createCircularRgn

Syntax

region createCircularRgn(int x, int y, int d)

Arguments

x
x defines abscissa (in DBUs) of upper-left corner of the bounding box (not the circle’s center!).
y
y defines ordinate (in DBUs) of upper-left corner of the bounding box (not the circle’s center!).
d
d defines the circle’s diameter

Return

Returns a handle/pointer to a circular region object (see comments)

Description

Allows to define a rounded circular visual region, that can be for instance handled by the functions refreshRgn or setDialogRegion

Example

setDialogRegion(createCircularRgn(20,20,200));

Also see

createEllipticRgn, createRectRgn, createRoundRectRgn, createCircularRgn, createPolyRgn, refreshRgn, setDialogRegion

Comments

"region" correspond to a particular FM type or object that might need to be better documented or defined. You can't directly cast it to an integer, despite it behaves like an integer.
createCircularRgn is a wrapper around the Windows Win32 built-in function CreateEllipticRgn, documented here: https://msdn.microsoft.com/en-us/library/windows/desktop/dd183496(v=vs.85).aspx