It's unlikely that anyone will want to have, say, a GtkWidget that
also acts as a GdkFrameClock, so an abstract base class is as
flexible as making GdkFrameClock an interface, but has advantages:
- If we decide to never make implementing your own frame clock
possible, we can remove the virtualization.
- We can put functionality like history into the base class.
- Avoids the oddity of a interface without a public interface
VTable, which may cause problems for language bindings.
Instead of making the frame clock a settable property of a window, make
toplevel windows inherently have a frame clock when created (getting
rid of the default frame clock.) We need to create or destroy frame
clocks when reparenting a window to be a toplevel, or to not be a
toplevel, but otherwise the frame clock for a window is immutable.
Add a very simple GtkWidget function for an "tick" callback, which
is connected to the ::update signal of GdkFrameClock.
Remove:
- GtkTimeline. The consensus is that it is too complex.
- GdkPaintClockTarget. In the rare cases where tick callbacks
aren't sufficient, it's possible to track the
paint clock with ::realize/::unrealize/::hierarchy-changed.
GtkTimeline is kept using ::update directly to allow using a GtkTimeline
with a paint clock but no widget.
If we get a focus event for a X window we don't recognize, just
ignore it and avoid a g-critical when
_gdk_device_manager_core_handle_focus() is called with a NULL window.
Deprecate gdk_window_enable_synchronized_configure() and
gdk_window_configure_done() and make them no-ops. Implement the
handling of _NET_WM_SYNC_REQUEST in terms of the frame cycle -
we know that all processing will be finished in the next frame
cycle after the ConfigureNotify is received.
The first version of the video-timer simply played back the video
according to the wall clock, and showed each frame at the neareste
presentatin time. But an alternative strategy for playing back
video is that if the frame-rate is an integer-divisor of the
display refresh rate, or very close to that, is to change the playback
speed to complete avoid frame drops and changes in latency.
(This would require resampling audio if present.)
Demonstrate this technique by adding a --pll option to the
video-timer demo.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Add a test case that simulates the timing operaton that goes on
when showing a constant frame rate stream like a video - each
frame is shown at the VBlank interval that is closest to when it
would ideally be timed.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
For an operation like synchronizing audio to video playback, we need to
be able to predict the time that a frame will be presented. The details
of this depend on the windowing system, so make the backend predict
a presentation time for ::begin-frame and set it on the GdkFrameTimings.
The timing algorithm of GdkFrameClockIdle is adjusted to give predictable
presentation times for frames that are not throttled by the windowing
system.
Helper functions:
gdk_frame_clock_get_current_frame_timings()
gdk_frame_clock_get_refresh_info()
are added for operations that would otherwise be needed multiple times
in different locations.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Show the average and standard deviation of the latency in addition to
the frame rate. Add options to print the output in machine-readable form,
and to control the frequency and total number of statistics that will be
output.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
We want the compositor to do different things for frames where
"slept before" is TRUE. Communicate to the compositor that
frame is a no-delay frame (slept_before=FALSE) by ending the frame
by increasing the counter value by 1, and that the frame is a
normal frame (slept_before=TRUE) by increasing the counter value
by 3.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Add functions that tell us whether the main loop slept before we drew
a frame. Blocking with the frame clock frozen doesn't count as sleeping.
We'll use this to advertise to the compositor whether we
are drawing as fast as possible (and it should do the same) or timing
frames carefully (and it should do the same.)
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Don't start the idle if we're in the middle of painting a frame -
this will prevent us from getting the timing right when starting
the idle after the frame.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
In order to be able to track statistics about how well we are drawing,
and in order to be able to do sophisticated things with frame timing
like predicting per-frame latencies and synchronizing audio with video,
we need to be able to track exactly when previous frames were drawn
to the screen.
Information about each frame is stored in a new GdkFrameTimings object.
A new GdkFrameHistory object is added which keeps a queue of recent
GdkFrameTimings (this is added to avoid further complicating the
implementation of GdkFrameClock.)
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Instead of communicating the start of a frame to the window manager
as soon as we begin a frame, start a frame only when we know we've
actually created damage to the contents of a window.
(This uses cairo_set_mime_data() as a notification mechanism - a
clever suggestion from Uli Schlachter.)
The advantage of this is that we aren't forcing the compositor to
do a frame cycle and send _NET_WM_FRAME_DRAWN - depending on how the
compositor is structured that might either cause it to do extra
work or it might send _NET_WM_FRAME_DRAWN early and upset frame
timing.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Since events can be paused independently for each window during processing,
make _gdk_display_pause_events() count how many times it is called
and only unpause when unpause_events() is called the same number of
times.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Unqueuing events from the windowing system when paused could result
in weird reordering if event filters resulted in application-visible
behavior. Since we now resume events when the frame clock is frozen,
we now no longer count on low-level event handling running while
event handling is paused.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Keeping events paused after the end of a frame put us in a
weird state where we had to process and queue events - so that
we would get the message from the compositor - but not deliver
them. Instead resume events before ending the frame.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
When we have pending motion events, instead of delivering them
directly, request the new FLUSH_EVENTS phase of the frame clock.
