aferrero2707/PhotoFlow — pull request #2 by jcupitt (2014-01-30 14:52:30+00:00)
Title: Display patch 2

- disable the backing pixmap and double-buffering, we get a better
result doing this ourselves

- fix up vips reference counting within imagearea

- use the vips_sink_screen() mask image to suppress painting of
uncalculated pixels

this fixes the nasty black "flash" we used to get when a toggle on the
right was changed

- remove the invalidate stuff again, vips-7.39+ does not need this

unless you use git master vips you'll see black pixels

add a couple of vips_image_invalidate_all() calls for earlier vipses