HiDPI and zoom levels interpolation

[François Guerraz <kubrick fgv6 net>]

Hello,

In tracking down bug #770266, I read parts of the code.

After reading eog-scroll-view.c:1409, I wonder if the following is
correct:

        if(!DOUBLE_EQUAL(priv->zoom, 1.0) && priv->force_unfiltered)
        {
                interp_type = CAIRO_FILTER_NEAREST;
                _set_hq_redraw_timeout(view);
        }

Surely "1.0" should be replaced by the inverse of the UI scale factor,
same for the hardcoded "1.0" value in is_zoomed_in().

What do you think?

François.