Add dependency on R 4.2.0 because works with more complex
classes returned by
xyListFromGrob() function to reduce grob (or gTree)
that contains potentially multiple shapes to a single list of sets of
x/y coordinates (for input to polyclip routines).
Makes aliases for
xyListPath() etc named
xyListToPath() etc (to match new
Add dependency on polyclip 1.10-0 because that now supports clipping of "open" polygons (lines). No more need for polyclip fork.
Add dependency on R 3.6.0 because require new