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/* GDK - The GIMP Drawing Kit
* Copyright (C) 2012 Red Hat, Inc.
*
* 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/>.
*/
#include "config.h"
#include "gdkframeclockprivate.h"
/**
* SECTION:gdkframetimings
* @Short_description: Object holding timing information for a single frame
* @Title: Frame timings
*
* A #GdkFrameTimings object holds timing information for a single frame
* of the application’s displays. To retrieve #GdkFrameTimings objects,
* use gdk_frame_clock_get_timings() or gdk_frame_clock_get_current_timings().
* The information in #GdkFrameTimings is useful for precise synchronization
* of video with the event or audio streams, and for measuring
* quality metrics for the application’s display, such as latency and jitter.
*/
G_DEFINE_BOXED_TYPE (GdkFrameTimings, gdk_frame_timings,
gdk_frame_timings_ref,
gdk_frame_timings_unref)
GdkFrameTimings *
_gdk_frame_timings_new (gint64 frame_counter)
{
GdkFrameTimings *timings;
timings = g_slice_new0 (GdkFrameTimings);
timings->ref_count = 1;
timings->frame_counter = frame_counter;
return timings;
}
/**
* gdk_frame_timings_ref:
* @timings: a #GdkFrameTimings
*
* Increases the reference count of @timings.
*
* Returns: @timings
* Since: 3.8
*/
GdkFrameTimings *
gdk_frame_timings_ref (GdkFrameTimings *timings)
{
g_return_val_if_fail (timings != NULL, NULL);
timings->ref_count++;
return timings;
}
/**
* gdk_frame_timings_unref:
* @timings: a #GdkFrameTimings
*
* Decreases the reference count of @timings. If @timings
* is no longer referenced, it will be freed.
*
* Since: 3.8
*/
void
gdk_frame_timings_unref (GdkFrameTimings *timings)
{
g_return_if_fail (timings != NULL);
g_return_if_fail (timings->ref_count > 0);
timings->ref_count--;
if (timings->ref_count == 0)
{
g_slice_free (GdkFrameTimings, timings);
}
}
/**
* gdk_frame_timings_get_frame_counter:
* @timings: a #GdkFrameTimings
*
* Gets the frame counter value of the #GdkFrameClock when this
* this frame was drawn.
*
* Returns: the frame counter value for this frame
* Since: 3.8
*/
gint64
gdk_frame_timings_get_frame_counter (GdkFrameTimings *timings)
{
return timings->frame_counter;
}
/**
* gdk_frame_timings_get_complete:
* @timings: a #GdkFrameTimings
*
* The timing information in a #GdkFrameTimings is filled in
* incrementally as the frame as drawn and passed off to the
* window system for processing and display to the user. The
* accessor functions for #GdkFrameTimings can return 0 to
* indicate an unavailable value for two reasons: either because
* the information is not yet available, or because it isn't
* available at all. Once gdk_frame_timings_get_complete() returns
* %TRUE for a frame, you can be certain that no further values
* will become available and be stored in the #GdkFrameTimings.
*
* Returns: %TRUE if all information that will be available
* for the frame has been filled in.
* Since: 3.8
*/
gboolean
gdk_frame_timings_get_complete (GdkFrameTimings *timings)
{
g_return_val_if_fail (timings != NULL, FALSE);
return timings->complete;
}
/**
* gdk_frame_timings_get_frame_time:
* @timings: A #GdkFrameTimings
*
* Returns the frame time for the frame. This is the time value
* that is typically used to time animations for the frame. See
* gdk_frame_clock_get_frame_time().
*
* Returns: the frame time for the frame, in the timescale
* of g_get_monotonic_time()
*/
gint64
gdk_frame_timings_get_frame_time (GdkFrameTimings *timings)
{
g_return_val_if_fail (timings != NULL, 0);
return timings->frame_time;
}
/**
* gdk_frame_timings_get_presentation_time:
* @timings: a #GdkFrameTimings
*
* Reurns the presentation time. This is the time at which the frame
* became visible to the user.
*
* Returns: the time the frame was displayed to the user, in the
* timescale of g_get_monotonic_time(), or 0 if no presentation
* time is available. See gdk_frame_timings_get_complete()
* Since: 3.8
*/
gint64
gdk_frame_timings_get_presentation_time (GdkFrameTimings *timings)
{
g_return_val_if_fail (timings != NULL, 0);
return timings->presentation_time;
}
/**
* gdk_frame_timings_get_predicted_presentation_time:
* @timings: a #GdkFrameTimings
*
* Gets the predicted time at which this frame will be displayed. Although
* no predicted time may be available, if one is available, it will
* be available while the frame is being generated, in contrast to
* gdk_frame_timings_get_presentation_time(), which is only available
* after the frame has been presented. In general, if you are simply
* animating, you should use gdk_frame_clock_get_frame_time() rather
* than this function, but this function is useful for applications
* that want exact control over latency. For example, a movie player
* may want this information for Audio/Video synchronization.
*
* Returns: The predicted time at which the frame will be presented,
* in the timescale of g_get_monotonic_time(), or 0 if no predicted
* presentation time is available.
* Since: 3.8
*/
gint64
gdk_frame_timings_get_predicted_presentation_time (GdkFrameTimings *timings)
{
g_return_val_if_fail (timings != NULL, 0);
return timings->predicted_presentation_time;
}
/**
* gdk_frame_timings_get_refresh_interval:
* @timings: a #GdkFrameTimings
*
* Gets the natural interval between presentation times for
* the display that this frame was displayed on. Frame presentation
* usually happens during the “vertical blanking interval”.
*
* Returns: the refresh interval of the display, in microseconds,
* or 0 if the refresh interval is not available.
* See gdk_frame_timings_get_complete().
* Since: 3.8
*/
gint64
gdk_frame_timings_get_refresh_interval (GdkFrameTimings *timings)
{
g_return_val_if_fail (timings != NULL, 0);
return timings->refresh_interval;
}
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