Right now this just has all of the files in one directory. We'll
be introducing more structure to this in the future, and build
a proper backend system.
I want the MetaCursorTracker to mostly be about retrieving cursor
information. Start moving the code that loads cursor images to a
new file, MetaCursor. Eventually, MetaCursorTracker's APIs will
all take MetaCursorReferences, and we can have a clean backend
split here.
display.c is getting a bit crowded. Move most of the handling
out to another file, events.c.
The long-term goal is to have generic event handling here, with
backend-specific handling for the types of windows and such.
This is specifically about managing X11 windows, not necessarily
running as an X11 compositor. By that I mean that this code is
still used for XWayland windows, and event handling is still and
modesetting / monitor management is still in core/.
This is also a fairly conservative move. We don't move anything
like screen.c or bell.c in here, even though those are really
only for X11 clients.
This is fairly simple and basic for now, with just skip_taskbar /
skip_pager, but eventually a lot of "WM policy" like this, including
move-resize, will be in subclasses for each individual surface.
The rendering logic before was somewhat complex. We had three independent
cases to take into account when doing rendering:
* X11 compositor. In this case, we're a traditional X11 compositor,
not a Wayland compositor. We use XCompositeNameWindowPixmap to get
the backing pixmap for the window, and deal with the COMPOSITE
extension messiness.
In this case, meta_is_wayland_compositor() is FALSE.
* Wayland clients. In this case, we're a Wayland compositor managing
Wayland surfaces. The rendering for this is fairly straightforward,
as Cogl handles most of the complexity with EGL and SHM buffers...
Wayland clients give us the input and opaque regions through
wl_surface.
In this case, meta_is_wayland_compositor() is TRUE and
priv->window->client_type == META_WINDOW_CLIENT_TYPE_WAYLAND.
* XWayland clients. In this case, we're a Wayland compositor, like
above, and XWayland hands us Wayland surfaces. XWayland handles
the COMPOSITE extension messiness for us, and hands us a buffer
like any other Wayland client. We have to fetch the input and
opaque regions from the X11 window ourselves.
In this case, meta_is_wayland_compositor() is TRUE and
priv->window->client_type == META_WINDOW_CLIENT_TYPE_X11.
We now split the rendering logic into two subclasses, which are:
* MetaSurfaceActorX11, which handles the X11 compositor case, in that
it uses XCompositeNameWindowPixmap to get the backing pixmap, and
deal with all the COMPOSITE extension messiness.
* MetaSurfaceActorWayland, which handles the Wayland compositor case
for both native Wayland clients and XWayland clients. XWayland handles
COMPOSITE for us, and handles pushing a surface over through the
xf86-video-wayland DDX.
Frame sync is still in MetaWindowActor, as it needs to work for both the
X11 compositor and XWayland client cases. When Wayland's video display
protocol lands, this will need to be significantly overhauled, as it would
have to work for any wl_surface, including subsurfaces, so we would need
surface-level discretion.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
The goal here is to make MetaWindow represent a toplevel, managed window,
regardless of if it's X11 or Wayland, and build an abstraction layer up.
Right now, most of the X11 code is in core/ and the wayland code in wayland/,
but in the future, I want to move a lot of the X11 code to a new toplevel, x11/.
Instead of hardcoded knowledge of certain classes in MetaWindowGroup,
create a generic interface that all actors can implement to get parts of
their regions culled out during redraw, without needing any special
knowledge of how to handle a specific actor.
The names now are a bit suspect. MetaBackgroundGroup is a simple
MetaCullable that knows how to cull children, and MetaWindowGroup is the
"toplevel" cullable that computes the initial two regions. A future
cleanup here could be to merge MetaWindowGroup / MetaBackgroundGroup so
that we only have a generic MetaSimpleCullable, and move the "toplevel"
cullability to be a MetaCullableToplevel.
https://bugzilla.gnome.org/show_bug.cgi?id=714706
Instead of having MetaWindowActor only have one single MetaShapedTexture
as actor drawing its content, introduce a new abstract MetaSurfaceActor
that takes care of drawing.
This is one step in the direction to decouple MetaWaylandSurface with a
MetaWindow and MetaWindowActor (except for shell/xdg surfaces) in order
to finally support subsurfaces like features, or any feature where
window is not drawn using a single texture.
