Ever since fake front was introduced in 63b51b5cf17ddde09b72a2811296f37b9a4c5ad2, we were skipping the XSync() in the non-fake-front path, so compositors like Firefox's GL canvas were having to manually put it in outside of glXWaitX().
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=52930 --- src/glx/dri2_glx.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/src/glx/dri2_glx.c b/src/glx/dri2_glx.c index 7ce5775..3cdd249 100644 --- a/src/glx/dri2_glx.c +++ b/src/glx/dri2_glx.c @@ -639,10 +639,23 @@ dri2_wait_x(struct glx_context *gc) struct dri2_drawable *priv = (struct dri2_drawable *) GetGLXDRIDrawable(gc->currentDpy, gc->currentDrawable); - if (priv == NULL || !priv->have_fake_front) - return; - - dri2_copy_drawable(priv, DRI2BufferFakeFrontLeft, DRI2BufferFrontLeft); + if (priv != NULL && priv->have_fake_front) { + /* Ask the server to update our copy of the front buffer from the real + * front buffer. This will round-trip with the server, so we can skip + * the XSync(). + */ + dri2_copy_drawable(priv, DRI2BufferFakeFrontLeft, DRI2BufferFrontLeft); + } else { + /* From the GLX 1.4 spec, page 33: + * + * "X rendering calls made prior to glXWaitX are guaranteed to be + * executed before OpenGL rendering calls made after + * glXWaitX. While the same result can be achieved using XSync, + * glXWaitX does not require a round trip to the server, and may + * therefore be more efficient." + */ + XSync(gc->currentDpy, False); + } } static void -- 1.8.3.rc0 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
