This function is called when the backend is being disposed - as a way
of releasing all ClutterShader. This doesn't take into account three
things:
- ClutterShader is deprecated
- the Backend is *never* disposed
- once the process terminates, all its resources are automatically
released by the OS
So the _clutter_shader_release_all() function is a pointless exercise
in futility.
For deprecation of APIs, in commits
522b8be3 (clutter_get_input_device_for_id())
6ef09dd1 (clutter_clear_glyph_cache())
01080dc5 (clutter_[sg]et_font_flags())
Just like GLIB_DEPRECATED and GLIB_DEPRECATED_FOR, Clutter should have
its own wrappers for G_DEPRECATED and G_DEPRECATED_FOR, to allow opting
out of deprecation warnings.
Deprecation warnings are enabled by default, now, even when building
Clutter.
This moves a couple of definitions to the common types header, and makes
sure that ClutterBehaviour subclasses include clutter-behaviour.h first,
so that their types can be fully expanded without necessarily have the
ClutterBehaviour header header included by their public headers. This is
the necessary prelude to have clutter-behaviour.[ch] moved to the
deprecated section.
The code that has been deprecated should live into its own directory,
both in the repository and when installed. This should make it clear
which functionality is actually maintained and which is not.
We start with an oldie: the frame source API.
On top of the existing "Settings" group in the settings.ini file we
should have two more groups:
Environment - contains all the configuration possible through
environment variables
Debug - contains all the possible debug variables
ClutterSettings should be able to load its initial state by using
configuration files in SYSCONFDIR and XDG_CONFIG_HOME. This allows
Clutter to have a system (and user) configuration on platforms that
do not have XSETTINGS bridges.
We already have two mechanisms for controlling the font rendering
quality on a per-application basis:
• ClutterSettings properties
• clutter_backend_set_font_options()
The font flags were always a stop-gap solution, and one that tried to
simplify a fairly complex issue beyond the point of actually being
useful.
https://bugzilla.gnome.org/show_bug.cgi?id=660786
The grab API is a relic of Clutter 0.6, and hasn't been through proper
vetting in a *long* time — mostly due to the fact that we don't really
like grabs, and point to the ::captured-event as a way to implement
"soft grabs" in toolkits and applications.
The implementation of full and device grabs uses weak references on
actors instead of using the ::destroy signal, which is meant exactly for
the case of releasing pointers to actors when they are disposed.
The API naming scheme is also fairly broken, especially for
device-related grabs.
Finally, keyboard device grabs are just not implemented.
We can, in one go, clean up this mess and deprecate a bunch of badly
named API by introducing generic device grab/ungrab methods on
ClutterInputDevice, and re-implement the current API on top of them.
GLib deprecated g_thread_init(), and threading support is initialized
by GObject, so Clutter already runs with threading support enabled. We
can drop the clutter_threads_init() call requirement, and initialize the
Big Clutter Lock™ on clutter_init(). This reduces the things that have
to be done when dealing with threads with Clutter, and the things that
can possibly go wrong.
The Big Clutter Lock™ can now be a static GMutex, since GLib supports
them. We can also drop a bunch of checks given the recent changes in
GLib threading API.
The static initializer for GMutex has been removed from GLib.
The g_thread_supported() call can also be removed: threading is always
enabled in GLib ≥ 2.31.
This commit introduces a unicode-to-keyval conversion function that
performs identical action as the gdk version of that function. Also
added is the necessary table holding all the conversion values.
https://bugzilla.gnome.org/show_bug.cgi?id=661015
If we do project() → get_bounding_box(), we'll try to complete the
volume twice, which whacks out all the lazily computed vertices.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
This is used as an alternative to calling
clutter_shader_effect_set_shader_source. A ClutterShaderEffect
subclass is now expected to implement this method to return the source
for the effect that will be used for all instances of this
subclass. It is only called once regardless of the number of instances
created. That way Clutter can avoid recompiling the shader source for
every new instance of the effect.
https://bugzilla.gnome.org/show_bug.cgi?id=660512
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
The asynchronous loading code could do with some modernization.
First of all, we should drop the internal GMutex held when manipulating
the boolean flags: it's far too expensive for its role, and modern GLib
provides us with bitlocks that are quite a lot faster.
Then we should consolidate most of the implementation into something
smaller and more manageable.
The ClutterGeometry type is a poor substitute of cairo_rectangle_int_t,
with unsigned integers for width and height to complicate matters.
Let's remove the internal usage of ClutterGeometry and switch to the
rectangle type from Cairo.
https://bugzilla.gnome.org/show_bug.cgi?id=656663
When testing the performance of an application, it's often useful to
force it to continuously redraw instead of going idle to help measure
the frame rate. This just adds a CLUTTER_PAINT=continuous-redraw which
causes the master clock to queue a redraw on all of the stages
just before it prepares its source.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
When the viewport gets expanded because the actor extends off the edge
of the screen, instead of applying the transformation to the root of
the modelview transformation it is now applied to the end of the
projection transformation. This should end up with the same
transformation. This fixes a problem when the offscreen effects are
nested and the inner effect would try to pick up the current modelview
transformation to rescale it to fit the new viewport size. In this
case the modelview would have already been scaled for the size of the
outer viewport so it would end up wrong.
https://bugzilla.gnome.org/show_bug.cgi?id=659601
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Reviewed-by: Robert Bragg <robert@linux.intel.com>
A ClutterText in password mode should have the ability to show the last
input character. This feature allows easier password entry on platforms
with unreliable keyboards, such as touchscreens or small devices.
https://bugzilla.gnome.org/show_bug.cgi?id=652588
Add a setting that controls whether ClutterText actors in password mode
should display the last input character for a defined time. This helps
on touch-based interfaces.
https://bugzilla.gnome.org/show_bug.cgi?id=652588
In _clutter_actor_set_default_paint_volume we were returning FALSE if an
actor has an empty allocation because we were claiming it doesn't have a
paint-volume. Actually an empty/degenerate pv is valid and has different
semantics to returning FALSE because FALSE means the pv is unknown and
so Clutter will have to assume the worst - that the pv is basically
un-bounded.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
This implicitly intersects any clip for redrawing with the stage window
bounds. Without this we were sometimes trying to set huge off screen
scissors leading to undefined clipping results.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Out-of-band transforms are considered to be all actor transforms done
directly with the Cogl API instead of via ClutterActor::apply_transform.
By running with CLUTTER_DEBUG=oob-transform then Clutter will explicitly
try to detect when un-expected transforms have been applied to the
modelview matrix stack.
Out-of-band transforms can lead to awkward bugs in Clutter applications
because Clutter itself doesn't know about them and this can disrupt
Clutter's input handling and calculations of actor paint-volumes
which can lead to visual artifacts.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
For god-knows-what reason, at-spi is trying various formats
of strings when registering listeners, triggering an ugly
(gnome-shell:4411): Clutter-WARNING **: invalid object type create
warning in .xsession-errors. Stop doing that.
Also don't leak temporary string arrays that are a side-effect
of passing parameters around as formatted strings.
https://bugzilla.gnome.org/show_bug.cgi?id=658721
A bunch of private functions we use when parsing got exposed accidentaly
to the list of public symbols by virtue of not having the leading '_'
that we use to filter them out of the shared object — all the while the
header that declares them is a private, non installed one.
Let's rectify this situation with a bit of minor surgery on the code.
The priv->text field cannot ever be NULL, so we don't need to check for
that in a series of places. We also need to assert() that pre-condition
in the couple of places where we set the contents of the ClutterText
actor, namely in set_text_internal() and set_markup_internal().
Based on a patch by: Dan Winship <danw@gnome.org>
http://bugzilla.clutter-project.org/show_bug.cgi?id=2629
Setting :use-markup and :text is currently not idempotent, and it
depends on the ordering, e.g.:
g_object_set (actor, "use-markup", TRUE, "text", value, NULL);
does not yield the same results as:
g_object_set (actor, "text", value, "use-markup", TRUE, NULL);
This is particularly jarring when using ClutterText from ClutterScript,
but in general GObject properties should not rely on the order when used
from g_object_set().
The fix is to store the contents of the ClutterText as a separate string
from the displayed text, and use the contents, instead of the displayed
text, when toggling the :use-markup property.
Let's also add a unit test for good measure, to try and catch
regressions.
https://bugzilla.gnome.org/show_bug.cgi?id=651940
The easing test is a nice example of what ClutterAnimation and
clutter_actor_animate() can do. The "tween ball to the pointer
event coordinates" is a bit of a staple in animation libraries
and their documentation.
When we paint a ClutterText we ask the actor for a PangoLayout that fits
inside the actor's allocation - both width and height.
Sadly, whenever a height is set on a PangoLayout, Pango will wrap its
contents - regardless of whether the layout should actually wrap or not.
This means that in certain easy to exploit cases, Clutter will paint a
Text actor with its contents wrapping even if the :wrap property is set
to FALSE.