The first step, implemented in this patch, is to not have
MetaWindowActor work directly with a shaped texture. There are still
some cases where it simply gets the texture and goes on as before, but
this should be changed by either removing the need of going via
MetaWindowActor or by adding some generic interface to MetaSurfaceActor
that doesn't limit its functionality to one shaped texture.
There should be no visible difference nor after this patch, but
meta_window_actor_get_texture() and meta_surface_actor_get_texture()
should be deprecated when equivalent functionality has been introduced.
Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
https://bugzilla.gnome.org/show_bug.cgi?id=705502
Using the new Cogl API to actually modeset (because we can't
use the DRM API directly without controlling buffer swap), we
can finally have a KMS monitor backend, which means full display
configuration when running on bare metal.
https://bugzilla.gnome.org/show_bug.cgi?id=706308
Switching meta/util.h to gi18n.h was wrong, mutter is a library
and needs gi18n-lib.h, but that cannot be included from a public
header (since it depends on config.h or command line options),
so split util.h into a public and a private part.
https://bugzilla.gnome.org/show_bug.cgi?id=707897
Add a new interface, gtk_shell, than can be used by gtk to
retrieve a surface extension called gtk_surface, which will be
used to communicate with mutter all the GTK extensions to EWMH
https://bugzilla.gnome.org/show_bug.cgi?id=707128
Add support for GTK application menus
To do so, we need to be able to set surface state before creating
the MetaWindow, so we introduce MetaWaylandSurfaceInitialState as
a staging area.
The gtk-shell-surface implementation would either write to the
initial state, or directly to the window.
At the same, implement set_title and set_class too, because it's
easy enough.
https://bugzilla.gnome.org/show_bug.cgi?id=707128
Once mutter is started from weston-launch on its own VT, there is
no way to change VT again (for example to actually start an application),
because the keyboard is put in raw mode.
So introduce some keybindings mimicking the standard X ones (Ctrl+Alt+Fn)
that switch the VT manually when activated.
https://bugzilla.gnome.org/show_bug.cgi?id=705861
Now that we have a setuid launcher binary, we can make use of
using a private protocol through the socket we're passed at startup.
We also use the new hook in clutter-evdev to ask mutter-launch for
the FDs of the input devices we need, and we emulate the old X
DRM lock with a nested GMainContext without sources.
In the future, mutter-launch will be replaced with the new logind
API currently in development.
https://bugzilla.gnome.org/show_bug.cgi?id=705861
Being a setuid binary, our LD_LIBRARY_PATH is cleared by glibc at
startup, but we need the spawned binary to see it, otherwise
jhbuild doesn't work, so hardcode it using the configured libdir.
https://bugzilla.gnome.org/show_bug.cgi?id=705861
To run mutter as a display server, one needs to acquire and
release the DRM master, which is only possible for root, so
we take advantage of weston-launch, a small setuid helper binary
written for the weston project. We import our own slightly
modified copy of it, because weston-launch only launches weston,
for security reasons.
https://bugzilla.gnome.org/show_bug.cgi?id=705861
Modify all visible instances of mutter with mutter-wayland
(libraries, folders, pkgconfig, etc.), so that the wayland
branch can be installed alongside the usual X11 mutter.
https://bugzilla.gnome.org/show_bug.cgi?id=705497
In the wayland branch of mutter, we want to build a wayland version
of the mutter libraries, and that's much easier if we just build
wayland support unconditionally.
The define is kept to avoid a huge diff, but should be removed
in a later patch.
Also, wayland support can still be disable at runtime, by
launching mutter without the --nested switch.
https://bugzilla.gnome.org/show_bug.cgi?id=705497
To allow other clients (gnome-session, gnome-settings-daemon)
to monitor user activity, introduce a DBus interface for the
idle monitor inside mutter.
https://bugzilla.gnome.org/show_bug.cgi?id=706005
When running as a wayland compositor, we can't use the xserver's
IDLETIME, because that's updated only in response to X events.
But we have all the events ourselves, so we can just run the timer
in process.
https://bugzilla.gnome.org/show_bug.cgi?id=706005
Under X, we need to use XFixes to watch the cursor changing, while
on wayland, we're in charge of setting and painting the cursor.
