mutter/clutter/glx/clutter-stage-glx.c
Robert Bragg 30296a3307 backend-glx: Avoid vblank waits/glFinish calls when throttling blits
If we have the GLX_SGI_video_sync extension then it's possible to always
keep track for the video sync counter each time we call glXSwapBuffers
or do a sub stage blit. This then allows us to avoid waiting before
issuing a blit if we can see that the counter has already progressed.

Also since we expect that glXCopySubBuffer is synchronized to the vblank
we don't need to use glFinish () in conjunction with the vblank wait
since the vblank wait's only purpose is to add a delay.
2010-06-09 02:11:17 +01:00

731 lines
25 KiB
C

/* Clutter.
* An OpenGL based 'interactive canvas' library.
* Authored By Matthew Allum <mallum@openedhand.com>
* Copyright (C) 2006-2007 OpenedHand
*
* 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
#include "clutter-backend-glx.h"
#include "clutter-stage-glx.h"
#include "clutter-glx.h"
#include "clutter-profile.h"
#include "../clutter-main.h"
#include "../clutter-feature.h"
#include "../clutter-color.h"
#include "../clutter-util.h"
#include "../clutter-event.h"
#include "../clutter-enum-types.h"
#include "../clutter-private.h"
#include "../clutter-debug.h"
#include "../clutter-units.h"
#include "../clutter-shader.h"
#include "../clutter-group.h"
#include "../clutter-container.h"
#include "../clutter-stage.h"
#include "../clutter-stage-window.h"
#include "cogl/cogl.h"
#include <GL/glx.h>
#include <GL/gl.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
#ifdef __linux__
#define DRM_VBLANK_RELATIVE 0x1;
struct drm_wait_vblank_request {
int type;
unsigned int sequence;
unsigned long signal;
};
struct drm_wait_vblank_reply {
int type;
unsigned int sequence;
long tval_sec;
long tval_usec;
};
typedef union drm_wait_vblank {
struct drm_wait_vblank_request request;
struct drm_wait_vblank_reply reply;
} drm_wait_vblank_t;
#define DRM_IOCTL_BASE 'd'
#define DRM_IOWR(nr,type) _IOWR(DRM_IOCTL_BASE,nr,type)
#define DRM_IOCTL_WAIT_VBLANK DRM_IOWR(0x3a, drm_wait_vblank_t)
#endif /* __linux__ */
static void clutter_stage_window_iface_init (ClutterStageWindowIface *iface);
static ClutterStageWindowIface *clutter_stage_glx_parent_iface = NULL;
G_DEFINE_TYPE_WITH_CODE (ClutterStageGLX,
clutter_stage_glx,
CLUTTER_TYPE_STAGE_X11,
G_IMPLEMENT_INTERFACE (CLUTTER_TYPE_STAGE_WINDOW,
clutter_stage_window_iface_init));
static void
clutter_stage_glx_unrealize (ClutterStageWindow *stage_window)
{
ClutterBackend *backend = clutter_get_default_backend ();
ClutterBackendX11 *backend_x11 = CLUTTER_BACKEND_X11 (backend);
ClutterStageX11 *stage_x11 = CLUTTER_STAGE_X11 (stage_window);
ClutterStageGLX *stage_glx = CLUTTER_STAGE_GLX (stage_window);
/* Note unrealize should free up any backend stage related resources */
CLUTTER_NOTE (BACKEND, "Unrealizing stage");
clutter_x11_trap_x_errors ();
if (stage_glx->glxwin != None)
{
glXDestroyWindow (backend_x11->xdpy, stage_glx->glxwin);
stage_glx->glxwin = None;
}
if (!stage_x11->is_foreign_xwin && stage_x11->xwin != None)
{
XDestroyWindow (backend_x11->xdpy, stage_x11->xwin);
stage_x11->xwin = None;
}
else
stage_x11->xwin = None;
XSync (backend_x11->xdpy, False);
clutter_x11_untrap_x_errors ();
CLUTTER_MARK ();
}
static gboolean
clutter_stage_glx_realize (ClutterStageWindow *stage_window)
{
