Commit Graph

3 Commits

Author SHA1 Message Date
Robert Bragg
211bf79854 ensure next iteration
Added an internal clutter function, _clutter_master_clock_ensure_next_iteration
that ensures another iteration of the master clock, can be called from repaint
functions as well as other threads.
2009-07-10 11:38:42 +01:00
Owen W. Taylor
dcd8d28314 Limit the frame rate when not syncing to VBLANK
clutter-master-clock.c clutter-master-clock.h: When the
  SYNC_TO_VBLANK feature is not available, wait for 1/frame_rate
  seconds since the start of the last frame before drawing the next
  frame. Add _clutter_master_clock_start_running() to abstract
  the usage of g_main_context_wakeup()

clutter-stage.c: Add _clutter_master_clock_start_running()

clutter-main.c: Update docs for clutter_set_default_frame_rate()
  clutter_get_default_frame_rate() to no longer talk about timeline
  frame rates.

test-text-perf.c test-text.c: Set a frame rate of 1000fps so that
  frame-rate limiting doesn't affect the result.

http://bugzilla.openedhand.com/show_bug.cgi?id=1637

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-06-09 15:03:56 +01:00
Emmanuele Bassi
678f99677f Use a single master "clock" to drive timelines
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.
2009-04-24 15:28:15 +01:00