MetaCursorTracker provides the abstraction layer for gnome-shell,
which can thus drop ShellXFixesCursor. In the future, it may grow
the ability to watch for pointer position too, especially if
CursorEvents are added to the next version of XInput2, and thus
it would also replace the PointerWatcher we use for gnome-shell's
magnifier.
https://bugzilla.gnome.org/show_bug.cgi?id=705911
Instead of keeping a forest of if backend else ..., use a subclass
and virtual functions to discriminate between XRandR and the
dummy backend (which lives in the parent class togheter with the
common code)
https://bugzilla.gnome.org/show_bug.cgi?id=705670
Add a new object, MetaMonitorConfig, that takes care of converting
between the logical configurations stored in monitors.xml and
the HW resources exposed by MonitorManager.
This commit includes loading and saving of configurations, but
still missing is the actual CRTC assignments and a default
configuration when none is found in the file.
https://bugzilla.gnome.org/show_bug.cgi?id=705670
This new interface will be used by the control center and possibly
the settings daemon to configure the screens. It is designed to
resemble a simplified XRandR, while still exposing all the quirks
of the hardware, so that the panel can limit the user choices
appropriately.
To do so, MetaMonitorMode needs to track CRTCs, outputs and modes,
so the low level objects have been decoupled from the high-level
MetaMonitorInfo, which is used by core and API and offers a simplified
view of HW, that hides away the details of what is cloned and how.
This is still not efficient as it should be, because on every
HW change we drop all data structures and rebuild them from scratch
(which is not expensive because there aren't many of them, but
at least in the XRandR path it involves a few sync X calls)
https://bugzilla.gnome.org/show_bug.cgi?id=705670
Consolidate all places that deal with output configuration in
MetaScreen, which gets it either from XRandR or from a dummy static configuration.
We still need to read the Xinerama config, even when running xwayland,
because we need the indices for _NET_WM_FULLSCREEN_MONITORS, but
now we do it only when needed.
https://bugzilla.gnome.org/show_bug.cgi?id=705670
When running Mutter under Cogl's KMS backend no cursor will be
provided so instead this makes it so the cursor will be painted as a
CoglTexture that gets moved in response to mouse motion events. The
painting is done in a subclass of ClutterStage so that we can
guarantee that the cursor will be painted on top of everything else.
This patch adds support for the set_cursor method on the pointer
interface so that clients can change the cursor image.
The set_pointer method sets a surface and a hotspot position to use
for the cursor image. The surface's buffer is converted to a
CoglTexture and attached to a pipeline to paint directly via Cogl. If
a new buffer is attached to the surface the image will be updated. The
cursor reverts back to the default image whenever to the pointer focus
is moved off of any surface.
The image for the pointer is taken from X. It gets installed into
a fixed data location for mutter.
This copies the basic input support from the Clayland demo compositor.
It adds a basic wl_seat implementation which can convert Clutter mouse
events to Wayland events. For this to work all of the wayland surface
actors need to be made reactive.
The wayland keyboard input focus surface is updated whenever Mutter
sees a FocusIn event so that it will stay in synch with whatever
surface Mutter wants as the focus. Wayland surfaces don't get this
event so for now it will just give them focus whenever they are
clicked as a hack to test the code.
Authored-by: Neil Roberts <neil@linux.intel.com>
Authored-by: Giovanni Campagna <gcampagna@src.gnome.org>
This adds support for running mutter as a hybrid X and Wayland
compositor. It runs a headless XWayland server for X applications
that presents wayland surfaces back to mutter which mutter can then
composite.
This aims to not break Mutter's existing support for the traditional X
compositing model which means a single build of Mutter can be
distributed supporting the traditional model and the new Wayland based
compositing model.
TODO: although building with --disable-wayland has at least been tested,
I still haven't actually verified that running as a traditional
compositor isn't broken currently.
Note: At this point no input is supported
Note: multiple authors have contributed to this patch:
Authored-by: Robert Bragg <robert@linux.intel.com>
Authored-by: Neil Roberts <neil@linux.intel.com>
Authored-by: Rico Tzschichholz.
Authored-by: Giovanni Campagna <gcampagna@src.gnome.org>
This adds a --with-xwayland-path configure option that can be used to
specify the absolute path of a headless X server binary supporting
the wayland xserver protocol.
This adds a --enable-wayland configure option to enable building mutter
as a hybrid X and Wayland compositor. By default the option is disabled.
If enabled then HAVE_WAYLAND is defined for C code and as an automake
conditional.
