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.
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.
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 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 noted in commit ce3f55292a an explict glFlush is needed for
both glBlitFramebuffer and glXCopySubBuffer.
_clutter_backend_glx_blit_sub_buffer was already doing an explicit
flush when using glBlitFramebuffer, so just do it unconditonally
and remove the call from clutter_stage_glx_redraw.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2558
In the future, we want event translators to be the way to handle events
in backends. For this reason, they should be a part of the base abstract
ClutterBackend class, and not an X11-only concept.
Instead of asking all backends to do that for us, we can call
ClutterStageWindow::redraw ourselves by default.
This changeset fixes all backends to actually do the right thing, and
move the stage implementation redraw inside the ClutterStageWindow
implementation itself.
Since we need to find the stage from the X11 Window, it's better to use
a static hashmap that gets updated every time the ClutterStageX11:xwin
member is changed, instead of iterating over every stage handled by the
global ClutterStageManager singleton.
Since we access it in order to get the X11 Display pointer, it makes
sense to have the ClutterBackendX11 already available inside the
ClutterStageX11 structure, and avoid the pattern:
ClutterBackend *backend = clutter_get_default_backend ();
ClutterBackendX11 *backend_x11 = CLUTTER_BACKEND_X11 (backend);
which costs us a function call, a type cast and an unused variable.
The x11 backend exposes a lot of symbols that are meant to only be used
when implementing a subclassed backend, like the glx and eglx ones.
The uninstalled headers are also filled with cruft declarations of
functions long since removed.
Let's try to clean up this mess.
This is a lump commit that is fairly difficult to break down without
either breaking bisecting or breaking the test cases.
The new design for handling X11 event translation works this way:
- ClutterBackend::translate_event() has been added as the central
point used by a ClutterBackend implementation to translate a
native event into a ClutterEvent;
- ClutterEventTranslator is a private interface that should be
implemented by backend-specific objects, like stage
implementations and ClutterDeviceManager sub-classes, and
allows dealing with class-specific event translation;
- ClutterStageX11 implements EventTranslator, and deals with the
stage-relative X11 events coming from the X11 event source;
- ClutterStageGLX overrides EventTranslator, in order to
deal with the INTEL_GLX_swap_event extension, and it chains up
to the X11 default implementation;
- ClutterDeviceManagerX11 has been split into two separate classes,
one that deals with core and (optionally) XI1 events, and the
other that deals with XI2 events; the selection is done at run-time,
since the core+XI1 and XI2 mechanisms are mutually exclusive.
All the other backends we officially support still use their own
custom event source and translation function, but the end goal is to
migrate them to the translate_event() virtual function, and have the
event source be a shared part of Clutter core.
The glx and egl(x) backends export some internal symbols. Hide these
symbols (using '_' prefix) to reduce ABI differentiation between the
glx and eglx flavours.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2267
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
If we have the GLX_SGI_video_sync extension then it's possible to always
keep track for the video sync counter each time we call glXSwapBuffers
or do a sub stage blit. This then allows us to avoid waiting before
issuing a blit if we can see that the counter has already progressed.
Also since we expect that glXCopySubBuffer is synchronized to the vblank
we don't need to use glFinish () in conjunction with the vblank wait
since the vblank wait's only purpose is to add a delay.
The GLX_SGI_video_sync spec explicitly says that it's only supported for
direct contexts so we don't setup up the function pointers if
glXIsDirect () returns GL_FALSE.
Neither glXCopySubBuffer or glBlitFramebuffer are integrated with the
swap interval of a framebuffer so that means when we do partial stage
updates (as Mutter does in response to window damage) then the blits
aren't throttled which means applications that throw lots of damage
events at the compositor can effectively cause Clutter to run flat out
taking up all the system resources issuing more blits than can even be
seen.
This patch now makes sure we use the GLX_SGI_video_sync or a
DRM_VBLANK_RELATIVE ioctl to throttle blits to the vblank frequency as
we do when using glXSwapBuffers.
Currently glXCopySubBufferMESA is used for sub stage redraws, but in case
a driver does not support GLX_MESA_copy_sub_buffer we fall back to redrawing
the complete stage which isn't really optimal.