ClutterStageX11 *stage_x11 = CLUTTER_STAGE_X11 (stage_window);
ClutterStageGLX *stage_glx = CLUTTER_STAGE_GLX (stage_window);
ClutterBackendX11 *backend_x11;
ClutterBackendGLX *backend_glx;
ClutterBackend *backend;
CLUTTER_NOTE (ACTOR, "Realizing stage '%s' [%p]",
G_OBJECT_TYPE_NAME (stage_window),
stage_window);
backend = clutter_get_default_backend ();
backend_glx = CLUTTER_BACKEND_GLX (backend);
backend_x11 = CLUTTER_BACKEND_X11 (backend);
if (stage_x11->xwin == None)
{
XSetWindowAttributes xattr;
unsigned long mask;
XVisualInfo *xvisinfo;
gfloat width, height;
CLUTTER_NOTE (MISC, "Creating stage X window");
xvisinfo = clutter_backend_x11_get_visual_info (backend_x11);
if (xvisinfo == NULL)
{
g_critical ("Unable to find suitable GL visual.");
return FALSE;
}
/* window attributes */
xattr.background_pixel = WhitePixel (backend_x11->xdpy,
backend_x11->xscreen_num);
xattr.border_pixel = 0;
xattr.colormap = XCreateColormap (backend_x11->xdpy,
backend_x11->xwin_root,
xvisinfo->visual,
AllocNone);
mask = CWBorderPixel | CWColormap;
/* Call get_size - this will either get the geometry size (which
* before we create the window is set to 640x480), or if a size
* is set, it will get that. This lets you set a size on the
* stage before it's realized.
*/
clutter_actor_get_size (CLUTTER_ACTOR (stage_x11->wrapper),
&width,
&height);
stage_x11->xwin_width = (gint)width;
stage_x11->xwin_height = (gint)height;
stage_x11->xwin = XCreateWindow (backend_x11->xdpy,
backend_x11->xwin_root,
0, 0,
stage_x11->xwin_width,
stage_x11->xwin_height,
0,
xvisinfo->depth,
InputOutput,
xvisinfo->visual,
mask, &xattr);
CLUTTER_NOTE (BACKEND, "Stage [%p], window: 0x%x, size: %dx%d",
stage_window,
(unsigned int) stage_x11->xwin,
stage_x11->xwin_width,
stage_x11->xwin_height);
XFree (xvisinfo);
}
if (stage_glx->glxwin == None)
{
int major;
int minor;
GLXFBConfig config;
/* Try and create a GLXWindow to use with extensions dependent on
* GLX versions >= 1.3 that don't accept regular X Windows as GLX
* drawables. */
if (glXQueryVersion (backend_x11->xdpy, &major, &minor) &&
major == 1 && minor >= 3 &&
_clutter_backend_glx_get_fbconfig (backend_glx, &config))
{
stage_glx->glxwin = glXCreateWindow (backend_x11->xdpy,
config,
stage_x11->xwin,
NULL);
}
}
if (clutter_x11_has_event_retrieval ())
{
if (clutter_x11_has_xinput ())
{
XSelectInput (backend_x11->xdpy, stage_x11->xwin,
StructureNotifyMask |
FocusChangeMask |
ExposureMask |
KeyPressMask | KeyReleaseMask |
EnterWindowMask | LeaveWindowMask |
PropertyChangeMask);
#ifdef HAVE_XINPUT
_clutter_x11_select_events (stage_x11->xwin);
#endif
}
else
XSelectInput (backend_x11->xdpy, stage_x11->xwin,
StructureNotifyMask |
FocusChangeMask |
ExposureMask |
PointerMotionMask |
KeyPressMask | KeyReleaseMask |
ButtonPressMask | ButtonReleaseMask |
EnterWindowMask | LeaveWindowMask |
PropertyChangeMask);
#ifdef GLX_INTEL_swap_event
if (clutter_feature_available (CLUTTER_FEATURE_SWAP_EVENTS))
{
GLXDrawable drawable =
stage_glx->glxwin ? stage_glx->glxwin : stage_x11->xwin;
glXSelectEvent (backend_x11->xdpy,
drawable,
GLX_BUFFER_SWAP_COMPLETE_INTEL_MASK);
}
#endif /* GLX_INTEL_swap_event */
}
/* no user resize.. */
clutter_stage_x11_fix_window_size (stage_x11,
stage_x11->xwin_width,
stage_x11->xwin_height);
clutter_stage_x11_set_wm_protocols (stage_x11);
CLUTTER_NOTE (BACKEND, "Successfully realized stage");
