diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2015-01-30 00:16:16 +0000 |
|---|---|---|
| committer | Robert Bragg <robert.bragg@intel.com> | 2015-02-04 19:31:40 +0000 |
| commit | 5ccd2825c724267d066c4e93190a4bec1ae0ced0 (patch) | |
| tree | 37563ddacd5bdd50c117f03b67bb1a6ba8720ddd | |
| parent | b9640c091f96cef0ad991785297a9290435464ca (diff) | |
glx: Precisely wait for the next vblank
Currently the code queries the current msc then tries to approximate the
value of the next msc satisfing the modulus 2 for when to wait. This
introduces some instability as the msc may tick over during the
roundtrip leading to a 32ms wait instead of a 16ms wait. This happens
often enough to cause jerky animations, and affect gnome-shell-perf-tool.
A simpler solution is just use a single roundtrip by using WaitForMsc to
ask the driver to compute the next vblank itself.
Cc: Owen W. Taylor <otaylor@fishsoup.net>
Cc: Robert Bragg <robert@linux.intel.com>
Reviewed-by: Robert Bragg <robert@sixbynine.org>
| -rw-r--r-- | cogl/winsys/cogl-winsys-glx.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/cogl/winsys/cogl-winsys-glx.c b/cogl/winsys/cogl-winsys-glx.c index 0487b79f..34fb0711 100644 --- a/cogl/winsys/cogl-winsys-glx.c +++ b/cogl/winsys/cogl-winsys-glx.c @@ -1626,10 +1626,8 @@ _cogl_winsys_wait_for_vblank (CoglOnscreen *onscreen) int64_t msc; int64_t sbc; - glx_renderer->glXGetSyncValues (xlib_renderer->xdpy, drawable, - &ust, &msc, &sbc); glx_renderer->glXWaitForMsc (xlib_renderer->xdpy, drawable, - 0, 2, (msc + 1) % 2, + 0, 1, 0, &ust, &msc, &sbc); info->presentation_time = ust_to_nanoseconds (ctx->display->renderer, drawable, |