So instead to directly fallback to complete redraws try using GL_EXT_framebuffer_blit
to do the BACK to FRONT buffer copies.
http://bugzilla.openedhand.com/show_bug.cgi?id=2128
While this is totally fine (None is 0L and, in the pointer context, will
be converted in the right internal NULL representation, which could be a
value with some bits to 1), I believe it's clearer to use NULL instead
of None when we talk about pointers.
glXSwapIntervalSGI only affects buffer swaps to the
current GLX drawable.
That means that calling it once in clutter_backend_glx_get_features
isn't sufficent, so set it up in clutter_backend_glx_ensure_context to
make sure it affects buffer swaps for the current drawable.
http://bugzilla.openedhand.com/show_bug.cgi?id=2044
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Fix clutter initialisation if argb visuals are enabled, setting a border
color on creating the dummy window. This should avoid BadMatch happening
when the depth of the root window visual is not the same of the depth
of the argb visual.
http://bugzilla.openedhand.com/show_bug.cgi?id=2011
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
A new (internal only currently) API, _clutter_actor_queue_clipped_redraw
can be used to queue a redraw along with a clip rectangle in actor
coordinates. This clip rectangle propagates up to the stage and clutter
backend which may optionally use the information to optimize stage
redraws. The GLX backend in particular may scissor the next redraw to
the clip rectangle and use GLX_MESA_copy_sub_buffer to present the stage
subregion.
The intention is that any actors that can naturally determine the bounds
of updates should queue clipped redraws to reduce the cost of updating
small regions of the screen.
Notes:
» If GLX_MESA_copy_sub_buffer isn't available then the GLX backend
ignores any clip rectangles.
» queuing multiple clipped redraws will result in the bounding box of
each clip rectangle being used.
» If a clipped redraw has a height > 300 pixels then it's promoted into
a full stage redraw, so that the GPU doesn't end up blocking too long
waiting for the vsync to reach the optimal position to avoid tearing.
» Note: no empirical data was used to come up with this threshold so
we may need to tune this.
» Currently only ClutterX11TexturePixmap makes use of this new API. This
is done via a new "queue-damage-redraw" signal that is emitted when
the pixmap is updated. The default handler queues a clipped redraw
with the assumption that the pixmap is being painted as a rectangle
covering the actors transformed allocation. If you subclass
ClutterX11TexturePixmap and change how it's painted you now also
need to override the signal handler and queue your own redraw.
Technically this is a semantic break, but it's assumed that no one
is currently doing this.
This still leaves a few unsolved issues with regards to optimizing sub
stage redraws that need to be addressed in further work so this can only
be considered a stepping stone a this point:
» Because we have no reliable way to determine if the painting of any
given actor is being modified any optimizations implemented using
_clutter_actor_queue_redraw_with_clip must be overridable by a
subclass, and technically must be opt-in for existing classes to avoid
a change in semantics. E.g. consider that a user connects to the paint
signal for ClutterTexture and paints a circle instead of a rectangle.
In this case any original logic to queue clipped redraws would be
incorrect.
» Currently only the implementation of an actor has enough information
with which to queue clipped redraws. E.g. It is not possible for
generic code in clutter-actor.c to queue a clipped redraw when hiding
an actor because actors have no way to report a "paint box". (remember
actors can draw outside their allocation and actors with depth may
also be projected outside of their allocation)
» The current plan is to add a actor_class->get_paint_cuboid()
virtual so actors can report a bounding cube for everything they
would draw in their current state and use that to queue clipped
redraws against the stage by projecting the paint cube into stage
coordinates.
» Our heuristics for promoting clipped redraws into full redraws to
avoid blocking the GPU while we wait for the vsync need improving:
» vsync issues aren't relevant for redirected/composited applications
so they should use different heuristics. In this case we instead
need to trade off the cost of blitting when using glXCopySubBuffer
vs promoting to a full redraw and flipping instead.
Since using addresses that might change is something that finally
the FSF acknowledge as a plausible scenario (after changing address
twice), the license blurb in the source files should use the URI
for getting the license in case the library did not come with it.
Not that URIs cannot possibly change, but at least it's easier to
set up a redirection at the same place.
