A clutter actor might be painted on a stage view with a view scale
other than 1. In this case, to show the content in full resolution, the
actor must use a higher resolution resource (e.g. texture), which will
be down scaled to the stage coordinate space, then scaled up again to
the stage view framebuffer scale.
Use a 'resource-scale' property to save information and notify when it
changes.
The resource scale is the ceiled value of the highest stage view scale a
actor is visible on. The value is ceiled because using a higher
resolution resource consistently results in better output quality. One
reason for this is that rendering is often not perfectly pixel aligned,
meaning even if we load a resource with a suitable size, due to us still
scaling ever so slightly, the quality is affected. Using a higher
resolution resource avoids this problem.
For situations inside clutter where the actual maximum view scale is
needed, a function _clutter_actor_get_real_resource_scale() is provided,
which returns the non-ceiled value.
Make sure we ignore resource scale computation requests during size
requests or allocation while ensure we've proper resource-scale on
pre-paint.
https://bugzilla.gnome.org/show_bug.cgi?id=765011https://gitlab.gnome.org/GNOME/mutter/merge_requests/3
This is an ABI break, hopefully an unimportant one since this signal/vmethod
is barely overridden.
The signal has been added an extra ClutterPaintVolume argument, and has been
given a boolean return value. The recursion to the parents has been taken
out of the default implementation and into the caller, using the returned
boolean parameter to control further propagation.
Passing the ClutterPaintVolume is easier on performance, as we don't need
setting this pointer as gobject data just to retrieve/unset it further
in propagation.
https://bugzilla.gnome.org/show_bug.cgi?id=782344