This copies the xserver.xml wayland protocol into a protocol/ directory
since wayland support will depend on this protocol for communicating
with an xwayland X server. Copying the spec like this is consistent with
Weston so we don't need a configure option to locate an external spec.
Background handling in GNOME is very roundabout at the moment.
gnome-settings-daemon uses gnome-desktop to read the background from
disk into a screen-sized pixmap. It then sets the XID of that pixmap
on the _XROOTPMAP_ID root window property.
mutter puts that pixmap into a texture/actor which gnome-shell then
uses.
Having the gnome-settings-daemon detour from disk to screen means we
can't easily let the compositor handle transition effects when
switching backgrounds. Also, having the background actor be
per-screen instead of per-monitor means we may have oversized
textures in certain multihead setups.
This commit changes mutter to read backgrounds from disk itself, and
it changes backgrounds to be per-monitor.
This way background handling/compositing is left to the compositor.
https://bugzilla.gnome.org/show_bug.cgi?id=682427
actor_is_untransformed is a function meta-window-group uses to determine
if an actor is relatively pixel aligned and not contorted. It then
returns the coordinates of the actor.
In a subsequent commit will need the function in a different file, so
this commit separates it out.
https://bugzilla.gnome.org/show_bug.cgi?id=682427
Instead of defining CLUTTER_ENABLE_EXPERIMENTAL_API and
COGL_ENABLE_EXPERIMENTAL_API in individual source files, enable
them on the command line. We weren't tracking exactly what pieces of
experimental API we were using and we were using the experimental
API in most source files that used Clutter and Cogl, so the
local #defines were annoying rather than useful.
https://bugzilla.gnome.org/show_bug.cgi?id=685463
Currently, we have a few function wrappers in the shell for pointer
barriers. If we want to implement interactive features on barriers,
we need some sort of signal to be notified of the interactivity.
In that case, we need to make a more sophisticated object-based wrapper
for a pointer barrier. Add one, and stick it in mutter.
https://bugzilla.gnome.org/show_bug.cgi?id=677215
Using ClutterEffect is not pratical on MetaBackgroundActor, as the FBO
redirection has a noticeable performance impact. Instead, allow adding
GLSL code directly to the pipeline used to draw the background texture.
At the same time, port MetaBackgroundActor to modern Cogl API.
https://bugzilla.gnome.org/show_bug.cgi?id=669798
The EXPORT_PACKAGES variable to the GIR makefile should be the
packages needed to use this gir. It's also unnecessary to set PACKAGES
(which is just used for CFLAGS at scan-time) since CFLAGS is already
pulls in all necessary CFLAGS.
https://bugzilla.gnome.org/show_bug.cgi?id=671092
After the changes in style handling in GTK+, mutter's tooltips no
longer match the tooltip style used in applications. Given that
all buttons in the default layout are well-known, killing tooltips
altogether rather than fixing the styling issues looks like a valid
approach.
https://bugzilla.gnome.org/show_bug.cgi?id=645101
ClutterTexture has many features that we simply don't use and don't make
sense for a subclass with custom drawing. Deriving directly from ClutterActor
simplifies our code by avoiding workarounds and makes things more robust.
Additionally, make it public. GNOME Shell was already assuming that any
MetaShapedTexture was also a ClutterTexture, and we need to replace these
bits with new API for GNOME Shell to use.
https://bugzilla.gnome.org/show_bug.cgi?id=660941
Rather than defining keybindings in static arrays generated at compile
time, store them in a hash table initialized in meta_display_init_keys()
and filled in init_builtin_keybindings().
This is a prerequisite for allowing to add/remove keybindings at runtime.
https://bugzilla.gnome.org/show_bug.cgi?id=663428
Move preferences to GSettings, using mainly shared schemas from
gsettings-desktop-schemas.