As a side note: this commit closes the oldes bug in Clutter's bug
report tool.
http://bugzilla.openedhand.com/show_bug.cgi?id=521
The code has gotten really complicated to follow.
As soon as we have a sync-to-vblank mechanism we should just bail out.
Also, __GL_SYNC_TO_VBLANK (which is used by nVidia) should be assumed
equivalent to a CLUTTER_VBLANK_GLX_SWAP.
Some of the ClutterDebugFlags are not meant as a logging facility: they
actually change Clutter's behaviour at run-time.
It would be useful to have this distinction ratified, and thus split
ClutterDebugFlags into two: one DebugFlags for logging facilities and
another set of flags for behavioural changes.
This split is warranted because:
• it should be possible to do "CLUTTER_DEBUG=all" and only have
log messages on the output
• it should be possible to use behavioural modifiers even on a
Clutter that has been compiled without debugging messages
support
The commit adds two new debugging flags:
ClutterPickDebugFlags - controlled by the CLUTTER_PICK environment
variable
ClutterPaintDebugFlags - controlled by the CLUTTER_PAINT environment
variable
The PickDebugFlags are:
nop-picking
dump-pick-buffers
While the PaintDebugFlags is:
disable-swap-events
The mechanism is equivalent to the CLUTTER_DEBUG environment variable,
but it does not depend on the debug level selected when configuring and
compiling Clutter. The picking and painting debugging flags are
initialized at clutter_init() time.
http://bugzilla.openedhand.com/show_bug.cgi?id=1991
OpenGL is an implementation detail for Cogl so it's not appropriate to
expose OpenGL extensions through the Cogl API.
Note: Clutter is currently still using this API, because it is still
doing raw GL calls in ClutterGLXTexturePixmap, so this introduces a
couple of (legitimate) build warnings while compiling Clutter.
This fixes some backwards logic for asserting that we have a GLX major
version == 1 and a minor version >= 2. (NB: Although we technically
depend on GLX 1.3 features, we still have to support drivers that report
GLX 1.2 because there are a lot of mesa drivers out there incorrectly
report GLX 1.2 even though they export extensions that depend on GLX
1.3)
If your OpenGL driver supports GLX_INTEL_swap_event that means when
glXSwapBuffers is called it returns immediatly and an XEvent is sent when
the actual swap has finished.
Clutter can use the events that notify swap completion as a means to
throttle rendering in the master clock without blocking the CPU and so it
should help improve the performance of CPU bound applications.
Some extensions only support GLX versions > 1.3 and may not support
old style X Windows as GLXDrawables, so we now create GLXWindows for
stages when possible.
The reason why we have a dummy, offscreen Window when we create the
GLX context is that GLX does not like it when you ask the context for
features if it's not made current to a Drawable. Maybe in the future
it will allow us to do so, but right now we have to make do with what
GLX offers us.
Instead of using g_critical() inside the create_context() implementation
of the ClutterBackendGLX we should use the passed GError, so that the
error message can bubble up to the caller.
Since we must guarantee that Cogl has a GL context to query, it is too
late to use the "dummy Window" trick from within the get_features()
virtual function implementation.
Instead, we can create a dummy Window from create_context() itself and
leave it around - basically trading a default stage with a dummy X
window.
We need to have the dummy X window around all the time so that the
GLX context can be selected and made current.
UProf is a small library that aims to help applications/libraries provide
domain specific reports about performance. It currently provides high
precision timer primitives (rdtsc on x86) and simple counters, the ability
to link statistics between optional components at runtime and makes report
generation easy.
This adds initial accounting for:
- Total mainloop time
- Painting
- Picking
- Layouting
- Idle time
The timing done by uprof is of wall clock time. It's not based on stochastic
samples we simply sample a counter at the start and end. When dealing with
the complexities of GPU drivers and with various kinds of IO this form of
profiling can be quite enlightening as it will be able to represent where
your application is blocking unlike tools such as sysprof.
To enable uprof accounting you must configure Clutter with --enable-profile
and have uprof-0.2 installed from git://git.moblin.org/uprof
If you want to see a report of statistics when Clutter applications exit you
should export CLUTTER_PROFILE_OUTPUT_REPORT=1 before running them.