/* chain up to the StageX11 implementation */
return clutter_stage_glx_parent_iface->realize (stage_window);
}
static int
clutter_stage_glx_get_pending_swaps (ClutterStageWindow *stage_window)
{
ClutterStageGLX *stage_glx = CLUTTER_STAGE_GLX (stage_window);
return stage_glx->pending_swaps;
}
static void
clutter_stage_glx_dispose (GObject *gobject)
{
G_OBJECT_CLASS (clutter_stage_glx_parent_class)->dispose (gobject);
}
static void
clutter_stage_glx_class_init (ClutterStageGLXClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->dispose = clutter_stage_glx_dispose;
}
static void
clutter_stage_glx_init (ClutterStageGLX *stage)
{
}
static gboolean
clutter_stage_glx_has_redraw_clips (ClutterStageWindow *stage_window)
{
ClutterStageGLX *stage_glx = CLUTTER_STAGE_GLX (stage_window);
/* NB: a degenerate clip means a full stage redraw is required */
if (stage_glx->initialized_redraw_clip &&
stage_glx->bounding_redraw_clip.width != 0)
return TRUE;
else
return FALSE;
}
static gboolean
clutter_stage_glx_ignoring_redraw_clips (ClutterStageWindow *stage_window)
{
ClutterStageGLX *stage_glx = CLUTTER_STAGE_GLX (stage_window);
/* NB: a degenerate clip means a full stage redraw is required */
if (stage_glx->initialized_redraw_clip &&
stage_glx->bounding_redraw_clip.width == 0)
return TRUE;
else
return FALSE;
}
/* A redraw clip represents (in stage coordinates) the bounding box of
* something that needs to be redraw. Typically they are added to the
* StageWindow as a result of clutter_actor_queue_clipped_redraw() by
* actors such as ClutterGLXTexturePixmap. All redraw clips are
* discarded after the next paint.
*
* A NULL stage_clip means the whole stage needs to be redrawn.
*
* What we do with this information:
* - we keep track of the bounding box for all redraw clips
* - when we come to redraw; if the bounding box is smaller than the
* stage we scissor the redraw to that box and use
* GLX_MESA_copy_sub_buffer to present the redraw to the front
* buffer. Some heuristics are used to decide when a clipped redraw
* should be promoted into a full stage redraw.
*
* Currently we simply check that the bounding box height is < 300
* pixels.
*
* XXX: we don't have any empirical data telling us what a sensible
* thresholds is!
*
* TODO - we should use different heuristics depending on whether the
* framebuffer is on screen and not redirected by a compositor VS
* offscreen (either due to compositor redirection or because we are
* rendering to a CoglOffscreen framebuffer)
*
* When not redirected glXCopySubBuffer (on intel hardware at least)
* will block the GPU until the vertical trace is at the optimal point
* so the copy can be done without tearing. In this case we don't want
* to copy tall regions because they increase the average time spent
* blocking the GPU.
*
* When rendering offscreen (CoglOffscreen or redirected by
* compositor) then no extra synchronization is needed before the copy
* can start.
*
* In all cases we need to consider that glXCopySubBuffer implies a
* blit which may be avoided by promoting to a full stage redraw if:
* - the framebuffer is redirected offscreen or a CoglOffscreen.
* - the framebuffer is onscreen and fullscreen.
* By promoting to a full stage redraw we trade off the cost involved
* in rasterizing the extra pixels vs avoiding to use a blit to
* present the back buffer.