This allows us to compress repeated motion events sent to the
same window.
In the FLUSH_EVENTS phase, which occur at priority GDK_PRIORITY_EVENTS + 1,
we deliver any pending motion events then turn off event delivery
until the end of the next frame. Turning off event delivery means
that we'll reliably paint the compressed motion events even if more
have arrived.
Add a motion-compression test case which demonstrates behavior when
an application takes too long handle motion events. It is unusable
without this patch but behaves fine with the patch.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Add a test of a window with an animated size and contents. The
test accepts load factor command line argument to see how things
work as the drawing of the content requires more GPU resources.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
When we have a looping animation for something like an angle,
we need to make sure that the distance we go past 1.0 becomes
the starting distance for the next frame. This prevents a
stutter at the loop position.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Use GdkFrameClock for the timing of GtkTimeline. This require the
user to provide either a GtkWidget or a GdkFrameClock when creating
the timeline. The default constructor now takes a GtkWidget. If you
want to create a GdkFrameClock without a widget, you need to use
g_object_new() and pass in a GdkFrameClock and GdkScreen.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
The frames-per-second for an animation should be controlled by how
fast we can process frames and the the frame-rate of the display; it's not
a meaningful app-settable property.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Add back the GtkTimeline code that previously made private and
then removed. It will be hooked up to GdkFrameClock. This commit
purely adds the old code back.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Switch GtkStyleContext to using GdkFrameClock. To do this, add a new
UPDATE phase to GdkFrameClock.
Add a GdkFrameClockTarget interface with a single set_clock() method,
and use this to deal with the fact that GtkWidget only has a frame
clock when realized.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
If the backend is throttling paints, then the frame clock will be
frozen at the end of the frame. If not, then we need to add throttling,
so wait until 16ms after the start of the frame before beginning the
next frame.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
By starting with an odd frame counter value, we make the mapping
and initial paint of the window an atomic operation, avoiding
any visual artifacts from an unpainted window.
Possible improvement: start the frame when doing gdk_window_show(),
so that the same improvement occurs for windows that were previously
shown and are being mapped again.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
When a window is unmapped, freeze its frame clock. This avoids doing
unnecessary work, but also means that we won't block waiting for
_NET_WM_FRAME_DRAWN messages that will never be received since the
frame ended while the window was withdrawn.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
As part of the extended _NET_WM_SYNC_REQUEST_COUNTER protocol,
we get a _NET_WM_FRAME_DRAWN message for each frame we draw. Use this
to synchronize the updates we are doing with the compositing manager's
drawing, and ultimately with with display refresh.
We now set the sync request counters on all windows, including
override-redirect windows, since it is also useful to do synchronized,
atomic updates for such windows.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
By exporting two XSync counters on a toplevel window, we subscribe
to an extended form of the _NET_WM_SYNC_REQUEST_COUNTER protocol,
where the window manager can initiate an atomic frame, as previously,
but the application can also do so by incrementing the new counter to
an odd value, and then to an even value to finish the frame.
See:
https://mail.gnome.org/archives/wm-spec-list/2011-October/msg00006.html
The support for 64-bit integers that GLib requires is used to
simplify the logic.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Add the ability to freeze a frame clock, which pauses its operation,
then thaw it again later to resume.
Initially this is used to implement freezing updates when we are
waiting for ConfigureNotify in response to changing the size of
a toplevel.
We need a per-window clock for this to work properly, so add that
for the X11 backend.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
Instead of having gdk_frame_clock_request_frame() have
gdk_frame_clock_request_phase() where we can say what phase we need.
This allows us to know if we get a frame-request during layout whether
it's just a request for drawing from the layout, or whether another
layout phase is needed.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
We may receive events because SubstructureNotifyMask has been selected
for the root window. (Most likely, this would occur because GTK+
is being used inside a window manager like Metacity or Mutter.)
This can confuse various types of internal accounting, so detect
such events and comprehensively ignore them for GDK's internal
purposes. We still need to generate GDK events for these cases
because you can select for substructure events with
GDK_SUBSTRUCTURE_MASK.
https://bugzilla.gnome.org/show_bug.cgi?id=685460
This is necessary in order to have async operations on it.
All the old copy/free functions keeps working, and g_boxed_copy on a GObject
also works, so this should be mostly compatible, but techncally its a minor
ABI break since the GType changes fundamental type. Changes like this has
happened before though, like with GVariant becomming its own fundamental
type.
https://bugzilla.gnome.org/show_bug.cgi?id=693802
