Compress events as part of the frame cycle

Instead of trying to guess about which motion events are
extraneous, queue up all events until we process a frame.
This allows us to look ahead and reliably compress consecutive
sequence of motion events.

clutter-main.c: Feed received events to the stage for queueing.
  Remove old compression code. Remove clutter_get_motion_events_frequency()
  clutter_set_motion_events_frequency()
clutter-stage.c: Keep a queue of pending events.
clutter-master-clock.c: Add processng of queued events to the
  clock source dispatch function.

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

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
This commit is contained in:
Owen W. Taylor 2009-06-06 19:10:41 -04:00 committed by Emmanuele Bassi
parent 89a8fd7755
commit 6e69692e22
5 changed files with 136 additions and 114 deletions

View File

@ -2004,6 +2004,29 @@ generate_enter_leave_events (ClutterEvent *event)
*/
void
clutter_do_event (ClutterEvent *event)
{
if (!event->any.stage)
return;
/* Instead of processing events when received, we queue them up to
* handle per-frame before animations, layout, and drawing.
*
* This gives us the chance to reliably compress motion events
* because we've "looked ahead" and know all motion events that
* will occur before drawing the frame.
*/
_clutter_stage_queue_event (event->any.stage, event);
}
/**
* _clutter_process_event
* @event: a #ClutterEvent.
*
* Does the actual work of processing an event that was queued earlier
* out of clutter_do_event().
*/
void
_clutter_process_event (ClutterEvent *event)
{
/* FIXME: This should probably be clutter_cook_event() - it would
* take a raw event from the backend and 'cook' it so its more tasty.
@ -2013,8 +2036,6 @@ clutter_do_event (ClutterEvent *event)
ClutterBackend *backend;
ClutterActor *stage;
ClutterInputDevice *device = NULL;
static gint32 motion_last_time = 0L;
gint32 local_motion_time;
context = clutter_context_get_default ();
backend = context->backend;
@ -2091,52 +2112,6 @@ clutter_do_event (ClutterEvent *event)
case CLUTTER_MOTION:
device = event->motion.device;
if (device)
local_motion_time = device->motion_last_time;
else
local_motion_time = motion_last_time;
/* avoid rate throttling for synthetic motion events or if
* the per-actor events are disabled
*/
if (!(event->any.flags & CLUTTER_EVENT_FLAG_SYNTHETIC) ||
!context->motion_events_per_actor)
{
gint32 frame_rate, delta;
/* avoid issuing too many motion events, which leads to many
* redraws in pick mode (performance penalty)
*/
frame_rate = clutter_get_motion_events_frequency ();
delta = 1000 / frame_rate;
CLUTTER_NOTE (EVENT,
"skip motion event: %s (last:%d, delta:%d, time:%d)",
(event->any.time < (local_motion_time + delta) ? "yes" : "no"),
local_motion_time,
delta,
event->any.time);
/* we need to guard against roll-overs and the
* case where the time is rolled backwards and
* the backend is not ensuring a monotonic clock
* for the events.
*
* see:
* http://bugzilla.openedhand.com/show_bug.cgi?id=1130
*/
if (event->any.time >= local_motion_time &&
event->any.time < (local_motion_time + delta))
break;
else
local_motion_time = event->any.time;
}
if (device)
device->motion_last_time = local_motion_time;
else
motion_last_time = local_motion_time;
/* Only stage gets motion events if clutter_set_motion_events is TRUE,
* and the event is not a synthetic event with source set.
*/
@ -2321,9 +2296,6 @@ clutter_base_init (void)
* Retrieves the default frame rate used when creating #ClutterTimeline<!--
* -->s.
*
* This value is also used to compute the default frequency of motion
* events.
*
* Return value: the default frame rate
*
* Since: 0.6
@ -2621,61 +2593,6 @@ clutter_get_keyboard_grab (void)
return context->keyboard_grab_actor;
}
/**
* clutter_get_motion_events_frequency:
*
* Retrieves the number of motion events per second that are delivered
* to the stage.
*
* See clutter_set_motion_events_frequency().
*
* Return value: the number of motion events per second
*
* Since: 0.6
*/
guint
clutter_get_motion_events_frequency (void)
{
ClutterMainContext *context = clutter_context_get_default ();
if (G_LIKELY (context->motion_frequency == 0))
{
guint frequency;
frequency = clutter_default_fps / 4;
frequency = CLAMP (frequency, 20, 45);
return frequency;
}
else
return context->motion_frequency;
}
/**
* clutter_set_motion_events_frequency:
* @frequency: the number of motion events per second, or 0 for the
* default value
*
* Sets the motion events frequency. Setting this to a non-zero value
* will override the default setting, so it should be rarely used.
*
* Motion events are delivered from the default backend to the stage
* and are used to generate the enter/leave events pair. This might lead
* to a performance penalty due to the way the actors are identified.
* Using this function is possible to reduce the frequency of the motion
* events delivery to the stage.
*
* Since: 0.6
*/
void
clutter_set_motion_events_frequency (guint frequency)
{
ClutterMainContext *context = clutter_context_get_default ();
/* never allow the motion events to exceed the default frame rate */
context->motion_frequency = CLAMP (frequency, 1, clutter_default_fps);
}
/**
* clutter_clear_glyph_cache:
*