*
*/
static void
clutter_stage_glx_add_redraw_clip (ClutterStageWindow *stage_window,
ClutterGeometry *stage_clip)
{
ClutterStageGLX *stage_glx = CLUTTER_STAGE_GLX (stage_window);
/* If we are already forced to do a full stage redraw then bail early */
if (clutter_stage_glx_ignoring_redraw_clips (stage_window))
return;
/* A NULL stage clip means a full stage redraw has been queued and
* we keep track of this by setting a degenerate
* stage_glx->bounding_redraw_clip */
if (stage_clip == NULL)
{
stage_glx->bounding_redraw_clip.width = 0;
return;
}
/* Do nothing on an empty clip to avoid confusing with out magic-flag
* degenerate clip
*/
if (stage_clip->width == 0 || stage_clip->height == 0)
return;
if (!stage_glx->initialized_redraw_clip)
{
stage_glx->bounding_redraw_clip.x = stage_clip->x;
stage_glx->bounding_redraw_clip.y = stage_clip->y;
stage_glx->bounding_redraw_clip.width = stage_clip->width;
stage_glx->bounding_redraw_clip.height = stage_clip->height;
}
else if (stage_glx->bounding_redraw_clip.width > 0)
{
clutter_geometry_union (&stage_glx->bounding_redraw_clip, stage_clip,
&stage_glx->bounding_redraw_clip);
}
/* FIXME: This threshold was plucked out of thin air! */
if (stage_glx->bounding_redraw_clip.height > 300)
{
/* Set a degenerate clip to force a full redraw */
stage_glx->bounding_redraw_clip.width = 0;
}
#if 0
redraw_area = (stage_glx->bounding_redraw_clip.width *
stage_glx->bounding_redraw_clip.height);
stage_area = stage_x11->xwin_width * stage_x11->xwin_height;
/* Redrawing and blitting >70% of the stage is assumed to be more
* expensive than redrawing the additional 30% to avoid the blit.
*
* FIXME: This threshold was plucked out of thin air!
*/
if (redraw_area > (stage_area * 0.7f))
{
g_print ("DEBUG: clipped redraw too big, forcing full redraw\n");
/* Set a degenerate clip to force a full redraw */
stage_glx->bounding_redraw_clip.width = 0;
}
#endif
stage_glx->initialized_redraw_clip = TRUE;
}
static void
clutter_stage_window_iface_init (ClutterStageWindowIface *iface)
{
clutter_stage_glx_parent_iface = g_type_interface_peek_parent (iface);
iface->realize = clutter_stage_glx_realize;
iface->unrealize = clutter_stage_glx_unrealize;
iface->get_pending_swaps = clutter_stage_glx_get_pending_swaps;
iface->add_redraw_clip = clutter_stage_glx_add_redraw_clip;
iface->has_redraw_clips = clutter_stage_glx_has_redraw_clips;
iface->ignoring_redraw_clips = clutter_stage_glx_ignoring_redraw_clips;
/* the rest is inherited from ClutterStageX11 */
}
#ifdef __linux__
static int
drm_wait_vblank(int fd, drm_wait_vblank_t *vbl)
{
int ret, rc;
do
{
ret = ioctl(fd, DRM_IOCTL_WAIT_VBLANK, vbl);
vbl->request.type &= ~DRM_VBLANK_RELATIVE;
rc = errno;
}
while (ret && rc == EINTR);
return rc;
}
#endif /* __linux__ */
static void
wait_for_vblank (ClutterBackendGLX *backend_glx)
{
if (backend_glx->vblank_type == CLUTTER_VBLANK_NONE)
return;
if (backend_glx->wait_video_sync)
{
unsigned int retraceCount;
CLUTTER_NOTE (BACKEND, "Waiting for vblank (wait_video_sync)");
backend_glx->get_video_sync (&retraceCount);
backend_glx->wait_video_sync (2,
(retraceCount + 1) % 2,
&retraceCount);
}
else
#ifdef __linux__
{
drm_wait_vblank_t blank;
CLUTTER_NOTE (BACKEND, "Waiting for vblank (drm)");
blank.request.type = DRM_VBLANK_RELATIVE;
blank.request.sequence = 1;
blank.request.signal = 0;
drm_wait_vblank (backend_glx->dri_fd, &blank);
}
#endif
}
void
clutter_stage_glx_redraw (ClutterStageGLX *stage_glx,
ClutterStage *stage)
{
ClutterBackend *backend;
ClutterBackendX11 *backend_x11;
ClutterBackendGLX *backend_glx;
ClutterStageX11 *stage_x11;
GLXDrawable drawable;
unsigned int video_sync_count;