In order to fix this we need to encode some more cases inside the
::paint implementation of ClutterText, and ask the cache for a layout
that is sized as the allocation's width, but not as its height; we also
need to perform a clip if we detect that the PangoLayout's logical size
is going to overflow the allocated size. This clip might cause some
performance issue, given that clipping breaks batching in the Cogl
journal; hopefully all clips for text are going to be screen-aligned, so
at the end of the batch it'll just scissor them out.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2339
Like commit d0439cfb586ca14282c89035119a4acbc0295df7 for
AlignConstraint, let's check that the BindConstraint source is not
a child or a grandchild of the actor attached to the Constraint.
AlignConstraint won't work if the source is a child or a grandchild of
the ClutterActorMeta:actor to which it has been attached to: the
allocation flows from the parent to its children, not the other way
around; in order to avoid weirdness, we better document and check
that when we set the actor and when we set the source.
The repaint functions list can (and should) be manipulated from
different threads, but it currently doesn't prevent multiple threads
from accessing it concurrently. We should have a simple lock and take it
when adding and removing elements from the list; the invocation is still
performed under the Big Clutter Lock™, so it doesn't require special
handling.
Because we have had several reports about significant performance
regressions since we enabled offscreen redirection by default for
handling correct opacity we are now turning this feature off by default.
We feel that clutter should prioritize performance over correctness in
this case. Correct opacity is still possible if required but the
overhead of the numerous offscreen allocations as well as the cost of
many render target switches per-frame seems too high relative the
improvement in quality for many cases.
On reviewing the offscreen_redirect property so we have a way to
disable redirection by default we realized that it makes more sense for
it to take a set of flags instead of an enum so we can potentially
extend the number of things that might result in offscreen redirection.
We removed the ability to say REDIRECT_ALWAYS_FOR_OPACITY, since it
seems that implies you don't trust the implementation of an actor's
has_overlaps() vfunc which doesn't seem right.
The default value if actor::redirect_offscreen is now 0 which
effectively means don't ever redirect the actor offscreen.
If an actor using a LayoutManager has attributes like margin or padding
then it'll have to shave them from the available allocation before
passing it to the LayoutManager::allocate() implementation. Layout
managers should, thus, not assume that the origin of the allocation is
in (0, 0), but take into account that the passed ActorBox might have a
different origin.
https://bugzilla.gnome.org/show_bug.cgi?id=649631
The actor is in charge of providing to the LayoutManager the available
allocation. ClutterBox should not just pass the box it got from its
parent: it should, instead, provide a normalized box, with an origin in
(0, 0) and the available size.
https://bugzilla.gnome.org/show_bug.cgi?id=649631
This adds experimental API to be able to get the CoglContext associated
with the ClutterBackend. The CoglContext is required to use some of the
experimental 2.0 Cogl API.
Note: Since CoglContext is itself experimental API this API should
considered experimental too. This patch introduces a
CLUTTER_ENABLE_EXPERIMENTAL_API #ifdef guard which anyone wanting to use
this API must define so it's explicitly clear to developers that they
are playing with experimental API.
Note: This API is not yet supported on OSX because OSX still uses the
stub Cogl winsys and the Clutter backend doesn't explicitly create a
CoglContext.
Note: even though this is experimental API we still promise that it
wont be changed during a stable release cycle. This means for example
that you can depend on this for the lifetime of the clutter-1.8 stable
release cycle.
The :fontconfig-timestamp is a write-only property that will get updated
by the underlying platform whenever the fontconfig configuration has
been changed — i.e. when the fontconfig caches should be rebuilt after
the user has installed a new font.
This makes ClutterText implement the Scriptable interface so that we can
have a custom property parser and setter for the font-description
property. This works by simply passing the string description through
to clutter_text_set_font_name.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Actually this change has two notable effects; firstly we no longer
perform culling during picking and secondly we avoid updating the
last-paint-volume of an actor when picking.
We shouldn't perform culling during picking until clutter-stage.c is
updated to setup the clipping planes appropriately.
Since the last-paint-volume is intended to represent the visible region
of the actor the last time it was painted on screen it doesn't make
sense to update this during off screen pick renders since we are liable
to end up with a last-paint-volume that maps to an actors new position
when we next come to paint for real.
This fixes a bug in gnome-shell with dragging dash icons leaving a
messy trail on the screen.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
All 2D coordinate spaces in Cogl have their origin at the top-left so we
shouldn't be flipping the coordinates we pass to
cogl_framebuffer_swap_region to be relative to the bottom of the
framebuffer.
This bumps the Cogl version requirement to 1.7.5 since we've had to fix
a bug in the semantics of cogl_framebuffer_swap_region.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Since commit 38b67e2884 of Cogl the naming scheme for winsys-specific
API has changed to be cogl_win32_onscreen_* instead of
cogl_onscreen_win32_* so it wouldn't build on Windows.
Added isHiding field to _ClutterStageOSX to allow windowDidResignKey
delegate to not order full screen window back whilst the full screen
window was being hidden. This caused other application windows to be
hidden. Also added code to keep hidden stage windows from being listed
in the application's Windows menu.
https://bugzilla.gnome.org/show_bug.cgi?id=655311
Added -windowDidChangeScreen: delegate to handle condition where moving
host window to a different screen would cause pick errors to be output.
The delegate just causes the stage to be redrawn which re-creates the
pick buffer.
https://bugzilla.gnome.org/show_bug.cgi?id=655306
The Animatable interface allows object classes to provide and animate
properties outside of the usual GObject property introspection API.
This change allows ClutterState to defer to the animatable objects the
property introspection and animation, just like ClutterAnimation does.
The animate_property() method of the Animatable interface is far less
than optimal:
• it has a direct reference to ClutterAnimation;
• it has an interval decomposed as two values.
These issues tie the Animatable interface with the Animation object,
even though it's neither necessary nor future-proof.
Let's introduce a new method, interpolate_value(), which does not
reference ClutterAnimation and uses a ClutterInterval to express the
initial and final states.
All ClutterModelIter virtual functions have a default implementation,
and G_TYPE_INSTANCE_GET_CLASS cannot return NULL unless in case of a
catastrophic event in the type system - which will most likely blow up
any application code way before you could call a ModelIter method.
Thus, the idiom:
klass = CLUTTER_MODEL_ITER_GET_CLASS (instance);
if (klass && klass->vfunc)
klass->vfunc (instance);
is utterly useless complication, and it can be perfectly replaced by:
CLUTTER_MODEL_ITER_GET_CLASS (instance)->vfunc (instance);
without any loss of safety.
Currently, only clutter_model_iter_set_valist() is in charge of emitting
the ClutterModel::row-changed signal. Both the set() and the
set_valist() functions can be called with multiple columns, so we
coalesce the signal emission at the end of the set_valist(), to have a
single ::row-changed emission per change.
The clutter_model_iter_set_value() function is just a thin wrapper
around the set_value() virtual function, but since it's called
internally we cannot add the signal emission there as well, as we'd
break the signal coalescing.
For this reason, we need some code refactoring inside the various set()
variants of ClutterModelIter:
- we only use the internal va_arg variant for both the set() and
set_valist() public functions, to avoid multiple type checks;
- the internal set_valist() calls an internal set_value() method
which calls the virtual function from the iterator vtable;
- a new internal emit_row_changed() method is needed to retrieve
the ClutterModel from the iterator, and emit the signal;
Now, all three variants of the value setter will call an internal
ClutterModelIter::set_value() wrapper, and emit the ::row-changed
signal.
To check that the intended behaviour has been implemented, and it's not
going to be broken, the test suite has grown a new unit which populates
a model and changes a random row.
Cally was initially created with Clutter 0.6 in mind. To check
recursively the visibility of a actor a custom method was added.
Since 0.8.4 clutter_actor_get_pain_visibility provides
the same functionality.
Also removed a dummy method. Lets add methods that provide a real
functionality.
Keeping the backing Cairo surface of a CairoTexture canvas in sync with
the actor's allocation is tedious and prone to mistakes. We can
definitely do better by simply exposing a property that does the surface
resize and invalidation automagically on ::allocate.
The current "create context/draw/destroy context" pattern presents
various problems. The first issue is that it defers memory management to
the caller of the create() or create_region() methods, which makes
bookkeeping of the cairo_t* harder for language bindings and third party
libraries. The second issue is that, while it's easier for
draw-and-forget texturs, this API is needlessly complicated for contents
that have to change programmatically - and it introduces constraints
like calling the drawing code explicitly after a surface resize (e.g.
inside an allocate() implementation).
By using a signal-based approach we can make the CairoTexture actor
behave like other actors, and like other libraries using Cairo as their
2D drawing API.
The semantics of the newly-introduced ::draw signal are the same as the
one used by GTK+:
- the signal is emitted on invalidation;
- the cairo_t* context is owned by the actor;
- it is safe to have multiple callbacks attached to the same
signal, to allow composition;
- the cairo_t* is already clipped to the invalidated area, so
that Cairo can discard geometry immediately before we upload
the texture data.
There are possible future improvements, like coalescing multiple
invalidations inside regions, and performing clipped draws during
the paint cycle; we could even perform clipped redraws if we know the
extent of the invalidated area.
