There are cases when we want to advance a timeline from another time
source. We cannot use _clutter_timeline_do_tick() directly, as that
assumes that the timeline is already playing, so we'll need to create a
wrapper that toggles the playing flag around it.
The ::completed signal emission is part of the current cycle; repeating,
like the automatic reverse of the timeline's direction, happens after
the ::completed chain of handlers has been called.
It should be possible to ask a timeline what is its duration, taking
into account eventual repeats, and which repeat is the one currently
in progress.
These two functions allow writing animations that depend on the current
state of another timeline.
Being able to easily set the number of repeats has been a request for
the animation framework for some time now. The usual way to implement
this is: connect to the ::completed signal, use a static counter, and
stop the timeline when the counter hits a specific spot.
In the same light as the :auto-reverse property, we can make it easier
to implement this common functionality by adding a :repeat-count
property that, when set, limits the amount of loops that a Timeline can
perform before stopping itself.
In fact, we can implement the :loop property in terms of the
:repeat-count property just by using a sentinel value mapping to
"infinity", and map loop=FALSE to repeat-count=0, and loop=TRUE to
repeat-count=-1.
The clutter_timeline_clone() method was a pretty dumb idea when it was
introduced, back when we still had the ClutterEffectTemplate and the
clutter_effect_* animation API. It has since become an API wart: we
cannot change or add new properties to be cloned without the risk of
breaking existing code. All in all, cloning a GObject is just a matter
of calling g_object_new() with the wanted properties.
Let's deprecate this throwback of the Olden Days™, so that we can remove
it for good once we break for 2.0.
When dereferencing GArray.data to a C structure you need a double cast
from guint8* to void*, and then from void* to the actual type. This
avoids compiler warnings, especially when using clang on OSX.
It should be possible to define markers in ClutterScript when
describing a ClutterTimeline.
The syntax is a trivial:
"markers" : [
{ "name", <marker-name>, "time" : <msecs> }
]
While at it, we should document it inside the API reference, as well
as fleshing out the ClutterTimeline description.
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
ClutterTimeline has special handling for the first time do_tick is
called which was not emitting a new-frame signal. This meant that an
application which directly uses the timeline would have to manually
setup the initial state of an animation after starting a timeline to
avoid painting a single frame with the wrong state. It seems to make
more sense to instead emit the new-frame signal so that the
application always sees a new-frame when the progress changes before a
paint.
Check that the timeline is still playing before executing in
_clutter_timeline_do_tick. This fixes the possibility of receiving a
new-frame signal when stopping a timeline in response to a different
timeline's signal emission.
Other frameworks expose the same functionality as "auto-reverse",
probably to match the cassette tape player. It actually makes sense
for Clutter to follow suit.
GLib 2.28 will deprecate GTimeVal and related API in favour of
standardizing on microseconds granularity for all time-based API.
Clutter should switch too.
All of the current users of GTimeVal convert to milliseconds when
doing time operations, and use GTimeVal only as storage. This can
effectively be replaced by a gint64.
The Master Clock uses a microsecond resolution, except when interacting
with the main loop itself, since the main loop has a millisecond
resolution - at least until Ryan Lortie manages to switch that too to
microseconds on Linux.
The clutter_timeline_do_tick() function was erroneously not privatized,
but it was still assumed to be private; we should just remove it from
the public symbols.
This adds a wrapper macro to clutter-private that will use
g_object_notify_by_pspec if it's compiled against a version of GLib
that is sufficiently new. Otherwise it will notify by the property
name as before by extracting the name from the pspec. The objects can
then store a static array of GParamSpecs and notify using those as
suggested in the documentation for g_object_notify_by_pspec.
Note that the name of the variable used for storing the array of
GParamSpecs is obj_props instead of properties as used in the
documentation because some places in Clutter uses 'properties' as the
name of a local variable.
