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Count timeline frames using the FPS instead of an integer interval

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.
This commit is contained in:
Neil Roberts 2009-03-09 17:12:27 +00:00
parent 2c1c836417
commit a93a93d007
10 changed files with 243 additions and 159 deletions

View file

@ -185,6 +185,7 @@ source_c = \
$(srcdir)/clutter-texture.c \
$(srcdir)/clutter-text.c \
$(srcdir)/clutter-timeline.c \
$(srcdir)/clutter-timeout-interval.c \
$(srcdir)/clutter-timeout-pool.c \
$(srcdir)/clutter-units.c \
$(srcdir)/clutter-util.c \
@ -199,6 +200,7 @@ source_h_priv = \
$(srcdir)/clutter-id-pool.h \
$(srcdir)/clutter-script-private.h \
$(srcdir)/clutter-stage-window.h \
$(srcdir)/clutter-timeout-interval.h \
$(NULL)
libclutter_@CLUTTER_FLAVOUR@_@CLUTTER_API_VERSION@_la_LIBADD = \

View file

@ -3,7 +3,7 @@
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
* Authored By Neil Roberts <neil@linux.intel.com>
*
* Copyright (C) 2008 OpenedHand
*
@ -28,6 +28,7 @@
#endif
#include "clutter-frame-source.h"
#include "clutter-timeout-interval.h"
typedef struct _ClutterFrameSource ClutterFrameSource;
@ -35,8 +36,7 @@ struct _ClutterFrameSource
{
GSource source;
GTimeVal start_time;
guint last_time, frame_time;
ClutterTimeoutInterval timeout;
};
static gboolean clutter_frame_source_prepare (GSource *source, gint *timeout);
@ -45,7 +45,7 @@ static gboolean clutter_frame_source_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data);
static GSourceFuncs clutter_frame_source_funcs =
static GSourceFuncs clutter_frame_source_funcs =
{
clutter_frame_source_prepare,
clutter_frame_source_check,
@ -57,7 +57,7 @@ static GSourceFuncs clutter_frame_source_funcs =
* clutter_frame_source_add_full:
* @priority: the priority of the frame source. Typically this will be in the
* range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
* @interval: the time between calls to the function, in milliseconds
* @fps: the number of times per second to call the function
* @func: function to call
* @data: data to pass to the function
* @notify: function to call when the timeout source is removed
@ -74,7 +74,7 @@ static GSourceFuncs clutter_frame_source_funcs =
* the interval time to execute then the function will be called again
* half the interval time after it finished. In contrast
* g_timeout_add_full() would not fire until a full interval after the
* function completes so the delay between calls would be @interval *
* function completes so the delay between calls would be 1.0 / @fps *
* 1.5. This function does not however try to invoke the function
* multiple times to catch up missing frames if @func takes more than
* @interval ms to execute.
@ -85,7 +85,7 @@ static GSourceFuncs clutter_frame_source_funcs =
*/
guint
clutter_frame_source_add_full (gint priority,
guint interval,
guint fps,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
@ -95,9 +95,7 @@ clutter_frame_source_add_full (gint priority,
sizeof (ClutterFrameSource));
ClutterFrameSource *frame_source = (ClutterFrameSource *) source;
frame_source->last_time = 0;
frame_source->frame_time = interval;
g_get_current_time (&frame_source->start_time);
_clutter_timeout_interval_init (&frame_source->timeout, fps);
if (priority != G_PRIORITY_DEFAULT)
g_source_set_priority (source, priority);
@ -113,7 +111,7 @@ clutter_frame_source_add_full (gint priority,
/**
* clutter_frame_source_add:
* @interval: the time between calls to the function, in milliseconds
* @fps: the number of times per second to call the function
* @func: function to call
* @data: data to pass to the function
*
@ -124,55 +122,25 @@ clutter_frame_source_add_full (gint priority,
* Since: 0.8
*/
guint
clutter_frame_source_add (guint interval,
clutter_frame_source_add (guint fps,
GSourceFunc func,
gpointer data)
{
return clutter_frame_source_add_full (G_PRIORITY_DEFAULT,
interval, func, data, NULL);
}
static guint
clutter_frame_source_get_ticks (ClutterFrameSource *frame_source)
{
GTimeVal time_now;
g_source_get_current_time ((GSource *) frame_source, &time_now);
return (time_now.tv_sec - frame_source->start_time.tv_sec) * 1000
+ (time_now.tv_usec - frame_source->start_time.tv_usec) / 1000;
fps, func, data, NULL);
}
static gboolean
clutter_frame_source_prepare (GSource *source, gint *timeout)
clutter_frame_source_prepare (GSource *source, gint *delay)
{
ClutterFrameSource *frame_source = (ClutterFrameSource *) source;
GTimeVal current_time;
guint now = clutter_frame_source_get_ticks (frame_source);
g_source_get_current_time (source, &current_time);
/* If time has gone backwards or the time since the last frame is
greater than the two frames worth then reset the time and do a
frame now */
if (frame_source->last_time > now ||
(now - frame_source->last_time) > frame_source->frame_time * 2)
{
frame_source->last_time = now - frame_source->frame_time;
if (timeout)
*timeout = 0;
return TRUE;
}
else if (now - frame_source->last_time >= frame_source->frame_time)
{
if (timeout)
*timeout = 0;
return TRUE;
}
else
{
if (timeout)
*timeout = frame_source->frame_time + frame_source->last_time - now;
return FALSE;
}
return _clutter_timeout_interval_prepare (&current_time,
&frame_source->timeout,
delay);
}
static gboolean
@ -183,16 +151,11 @@ clutter_frame_source_check (GSource *source)
static gboolean
clutter_frame_source_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data)
GSourceFunc callback,
gpointer user_data)
{
ClutterFrameSource *frame_source = (ClutterFrameSource *) source;
if ((* callback) (user_data))
{
frame_source->last_time += frame_source->frame_time;
return TRUE;
}
else
return FALSE;
return _clutter_timeout_interval_dispatch (&frame_source->timeout,
callback, user_data);
}

