AddCircleToPath(id, xc, yc, radius)
ycarguments. The circle's radius has to be passed in the fourth argument.
AddCircleToPath() only starts a new subpath in case there is no
active subpath. Otherwise it will simply connect its vertices to the currently
active subpath. If you don't want this, you'll have to manually open a new
subpath before calling
AddCircleToPath() also won't
close the active subpath when it is finished.