View File

@ -144,8 +144,6 @@ void clutter_threads_remove_repaint_func (guint handle_id
void clutter_set_motion_events_enabled (gboolean enable);
gboolean clutter_get_motion_events_enabled (void);
void clutter_set_motion_events_frequency (guint frequency);
guint clutter_get_motion_events_frequency (void);
void clutter_set_default_frame_rate (guint frames_per_sec);
guint clutter_get_default_frame_rate (void);

View File

@ -115,7 +115,8 @@ master_clock_is_running (ClutterMasterClock *master_clock)
stages = clutter_stage_manager_peek_stages (stage_manager);
for (l = stages; l; l = l->next)
if (_clutter_stage_needs_update (l->data))
if (_clutter_stage_has_queued_events (l->data) ||
_clutter_stage_needs_update (l->data))
return TRUE;
return FALSE;
@ -179,11 +180,20 @@ clutter_clock_dispatch (GSource *source,
ClutterClockSource *clock_source = (ClutterClockSource *) source;
ClutterMasterClock *master_clock = clock_source->master_clock;
ClutterStageManager *stage_manager = clutter_stage_manager_get_default ();
const GSList *stages, *l;
GSList *stages, *l;
CLUTTER_NOTE (SCHEDULER, "Master clock [tick]");
stages = clutter_stage_manager_peek_stages (stage_manager);
/* We need to protect ourselves against stages being destroyed during
* event handling
*/
stages = clutter_stage_manager_list_stages (stage_manager);
g_slist_foreach (stages, (GFunc)g_object_ref, NULL);
/* Process queued events
*/
for (l = stages; l != NULL; l = l->next)
_clutter_stage_process_queued_events (l->data);
_clutter_master_clock_advance (master_clock);
@ -193,6 +203,9 @@ clutter_clock_dispatch (GSource *source,
for (l = stages; l != NULL; l = l->next)
_clutter_stage_do_update (l->data);
g_slist_foreach (stages, (GFunc)g_object_unref, NULL);
g_slist_free (stages);
return TRUE;
}