Unlike GConf, GSettings support is not optional, as Gio is already
a hard dependency of GTK+.
https://bugzilla.gnome.org/show_bug.cgi?id=635378
meta-texture-rectangle and meta-shaped-texture both create textures
with GL_TEXTURE_RECTANGLE_ARB as the target using direct GL
calls. This patch moves that code into a shared utility function in a
separate file instead. The function resolves the required GL symbols
dynamically instead of linking to them directly so that if Clutter
eventually stops linking to -lGL mutter will continue to build. The
function also splits the texture creation into a separate texture
creation and data upload stage so that it can use
cogl_texture_set_region to upload the data. That way it can avoid
clobbering the glPixelStore state and it can let Cogl do any necessary
format conversion. The code preserves the old value of the rectangle
texture binding instead of clobbering it because Cogl expects to be
able to cache this value to avoid redundant glBindTexture
calls. Finally, the function uses cogl_object_set_data to
automatically destroy the GL texture when the Cogl texture is
destroyed. This avoids having to have special code to destroy the cogl
texture.
https://bugzilla.gnome.org/show_bug.cgi?id=654569
This patch fixes an issue encountered when building mutter
out-of-tree:
* When generating mutter-enum-types.[ch], the glib-mkenums command is
executed from $(srcdir), so it is wrong to prepend $(srcdir) to the
template file.
https://bugzilla.gnome.org/show_bug.cgi?id=624910
Back the API version down to 3.0; since we don't make any stability
guarantees, there's no reason to have a merry-go-round of different
directories and filenames that people have to keep up with.
If mutter is going to be a "real" library, then it should install its
includes so that users can do
#include <meta/display.h>
rather than
#include <display.h>
So rename the includedir accordingly, move src/include to src/meta,
and fix up all internal references.
There were a handful of header files in src/include that were not
installed; this appears to have been part of a plan to keep core/,
ui/, and compositor/ from looking at each others' private includes,
but that wasn't really working anyway. So move all non-installed
headers back into core/ or ui/.
https://bugzilla.gnome.org/show_bug.cgi?id=643959
Move all of the mutter code into a new libmutter-wm.so, split its
main() method into meta_get_option_context(), meta_init() and
meta_run(), add methods for using in-process plugins, and add
libmutter-wm.pc pointing to the new library.
The mutter binary is now just a tiny program that links against
libmutter-wm. The --version and --mutter-plugins options are handled
at the mutter level, not in libmutter-wm, and a few strange unused
command-line options (--no-force-fullscreen and --no-tab-popup) have
been removed.
https://bugzilla.gnome.org/show_bug.cgi?id=643959
This changes the introspection configure flag from
--with/--without-introspection to --enable/--disable-introspection,
and changes it so that trying to enable introspection when g-i is not
installed results in an error, rather than being silently ignored.
https://bugzilla.gnome.org/show_bug.cgi?id=643959
We want switching between the windows of an application to be an easily
accessible operation. The convenient and memorable keybinding is the
key above the tab key - but the keysym for that key isn't consistent
across different keyboard layouts.
Add code that figures out the key from the XKB geometry and a magic
keysym name "Above_Tab" that refers to this key and switch
the default binding for cycle_group to <Alt>Above_Tab. (This will
have no effect for the normal case of getting the key binding from
GConf until this patch is applied to Metacity as well.)
https://bugzilla.gnome.org/show_bug.cgi?id=635569
Add code to track and draw the root window background. The advantage of doing
it here as compared to in a plugin is that we can use the visiblity smarts
of MetaWindowGroup to optimize out drawing the background when obscured.
If handling other than tracking the _XROOTPMAP_ID property is desired in the
future, more functionality like setting the background from a file or doing
cross-fades can be added.
The new background actor is exposed to plugins via meta_plugin_get_background_actor()
similar to other exposed actors to allow cloning the background for use in
other displays. The actual class is not installed for public consumption at
the moment since it has no useful methods.
https://bugzilla.gnome.org/show_bug.cgi?id=634833
Create new cogl-utils.[ch] and move a helper function from
MetaShadowFactory there as meta_create_texture_material(); this
allows us to create single-layer materials from different parts of
Mutter and have them share the same template material.
Also expose a function for creating a 1x1 texture of a given
color meta_create_color_texture_4ub().
https://bugzilla.gnome.org/show_bug.cgi?id=634833
The basic MetaShadowFactory type is moved to a public header, while
the functions to fetch and paint shadows are kept private.
The public object will be used for configuration of shadows by
plugins.
https://bugzilla.gnome.org/show_bug.cgi?id=592382
The current shadow code just uses a single fixed texture (the Gaussian
blur of a rectangle with a fixed blur radius) for drawing all window
shadows. This patch adds the ability
* Implement efficient blurring of arbitrary regions by approximating
a Gaussian blur with multiple box blurs.