ClutterTexture relies too much on GError, even for things that are
clearly programmer errors. Also, no error message passed to GError
is marked for translation as it should.
We should move the programmer errors, like passing the wrong bpp
value with regards to the presence of the alpha channel, to real
warnings; we should also try and harmonize all the error messages,
and not mention Cogl — especially in the ones marked for translation.
This avoids explicitly including gl or egl headers in
clutter-egl-headers.h. We were getting build failures when building
clutter against a libcogl that has runtime support for GL and GLES
because cogl-defines.h was including gl.h and then clutter-egl-headers.h
was later including GLES2/gl.h with typedef conflicts. Clutter relies on
Cogl to abstract GL and GLES and the winsys APIs like EGL and GLX so
Clutter should just rely on cogl.h to include the appropriate egl.h in
clutter-egl-headers.h.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Setting up the call and calling the GClosure was showing up in profiles
and seemed an easy one to remove.
Instead of calling the closure, let's remember the alpha func and the
user_data when possible (ie set_mode() and set_func()) and use it in
get_alpha().
https://bugzilla.gnome.org/show_bug.cgi?id=654727
The "editable" property is documented to default to TRUE, but is
initialized to FALSE in the _init() function.
Third party code would be affected if we changed the default to be
TRUE, so we have to change the default value in the GParamSpec.
https://bugzilla.gnome.org/show_bug.cgi?id=654726
When emitting a new-frame signal, priv->elapsed_time is passed as a
parameter. This is a gint64. The closure marshal uses an INT. On some
platforms, this is not received correctly by signal handlers (they
receive 0). One solution is to cast priv->elapsed_time to a gint when
emitting the signal.
We cannot change the signature of the signal without breaking ABI.
https://bugzilla.gnome.org/show_bug.cgi?id=654066
If the meta for the animation property is not found, the name of the
property to look for is still from the token, and we need to free the
memory allocated for it.
https://bugzilla.gnome.org/show_bug.cgi?id=654656
Clutter may be used together with GTK+, which indirectly may use
XInput2 too, so the cookie data must persist when both are handling
events.
What happens now in a nutshell is, Clutter is only guaranteed to allocate
the cookie itself after XNextEvent(), and only frees the cookie if its
XGetEventData() call allocated the cookie data.
The X[Get|Free]EventData() calls happen now in clutter-event-x11.c as
hypothetically different event translators could also handle other set
of X Generic Events, or other libraries handling events for that matter.
When picking we need to disable dithering to be sure that the hardware
will not modify the colors we use as actor identifiers. Clutter was
manually calling glEnable/Disable GL_DITHER to handle this, but that was
a layering violation since Cogl is intended to handle all interactions
with OpenGL. Since we are now striving for GL vs GLES to be a runtime
choice we need to remove this last direct usage of GL from Clutter so it
doesn't have to be linked with GL at build time.
Signed-off-by: Neil Roberts <neil@linux.intel.com>
This updates _clutter_paint_volume_get_stage_paint_box to try and
calculate more stable paint-box sizes for fixed sized paint-volumes by
not basing the size on the volume's sub-pixel position.
So the aim is that for a given rectangle defined with floating point
coordinates we want to determine a stable quantized size in pixels that
doesn't vary due to the original box's sub-pixel position.
The reason this is important is because effects will use this API to
determine the size of offscreen framebuffers and so for a fixed-size
object that may be animated across the screen we want to make sure that
the stage paint-box has an equally stable size so that effects aren't
made to continuously re-allocate a corresponding fbo.
The other thing we consider is that the calculation of this box is
subject to floating point precision issues that might be slightly
different to the precision issues involved with actually painting the
actor, which might result in painting slightly leaking outside the
user's calculated paint-volume. This patch now adds padding to consider
this too.
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Instead of relying on C to round the floating point allocation to
integers by flooring the values we now use CLUTTER_NEARBYINT to round
the allocation's position and size to the nearest integers instead. Using
floor leads to rather unstable rounding for the width and height when
there may be tiny fluctuations in the floating point width/height.
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
This is a replacement for the nearbyint function which always rounds to
the nearest integer. nearbyint is a C99 function so it might not always
be available but also it seems in glibc it is defined as a function call
so this macro could end up faster anyway. We can't just add 0.5 because
it will break for negative numbers.
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The implementation of _clutter_actor_set_default_paint_volume which
simply uses the actor's allocation to determine a paint-volume was
needlessly using the allocation rounded to integers by internally using
clutter_actor_get_allocation_geometry instead of
clutter_actor_get_allocation_box. This was introducing a lot of
instability into the paint-volume due to the way rounding was done.
The code has now been updated to use clutter_actor_get_allocation_box
so we are dealing with the floating point allocation instead.
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
If we're building on/for Windows, set 'win32' as the default flavour; if
we're building on OS X, set 'osx' as the default flavour. For everything
else, use 'glx'.
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.
Cogl changed has changed the name of cogl_context_egl_get_egl_context to
cogl_egl_context_get_egl_context to be consistent with other platform
specific symbols.
The class is of dubious utility, now that we have a complex animation
API in ClutterAnimator and ClutterState, as opposed to a simple one
in ClutterBehaviour. The Score API also suffers from some naïve design
issues that made it far less useful than intended.
Commit 0ede622f51 inadvertently made it so that shaders are applied
during picking. This was making test-shader fail to respond to clicks.
The commit also makes it so that culling is applied during
picking. Presumably this is also unintentional because the commit
message does not mention it. However I think it may make sense to do
culling during picking so it might as well stay that way.
https://bugzilla.gnome.org/show_bug.cgi?id=653959
The cursor's on-screen rectangle is defined in terms of the text
length, the current index, and text_x and text_y, which hold the text
offset in overflowing text fields.
When deleting large amounts of text, text_x is set to 0. In some
edge case branch paths, the cursor rectangle could be calculated
after the current index and text length were updated, but before
the text_x offset could be. This left a negative x position, which
consequently blew up Cogl and the widget.
https://bugzilla.gnome.org/show_bug.cgi?id=651079
It was already the intention that the ClutterGLXTexturePixmap API should
be built and made available on any X11 based platforms since there was
nothing specific about the API and it is useful to have for
compatibility. There was a mistake in the Makefile.am though which meant
only the header was getting installed but the code wasn't being built.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Since the implementation of ClutterGLXTexturePixmap has nothing GLX
specific about it (it is simply layered on top of
ClutterX11TexturePixmap) we don't need to include glx.h. Removing this
include also means that the code can be built for compatibility against
GLES drivers.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
This removes the is_axis_aligned assertions for the width/height/depth
getters and setters, since for example it is legitimate to query the
width, height or depth of a container's child actors which aren't
necessarily axis aligned.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
cogl_renderer_xlib_set_foreign_display was renamed to
cogl_xlib_renderer_set_foriegn_display so this is the corresponding
change to clutter.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
The generic cogl_renderer_handle_native_event API was removed from the
Cogl public API in favour of typesafe functions, so this updates the
win32 backend in line with that change.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
It is possible, by calling clutter_set_motion_events_enabled() prior to
the creation of any stage, to control the per-actor motion event
delivery flag on each newly created stage. Since we deprecated the
global accessor functions in favour of the per-Stage ones, we need to
remove the call to clutter_get_motion_events_enabled() inside the
ClutterStage instance initialization, and replace it with an internal
function.
This code will go away when we can finally break API and remove the
deprecated functions.
Complete the quest of commit bc548dc862
by making the ClutterStage methods for controlling the per-actor motion
and crossing event delivery public, and deprecating the global ones.
Although this patch doesn't make them public, it documents the
_clutter_actor_get/apply_relative_transform_matrix functions so they
could easily be made public if desired. I think these API could be
useful to have publicly, and I originally documented them because I
thought they would be needed in the MX toolkit.
Previously ClutterActor was using priv->propagated_one_redraw to
determine whether to pass CLUTTER_EFFECT_PAINT_ACTOR_DIRTY to the
paint method of the effect. This isn't a good idea because the
propagated_one_redraw flag is cleared whenever clutter_actor_paint is
called, even if the actor isn't actually painted because of the zero
opacity shortcut. Instead of this, ClutterActor now has a separate
flag called is_dirty that gets set whenever queue_redraw_full is
called or whenever the queue redraw signal is bubbled up from a child
actor. The flag is only cleared in clutter_actor_paint if the effects
are actually run. Therefore it will stay set even if the opacity is
zero or if the parent actor decides not to paint the child.
Previously there were two places set propagated_one_redraw to FALSE -
once if the opacity is zero and once just before we emit the paint
signal. Now that propagated_one_redraw is only used to determine
whether to pass on the queue redraw signal it seems to make sense to
just clear it in one place right at the start of clutter_actor_paint.
https://bugzilla.gnome.org/show_bug.cgi?id=651784
On reviewing the clutter-actor.c code using
_apply_modelview_transform_recursive I noticed various comments stating
that it will never call the stage's ->apply_transform vfunc to transform
into eye coordinates, but actually looking at the implementation that's
not true. The comments probably got out of sync with an earlier
implementation that had that constraint. This removes the miss-leading
comments and also updates various uses of the api where we were manually
applying the stage->apply_transform.