View file

@ -32,12 +32,12 @@
G_BEGIN_DECLS
guint clutter_frame_source_add (guint interval,
guint clutter_frame_source_add (guint fps,
GSourceFunc func,
gpointer data);
guint clutter_frame_source_add_full (gint priority,
guint interval,
guint fps,
GSourceFunc func,
gpointer data,
GDestroyNotify notify);

View file

@ -919,7 +919,7 @@ clutter_threads_add_timeout (guint interval,
* clutter_threads_add_frame_source_full:
* @priority: the priority of the frame source. Typically this will be in the
* range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
* @interval: the time between calls to the function, in milliseconds
* @fps: the number of times per second to call the function
* @func: function to call
* @data: data to pass to the function
* @notify: function to call when the timeout source is removed
@ -948,7 +948,7 @@ clutter_threads_add_timeout (guint interval,
*/
guint
clutter_threads_add_frame_source_full (gint priority,
guint interval,
guint fps,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
@ -963,14 +963,14 @@ clutter_threads_add_frame_source_full (gint priority,
dispatch->notify = notify;
return clutter_frame_source_add_full (priority,
interval,
fps,
clutter_threads_dispatch, dispatch,
clutter_threads_dispatch_free);
}
/**
* clutter_threads_add_frame_source:
* @interval: the time between calls to the function, in milliseconds
* @fps: the number of times per second to call the function
* @func: function to call
* @data: data to pass to the function
*
@ -981,14 +981,14 @@ clutter_threads_add_frame_source_full (gint priority,
* Since: 0.8
*/
guint
clutter_threads_add_frame_source (guint interval,
clutter_threads_add_frame_source (guint fps,
GSourceFunc func,
gpointer data)
{
g_return_val_if_fail (func != NULL, 0);
return clutter_threads_add_frame_source_full (G_PRIORITY_DEFAULT,
interval,
fps,
func, data,
NULL);
}