Just a final word of caution; this stuff is new and the manual nature of
adding uprof instrumentation means it is prone to some errors when modifying
code. This just means that when you question strange results don't rule out
a mistake in the instrumentation. Obviously though we hope the benfits out
weigh e.g. by focusing on very key stats and by having automatic reporting.
Since asking for ARGB by default is still somewhat experimental on X11
and not every toolkit or complex widgets (like WebKit) still do not like
dealing with ARGB visuals, we should switch back to RGB by default - now
that at least we know it works.
For applications (and toolkit integration libraries) that want to enable
the ClutterStage:use-alpha property there is a new function:
void clutter_x11_set_use_argb_visual (gboolean use_argb);
which needs to be called before clutter_init().
The CLUTTER_DISABLE_ARGB_VISUAL environment variable can still be used
to force this value off at run-time.
When Clutter tries to pick an ARGB visual it tried to set the
GLX_TRANSPARENT_TYPE attribute of the FBConfig to
GLX_TRANSPARENT_RGB. However the code to do this was broken so that it
was actually trying to set the non-existant attribute number 0x8008
instead. Mesa silently ignored this so it appeared as if it was
working but the Nvidia drivers do not like it.
It appears that the TRANSPARENT_TYPE attribute is not neccessary for
getting an ARGB visual anyway and instead it is intended to support
color-key transparency. Therefore we can just remove it and get all of
the FBConfigs. Then if we need an ARGB visual we can just walk the
list to look for one with depth == 32.
The fbconfig is now stored in a single variable instead of having a
separate variable for the rgb and rgba configs because the old code
only ever retrieved one of them anyway.
When requesting the GLXFBConfig for creating the GLX context, we should
always request one that links to an ARGB visual instead of a plain RGB
one.
By using an ARGB visual we allow the ClutterStage:use-alpha property to
work as intended when running Clutter under a compositing manager.
The default behaviour of requesting an ARGB visual can be disabled by
using the:
CLUTTER_DISABLE_ARGB_VISUAL
Environment variable.
This replaces calls to the old (glx 1.2) functions glXChooseVisual,
glXCreateContext, glXMakeCurrent with the 1.3+ fbconfig varients
glXChooseFBConfig, glXCreateNewContext, glXMakeContextCurrent.
The only backend that tried to implement offscreen stages was the GLX backend
and even this has apparently be broken for some time without anyone noticing.
The property still remains and since the property already clearly states that
it may not work I don't expect anyone to notice.
This simplifies quite a bit of the GLX code which is very desireable from the
POV that we want to start migrating window system code down to Cogl and the
simpler the code is the more straight forward this work will be.
In the future when Cogl has a nicely designed API for framebuffer objects then
re-implementing offscreen stages cleanly for *all* backends should be quite
straightforward.
Instead of using ClutterActor for the base class of the Stage
implementation we should extend the StageWindow interface with
the required bits (geometry, realization) and use a simple object
class.
This require a wee bit of changes across Backend, Stage and
StageWindow, even though it's mostly re-shuffling.
First of all, StageWindow should get new virtual functions:
* geometry:
- resize()
- get_geometry()
* realization
- realize()
- unrealize()
This covers all the bits that we use from ClutterActor currently
inside the stage implementations.
The ClutterBackend::create_stage() virtual function should create
a StageWindow, and not an Actor (it should always have been; the
fact that it returned an Actor was a leak of the black magic going
on underneath). Since we never guaranteed ABI compatibility for
the Backend class, this is not a problem.
Internally to ClutterStage we can finally drop the shenanigans of
setting/unsetting actor flags on the implementation: if the realization
succeeds, for instance, we set the REALIZED flag on the Stage and
we're done.
As an initial proof of concept, the X11 and GLX stage implementations
have been ported to the New World Order(tm) and show no regressions.
Right now we just check for a NULL stage before calling glXMakeCurrent().
We can, though, get a valid stage without an implementation attached to
it while we are disposing a stage after a CLUTTER_DELETE event, since the
events processing is performed on a vblank-locked basis.