View File

@ -70,7 +70,6 @@ typedef enum {
struct _ClutterInputDevice
{
gint id;
gint32 motion_last_time;
ClutterActor *pointer_grab_actor;
ClutterActor *motion_last_actor;
@ -99,7 +98,6 @@ struct _ClutterMainContext
ClutterPickMode pick_mode; /* Indicates pick render mode */
guint motion_frequency; /* Motion events per second */
gint num_reactives; /* Num of reactive actors */
ClutterIDPool *id_pool; /* mapping between reused integer ids
@ -178,6 +176,11 @@ void _clutter_stage_maybe_relayout (ClutterActor *sta
gboolean _clutter_stage_needs_update (ClutterStage *stage);
void _clutter_stage_do_update (ClutterStage *stage);
void _clutter_stage_queue_event (ClutterStage *stage,
ClutterEvent *event);
gboolean _clutter_stage_has_queued_events (ClutterStage *stage);
void _clutter_stage_process_queued_events (ClutterStage *stage);
/* vfuncs implemented by backend */
GType _clutter_backend_impl_get_type (void);
@ -207,6 +210,9 @@ gfloat _clutter_backend_get_units_per_em (ClutterBackend *backend
void _clutter_feature_init (void);
/* Reinjecting queued events for processing */
void _clutter_process_event (ClutterEvent *event);
/* Picking code */
ClutterActor *_clutter_do_pick (ClutterStage *stage,
gint x,

View File

@ -87,6 +87,8 @@ struct _ClutterStagePrivate
gchar *title;
ClutterActor *key_focused_actor;
GQueue *event_queue;
guint redraw_pending : 1;
guint is_fullscreen : 1;
guint is_offscreen : 1;
@ -389,6 +391,86 @@ clutter_stage_real_fullscreen (ClutterStage *stage)
CLUTTER_ALLOCATION_NONE);
}
void
_clutter_stage_queue_event (ClutterStage *stage,
ClutterEvent *event)
{
ClutterStagePrivate *priv;
g_return_if_fail (CLUTTER_IS_STAGE (stage));
priv = stage->priv;
g_queue_push_tail (priv->event_queue,
clutter_event_copy (event));
}
gboolean
_clutter_stage_has_queued_events (ClutterStage *stage)
{
ClutterStagePrivate *priv;
g_return_val_if_fail (CLUTTER_IS_STAGE (stage), FALSE);
priv = stage->priv;
return priv->event_queue->length > 0;
}
void
_clutter_stage_process_queued_events (ClutterStage *stage)
{
ClutterStagePrivate *priv;
GList *events, *l;;
g_return_if_fail (CLUTTER_IS_STAGE (stage));
priv = stage->priv;
if (priv->event_queue->length == 0)
return;
/* In case the stage gets destroyed during event processing */
g_object_ref (stage);
/* Steal events before starting processing to avoid reentrancy
* issues */
events = priv->event_queue->head;
priv->event_queue->head = NULL;
priv->event_queue->tail = NULL;
priv->event_queue->length = 0;
for (l = events; l; l = l->next)
{
ClutterEvent *event;
ClutterEvent *next_event;
event = l->data;
next_event = l->next ? l->next->data : NULL;
/* Skip consecutive motion events */
if (next_event &&
event->type == CLUTTER_MOTION &&
(next_event->type == CLUTTER_MOTION ||
next_event->type == CLUTTER_LEAVE))
{
CLUTTER_NOTE (EVENT,
"Omitting motion event at %.2f, %.2f",
event->motion.x, event->motion.y);
goto next_event;
}
_clutter_process_event (event);
next_event:
clutter_event_free (event);
}
g_list_free (events);
g_object_unref (stage);
}
/**
* _clutter_stage_needs_update:
* @stage: A #ClutterStage
@ -635,6 +717,10 @@ static void
clutter_stage_finalize (GObject *object)
{
ClutterStage *stage = CLUTTER_STAGE (object);
ClutterStagePrivate *priv = stage->priv;
g_queue_foreach (priv->event_queue, (GFunc)clutter_event_free, NULL);
g_queue_free (priv->event_queue);
g_free (stage->priv->title);
@ -908,6 +994,8 @@ clutter_stage_init (ClutterStage *self)
/* make sure that the implementation is considered a top level */
CLUTTER_SET_PRIVATE_FLAGS (priv->impl, CLUTTER_ACTOR_IS_TOPLEVEL);
priv->event_queue = g_queue_new ();
priv->is_offscreen = FALSE;
priv->is_fullscreen = FALSE;
priv->is_user_resizable = FALSE;