Fill in unused bits so they can be used for the depth-32 target case.

Fill in unused bits so they can be used for the depth-32 target case.

2005-05-09  Owen Taylor  <otaylor@redhat.com>

        * gdk/gdkrgb.c (gdk_rgb_convert_0888_br, gdk_rgb_convert_8880_br):
        Fill in unused bits so they can be used for the depth-32 target case.
        Rewrite so that that gives a marginal speedup rather than a
        marginal slowdown. (on x86)

        * gdk/gdkscreen.h gdk/x11/gdkscreen-x11.[ch] gdk/x11/gdkvisual-x11.c:
        Add gdk_screen_get_rgba_colormap/visual to get a visual for
        windows with an alpha channel, if one exists.

        * gdk/win32/gdkscreen-win32.c gdk/linux-fb/gdkscreen-fb.c:
        Stub out gdk_screen_get_rgba_colormap/visual.

        * gdk/x11/gdkcolor-x11.c (gdk_colormap_alloc_colors): computation of
        "unused" wasn't right for depth == 32, since it depended on
        shifting by 32.

        * gdk/gdkrgb.c: Fill in alpha bits with 1s. (Based on patch from
        Keith Packard,
        http://mail.gnome.org/archives/gtk-devel-list/2004-June/msg00080.html)

        * gdk/x11/gdkdrawable-x11.c (gdk_x11_drawable_get_picture):
        Implement again, without using Xft.

        * tests/testgtk.c: Add a test for windows with an alpha channel.