* Detect when multiple windows can use the same shadow texture by
converting their shape into a size-invariant MetaWindowShape.
* Add properties shadow-radius, shadow-x-offset, shadow-y-offset,
shadow-opacity to allow the shadow for a window to be configured.
* Add meta_window_actor_paint() and draw the shadow directly
from there rather than using a child actor.
* Remove TidyTextureFrame, which is no longer used
https://bugzilla.gnome.org/show_bug.cgi?id=592382
While the Meego developers agreed to switching mutter to GTK+-3.0
unconditionally a while ago, Canonical used a GTK+-2.0 build for their
Unity project. As Canonical now announced a switch to compiz as their
window manager, there is no longer a reason to maintain GTK+-2.0
compatibility.
https://bugzilla.gnome.org/show_bug.cgi?id=633133
Remove --allow-unprefixed option to the scanner, and fix resulting
problems:
* theme.h and boxes.h are split into a main -header and a private
header that includes stuff that is not generally useful and
hard to introspect. Merge theme-parser.h into theme.h.
* meta_display_get_atom() and meta_window_get_window_type_atom()
are marked as (skip)
* Fix annotation: (element-type Strut) => (element-type Meta.Strut)
https://bugzilla.gnome.org/show_bug.cgi?id=632494
Move all objects and functions namespaced with Mutter into the Meta namespace
to get a single consistent namespace. Changes that aren't simply changing mutter
to meta:
MutterWindow => MetaWindowActor
mutter_get_windows => meta_get_window_actors
mutter_plugin_get_windows => meta_plugin_get_window_actors
https://bugzilla.gnome.org/show_bug.cgi?id=628520
In many places, MetaRegion was being used entirely internally, rather
than for gtk2/gtk3 compatibility. In these cases, it's simpler to just
depend on cairo-1.10 (for both gtk2 and gtk3) and use cairo_region_t.
The few places where we did need GDK compatibility (GdkEvent.region and
gdk_window_shape_combine_mask) are replaced with a combination of
converting GdkRegion to cairo_region_t and conditional code.
https://bugzilla.gnome.org/show_bug.cgi?id=632474
This commit is in preparation for the work happening in GTK3, which will
use Cairo for drawing exclusively. So it is necessary to move all
drawing code to Cairo. In this commit the "gtk2" code is used for both
gtk2 and gtk3; compatibility with newer versions of gtk3 where different
code is needed will be added subsequently.
For compatibility with older GTK versions, the file gdk2-drawing-utils.h
provides a compatibility layer.
The commit changes the API of libmutter-private.
https://bugzilla.gnome.org/show_bug.cgi?id=630203
When dragging a window over a screen edge and dropping it there,
maximize it vertically and scale it horizontally to cover the
corresponding half of the current monitor.
Whenever a "hot area" which triggers this behavior is entered, an
indication of window's target size is displayed after a short delay
to avoid distraction when moving a window between monitors.
https://bugzilla.gnome.org/show_bug.cgi?id=606260
Cleanly build with --warn-fatal. Implementation:
* Liberally apply (skip) where the API is clearly C only, e.g. uses
XLib. The theming code and MutterPlugin are skipped too.
* Add missing (transfer) and (element-type) annotations
For a few functions that had a comment, I turned it into gtk-doc, but
I didn't (with a few exceptions) try to write new documentation in
this pass.
Libmutter-private's preview-widget.h depends on region.h, so that one
needs to be installed as well in order to keep dependees build.
Signed-off-by: Tomas Frydrych <tf@linux.intel.com>
g-ir-scanner is currently buggy and confuses the Gdk.Rectangle alias
with MetaRectangle. Since this is moderately hard to fix in
gobject-introspection and the fix would conflict with in-progress
changes, work around by doing a 'sed job' on the generated Meta.gir.
https://bugzilla.gnome.org/show_bug.cgi?id=623639
In order to replace calls to deprecated GDK code, the current
development version of GTK+ is required. Add some basic compatibility
code to allow building mutter with GTK+ 2.18.
https://bugzilla.gnome.org/show_bug.cgi?id=587991
To replace all calls to deprecated code, GTK+ 2.20 is required - add
some basic compatibility code, so that it is still possible to build
mutter with GTK+ 2.18 when not using -DGSEAL_ENABLE.
https://bugzilla.gnome.org/show_bug.cgi?id=595496
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
