set-arc in region%
Sets the region to the interior of the specified wedge.
See also
draw-ellipse in dc<%>, since the region content is determined the same way as brush-based
filling in a dc<%>.
The result is reliable for both unsmoothed and smoothed drawing. For
smoothed drawing, the region corresponds to a clockwise path with a
'winding fill. The region is also atomic for the
purposes of region combination.
(-> voidsenda-regionset-arcxywidthheightstart-radiansend-radians)
x: real number
y: real number
width: non-negative real number
height: non-negative real number
start-radians: real number
end-radians: real number