All OS filled polygon

[ozzie]

I'm wanting to draw 5-sided pointers for my own sliders, but can't find any easy way to provide this, especially as I want to support Mac OS X and Linux platforms as well as Windows. A Polygon function would be very useful.

Mike

[Little John]

A Polygon function would be very useful.

We can easily write it ourselves (PB 4.20, tested on Windows, should be x-plat):

Code: Select all

EnableExplicit

Macro Ubound (array)
   (PeekL(@array-8)-1)
EndMacro

Structure point_xy
   x.l
   y.l
EndStructure


Procedure Polygon (points.point_xy(1), color.l, connect.l=#True)
   Protected i

   For i = 1 To Ubound(points())
      LineXY(points(i-1)\x, points(i-1)\y, points(i)\x, points(i)\y, color)
   Next
   If connect
      LineXY(points(Ubound(points()))\x, points(Ubound(points()))\y, points(0)\x, points(0)\y, color)
   EndIf
EndProcedure


;-- Demo
Dim points.point_xy(4)

points(0)\x = 40: points(0)\y = 40
points(1)\x = 50: points(1)\y = 60
points(2)\x = 70: points(2)\y = 60
points(3)\x = 60: points(3)\y = 30
points(4)\x = 50: points(4)\y = 30

Define width.l, height.l, color.l, event.l
Width = 100
Height = 100
Color = 0

If OpenWindow(0, 0, 0, Width, Height, "Polygon", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
   If StartDrawing(WindowOutput(0))
      Polygon(points(), color, #False)
      StopDrawing()
   EndIf

   Repeat
      Event = WaitWindowEvent()
   Until Event = #PB_Event_CloseWindow
EndIf

Regards, Little John

[ozzie]

Thanks, Little John. That helps, but doesn't give me a filled polygon. I note that the box, circle and ellipse commands all provide filled drawings. With your demo I can add a FillArea command to fill the polygon, but that relies on the area within the polygon not currently contain any instance of the border color.

Mike

[Little John]

With your demo I can add a FillArea command to fill the polygon,

Yes, that was my idea.

but that relies on the area within the polygon not currently contain any instance of the border color.

Ooops. Didn't think of that. Then I also would like to have a built-in polygon command with the mentioned capabilities.

Regards, Little John

[Seymour Clufley]

+1