Instead of using the cogl_vertex_buffer API this uses the more concise
cogl_primitive API instead. The aim is to get rid of the
cogl_vertex_buffer API eventually so we should be trying out the
replacement API wherever possible.
When using CLUTTER_PAINT=paint-volumes to visualize the paint-volumes of
actors we were already disabling clipped-redraws because we are drawing
extra geometry that the actors don't know about but we didn't disable
culling. This was resulting in actors disappearing while using this
debug option.
This makes sure we don't try and draw paint-volumes or culling results
during a pick cycle since that results in us reading back invalid ids
from the pick-buffer.
This adds CLUTTER_PAINT=disable-offscreen-redirect to help diagnose
problems with the correct opacity changes. This just makes it so that
it never installs the flatten effect so it will never automatically
redirect an actor offscreen.
This removes the pv->is_xis_aligned assertion in
_clutter_paint_volume_union. We were already considering the case where
the second volume may not be axis aligned and aligning it into a
temporary variable in that case, but we now also consider that the first
pv may also not be aligned.
The removes the pv->is_complete assertion from
_clutter_paint_volume_axis_align() and instead if the volume isn't
complete it calls _clutter_paint_volume_complete().
When calculating the union of a volume with an empty volume we aim to
simply take the contents of the non-empty volume, but we were not
copying the flags across. We now use
_clutter_paint_volume_set_from_volume which copies all the flags except
the is_static flag.
In _clutter_paint_volume_set_from_volume we were using memcpy to simply
copy everything from one volume to another, but that meant we were
trashing the is_static flag which determines if the destination
paint-volume was slice allocated or not.
This removes the constraint that a paint-volume must be axis aligned
before _clutter_paint_volume_complete can be called. NB: A paint volume
is represented by one origin vertex and then three axis vertices to
define the width, height and depth of the volume. It's straightforward
to use the vectors from the origin to the axis vertices to deduce the
other 4 vertices so we can remove the is_axis_aligned assertion.
Since eef9078f the translation of the camera away from the z=zero
plane was hardcoded at 50 which is approximately half way between the
default z_near and z_far values. This ended up with quite a small
distance in user-space coordinates to the far plane with the default
stage size and this was causing test-texture-quality to clip the actor
early.
This patch makes it try to calculate a reasonable value for the
position of the z=0 plane as well as a value for z_far so we maximize
the space in between the z=0 plane and the near plane and we have a
predictable amount of space behind the stage before hitting the far
clipping plane, while considering the trade off of loosing depth
precision by pushing the far plane too far back relative to the near
plane.
With the default fov of 60° it's not possible to use the stage size to
define the gap in-front of the stage plane; only ~87% of the stage size
is possible as an upper limit. We make 85% of the stage_height available
assuming you have a fov of 60°. We consistently provide 10 times the
stage height of space behind the stage regardless of the fov.
It seems worth noting here that we went around in circles a few times
over how to calculate the gaps since there are a number of trade offs to
consider and they also affect the complexity of the solution. In the end
we went for simplicity but commented the issues well enough hopefully so
we can develop a more elaborate solution if we ever have a use-case.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2625
Since eef9078f ClutterStage updates the aspect ratio of the
perspective matrix whenever the size of the stage changes. This meant
that if an application tries to set its own perspective matrix then
part of it would get overridden. It's not really clear what the
use-case of setting the perspective on the stage should be but it
seems like the safest bet is to always try to preserve the
application's request. The documentation for the function has been
tweaked to discourage its use.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2625
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
We hadn't updated the egl backend inline with a change to the arguments
that cogl_onscreen_x11_set_foreign_window_xid would expect and that was
causing a compilation error.
* swipe-action:
test-swipe-action: Clean up the test code
docs: Add the new actions to the API reference
gesture-action: Remove the multi-device entry points
swipe-action: Remove the required devices call
swipe-action: Clean up
gesture-action: Clean up
Add ClutterSwipeAction and ClutterGestureAction
Do not just allow animating states connected to signals: add a "warp"
optional key that ends up calling clutter_state_warp_to_state(). This
is useful for debugging.
Currently, defining states for object signals can only be done by
defining a ClutterState inside the ClutterScript definition. We should
allow creating a (named) ClutterState in code, and associating it to a
ClutterScript instance — and have the Script resolve the "state" field
of a signal definition correctly.
One of the uses of a ClutterState state machine along with ClutterScript
is to provide a quick way to transition from state to state in response
to signal emitted on specific instances.
Connecting a real function, in code, to a specific signal does not
improve the ease of use of ClutterScript to define scenes.
By adding a new signal definition to the current one we can have both a
simple way to define application logic in code and in the UI definition
file.
The new syntax is trivial:
{
"name" : <signal name>,
"state" : <state machine script id>,
"target-state" : <target state>
}
The ClutterState instance is identified by its script id, and the target
state is resolved at run-time, so it can be defined both in
ClutterScript or in code. Ideally, we should find a way to associate a
default ClutterState instance to the ClutterScript one that parses the
definition; this way we would be able to remove the "state" member, or
even "style" the behaviour of an object by replacing the ClutterState
instance.
The implementation uses a signal emission hook, to avoid knowing the
signal signature; we check the emitter of the signal against the object
that defined the signal, to avoid erroneous state changes.
cairo.h is intended to be included as <cairo.h> not <cairo/cairo.h> as
is the style for clutter.h. If you have installed cairo to a custom
prefix then using cairo/cairo.h can result in unintentional use of the
system cairo headers, or if they aren't installed then it will result in
a failure to find the header.
GestureAction supports a single device/touch point. We'll need touch
events supported in Clutter before adding the ability to set required
device/touch points on gestures.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2585
The GestureAction is marked as abstract, but it has a constructor. It
should be possible to create simple gesture recognizers through signal
handling alone, so we might as well have GestureAction be a concrete
class from the start.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2585
Previously ClutterText was just reporting the allocation as the paint
volume. The preferred size of a ClutterText is just the logical
rectangle of the layout. A pango layout can sometimes draw outside of
its logical rectangle for example with an italicised font with large
serifs. Additionally, ClutterText doesn't make any attempt to clip the
text if the actor gets allocated a size too small for the text so it
would also end up drawing outside of the paint volume in that case. To
fix this, the paint volume is now reported as the ink rect of the
Pango layout. The rectangle for the cursor and selection is also
unioned into that because it won't necessarily be within the ink
rectangle.
The function for drawing the selection rectangles has been split up
into a generic function that calculates the rectangles that need to be
drawn and a function that draws them. That way the get_paint_volume
virtual can share the code to calculate the rectangles.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2599
When the cursor is at the leftmost position in the text the drawn
pixel position is moved to the left by the size of the cursor. There's
no explanation for why this happens and it doesn't seem to make any
sense so this patch removes it. It makes multi-line texts looks odd
because the cursor ends up at a different horizontal position when it
is on the first line from any other line. It also makes using
priv->cursor_pos difficult in any other part of the code because the
paint function modifies it.
The original patch that added this can be traced back to Tidy commit
c356487c15. There's no explanation in the commit message either.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2599
A long press is a special form of click action; the default
implementation uses a single signal with multiple states: query, action
and cancel. On click we use the "query" state to check whether the
ClutterClickAction supports long presses; if the callback returns TRUE
then we install a timeout and we either emit the "activate" state when
the timeout expires or we emit the "cancel" state if the pointer leaves
the actor, or if the pointer moves outside a certain threshold. If the
long press reached the "activate" state then we skip the clicked signal
emission.
A property to control the minimum time that has to elapse before a press
is recognized as a long press. This will be used by ClutterClickAction,
but it can be shared across touch-based gestures.
The G_CONST_RETURN define in GLib is, and has always been, a bit fuzzy.
We always used it to conform to the platform, at least for public-facing
API.
At first I assumed it has something to do with brain-damaged compilers
or with weird platforms where const was not really supported; sadly,
it's something much, much worse: it's a define that can be toggled at
compile-time to remove const from the signature of public API. This is a
truly terrifying feature that I assume was added in the past century,
and whose inception clearly had something to do with massive doses of
absynthe and opium — because any other explanation would make the
existence of such a feature even worse than assuming drugs had anything
to do with it.
Anyway, and pleasing the gods, this dubious feature is being
removed/deprecated in GLib; see bug:
https://bugzilla.gnome.org/show_bug.cgi?id=644611
Before deprecation, though, we should just remove its usage from the
whole API. We should especially remove its usage from Cally's internals,
since there it never made sense in the first place.
If an actor or the stage to which it belongs are being destroyed then
there is no point in queueing a redraw that will not be seen anyway.
Bailing out early also avoids the case in which a redraw is queued
during destruction wil cause redraw entries will be added to the Stage,
which will take references on it and cause the Stage never to be
finalized.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2652
With the instantiatable ClutterShaderEffect, the only reason for
ClutterShader to exist is to make the ClutterActor::paint implementation
miserable.