CLUTTER_STATIC_TIMER (painting_timer,
"Redrawing", /* parent */
"Painting actors",
"The time spent painting actors",
0 /* no application private data */);
CLUTTER_STATIC_TIMER (swapbuffers_timer,
"Redrawing", /* parent */
"glXSwapBuffers",
"The time spent blocked by glXSwapBuffers",
0 /* no application private data */);
CLUTTER_STATIC_TIMER (blit_sub_buffer_timer,
"Redrawing", /* parent */
"glx_blit_sub_buffer",
"The time spent in _glx_blit_sub_buffer",
0 /* no application private data */);
backend = clutter_get_default_backend ();
backend_x11 = CLUTTER_BACKEND_X11 (backend);
backend_glx = CLUTTER_BACKEND_GLX (backend);
stage_x11 = CLUTTER_STAGE_X11 (stage_glx);
CLUTTER_TIMER_START (_clutter_uprof_context, painting_timer);
if (backend_glx->can_blit_sub_buffer &&
/* NB: a degenerate redraw clip width == full stage redraw */
(stage_glx->bounding_redraw_clip.width != 0) &&
G_LIKELY (!(clutter_paint_debug_flags &
CLUTTER_DEBUG_DISABLE_CLIPPED_REDRAWS)))
{
cogl_clip_push_window_rectangle (stage_glx->bounding_redraw_clip.x,
stage_glx->bounding_redraw_clip.y,
stage_glx->bounding_redraw_clip.width,
stage_glx->bounding_redraw_clip.height);
clutter_actor_paint (CLUTTER_ACTOR (stage));
cogl_clip_pop ();
}
else
clutter_actor_paint (CLUTTER_ACTOR (stage));
cogl_flush ();
CLUTTER_TIMER_STOP (_clutter_uprof_context, painting_timer);
if (stage_x11->xwin == None)
return;
drawable = stage_glx->glxwin ? stage_glx->glxwin : stage_x11->xwin;
/* If we might ever use _clutter_backend_glx_blit_sub_buffer then we
* always need to keep track of the video_sync_count so that we can
* throttle blits.
*
* Note: we get the count *before* we issue any glXCopySubBuffer or
* blit_sub_buffer request in case the count would go up before
* returning control to us.
*/
if (backend_glx->can_blit_sub_buffer && backend_glx->get_video_sync)
backend_glx->get_video_sync (&video_sync_count);
/* push on the screen */
if (backend_glx->can_blit_sub_buffer &&
/* NB: a degenerate redraw clip width == full stage redraw */
(stage_glx->bounding_redraw_clip.width != 0) &&
G_LIKELY (!(clutter_paint_debug_flags &
CLUTTER_DEBUG_DISABLE_CLIPPED_REDRAWS)))
{
ClutterGeometry *clip = &stage_glx->bounding_redraw_clip;
ClutterGeometry copy_area;
CLUTTER_NOTE (BACKEND,
"_glx_blit_sub_buffer (window: 0x%lx, "
"x: %d, y: %d, "
"width: %d, height: %d)",
(unsigned long) drawable,
stage_glx->bounding_redraw_clip.x,
stage_glx->bounding_redraw_clip.y,
stage_glx->bounding_redraw_clip.width,
stage_glx->bounding_redraw_clip.height);
if (clutter_paint_debug_flags & CLUTTER_DEBUG_REDRAWS)
{
static CoglHandle outline = COGL_INVALID_HANDLE;
CoglHandle vbo;
float x_1 = clip->x;
float x_2 = clip->x + clip->width;
float y_1 = clip->y;
float y_2 = clip->y + clip->height;
float quad[8] = {
x_1, y_1,
x_2, y_1,
x_2, y_2,
x_1, y_2
};
if (outline == COGL_INVALID_HANDLE)
{
outline = cogl_material_new ();
cogl_material_set_color4ub (outline, 0xff, 0x00, 0x00, 0xff);
}
vbo = cogl_vertex_buffer_new (4);
cogl_vertex_buffer_add (vbo,
"gl_Vertex",
2, /* n_components */
COGL_ATTRIBUTE_TYPE_FLOAT,
FALSE, /* normalized */
0, /* stride */
quad);
cogl_vertex_buffer_submit (vbo);
cogl_set_source (outline);
cogl_vertex_buffer_draw (vbo, COGL_VERTICES_MODE_LINE_LOOP,
0 , 4);
cogl_flush ();
}
/* XXX: It seems there will be a race here in that the stage
* window may be resized before glXCopySubBufferMESA is handled
* and so we may copy the wrong region. I can't really see how
* we can handle this with the current state of X but at least
* in this case a full redraw should be queued by the resize
* anyway so it should only exhibit temporary artefacts.
