The iclip operator
This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP
internaldict name iclip any
The standard PostScript language operators clip
and eoclip
provide two ways of describing a clipping path (the area to which marks drawn on the page will be restricted). Iclip
offers a third. While clip
and eoclip
constrain the existing clipping area to the intersection of the current path and the existing clipping area, iclip
restricts it to the area enclosed by the current clipping path which is not also enclosed by the current path. The path to be excluded by iclip
is interpreted according to the non-zero winding rule.
This is particularly useful for implementing a “choke”, where one wants to draw a border around an object. The technique is to set the clipping path to the original shape (using clip
). Then use strokepath
with an appropriate line width on the same path. Then use iclip
to restrict further painting to the difference between the two.