Yes, ClutterShader doesn't use a FBO, so it's "more efficient" on
ClutterTextures. It's also generally wrong unless you know *exactly* how
the actor's pipeline is set up — something we cannot even guarantee
internally unless we start doing lame type checks.
ClutterShaderEffect doesn't require to be sub-classed in order to be
useful. It is possible to just create an instance, set the source and
the uniforms, and attach it to an actor. This should effectively replace
ClutterShader for good.
We were mistakenly using the constant 4 to determine the number of
vertices that need to be culled for a paint-volume to be considered
fully culled too. This is only ok for 2d volumes and was resulting in
some 3d volumes being considered culled whenever 4 out of 8 vertices
were culled. This fix is simply to reference the vertex_count variable
instead of assuming 4.
_clutter_stage_do_pick called by interactive picking and
clutter_stage_get_actor_at_pos could be accidentally reading back the wrong
actor id's if an other stage has had a more recent render due to animation.
This should resolve some multi stage / ClutterGtk related pick id warnings.
Commit 13ac1fe7 purported to extend the _clutter_id_pool_lookup()
warning to the case where the id referred to a deleted actor, but did
not actually do so, because _clutter_id_pool_remove() set deleted IDs
to 0xdecafbad, not NULL. Fix this.
https://bugzilla.gnome.org/show_bug.cgi?id=650597
Those were added on the old "just for automatic testing" times. That was
somewhat silly on that moment. Now is just silly (ie: having the stage
returning as default name "Stage").
The real description should be set by the app, or provided by the
context of a specific actor feature (like the tooltip on StWidget).
The current information provided by the default description can be
mostly obtained from the ATK_ROLE, and the indirect debugging
advantage of having always a meaningful description is just not enough
to justify them, and you can solve that by proper debug logging.
Fixes: http://bugzilla.clutter-project.org/show_bug.cgi?id=2482
In Cogl, cogl-pango.h has moved to <cogl-pango/cogl-pango.h>. When
using the experimental 2.0 API (which Clutter does) it is no longer
possible to include it under the old name of <cogl/cogl-pango.h> so we
need to update the include location.
In _clutter_actor_queue_redraw_with_clip, there was the possibility that
the actor will add itself to the stage's redraw queue without keeping track
of the allocated list member.
In clutter_actor_unparent, the redraw queue entry was being invalidated
before the mapped notify signal was being fired, meaning that queueing a
redraw of an unmapped actor in the mapped notification callback could
cause a crash.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2621
Since ClutterText has overlapping primitives when selecting, or a
visible cursor, then we need to report that to Clutter, to avoid
bleeding colors through when a Text actor is non-fully opaque.
_clutter_stage_queue_actor_redraw returns a pointer to the
ClutterStageQueueRedrawEntry struct which it allocates. The actor is
expected to store a pointer to this so that it doesn't need to search
the list of queued redraws next time a queue redraw is called. However
_clutter_actor_queue_redraw_full wasn't storing this pointer which
meant that it thought every queue redraw was the first queue
redraw. That meant that queueing a redraw with a clip or an effect
would override any previous attempts to queue a redraw instead of
trying to combine them.
I think this happened because the old queue_redraw_with_clip also
didn't store the pointer and queue_redraw_full was based on that.
This adds a virtual to ClutterActor so that an actor subclass can
report whether it has overlapping primitives. ClutterActor uses this
to determine whether it needs to use ClutterFlattenEffect to implement
the opacity property. The default implementation of the virtual
returns TRUE which means that most actors will end up being redirected
offscreen when the opacity != 255. ClutterTexture and ClutterRectangle
override this to return FALSE because they should never need to be
redirected. ClutterClone overrides it to divert to the source.
The values for the ClutterOffscreenRedirect enum have changed to:
AUTOMATIC_FOR_OPACITY
The actor will only be redirected if has_overlaps returns TRUE and
the opacity is < 255
ALWAYS_FOR_OPACITY
The actor will always be redirected if the opacity < 255 regardless
of the return value of has_overlaps
ALWAYS
The actor will always be redirected offscreen.
This means that the property can't be used to prevent the actor from
being redirected but only to increase the likelihood that it will be
redirected.
ClutterActor now adds and removes the flatten effect depending on
whether flattening is needed directly in clutter_actor_paint(). There
are new internal versions of add/remove_effect that don't queue a
redraw. This means that ClutterFlattenEffect is now just a no-op
subclass of ClutterOffscreen. It is only needed because
ClutterOffscreen is abstract. Removing the effect also makes it so
that the cached image will be freed as soon as an actor is repainted
without being flattened.
This adds a property which can be used to redirect the actor through
an FBO before painting so that it becomes flattened in an image. The
image can be used as a cache to avoid having to repaint the actor if
something unrelated in the scene changes. It can also be used to
implement correct opacity even if the actor has overlapping
primitives. The property is an enum that takes three values:
CLUTTER_OFFSCREEN_REDIRECT_NEVER: The default behaviour which is to
never flatten the actor.
CLUTTER_OFFSCREEN_REDIRECT_ALWAYS: The actor is always redirected
through an FBO.
CLUTTER_OFFSCREEN_REDIRECT_ONLY_FOR_OPACITY: The actor is only
redirected through an FBO if the paint opacity is not 255. This
value would be used if the actor wants correct opacity. It will
avoid the overhead of using an FBO whenever the actor is fully
opaque.
The property is implemented by installing a ClutterFlattenEffect.
ClutterFlattenEffect is a new internal class which subclasses
ClutterOffscreen to redirect the painting to an FBO. When
ClutterOffscreen paints, the effect sets an opacity override on the
actor so that the image will always contain the actor at full
opacity. The opacity is then applied to the resulting image before
painting it to the stage. This means the actor does not need to be
redrawn while the opacity is being animated.
The effect has a high internal priority so that it will always occur
before any other effects and it gets hidden from the application.
When calling clutter_actor_clear_constraints the layout of the actor
may change so we need to queue a relayout. Similarly when the effects
are cleared we need to queue a redraw.
This adds a priority property to all ClutterActorMetas. The
ClutterMetaGroup keeps the list sorted so that higher priority metas
remain at the beginning of the list. The priority is a signed integer
with the default as zero. An actor meta can therefore be put before
all default metas with a positive number, or after with a negative
number.
There are constants to set an 'internal' priority. The intention is
that applications wouldn't be allowed to use these values so that we
can keep special internal metas to that are before or after all
application metas.
The property isn't a real GObject property because for now it is
completely internal and only used to implement the 'transparency'
property of ClutterActor. ClutterMetaGroup doesn't currently resort
the list if the property changes so if we wanted to make it public we
should either make it construct-only or make the meta group listen for
changes on the property and resort accordingly.
The methods in ClutterActor that get the list of metas now use a new
function that filters out internal metas from the meta
group. Similarly for clearing the metas, the internal metas are left
in.
This adds a new public function to queue a rerun of an effect. If
nothing else queues a redraw then when the effect's actor is painted
the effect will be run without the CLUTTER_EFFECT_RUN_ACTOR_DIRTY
flag. This allows parametrised offscreen effects to report that they
need to redraw the image without having to redraw the underlying
actor. This will be used to implement the 'transparency' effect of
ClutterActor.
If multiple redraws are queued with different effects then redrawing
is started from the one that occurs last in the list of effects.
Internally the function is a wrapper around the new function
_clutter_actor_queue_redraw_full. This is intended to be the sole
point of code for queuing redraws on an actor. It has parameters for
the clip and the effect. The other two existing functions to queue a
redraw (one with a clip and one without) now wrap around this function
by passing a NULL effect.
When painting an actor, it now tries to determine if the last paint of
the offscreen was using the same matrix and the actor isn't dirty. If
so, it can skip calling clutter_actor_continue_paint and avoid
actually painting the actor. Instead just the offscreen image will be
painted.
This adds a new virtual to ClutterEffect which is intended to be a
more flexible replacement for the pre and post_paint functions. The
implementation of a run virtual would look something like this:
void
effect_run (ClutterEffect *effect,
ClutterEffectRunFlags flags)
{
/* Set up state */
/* ... */
/* Chain to the next item in the paint sequence */
clutter_actor_continue_paint (priv->actor);
/* Clean up state */
/* ... */
}
ClutterActor now just calls this virtual instead of the pre_paint and
post_paint functions. It keeps track of the next effect in the list so
that it knows what to do when clutter_actor_continue_paint is
called. clutter_actor_continue_paint is a new function added just for
implementing effects.
The default implementation of the run virtual just calls pre_paint and
post_paint so that existing effects will continue to work.
An effect is allowed to conditionally skip calling
clutter_actor_continue_paint(). This is useful to implement effects
that cache the image of an actor. The flags parameter can be used to
determine if the actor is dirty since the last paint. ClutterActor
sets this flag whenever propagated_one_redraw is TRUE which means that
a redraw for this actor or one of its children was queued.
