(PECL ps >= 1.1.0)
ps_circle — Draws a circle
$psdoc,$x,$y,$radius
Draws a circle with its middle point at (x,
y). The circle starts and ends at position
(x+radius,
y). If this function is called outside a path it
will start a new path. If it is called within a path it will add the circle
as a subpath. If the last drawing operation does not end in point
(x+radius,
y) then there will be a gap in the path.
psdocResource identifier of the postscript file as returned by ps_new().
xThe x-coordinate of the circle's middle point.
yThe y-coordinate of the circle's middle point.
radiusThe radius of the circle
成功時(shí)返回 true， 或者在失敗時(shí)返回 false。