(v13) 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.