🚀 go-pugleaf

I wish one could do something to an extension in screen coordinates.
Something like
    Extension::increment(
	Coord xbegin_increment,
	Coord xend_increment,
	Coord ybegin_increment,
	Coord ybegin_increment
    );
					
My problem is that vertical and horizontal lines sometimes don't get
drawn because their x or y allocation is 0 and it is difficult to
take the width into account (especially during a requisition) because
the glyphs are relative to model coordinates.