Add MutterTextureTower, an abstraction for getting a image with
the right level of detail for rendering at a particular scale,
by manually scaling down by powers of two.
This results in much better looking scaled window images when
mipmaps can't be used with texture_from_pixmap (which is the
typical case for current GL drivers.)
When framebuffer objects are available, they are used to do
the scaledown using the GPU without having to pull the data
back from video memory. A software codepath is also available
for the case when FBO's are not present, though performance
will suffer
https://bugzilla.gnome.org/show_bug.cgi?id=601032
When we are painting a stack of 5-10 maximized windows, the
standard bottom-to-top method of drawing every actor results
in a tremendous amount of overdraw and can easily max out
the available memory bandwidth on a low-end* graphics chipset.
It's even worse if window textures are being accessed over
the AGP bus.
When we have opaque windows, we can go ahead and compute visibility
ourselves (in classic X-server fashion) and use that information to
restrict drawing obscured actors.
* Add MutterWindowGroup - a ClutterGroup subclass with logic
for figuring out obscured regions.
* Add mutter_window_get_obscured_region() to get the region
obscured by that window.
* Add mutter_shaped_texture_set_clip_region() to hint
a clip region to the painting code; this is set based on
the computed visible region of MutterWindowGroup.
* Add tidy_texture_frame_set_needs_paint() to hint that the
paint can be skipped entirely; this is used when we detect
that the window shadow is entirely obscured.
http://bugzilla.gnome.org/show_bug.cgi?id=587344
Mutter is a Clutter-based compositing manager. So, remove the code for
the XRender-based compositor, and make it mandatory to have XComposite,
XRender and Clutter.
Run-time support for non-composited operation is left for now.
* src/compositor/mutter/: Move files from this subdirectory into
the main compositor/ directory.
* compositor/compositor-xrender.ccompositor/compositor-xrender.h:
Remove
* include/compositor-clutter.h: Remove this stray file, it had been
replaced with compositor-mutter.h some time back.
http://bugzilla.gnome.org/show_bug.cgi?id=581813
