On Wed, Jul 25, 2012 at 2:04 AM, Jeremy Huddleston Sequoia <[email protected]> wrote: > Yick. This is why origin/size are better descriptors =( > > Reviewed-by: Jeremy Huddleston Sequoia <[email protected]> > > On Jul 20, 2012, at 16:41, Yufeng Shen <[email protected]> wrote: > >> Scale_to_desktop() converts ABS events from device coordinates >> to screen coordinates: >> [dev_X_min, dev_X_max] -> [screen_X_min, screen_X_max] >> [dev_Y_min, dev_Y_max] -> [screen_Y_min, screen_Y_max] >> >> An edge ABS event with X = dev_X_max (e.g., generated from the >> edge of a touchscreen) will be converted to have screen X value >> = screen_X_max, which, however, will be filterd out when xserver >> tries to find proper Window to receive the event, because the >> range check for a Window to receive events is >> window_X_min <= event_screen_X < window_X_max >> Events with event_screen_X = screen_X_max will fail the test get >> and rejected by the Window. >> >> To fix this, we change the device to screen coordinates mapping to >> [dev_X_min, dev_X_max] -> [screen_X_min, screen_X_max-1] >> [dev_Y_min, dev_Y_max] -> [screen_Y_min, screen_Y_max-1] >> >> Signed-off-by: Yufeng Shen <[email protected]> >> --- >> dix/getevents.c | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/dix/getevents.c b/dix/getevents.c >> index b78d5ce..9898c6a 100644 >> --- a/dix/getevents.c >> +++ b/dix/getevents.c >> @@ -890,9 +890,9 @@ scale_to_desktop(DeviceIntPtr dev, ValuatorMask *mask, >> >> /* scale x&y to desktop coordinates */ >> *screenx = rescaleValuatorAxis(x, dev->valuator->axes + 0, NULL, >> - screenInfo.x, screenInfo.width); >> + screenInfo.x, screenInfo.width - 1);
Hi Yufeng, rescaleValuatorAxis() expects min/max for its last two arguments. Technically, this patch (and the original code) looks like it is assuming that screenInfo.x == 0. This is probably a good assumption (since this is the global origin for all screens together). However, I think something like the following is probably safer: *screenx = rescaleValuatorAxis(x, dev->valuator->axes + 0, NULL, screenInfo.x, screenInfo.x + screenInfo.width - 1); *screeny = rescaleValuatorAxis(y, dev->valuator->axes + 0, NULL, screenInfo.y, screenInfo.y + screenInfo.height - 1); Also, can you double check to make sure that the arguments to rescaleValuatorAxis() are set correctly elsewhere as well? A quick glance shows that (a) positionSprite() has the exact same issue, and (b) other callers seem to be treating them as "origin / width", and not "min / max". Thanks, -Daniel >> *screeny = rescaleValuatorAxis(y, dev->valuator->axes + 1, NULL, >> - screenInfo.y, screenInfo.height); >> + screenInfo.y, screenInfo.height - 1); >> >> *devx = x; >> *devy = y; >> -- >> 1.7.7.3 >> >> _______________________________________________ >> [email protected]: X.Org development >> Archives: http://lists.x.org/archives/xorg-devel >> Info: http://lists.x.org/mailman/listinfo/xorg-devel >> > > _______________________________________________ > [email protected]: X.Org development > Archives: http://lists.x.org/archives/xorg-devel > Info: http://lists.x.org/mailman/listinfo/xorg-devel _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel
