Compositors need more detailed information about motion events. Make it
possible to retrieve this information when running the evdev backend by
adding the information to the backend specific event struct.
https://bugzilla.gnome.org/show_bug.cgi?id=752752
Since commit 6183eb3632 we disabled swap
throttling in favour of being driven by the GDK frame clock (and thus by
the compositor).
Compositors may decide to unredirect full screen windows to avoid the
performance penalty of the additional copy, especially on X11, which
means that a Clutter application marked as full screen is not going to
be driven by the compositor, and it's not going to be throttled by the
underlying GL machinery. This has a performance impact on constrained
platforms.
For this reason, we should re-enable swap throttling when the window is
full screen.
As the change was introduced especially because of Wayland, we should
check that we're not running as clients under a Wayland compositor; if
we do, we always keep swap throttling disabled, as the compositor will
always manage our output, even when full screen.
Those can be used to implement different scrolling behaviors.
The fields have been added to ClutterScrollEvent itself. According
to pahole, this makes the struct as big as ClutterButtonEvent and
ClutterTouchEvent, so already at the limit of the ClutterEvent
union.
https://bugzilla.gnome.org/show_bug.cgi?id=757026
So that we can set it to 'check', and do configure-time discovery of the
dependencies, instead of enabling it explicitly.
This should make it easier to spot build issues on environments like
Continuous, which build Clutter and Cogl for running as part of the
display server infrastructure on Wayland.
We should allow a configuration file to set up the initial state of the
global state, which also implies being able to set the backend.
If the allowed backends have already been set programmatically via the
clutter_set_windowing_backend(), though, then the application code takes
precedence, as we assume that the application author knows better than
us what their code supports or requires.
The configuration file should set up the global state before we
initialize it; instead of relying on implicit ordering, explicitly read
the configuration file once, when creating the global shared context
data structure.
Like CLUTTER_DRIVER, we want to allow users to specify a list of
backends to test, and fall back to the internally defined priority as a
default.
This requires changing the way the allowed backend string is parsed,
both for the CLUTTER_BACKEND environment variable and for the
clutter_set_windowing_backend() function. Existing callers are still
supported with the exact same semantics.
Using environment variables only is not convenient for all platforms,
and in some cases it's beneficial to decide the default driver when
building Clutter. Cogl already has a similar configuration switch, and
since Clutter is overriding the default Cogl behaviour, it should offer
the same mechanism.
https://bugzilla.gnome.org/show_bug.cgi?id=742678
We have an hardcoded list of drivers we have to go through when creating
a Cogl context. Some platforms may expose those drivers, but not be the
preferred ones.
In order to allow users and system integrators to override the list of
drivers, we should crib the same approach used by GDK, and have an
environment variable with a list of drivers to try.
The new environment variable is called `CLUTTER_DRIVER` and accepts a
comma-separated list of driver names, which will be tested in sequence
until one succeeds. There's also an additional '*' token which is used
to ask Clutter to fall back to the internally defined preferred list of
drivers.
https://bugzilla.gnome.org/show_bug.cgi?id=742678