Mose of the classes in Clutter have been converted using the script in
the bug report. Some classes have not been modified even though the
script picked them up as described here:
json-generator:
We probably don't want to modify the internal copy of JSON
behaviour-depth:
rectangle:
score:
stage-manager:
These aren't using the separate GParamSpec* variable style.
blur-effect:
win32/device-manager:
Don't actually define any properties even though it has the enum.
box-layout:
flow-layout:
Have some per-child properties that don't work automatically with
the script.
clutter-model:
The script gets confused with ClutterModelIter
stage:
Script gets confused because PROP_USER_RESIZE doesn't match
"user-resizable"
test-layout:
Don't really want to modify the tests
http://bugzilla.clutter-project.org/show_bug.cgi?id=2150
The marshallers we use for the signals are declared in a private header,
and it stands to reason that they should also be hidden in the shared
object by using the common '_' prefix. We are also using some direct
g_cclosure_marshal_* symbol from GLib, instead of consistently use the
clutter_marshal_* symbol.
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
If the system clock rolls back between two frames then we need
to account for the change, to avoid stopping the timeline.
The best option, since a roll back can be any arbitrary amount
of milliseconds, is to skip a frame.
Fixes bug:
http://bugzilla.moblin.org/show_bug.cgi?id=3839
Markers added at the start of the timeline need to be special cased
because we effectively check whether the marker time is greater than
the old frame time or less than or equal to the new frame time but we
never actually emit a frame for the start of the timeline.
If the timeline is looping then it adjusts the position to interpolate
a wrapped around position. However we do not emit a new frame after
setting this position so we need to check for markers again there.
clutter_timeline_get_delta should return the actual wall clock time
between emissions of the new-frame signal - even if the elapsed time
has been fudged at the end of the timeline. To make this work it no
longer directly manipulates priv->msecs_delta but instead passes a
delta value to check_markers.
This reverts commit 9c5663d671.
The patch was causing problems for applications that expect the
elapsed_time to be at either end of the timeline when the completed
signal is fired. For example test-behave swaps the direction of the
timeline in the completed handler but if the time has overflowed the
end then the timeline would only take a short time to get back the
beginning. This caused the animation to just vibrate around the
beginning.
The new-frame signal of a timeline was previously guaranteed to be
emitted with the elapsed_time set to the end before it emits the
completed signal. This doesn't necessarily make sense for looping
timelines because it would cause the elapsed time to be clamped to a
slightly off value whenever the timeline restarts. This patch makes it
perform the wrap around before emitting the new-frame signal so that
the elapsed time always corresponds to the time elapsed since the
timeline was started.
Additionally it no longer fudges the msecs_delta property to make the
marker check work so clutter_timeline_get_delta will always return the
wall clock time since the last frame.
Instead of calculating a delta in the master clock, and passing that
into each timeline, make each timeline individually responsible for
remembering the last time and computing the delta.
This:
- Fixes a problem where we could spin infinitely processing
timeline-only frames with < 1msec differences.
- Makes timelines consistently start timing on the first frame;
instead of doing different things for the first started timeline
and other timelines.
- Improves accuracy of elapsed time computations by avoiding
accumulating microsecond => millisecond truncation errors.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Instead of keeping a list of all timelines, and connecting to
signals and weak notifies, simply keep a list of running timelines;
this greatly simplifies both the book-keeping, and also determining
if there are any running timelines.
http://bugzilla.openedhand.com/show_bug.cgi?id=1637
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
When we complete a timeline, we clamp the elapsed_time variable
to the range of the timeline. We need to adjust msecs_delta so that
when we check for hit markers we have the correct interval.
http://bugzilla.openedhand.com/show_bug.cgi?id=1641
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Correctly apply De Morgan's laws to the short-circuit test in
clutter_timeline_pause(); it was short-circuiting always and
never actually pausing.
http://bugzilla.openedhand.com/show_bug.cgi?id=1629
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Timelines no longer work in terms of a frame rate and a number of
frames but instead just have a duration in milliseconds. This better
matches the working of the master clock where if any timelines are
running it will redraw as fast as possible rather than limiting to the
lowest rated timeline.
