Starting from the 2.27 cycle, GLib is exposing a monotonic clock with
microseconds granularity throughout the time-based API. We can start
using it, given that the old, non-monotonic version is going to be
deprecated by the same cycle.
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.
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.