The id pool used for the actor's id should be a per-stage field. At some
point, we might have a Stage mapped to multiple framebuffers, or each
Stage mapped to a different framebuffer; also, on backend with low
color precision we don't want to exhaust the size of the available ids
with a global pool. Finally, it's yet another thing we can remove from
the global Clutter context.
Having the id pool allocated per-stage, and the pick id assigned on
Actor:mapped will make the whole pick-id more reliable and future proof.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2633https://bugzilla.gnome.org/show_bug.cgi?id=647876
In test-pixmap.c instead of using the GdkPixbuf API to load the
redhand.png image we now use the cairo API to load the png into a xlib
surface which wraps our Pixmap.
This test was the last thing that depended on the gdk API and since
it's more concise to use Cairo here which is a hard dependency for
Clutter this change means we avoid depending on GdkPixbuf directly.
Cogl has now been split out into a standalone project with a separate
repository at git://git.gnome.org/cogl. From now on the Clutter build
will now simply look for a cogl-1.0 pkg-config file to find a suitable
Cogl library to link against at build time.
Do not use GdkPixbuf just for getting image data down into a PNG; Cairo
is perfectly capable of doing the same, at least just for debugging
purposes.
https://bugzilla.gnome.org/show_bug.cgi?id=647875
It stands to reason that any piece of code using Cairo and Cogl at the
same time, and dealing with texture data, will want to use the same
logic Clutter uses to determine the compatible pixel format between the
two.
https://bugzilla.gnome.org/show_bug.cgi?id=647875
When comparing the wrap modes of two pipeline layers it now considers
COGL_WRAP_MODE_AUTOMATIC to be equivalent to CLAMP_TO_EDGE. By the
time the pipeline is in the journal, the upper primitive code is
expected to have overridden this wrap mode with something else if it
wants any other behaviour. This is important for getting text to batch
together with textures because the text explicitly sets the wrap mode
to CLAMP_TO_EDGE on its pipeline.
The material cache will now only set the special combine mode if the
texture only has an alpha component. The atlased textures will have
all four components so it will leave the combine functions at the
default. This increases the chances of batching between glyphs and
images.
When using the global atlas, the glyph from cairo is now rendered into
an ARGB surface rather than an alpha-only surface.
Instead of creating just two materials (one for texturing and one for
solid primitives) the pango renderer now maintains a cache of
pipelines. The display list can request a pipeline for a texture from
the cache. The same pipeline cache is used by all display lists so
that the pipelines can be shared. This avoids changing the texture on
the material during a paint run.
It now avoids trying to reserve space for zero-sized glyphs. That
happens for example when the layout contains a space. This was causing
the regular glyph cache to be used because the global atlas does not
support zero-sized images. That would then break up the
batching. Instead it now still reserves an entry in the cache but
leaves the texture as COGL_INVALID_HANDLE.
When rendering a glyph from a texture, instead of adding the glyph's
texture handle to the display list it now retrieves the base texture
using _cogl_texture_foreach_subtexture_in_region and adds that
instead. That way the display can recognise that glyphs in the global
atlas are sharing the same texture and combine them into one VBO.
Whenever the glyph cache puts a glyph in the global atlas it will now
register for notifications of reorganisation of the global
atlases. When this happens it will forward this on as a notification
of reorganisation of the glyph cache.
This adds cogl_atlas_texture_* functions to register a callback that
will get invoked whenever any of the CoglAtlas's the textures use get
reorganized. The callback is global and is not tied to any particular
atlas texture.
If mipmapping is disabled, it will now try to create a standalone
atlas texture for a glyph rather than putting it in the atlas.
If the atlas texture can't be created then it will fallback to the
glyph cache.
This adds a new function called _cogl_atlas_texture_new_with_size. The
old new_from_bitmap function now just calls this and updates the
texture with the data.
If the texture can't be hardware repeated (ie, if it is sliced or it
has waste) then Cogl will reject the layer when rendering with a
VBO. In this case we should always fall back to rendering with
cogl_rectangle.
This commit is only needed temporarily because Cogl will end up
putting atlas textures in the display list. A later commit in the
series will make it so that the display list always has primitive
textures in it so this commit can be reverted.
This reverts the changes in 54d8aadf which combined the two glyph
caches into one. We want to start using separate caches again so that
we can non-mipmapped textures into the global atlas.
This extends cogl_onscreen_x11_set_foreign_xid to take a callback to a
function that details the event mask the Cogl requires the application
to select on foreign windows. This is required because Cogl, for
example, needs to track size changes of a window and may also in the
future want other notifications such as map/unmap.
Most applications wont need to use the foreign xwindow apis, but those
that do are required to pass a valid callback and update the event mask
of their window according to Cogl's requirements.
This adds Cogl API to show and hide onscreen framebuffers. We don't want
to go too far down the road of abstracting window system APIs with Cogl
since that would be out of its scope but the previous idea that we would
automatically map framebuffers on allocation except for those made from
foreign windows wasn't good enough. The problem is that we don't want to
make Clutter always create stages from foreign windows but with the
automatic map semantics then Clutter doesn't get an opportunity to
select for all the events it requires before mapping. This meant that we
wouldn't be delivered a mouse enter event for windows mapped underneath
the cursor which would break Clutters handling of button press events.
When building on windows for example we need to ensure we pass
-no-undefined to the linker. Although we were substituting a
COGL_EXTRA_LDFLAGS variable from our configure.ac we forgot to
reference that when linking cogl-pango.
For compatibility with the way we build Cogl as part of Clutter we now
substitute an empty MAINTAINER_CFLAGS variable. When building Cogl
standalone all our extra CFLAGS go through COGL_EXTRA_CFLAGS so the
separate MAINTAINER_CFLAGS aren't used, but automake will get confused
if a substitution isn't made.
This fixes the gdk-pixbuf check to not mistakenly check for the "xi"
package instead of gdk-pixbuf and remove a spurious listing "gl" in
COGL_PKG_REQUIRES which should only be there when we are using using
opengl not if we are using gles.
When building on windows for example we need to ensure we pass
-no-undefined to the linker. Although we were substituting a
COGL_EXTRA_LDFLAGS variable from our configure.ac we forgot to
reference that when linking cogl.
Until Cogl gains native win32/OSX support this remove the osx and win32
winsys files and instead we'll just rely on the stub-winsys.c to handle
these platforms. Since the only thing the platform specific files were
providing anyway was a get_proc_address function; it was trivial to
simply update the clutter backend code to handle this directly for now.
This is a workaround for a bug on OSX for some radeon hardware that
we can't verify and the referenced bug link is no longer valid.
If this is really still a problem then a new bug should be opened and we
can look at putting the fix in some more appropriate place than
cogl-gl.c
We want to be able to split Cogl out as a standalone project but there
are still some window systems that aren't natively supported by Cogl.
This allows Clutter to support those window systems directly but still
work with a standalone Cogl library.
This also ensures we set the SUPPORT_STUB conditional in clutter's
configure.ac when building for win32/osx and wayland.
For now we are going for the semantics that when a CoglOnscreen is first
allocated then it will automatically be mapped. This is for convenience
and if you don't want that behaviour then it is possible to instead
create an Onscreen from a foreign X window and in that case it wont be
mapped automatically.
This approach means that Cogl doesn't need onscreen_map/unmap functions
but it's possible we'll decide later that we can't avoid adding such
functions and we'll have to change these semantics.
Instead of using AC_DEFINE for the various COGL_HAS_PLATFORM defines
this now adds them to the COGL_DEFINES_SYMBOLS variable which gets
substituted into the public cogl-defines.h header.
This adds a simple standalone Cogl application that can be used to
smoke test a standalone build of Cogl without Clutter.
This also adds an x11-foreign app that shows how a toolkit can ask Cogl
to draw to an X Window that it owns instead of Cogl being responsible
for automatically creating and mapping an X Window for CoglOnscreen.
This allows more detailed control over the driver and winsys features
that Cogl should have. Cogl is designed so it can support multiple
window systems simultaneously so we have enable/disable options for
the drivers (gl vs gles1 vs gles2) and options for the individual window
systems; currently glx and egl. Egl is broken down into an option
for each platform.
The GDL API is used for example on intel ce4100 (aka Sodaville) based
systems as a way to allocate memory that can be composited using the
platforms overlay hardware. This updates the Cogl EGL winsys and the
support in Clutter so we can continue to support these platforms.
So that we can dynamically select what winsys backend to use at runtime
we need to have some indirection to how code accesses the winsys instead
of simply calling _cogl_winsys* functions that would collide if we
wanted to compile more than one backend into Cogl.
This moves the GLX specific code from cogl-texture-pixmap-x11.c into
cogl-winsys-glx.c. If we want the winsys components to by dynamically
loadable then we can't have GLX code scattered outside of
cogl-winsys-glx.c. This also sets us up for supporting the
EGL_texture_from_pixmap extension which is almost identical to the
GLX_texture_from_pixmap extension.
As was recently done for the GLX window system code, this commit moves
the EGL window system code down from the Clutter backend code into a
Cogl winsys.
