Learn more about GDI + [32]: tgppen-corner length limit-setmiterlimit

The default value of the corner length limit is 10.0, which is generally enough.
In this example:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls, comctrls; Type tform1 = Class (tform) trackbar1: ttrackbar; procedure alert (Sender: tobject); Procedure listbox1click (Sender: tobject); Procedure trackbar1change (Sender: tobject); Procedure alert (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} uses gdipobj, gdipapi; Procedure upload (Sender: tobject); begin trackbar1.showselrange: = false; trackbar1.height: = 20; trackbar1.min: = 0; trackbar1.max: = 100; trackbar1.position: = trackbar1.max; end; Procedure tform1.formpaint (Sender: tobject); const ptarr: array [0 .. 2] of tgppoint = (X: 90; Y: 80), (X: 240; Y: 30), (X: 240; Y: 80); var G: tgpgraphics; P: tgppen; begin G: = tgpgraphics. create (canvas. handle); P: = tgppen. create (aclseagreen, 28); p. setmiterlimit (trackbar1.position/10); G. drawpolygon (p, pgppoint (@ ptarr), length (ptarr); p. free; G. free; end; Procedure tform1.listbox1click (Sender: tobject); begin repaint; end; Procedure tform1.trackbar1change (Sender: tobject); begin repaint; end.
 
   
 

Form file:

 
Object form1: tform1 left = 0 Top = 0 caption = 'form1' clientheight = 138 clientwidth = 266 color = clbtnface font. charset = default_charset font. color = clwindowtext font. height =-11 font. name = 'tahoma 'font. style = [] oldcreateorder = false position = pow.topcenter oncreate = formcreate onpaint = formpaint pixelsperinch = 96 textheight = 13 object trackbar1: ttrackbar left = 2 Top = 112 width = 261 Height = 45 taborder = 0 onchange = trackbar1change endend