Learn more about GDI + [52]: Path-reverse, reset

In this example:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls; Type tform1 = Class (tform) checkbox1: tcheckbox; checkbox2: tcheckbox; procedure alert (Sender: tobject); Procedure checkbox1click (Sender: tobject); Procedure checkbox2click (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} uses gdipobj, gdipapi; var PTS: array [0 .. 6] of tgppoint; Procedure tform1.formcreate (Sender: tobject); begin PTS [0]. x: = 10; PTS [0]. y: = 50; PTS [1]. x: = 40; PTS [1]. y: = 90; PTS [2]. x: = 80; PTS [2]. y: = 10; PTS [3]. x: = 110; PTS [3]. y: = 50; PTS [4]. x: = 140; PTS [4]. y: = 10; PTS [5]. x: = 180; PTS [5]. y: = 90; PTS [6]. x: = 210; PTS [6]. y: = 50; checkbox1.caption: = 'point in the flipped path'; checkbox2.caption: = 'clear vertex in the path'; end; Procedure tform1.formpaint (Sender: tobject); var G: tgpgraphics; p: tgppen; Path: tgpgraphicspath; pathpts: array of tgppoint; I: integer; begin G: = tgpgraphics. create (canvas. handle); P: = tgppen. create (aclred, 2); Path: = tgpgraphicspath. create; Path. addbeziers (pgppoint (@ PTS), length (PTS); If checkbox1.checked then path. reverse; If checkbox2.checked then path. when reset; {reset, The pathpoints and pathtypes arrays are cleared and the fillmode is set to fillmodealternate} setlength (pathpts, path. getpointcount); Path. getpathpoints (pgppoint (pathpts), length (pathpts); canvas. pen. color: = clgray; for I: = low (pathpts) to high (pathpts) Do canvas. textout (pathpts [I]. x, pathpts [I]. y, inttostr (I + 1); G. drawpath (p, PATH); Path. free; p. free; G. free; end; Procedure tform1.checkbox1click (Sender: tobject); begin repaint; end; Procedure tform1.checkbox2click (Sender: tobject); begin repaint; end.
 
   
 

Form file:

 
Object form1: tform1 left = 0 Top = 0 caption = 'form1' clientheight = 156 clientwidth = 232 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 checkbox1: tcheckbox left = 12 Top = 126 width = 113 Height = 17 caption = 'checkbox1' taborder = 0 onclick = checkbox1click end object checkbox2: tcheckbox left = 123 Top = 126 width = 106 Height = 17 caption = 'checkbox2 'taborder = 1 onclick = checkbox2click endend