Note: currently the cogl/configure.ac is hard coded to only build the GLX
winsys so currently this is only available when building Cogl as part
of Clutter.
The "DRM_SURFACELESS" EGL platform was invented when we were adding the
wayland backend to Clutter but in the end we added a dedicated backend
instead of extending the EGL backend so actually the platform name isn't
used.
Commit b061f737 moved _cogl_winsys_has_feature to the common winsys
code so there's no need to define it in the stub winsys any more. This
was breaking builds for backends using the stub winsys.
The comparison for finding onscreen framebuffers in
find_onscreen_for_xid had a small thinko so that it would ignore
framebuffers when the negation of the type is onscreen. This ends up
doing the right thing anyway because the onscreen type has the value 0
and the offscreen type has the value 1 but presumably it would fail if
we ever added any other framebuffer types.
The dispose function may be called multiple times during destruction
so it needs to be resilient against destroying any resources
twice. This wasn't the case for the reference to the Cogl context.
The code for _cogl_winsys_has_feature will be identical in all of the
winsys backends for the time being, so it seems to make sense to have
it in the common cogl-winsys.c file.
Previously the mask of available winsys features was stored in a
CoglBitmask. That isn't the ideal type to use for this because it is
intended for a growable array of bits so it can allocate extra memory
if there are more than 31 flags set. For the winsys feature flags the
highest used bit is known at compile time so it makes sense to
allocate a fixed array instead. This is conceptually similar to the
CoglDebugFlags which are stored in an array of integers with macros to
test a bit in the array. This moves the macros used for CoglDebugFlags
to cogl-flags.h and makes them more generic so they can be shared with
CoglContext.
Instead of having cogl_renderer_xlib_add_filter and friends there is
now cogl_renderer_add_native_filter which can be used regardless of
the backend. The callback function for the filter now just takes a
void pointer instead of an XEvent pointer which should be interpreted
differently depending on the backend. For example, on Xlib it would
still be an XEvent but on Windows it could be a MSG. This simplifies
the code somewhat because the _cogl_xlib_add_filter no longer needs to
have its own filter list when a stub renderer is used because there is
always a renderer available.
cogl_renderer_xlib_handle_event has also been renamed to
cogl_renderer_handle_native_event. This just forwards the event on to
all of the listeners. The backend renderer is expected to register its
own event filter if it wants to process the events in some way.
ClutterAnimation uses the weak ref machinery of GObject when associated
to ClutterActor by clutter_actor_animate() and friends - all the while
taking a reference on the actor itself. In order to trigger the weak ref
callback, external code would need to unref the Actor at least twice,
which has slim chance of happening. Plus, the way to destroy an Actor is
to call destroy(), not call unref().
The destruction sequence of ClutterActor emits the ::destroy signal, which
should be used by classes to release external references the might be
holding. My oh my, this sounds *exactly* the case!
So, let's switch to using the ::destroy signal for clutter_actor_animate()
and friends, since we know that the object bound to the Animation is
an Actor, and has a ::destroy signal.
This change has the added benefit of allowing destroying an actor as the
result of the Animation::completed signal without getting a segfault or
other bad things to happen.
Obviously, the change does not affect other GObject classes, or Animation
instances created using clutter_animation_new(); for those, the current
"let's take a reference on the object to avoid it going away in-flight"
mechanism should still suffice.
Side note: it would be interesting if GObject had an interface for
"destructible" objects, so that we could do a safe type check. I guess
it's a Rainy Day Project(tm)...
Do not use the generic GType class name: we have a :name property on
ClutterActor that is generally used for debugging purposes — so we
should use it when creating debugging spew in a consistent way.
The Cogl rework removed the Window creation from realize and its
relative destruction from unrealize; the two vfuncs also managed
the mapping between Window and Stage implementation that we use
when dealing with event handling. Sadly, the missing unrealization
left entries in the mapping dangling.
Since ClutterStageX11 already provides a ::realize implementation
that sub-classes are supposed to chain up to, and the Window ↔ Stage
mapping is private to clutter-stage-x11.c, it seems only fair that
the ClutterStageX11 should also provide an ::unrealize implementation
matching the ::realize.
This implementation just removes the StageX11 pointer from the X11
Window ↔ ClutterStageX11 mapping we set up in ::realize, since the
X11 Window is managed by Cogl, now.
Older drivers for PowerVR SGX hardware have the vendor-specific
GL_IMG_TEXTURE_NPOT extension instead of the
functionally-equivalent GL_OES_TEXTURE_NPOT extension.
We need to guard the usage of symbols related to the
GLX_INTEL_swap_event extension, to avoid breaking on platforms and/or
versions of Mesa that do not expose that extension.
It's generally useful to be able to query the width and height of a
framebuffer and we expect to need this in Clutter when we move the
eglnative backend code into Cogl since Clutter will need to read back
the fixed size of the framebuffer when realizing the stage.
This backend hasn't been used for years now and so because it is
untested code and almost certainly doesn't work any more it would be a
burdon to continue trying to maintain it. Considering that we are now
looking at moving OpenGL window system integration code down from
Clutter backends into Cogl that will be easier if we don't have to
consider this backend.
This makes it possible to build Clutter against a standalone build of
Cogl instead of having the Clutter build traverse into the clutter/cogl
subdirectory.
This adds an autogen.sh, configure.ac and build/autotool files etc under
clutter/cogl and makes some corresponding Makefile.am changes that make
it possible to build and install Cogl as a standalone library.
Some notable things about this are:
A standalone installation of Cogl installs 3 pkg-config files;
cogl-1.0.pc, cogl-gl-1.0.pc and cogl-2.0.pc. The second is only for
compatibility with what clutter installed though I'm not sure that
anything uses it so maybe we could remove it. cogl-1.0.pc is what
Clutter would use if it were updated to build against a standalone cogl
library. cogl-2.0.pc is what you would use if you were writing a
standalone Cogl application.
A standalone installation results in two libraries currently, libcogl.so
and libcogl-pango.so. Notably we don't include a major number in the
sonames because libcogl supports two major API versions; 1.x as used by
Clutter and the experimental 2.x API for standalone applications.
Parallel installation of later versions e.g. 3.x and beyond will be
supportable either with new sonames or if we can maintain ABI then we'll
continue to share libcogl.so.
The headers are similarly not installed into a directory with a major
version number since the same headers are shared to export the 1.x and
2.x APIs (The only difference is that cogl-2.0.pc ensures that
-DCOGL_ENABLE_EXPERIMENTAL_2_0_API is used). Parallel installation of
later versions is not precluded though since we can either continue
sharing or later add a major version suffix.
This migrates all the GLX window system code down from the Clutter
backend code into a Cogl winsys. Moving OpenGL window system binding
code down from Clutter into Cogl is the biggest blocker to having Cogl
become a standalone 3D graphics library, so this is an important step in
that direction.
As part of the process of splitting Cogl out as a standalone graphics
API we need to introduce some API concepts that will allow us to
initialize a new CoglContext when Clutter isn't there to handle that for
us...
The new objects roughly in the order that they are (optionally) involved
in constructing a context are: CoglRenderer, CoglOnscreenTemplate,
CoglSwapChain and CoglDisplay.
Conceptually a CoglRenderer represents a means for rendering. Cogl
supports rendering via OpenGL or OpenGL ES 1/2.0 and those APIs are
accessed through a number of different windowing APIs such as GLX, EGL,
SDL or WGL and more. Potentially in the future Cogl could render using
D3D or even by using libdrm and directly banging the hardware. All these
choices are wrapped up in the configuration of a CoglRenderer.
Conceptually a CoglDisplay represents a display pipeline for a renderer.
Although Cogl doesn't aim to provide a detailed abstraction of display
hardware, on some platforms we can give control over multiple display
planes (On TV platforms for instance video content may be on one plane
and 3D would be on another so a CoglDisplay lets you select the plane
up-front.)
Another aspect of CoglDisplay is that it lets us negotiate a display
pipeline that best supports the type of CoglOnscreen framebuffers we are
planning to create. For instance if you want transparent CoglOnscreen
framebuffers then we have to be sure the display pipeline wont discard
the alpha component of your framebuffers. Or if you want to use
double/tripple buffering that requires support from the display
pipeline.
CoglOnscreenTemplate and CoglSwapChain are how we describe our default
CoglOnscreen framebuffer configuration which can affect the
configuration of the display pipeline.
The default/simple way we expect most CoglContexts to be constructed
will be via something like:
if (!cogl_context_new (NULL, &error))
g_error ("Failed to construct a CoglContext: %s", error->message);
Where that NULL is for an optional "display" parameter and NULL says to
Cogl "please just try to do something sensible".
If you want some more control though you can manually construct a
CoglDisplay something like:
display = cogl_display_new (NULL, NULL);
cogl_gdl_display_set_plane (display, plane);
if (!cogl_display_setup (display, &error))
g_error ("Failed to setup a CoglDisplay: %s", error->message);
And in a similar fashion to cogl_context_new() you can optionally pass
a NULL "renderer" and/or a NULL "onscreen template" so Cogl will try to
just do something sensible.
