine1: TgtPDFEngine;
begin
  gtPDFEngine1 := TgtPDFEngine.Create(Nil);

  // Specify coordinate of vertices
  arrVertices[0].X := 4;
  arrVertices[0].Y := 1;
  arrVertices[1].X := 5;
  arrVertices[1].Y := 2;
  arrVertices[2].X := 6;
  arrVertices[2].Y := 3;
  arrVertices[3].X := 2;
  arrVertices[3].Y := 2;
  arrVertices[4].X := 1;
  arrVertices[4].Y := 1;

  // Create a polygon annotation with the vertices
  gtPDFPolygonAnnot1 := TgtPDFPolygonAnnot.Create;
  gtPDFPolygonAnnot1.SetVertices(arrVertices);
  gtPDFPolygonAnnot1.InteriorColor := clYellow;
  gtPDFPolygonAnnot1.BorderColor := clRed;
  gtPDFPolygonAnnot1.BorderStyle := brDashed;
  gtPDFPolygonAnnot1.BorderWidth := 3;
  gtPDFPolygonAnnot1.Title := 'Polygon annotation demo';
  gtPDFPolygonAnnot1.Contents :=
      'The first and last vertices are connected to make a closed figure.';


  with gtPDFEngine1 do
  begin
    Preferences.ShowSetupDialog := False;
    Preferences.OpenAfterCreate := True;
    FileName := 'polygon_annotation.pdf';

    BeginDoc; // Create a PDF document
    // Add the annotation to the current page
    AddAnnotItem(gtPDFPolygonAnnot1);
    EndDoc; // Save the PDF document
  end;
end;