View file

@ -128,12 +128,12 @@ guint clutter_threads_add_timeout_full (gint priority,
GSourceFunc func,
gpointer data,
GDestroyNotify notify);
guint clutter_threads_add_frame_source (guint interval,
guint clutter_threads_add_frame_source (guint fps,
GSourceFunc func,
gpointer data);
guint clutter_threads_add_frame_source_full
(gint priority,
guint interval,
guint fps,
GSourceFunc func,
gpointer data,
GDestroyNotify notify);

View file

@ -93,8 +93,6 @@
G_DEFINE_TYPE (ClutterTimeline, clutter_timeline, G_TYPE_OBJECT);
#define FPS_TO_INTERVAL(f) (1000 / (f))
struct _ClutterTimelinePrivate
{
ClutterTimelineDirection direction;
@ -174,7 +172,7 @@ timeline_pool_init (void)
}
static guint
timeout_add (guint interval,
timeout_add (guint fps,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
@ -185,13 +183,13 @@ timeout_add (guint interval,
{
g_assert (timeline_pool != NULL);
res = clutter_timeout_pool_add (timeline_pool,
interval,
fps,
func, data, notify);
}
else
{
res = clutter_threads_add_frame_source_full (CLUTTER_PRIORITY_TIMELINE,
interval,
fps,
func, data, notify);
}
@ -814,7 +812,7 @@ timeline_timeout_func (gpointer data)
static guint
timeline_timeout_add (ClutterTimeline *timeline,
guint interval,
guint fps,
GSourceFunc func,
gpointer data,
GDestroyNotify notify)
@ -833,7 +831,7 @@ timeline_timeout_add (ClutterTimeline *timeline,
priv->skipped_frames = 0;
priv->msecs_delta = 0;
return timeout_add (interval, func, data, notify);
return timeout_add (fps, func, data, notify);
}
static gboolean
@ -845,7 +843,7 @@ delay_timeout_func (gpointer data)
priv->delay_id = 0;
priv->timeout_id = timeline_timeout_add (timeline,
FPS_TO_INTERVAL (priv->fps),
priv->fps,
timeline_timeout_func,
timeline, NULL);
@ -884,7 +882,7 @@ clutter_timeline_start (ClutterTimeline *timeline)
else
{
priv->timeout_id = timeline_timeout_add (timeline,
FPS_TO_INTERVAL (priv->fps),
priv->fps,
timeline_timeout_func,
timeline, NULL);
@ -1150,7 +1148,7 @@ clutter_timeline_set_speed (ClutterTimeline *timeline,
timeout_remove (priv->timeout_id);
priv->timeout_id = timeline_timeout_add (timeline,
FPS_TO_INTERVAL (priv->fps),
priv->fps,
timeline_timeout_func,
timeline, NULL);
}