If you need to change the CoglOnscreen defaults you can provide a
template something like:
chain = cogl_swap_chain_new ();
cogl_swap_chain_set_has_alpha (chain, TRUE);
cogl_swap_chain_set_length (chain, 3);
onscreen_template = cogl_onscreen_template_new (chain);
cogl_onscreen_template_set_pixel_format (onscreen_template,
COGL_PIXEL_FORMAT_RGB565);
display = cogl_display_new (NULL, onscreen_template);
if (!cogl_display_setup (display, &error))
g_error ("Failed to setup a CoglDisplay: %s", error->message);
This tries to make the naming style of files under cogl/winsys/
consistent with other cogl source files. In particular private header
files didn't have a '-private' infix.
This gives us a way to clearly track the internal Cogl API that Clutter
depends on. The aim is to split Cogl out from Clutter into a standalone
3D graphics API and eventually we want to get rid of any private
interfaces for Clutter so its useful to have a handle on that task.
Actually it's not as bad as I was expecting though.
This extends visualization for CLUTTER_PAINT=redraws so it now also
draws outlines for actors to show how they are being culled. Actors get
a green outline if they are fully inside the clip region, blue if fully
outside and greeny-blue if only partially inside.
This adds an internal _clutter_stage_get_active_framebuffer function
that can be used to get a pointer to the current CoglFramebuffer pointer
that is in use, in association with a given stage.
The "active" infix in the function name is there because we shouldn't
assume that a stage will always correspond to only a single framebuffer
so we aren't getting a pointer to a sole framebuffer, we are getting
a pointer to the framebuffer that is currently in use/being painted.
This API is now used for culling purposes where we need to check if we
are currently painting an actor to a framebuffer that is offscreen, that
doesn't correspond to the stage.
This renames the two internal functions _cogl_get_draw/read_buffer
as cogl_get_draw_framebuffer and _cogl_get_read_framebuffer. The
former is now also exposed as experimental API.
The long term goal with the Cogl API is that we will get rid of the
default global context. As a step towards this, this patch tracks a
reference back to the context in each CoglFramebuffer so in a lot of
cases we can avoid using the _COGL_GET_CONTEXT macro.
There is no corresponding implementation of _cogl_features_init any more
so it was simply an oversight that the prototype wasn't removed when the
implementation was removed.
Recently _cogl_swap_buffers_notify was added (in 142b229c5c) so that
Cogl would be notified when Clutter performs a swap buffers request for
a given onscreen framebuffer. It was expected this would be required for
the recent cogl_read_pixel optimization that was implemented (ref
1bdb0e6e98) but in the end it wasn't used.
Since it wasn't used in the end this patch removes the API.
This moves the functionality of _cogl_create_context_driver from
driver/{gl,gles}/cogl-context-driver-{gl,gles}.c into
driver/{gl,gles}/cogl-{gl,gles}.c as a static function called
initialize_context_driver.
cogl-context-driver-{gl,gles}.[ch] have now been removed.
This adds a new experimental function (you need to define
COGL_ENABLE_EXPERIMENTAL_API to access it) which takes us towards being
able to have a standalone Cogl API. This is really a minor aesthetic
change for now since all the GL context creation code still lives in
Clutter but it's a step forward none the less.
Since our current designs introduce a CoglDisplay object as something
that would be passed to the context constructor this provides a stub
cogl-display.h with CoglDisplay typedef.
_cogl_context_get_default() which Clutter uses to access the Cogl
context has been modified to use cogl_context_new() to initialize
the default context.
There is one rather nasty hack used in this patch which is that the
implementation of cogl_context_new() has to forcibly make the allocated
context become the default context because currently all the code in
Cogl assumes it can access the context using _COGL_GET_CONTEXT including
code used to initialize the context.
This moves the implementation of _clutter_do_pick to clutter-stage.c and
renames it _clutter_stage_do_pick. This function can be compared to
_clutter_stage_do_update/redraw in that it prepares for and starts a
traversal of a scenegraph descending from a given stage. Since it is
desirable that this function should have access to the private state of
the stage it is awkward to maintain outside of clutter-stage.c.
Besides moving _clutter_do_pick this patch is also able to remove the
following private state accessors from clutter-stage-private.h:
_clutter_stage_set_pick_buffer_valid,
_clutter_stage_get_pick_buffer_valid,
_clutter_stage_increment_picks_per_frame_counter,
_clutter_stage_reset_picks_per_frame_counter and
_clutter_stage_get_picks_per_frame_counter.
This updates the inner loops of the cull function so now the vertices of
the polygon being culled are iterated in the inner loop instead of the
clip planes and we count how many vertices are outside the current
plane so we can bail out immediately if all the vertices are outside of
any plane and so we can correctly track partial intersections with the
clip region.
The previous approach could catch some partial intersections but for
example a rectangle that was larger than the clip region centred over
the clip region with all corners outside would be reported as outside,
not as a partial intersection.
In 047227fb cogl_atlas_new was changed so that it can take a flags
parameter to specify whether to clear the new atlases and whether to
copy images to the new atlas after reorganisation. This was done so
that the atlas code could be shared with the glyph cache. At some
point during the development of this patch the flag was just a single
boolean instead and this is accidentally how it is used from the glyph
cache. The glyph cache therefore passes 'TRUE' as the set of flags
which means it will only get the 'clear' flag and not the
'disable-migration' flag. When the glyph cache gets full it will
therefore try to copy the texture to the new atlas as well as
redrawing them with cairo. This causes problems because the glyph
cache needs to work in situations where there is no FBO support.
In _cogl_pipeline_prune_empty_layer_difference if the layer's parent
has no owner then it just takes ownership of it. However this could
theoretically end up taking ownership of the root layer because
according to the comment above in the same function that should never
have an owner. This patch just adds an extra check to ensure that the
unowned layer has a parent.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2588
In _cogl_pipeline_prune_empty_layer_difference if we are reverting to
the immediate parent of an empty/redundant layer then it is not enough
to simply add a reference to the pipeline's ->layer_differences list
without also updating parent_layer->owner to point back to its new
owner.
This oversight was leading us to break the invariable that all layers
referenced in layer_differences have an owner and was also causing us to
break another invariable whereby after calling
_cogl_pipeline_layer_pre_change_notify the returned layer must always be
owned by the given 'required_owner'.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2588
When we come to presenting the result of a clipped redraw to the front
buffer with a blit we need to ensure that all the rendering is done,
otherwise redraw operations that are slower than the framerate can queue
up in the pipeline during a heavy animation, causing a larger and larger
backlog of rendering visible as lag to the user.
Note: Since calling glFinish() and sycnrhonizing the CPU with the GPU is
far from ideal, we hope that this is only a short term solution.
One idea is to using sync objects to track render completion so we can
throttle the backlog (ideally with an additional extension that lets us
get notifications in our mainloop instead of having to busy wait for the
completion.)
Another option is to support clipped redraws by reusing the contents of
old back buffers such that we can flip instead of using a blit and then
we can use GLX_INTEL_swap_events to throttle. For this though we would
still probably want an additional extension so we can report the limited
region of the window damage to X/compositors.
Thanks to Owen Taylor and Alexander Larsson for reporting the problem.
clutter_clone_get_paint_volume was being exported from the shared
library because the function wasn't declared static. This function
shouldn't be exposed because it should be accessed through
clutter_actor_get_paint_volume.
The texture containing the image for the redirected actor will always
be painted at a 1:1 texel:pixel ratio so there's no need to use linear
filtering. This should also counteract some of the effects of rounding
errors when calculating the geometry for the quad.
if cross compiling clutter using mingw using an out of tree build
directory then a pre-requisite for creating the resources.o file
containing the transparent cursor is for the win32 directory itself to
be created at $(top_builddir)/clutter/win32.
glib already has a data type to manage a list of callbacks called a
GHookList so we might as well use it instead of maintaining Cogl's own
type. The glib version may be slightly more efficient because it
avoids using a GList and instead encodes the prev and next pointers
directly in the GHook structure. It also has more features than
CoglCallbackList.
Previously we were applying the culling optimization to any actor
painted without considering that we may be painting to an offscreen
framebuffer where the stage clip isn't applicable.
For now we simply expose a getter for the current draw framebuffer
and we can assume that a return value of NULL corresponds to the
stage.
Note: This will need to be updated as stages start to be backed by real
CoglFramebuffer objects and so we won't get NULL in those cases.
To give quick visibility to the things going on relating to clipping and
culling this adds some more CLIPPING debug notes to clutter-actor.c and
clutter-stage.c
As documented in cogl-pipeline-private.h, there is a precedence to the
ClutterPaintVolume bitfields that should be considered whenever we
implement code that manipulates PaintVolumes...
Firstly if ->is_empty == TRUE then the values for ->is_complete and
->is_2d are undefined, so we should typically check ->is_empty as the
first priority.
This fixes a bug in _clutter_paint_volume_cull() whereby we were
checking pv->is_complete before checking pv->is_empty which was
resulting in assertions for actors with no size.