Most applications will just create animations and expect them to
finish in a certain amount of time without caring about how many
frames are drawn. If a frame is going to be drawn it might as well
update all of the animations to some fraction of the total animation
rather than rounding to the nearest whole frame.
The 'frame_num' parameter of the new-frame signal is now 'msecs' which
is a number of milliseconds progressed along the
timeline. Applications should use clutter_timeline_get_progress
instead of the frame number.
Markers can now only be attached at a time value. The position is
stored in milliseconds rather than at a frame number.
test-timeline-smoothness and test-timeline-dup-frames have been
removed because they no longer make sense.
The commit 762873e79e is completely
and utterly wrong and I should have never pushed it.
Serves me well for trying to work on three different branches and
on three different things.
Currently, the clock source spins a redraw every time there is at
least a timeline running. If the timelines were not advanced in
the previous frame, though, because their interval is larger than
the vblanking interval then this will lead to excessive redraws of
the scenegraph even if nothing has changed.
To avoid this a simple guard should be set by the MasterClock::advance
method in case no timeline was effectively advanced, and checked
before dispatching the stage redraws.
The clutter frame source tries to average out the frame deltas so that
if one frame takes 1 interval plus a little bit of extra time then the
next frame will be 1 interval minus that little bit of extra
time. Therefore the deltas can sometimes be less than the frame
interval. ClutterTimeline should accumulate these small differences
otherwise it will end up missing out frames so the total duration of
the timeline will be a lot longer.
For example this was causing test-actors to appear to run very slow.
The method of ClutterTimeline that advances the timeline by a
delta (in millisecond) is going to be useful for testing the
timeline's behaviour -- and unbreak the timeline test suite that
was broken by the MasterClock merge.
Currently, all timelines install a timeout inside the TimeoutPool
they share. Every time the main loop spins, all the timeouts are
updated. This, in turn, will usually lead to redraws being queued
on the stages.
This behaviour leads to the potential starvation of timelines and
to excessive redraws.
One lesson learned from the games developers is that the scenegraph
should be prepared in its entirety before the GL paint sequence is
initiated. This means making sure that every ::new-frame signal
handler is called before clutter_redraw() is invoked.
In order to do so a TimeoutPool is not enough: we need a master
clock. The clock will be responsible for advancing all the active
timelines created inside a scene, but only when the stage is
being redrawn.
The sequence is:
+ queue_redraw() is invoked on an actor and bubbles up
to the stage
+ if no redraw() has already been scheduled, install an
idle handler with a known priority
+ inside the idle handler:
- advance the master clock, which will in turn advance
every playing timeline by the amount of milliseconds
elapsed since the last redraw; this will make every
playing timeline emit the ::new-frame signal
- queue a relayout
- call the redraw() method of the backend
This way we trade multiple timeouts with a single frame source
that only runs if a timeline is playing and queues redraws on
the various stages.
Bug 1495 - Timelines run 4% short
Previously the timelines were timed by calculating the interval
between each frame stored as an integer number of milliseconds so some
precision is lost. For example, requesting 60 frames per second gets
converted to 16 ms per frame which is actually 62.5 frames per
second. This makes the timeline shorter by 4%.
This patch merges the common code for timing from the timeout pools
and frame sources into an internal clutter-timeout-interval file. This
stores the interval directly as the FPS and counts the number of
frames that have been reached instead of the elapsed time.
Add annotations such as (transfer-none) (out) (element-type ClutterActor),
and so forth to the doc comments as appropriate.
The annotations added here are a combination of the annotations previously
in gir-repository for Clutter and annotations found in a review of all
return values with that were being parsed with a transfer of "full".
http://bugzilla.openedhand.com/show_bug.cgi?id=1452
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Bug 1464 - clutter_timeline_list_markers should set n_markers=0 when
there are no markers
If no markers are registered and we bail out we should also set the
n_markers out parameter to 0 so that code checking the number of
markers will still work.
