/* 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-actor-private.h"
#include "clutter-debug.h"
#include "clutter-event.h"
#include "clutter-enum-types.h"
#include "clutter-feature.h"
#include "clutter-main.h"
#include "clutter-private.h"
#include "clutter-stage-private.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 HAVE_DRM
#include <drm.h>
#endif
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;
int event_flags;
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);
}
}
/* the masks for the events we want to select on a stage window;
* KeyPressMask and KeyReleaseMask are necessary even with XI1
* because key events are broken with that extension, and will
* be fixed by XI2
*/
event_flags = StructureNotifyMask
| FocusChangeMask
| ExposureMask
| PropertyChangeMask
| EnterWindowMask
| LeaveWindowMask
| KeyPressMask
| KeyReleaseMask;
/* if we don't use XI1 then we also want core pointer events */
if (!clutter_x11_has_xinput ())
event_flags |= (ButtonPressMask | ButtonReleaseMask | PointerMotionMask);
#ifdef HAVE_XINPUT
else
_clutter_x11_select_events (stage_x11->xwin);
#endif
/* we unconditionally select input events even with event retrieval
* disabled because we need to guarantee that the Clutter internal
* state is maintained when calling clutter_x11_handle_event() without
* requiring applications or embedding toolkits to select events
* themselves. if we did that, we'd have to document the events to be
* selected, and also update applications and embedding toolkits each
* time we added a new mask, or a new class of events.
*
* see: http://bugzilla.clutter-project.org/show_bug.cgi?id=998
* for the rationale of why we did conditional selection. it is now
* clear that a compositor should clear out the input region, since
* it cannot assume a perfectly clean slate coming from us.
*
* see: http://bugzilla.clutter-project.org/show_bug.cgi?id=2228
* for an example of things that break if we do conditional event
* selection.
*/
XSelectInput (backend_x11->xdpy, stage_x11->xwin, event_flags);
#ifdef GLX_INTEL_swap_event
if (clutter_feature_available (CLUTTER_FEATURE_SWAP_EVENTS))
{
GLXDrawable drawable =
stage_glx->glxwin ? stage_glx->glxwin : stage_x11->xwin;
/* similarly to above, we unconditionally select this event
* because we rely on it to advance the master clock, and
* drive redraw/relayout, animations and event handling.
*/
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: at the start of each new frame there is an implied clip that
* clips everything (i.e. nothing would be drawn) so we need to make
* sure we return True in the un-initialized case here.
*
* NB: a clip width of 0 means a full stage redraw has been queued
* so we effectively don't have any redraw clips in that case.
*/
if (!stage_glx->initialized_redraw_clip ||
(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 clip width of 0 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 zero width
* stage_glx->bounding_redraw_clip */
if (stage_clip == NULL)
{
stage_glx->bounding_redraw_clip.width = 0;
stage_glx->initialized_redraw_clip = TRUE;
return;
}
/* Ignore requests to add degenerate/empty clip rectangles */
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);
}
#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 zero width 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 HAVE_DRM
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 /* HAVE_DRM */
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 HAVE_DRM
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);
#else
CLUTTER_NOTE (BACKEND, "No vblank mechanism found");
#endif /* HAVE_DRM */
}
}
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;
gboolean may_use_clipped_redraw;
gboolean use_clipped_redraw;
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 (G_LIKELY (backend_glx->can_blit_sub_buffer) &&
/* NB: a zero width redraw clip == full stage redraw */
stage_glx->bounding_redraw_clip.width != 0 &&
/* some drivers struggle to get going and produce some junk
* frames when starting up... */
G_LIKELY (stage_glx->frame_count > 3) &&
/* While resizing a window clipped redraws are disabled to avoid
* artefacts. See clutter-event-x11.c:event_translate for a
* detailed explanation */
G_LIKELY (stage_x11->clipped_redraws_cool_off == 0))
may_use_clipped_redraw = TRUE;
else
may_use_clipped_redraw = FALSE;
if (may_use_clipped_redraw &&
G_LIKELY (!(clutter_paint_debug_flags &
CLUTTER_DEBUG_DISABLE_CLIPPED_REDRAWS)))
use_clipped_redraw = TRUE;
else
use_clipped_redraw = FALSE;
if (use_clipped_redraw)
{
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_stage_do_paint (stage, &stage_glx->bounding_redraw_clip);
cogl_clip_pop ();
}
else
_clutter_stage_do_paint (stage, NULL);
if (clutter_paint_debug_flags & CLUTTER_DEBUG_REDRAWS &&
may_use_clipped_redraw)
{
ClutterGeometry *clip = &stage_glx->bounding_redraw_clip;
static CoglMaterial *outline = NULL;
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
};
CoglMatrix modelview;
if (outline == NULL)
{
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_push_matrix ();
cogl_matrix_init_identity (&modelview);
_clutter_actor_apply_modelview_transform (CLUTTER_ACTOR (stage),
&modelview);
cogl_set_modelview_matrix (&modelview);
cogl_set_source (outline);
cogl_vertex_buffer_draw (vbo, COGL_VERTICES_MODE_LINE_LOOP,
0 , 4);
cogl_pop_matrix ();
cogl_object_unref (vbo);
}
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 (use_clipped_redraw)
{
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);
/* 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 &&
backend_glx->vblank_type != CLUTTER_VBLANK_NONE)
{
/* 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;
stage_glx->frame_count++;
}