TIECanvas.PolylineD

Declaration

procedure PolylineD(Points: array of TDPoint; PolylineClosed: Boolean = False);

Description

Draw a series of joined lines specified by multiple points.
If PolylineClosed = True, then it performs a PolygonD

Note:
◼For a TPoint version use, Polyline
◼For advanced polygon drawing, use AdvancedDrawPolyline
◼You can create multiple polylines by specifying a break of point($FFFFF, $FFFFF), or point($FFFEE, $FFFEE) if the break should close the polygon (i.e. with PolylineClosed=False, you can optionally close polylines)

GDI+ Method: GdipDrawLines

Examples

// Draw a 5-pointed star
var
  pp: array[0..10] of TDPoint;
begin
  ImageEnView1.IEBitmap.IECanvas.Pen.Color := clOrangeRed;
  ImageEnView1.IEBitmap.IECanvas.Pen.Width := 3;


  pp[0]  := DPoint(175, 50);
  pp[1]  := DPoint(205, 145);
  pp[2]  := DPoint(300, 145);
  pp[3]  := DPoint(225, 205);
  pp[4]  := DPoint(252.5, 300);
  pp[5]  := DPoint(175, 242.5);
  pp[6]  := DPoint(97.5, 300);
  pp[7]  := DPoint(127.5, 205);
  pp[8]  := DPoint(50, 145);
  pp[9]  := DPoint(147.5, 145);
  pp[10] := DPoint(175, 50);

  ImageEnView1.IEBitmap.IECanvas.PolylineD(pp);
  ImageEnView1.Update();
end;


// Draw an arrow at the end of a line that runs from x1, y1 to x2, y2
procedure IEDrawLineArrow(Canvas: TIECanvas; x1, y1, x2, y2: integer; w, h: integer);
const
  A90 = PI / 2;
var
  aa, bb, hw: double;
  pp: array[0..2] of TPoint;
  p1x, p1y: integer;
begin
  with Canvas do
  begin
    hw := w / 2;
    aa := IEAngle(x1, y1, x2, y2, x1, y2);
    if x1 = x2 then
      if y1 < y2 then
        aa := -A90
      else
        aa := A90;
    if ((x1 > x2) and (y2 < y1)) or ((x1 < x2) and (y1 < y2)) then
      bb := 2 * pi - aa + A90
    else
      bb := aa + A90;
    if ((x2 < x1) and (y2 > y1)) or ((x2 < x1) and (y2 < y1)) or ((x1 < x2) and (y1 = y2)) then
    begin
      p1x := x1 + trunc(cos(bb - A90) * h);
      p1y := y1 + trunc(sin(bb - A90) * h);
    end
    else
    begin
      p1x := x1 + trunc(cos(bb + A90) * h);
      p1y := y1 + trunc(sin(bb + A90) * h);
    end;

    pp[0].x := p1x + trunc(cos(bb) * hw);
    pp[0].y := p1y + trunc(sin(bb) * hw);
    pp[1].x := p1x + trunc(cos(bb + pi) * hw);
    pp[1].y := p1y + trunc(sin(bb + pi) * hw);
    pp[2].x := x1;
    pp[2].y := y1;

    PolylineD(pp);
  end;
end;

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