View file

@ -0,0 +1,126 @@
/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Neil Roberts <neil@linux.intel.com>
*
* Copyright (C) 2009 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
/* This file contains the common code to check whether an interval has
expired used in clutter-frame-source and clutter-timeout-pool. */
#include "clutter-timeout-interval.h"
void
_clutter_timeout_interval_init (ClutterTimeoutInterval *interval,
guint fps)
{
g_get_current_time (&interval->start_time);
interval->fps = fps;
interval->frame_count = 0;
}
static guint
_clutter_timeout_interval_get_ticks (const GTimeVal *current_time,
ClutterTimeoutInterval *interval)
{
return ((current_time->tv_sec - interval->start_time.tv_sec) * 1000
+ (current_time->tv_usec - interval->start_time.tv_usec) / 1000);
}
gboolean
_clutter_timeout_interval_prepare (const GTimeVal *current_time,
ClutterTimeoutInterval *interval,
gint *delay)
{
guint elapsed_time
= _clutter_timeout_interval_get_ticks (current_time, interval);
guint new_frame_num = elapsed_time * interval->fps / 1000;
/* If time has gone backwards or the time since the last frame is
greater than the two frames worth then reset the time and do a
frame now */
if (new_frame_num < interval->frame_count ||
new_frame_num - interval->frame_count > 2)
{
/* Get the frame time rounded up to the nearest ms */
guint frame_time = (1000 + interval->fps - 1) / interval->fps;
/* Reset the start time */
interval->start_time = *current_time;
/* Move the start time as if one whole frame has elapsed */
g_time_val_add (&interval->start_time, -(gint) frame_time * 1000);
interval->frame_count = 0;
if (delay)
*delay = 0;
return TRUE;
}
else if (new_frame_num > interval->frame_count)
{
if (delay)
*delay = 0;
return TRUE;
}
else
{
if (delay)
*delay = ((interval->frame_count + 1) * 1000 / interval->fps
- elapsed_time);
return FALSE;
}
}
gboolean
_clutter_timeout_interval_dispatch (ClutterTimeoutInterval *interval,
GSourceFunc callback,
gpointer user_data)
{
if ((* callback) (user_data))
{
interval->frame_count++;
return TRUE;
}
else
return FALSE;
}
gint
_clutter_timeout_interval_compare_expiration (const ClutterTimeoutInterval *a,
const ClutterTimeoutInterval *b)
{
guint a_delay = 1000 / a->fps;
guint b_delay = 1000 / b->fps;
glong b_difference;
gint comparison;
b_difference = ((a->start_time.tv_sec - b->start_time.tv_sec) * 1000
+ (a->start_time.tv_usec - b->start_time.tv_usec) / 1000);
comparison = ((gint) ((a->frame_count + 1) * a_delay)
- (gint) ((b->frame_count + 1) * b_delay + b_difference));
return (comparison < 0 ? -1
: comparison > 0 ? 1
: 0);
}

View file

@ -0,0 +1,56 @@
/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Neil Roberts <neil@linux.intel.com>
*
* Copyright (C) 2009 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __CLUTTER_TIMEOUT_INTERVAL_H__
#define __CLUTTER_TIMEOUT_INTERVAL_H__
#include <glib.h>
G_BEGIN_DECLS
typedef struct _ClutterTimeoutInterval ClutterTimeoutInterval;
struct _ClutterTimeoutInterval
{
GTimeVal start_time;
guint frame_count, fps;
};
void _clutter_timeout_interval_init (ClutterTimeoutInterval *interval,
guint fps);
gboolean _clutter_timeout_interval_prepare (const GTimeVal *current_time,
ClutterTimeoutInterval *interval,
gint *delay);
gboolean _clutter_timeout_interval_dispatch (ClutterTimeoutInterval *interval,
GSourceFunc callback,
gpointer user_data);
gint _clutter_timeout_interval_compare_expiration
(const ClutterTimeoutInterval *a,
const ClutterTimeoutInterval *b);
G_END_DECLS
#endif /* __CLUTTER_TIMEOUT_INTERVAL_H__ */

