This adds a public function to get the bounds of the current clipped
redraw on a stage. This should only be called while the stage is being
painted. The function diverts to a virtual function on the
ClutterStageWindow implementation. If the function isn't implemented
or it returns FALSE then the entire stage is reported. The clip bounds
are in integer pixel coordinates in the stage's coordinate space.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2421
Cogl recently renamed symbols with the form
cogl_onscreen_<platform>_blah to be consistent with other platform
specific APIs so they are now named like cogl_<platform>_onscreen_blah.
This makes the corresponding change to clutter.
Some parts of the StageWindow interface aren't meaningful for all window
systems. This makes stage_window_set_title/fullscreen/cursor_visible
optional instead of requiring those window systems to implement empty
stubs. Notably the empty stubs we had in the Cogl backend (previously
the EGL backend) used g_warning to report the feature as unsupported and
that was causing conformance test failures.
Since GLX and EGL are abstracted by Cogl the two backends are both
implementing everything using the Cogl API and they are almost
identical.
This updates the egl backend to support everything that the glx backend
supports. Now that EGL and GLX are abstracted by Cogl, the plan is that
we will squash the clutter-egl/glx backends into one. Since the EGL
backend in clutter can conditionally not depend on X11 we will use the
EGL backend as the starting point of our common backend.
https://bugzilla.gnome.org/show_bug.cgi?id=649826