*/
copy_area.y = clutter_actor_get_height (CLUTTER_ACTOR (stage))
- clip->y - clip->height;
copy_area.x = clip->x;
copy_area.width = clip->width;
copy_area.height = clip->height;
/* glXCopySubBufferMESA and glBlitFramebuffer are not integrated
* with the glXSwapIntervalSGI mechanism which we usually use to
* throttle the Clutter framerate to the vertical refresh and so
* we have to manually wait for the vblank period...
*/
/* Here 'is_synchronized' only means that the blit won't cause a
* tear, ie it won't prevent multiple blits per retrace if they
* can all be performed in the blanking period. If that's the
* case then we still want to use the vblank sync menchanism but
* we only need it to throttle redraws.
*/
if (!backend_glx->blit_sub_buffer_is_synchronized)
{
/* XXX: note that glXCopySubBuffer, at least for Intel, is
* synchronized with the vblank but glBlitFramebuffer may
* not be so we use the same scheme we do when calling
* glXSwapBuffers without the swap_control extension and
* call glFinish () before waiting for the vblank period.
*
* See where we call glXSwapBuffers for more details.
*/
glFinish ();
wait_for_vblank (CLUTTER_BACKEND_GLX (backend));
}
else if (backend_glx->get_video_sync)
{
/* If we have the GLX_SGI_video_sync extension then we can
* be a bit smarter about how we throttle blits by avoiding
* any waits if we can see that the video sync count has
* already progressed. */
if (backend_glx->last_video_sync_count == video_sync_count)
wait_for_vblank (CLUTTER_BACKEND_GLX (backend));
}
else
wait_for_vblank (CLUTTER_BACKEND_GLX (backend));
CLUTTER_TIMER_START (_clutter_uprof_context, blit_sub_buffer_timer);
_clutter_backend_glx_blit_sub_buffer (backend_glx,
drawable,
copy_area.x,
copy_area.y,
copy_area.width,
copy_area.height);
CLUTTER_TIMER_STOP (_clutter_uprof_context, blit_sub_buffer_timer);
}
else
{
CLUTTER_NOTE (BACKEND, "glXSwapBuffers (display: %p, window: 0x%lx)",
backend_x11->xdpy,
(unsigned long) drawable);
/* If we have GLX swap buffer events then glXSwapBuffers will return
* immediately and we need to track that there is a swap in
* progress... */
if (clutter_feature_available (CLUTTER_FEATURE_SWAP_EVENTS))
stage_glx->pending_swaps++;
if (backend_glx->vblank_type != CLUTTER_VBLANK_GLX_SWAP)
{
/* If we are going to wait for VBLANK manually, we not only
* need to flush out pending drawing to the GPU before we
* sleep, we need to wait for it to finish. Otherwise, we
* may end up with the situation:
*
* - We finish drawing - GPU drawing continues
* - We go to sleep - GPU drawing continues
* VBLANK - We call glXSwapBuffers - GPU drawing continues
* - GPU drawing continues
* - Swap buffers happens
*
* Producing a tear. Calling glFinish() first will cause us
* to properly wait for the next VBLANK before we swap. This
* obviously does not happen when we use _GLX_SWAP and let
* the driver do the right thing
*/
glFinish ();
wait_for_vblank (CLUTTER_BACKEND_GLX (backend));
}
CLUTTER_TIMER_START (_clutter_uprof_context, swapbuffers_timer);
glXSwapBuffers (backend_x11->xdpy, drawable);
CLUTTER_TIMER_STOP (_clutter_uprof_context, swapbuffers_timer);
}
backend_glx->last_video_sync_count = video_sync_count;
/* reset the redraw clipping for the next paint... */
stage_glx->initialized_redraw_clip = FALSE;
}