View file

@ -36,6 +36,7 @@
#include "clutter-debug.h"
#include "clutter-timeout-pool.h"
#include "clutter-timeout-interval.h"
typedef struct _ClutterTimeout ClutterTimeout;
typedef enum {
@ -49,8 +50,7 @@ struct _ClutterTimeout
ClutterTimeoutFlags flags;
gint refcount;
guint interval;
guint last_time;
ClutterTimeoutInterval interval;
GSourceFunc func;
gpointer data;
@ -94,7 +94,6 @@ clutter_timeout_sort (gconstpointer a,
{
const ClutterTimeout *t_a = a;
const ClutterTimeout *t_b = b;
gint comparison;
/* Keep 'ready' timeouts at the front */
if (TIMEOUT_READY (t_a))
@ -103,16 +102,8 @@ clutter_timeout_sort (gconstpointer a,
if (TIMEOUT_READY (t_b))
return 1;
/* Otherwise sort by expiration time */
comparison = (t_a->last_time + t_a->interval)
- (t_b->last_time + t_b->interval);
if (comparison < 0)
return -1;
if (comparison > 0)
return 1;
return 0;
return _clutter_timeout_interval_compare_expiration (&t_a->interval,
&t_b->interval);
}
static gint
@ -124,15 +115,17 @@ clutter_timeout_find_by_id (gconstpointer a,
return t_a->id == GPOINTER_TO_UINT (b) ? 0 : 1;
}
static guint
clutter_timeout_pool_get_ticks (ClutterTimeoutPool *pool)
static ClutterTimeout *
clutter_timeout_new (guint fps)
{
GTimeVal time_now;
ClutterTimeout *timeout;
g_source_get_current_time ((GSource *) pool, &time_now);
return (time_now.tv_sec - pool->start_time.tv_sec) * 1000
+ (time_now.tv_usec - pool->start_time.tv_usec) / 1000;
timeout = g_slice_new0 (ClutterTimeout);
_clutter_timeout_interval_init (&timeout->interval, fps);
timeout->flags = CLUTTER_TIMEOUT_NONE;
timeout->refcount = 1;
return timeout;
}
static gboolean
@ -140,66 +133,12 @@ clutter_timeout_prepare (ClutterTimeoutPool *pool,
ClutterTimeout *timeout,
gint *next_timeout)
{
guint now = clutter_timeout_pool_get_ticks (pool);
GTimeVal now;
/* If time has gone backwards or the time since the last frame is
greater than the two frames worth then reset the time and do a
frame now */
if (timeout->last_time > now || now - timeout->last_time
> timeout->interval * 2)
{
timeout->last_time = now - timeout->interval;
if (next_timeout)
*next_timeout = 0;
return TRUE;
}
else if (now - timeout->last_time >= timeout->interval)
{
if (next_timeout)
*next_timeout = 0;
return TRUE;
}
else
{
if (next_timeout)
*next_timeout = timeout->interval + timeout->last_time - now;
return FALSE;
}
}
g_source_get_current_time (&pool->source, &now);
static gboolean
clutter_timeout_dispatch (GSource *source,
ClutterTimeout *timeout)
{
gboolean retval = FALSE;
if (G_UNLIKELY (!timeout->func))
{
g_warning ("Timeout dispatched without a callback.");
return FALSE;
}
if (timeout->func (timeout->data))
{
timeout->last_time += timeout->interval;
retval = TRUE;
}
return retval;
}
static ClutterTimeout *
clutter_timeout_new (guint interval)
{
ClutterTimeout *timeout;
timeout = g_slice_new0 (ClutterTimeout);
timeout->interval = interval;
timeout->flags = CLUTTER_TIMEOUT_NONE;
timeout->refcount = 1;
return timeout;
return _clutter_timeout_interval_prepare (&now, &timeout->interval,
next_timeout);
}
/* ref and unref are always called under the main Clutter lock, so there
@ -350,7 +289,8 @@ clutter_timeout_pool_dispatch (GSource *source,
l->next = pool->dispatched_timeouts;
pool->dispatched_timeouts = l;
if (!clutter_timeout_dispatch (source, timeout))
if (!_clutter_timeout_interval_dispatch (&timeout->interval,
timeout->func, timeout->data))
{
/* The timeout may have already been removed, but nothing
* can be added to the dispatched_timeout list except in this
@ -500,7 +440,6 @@ clutter_timeout_pool_add (ClutterTimeoutPool *pool,
retval = timeout->id = pool->next_id++;
timeout->last_time = clutter_timeout_pool_get_ticks (pool);
timeout->func = func;
timeout->data = data;
timeout->notify = notify;

View file

@ -43,7 +43,7 @@ typedef struct _ClutterTimeoutPool ClutterTimeoutPool;
ClutterTimeoutPool *clutter_timeout_pool_new (gint priority);
guint clutter_timeout_pool_add (ClutterTimeoutPool *pool,
guint interval,
guint fps,
GSourceFunc func,
gpointer data,
GDestroyNotify notify);