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| author | Peter Hutterer <peter.hutterer@who-t.net> | 2013-11-20 11:58:08 +1000 |
|---|---|---|
| committer | Peter Hutterer <peter.hutterer@who-t.net> | 2013-12-10 19:39:47 +1000 |
| commit | 546efc783c7b952db1ebe6f10430ed7d73a2cb81 (patch) | |
| tree | dbe47f19c6dfc9ce799dffc41abba7fc626756b6 /libevdev/libevdev.h | |
| parent | 714c2ffa9e5891fe423212f623572c5dd6b7a04b (diff) | |
| download | libevdev-546efc783c7b952db1ebe6f10430ed7d73a2cb81.tar.gz | |
Don't treat devices with (ABS_MT_SLOT - 1) as multitouch devices
Some devices (PS3 sixaxis controller) merely have a bunch of axes, without the
semantic information that linux/input.h requires. For those, the ABS_MT range
may be merely another axis, not the special range that we need to treat it
with.
Use a simple heuristic: if ABS_MT_SLOT - 1 is enabled, don't treat ABS_MT as
multitouch axes. The ABS_MT_SLOT - 1 axis is not used for a real axis.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Diffstat (limited to 'libevdev/libevdev.h')
| -rw-r--r-- | libevdev/libevdev.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/libevdev/libevdev.h b/libevdev/libevdev.h index 2b6f48a..44aa3a6 100644 --- a/libevdev/libevdev.h +++ b/libevdev/libevdev.h @@ -361,6 +361,15 @@ extern "C" { * * As with @ref bits, the logical state of the device as seen by the library * depends on the caller using libevdev_next_event(). + * + * The Linux kernel requires all axes on a device to have a semantic + * meaning, matching the axis names in linux/input.h. Some devices merely + * export a number of axes beyond the available axis list. For those + * devices, the multitouch information is invalid. Specfically, if a device + * provides the ABS_MT_SLOT axis AND also the (ABS_MT_SLOT - 1) axis, the + * device is not treated as multitouch device. No slot information is + * available and the ABS_MT axis range for these devices is treated as all + * other EV_ABS axes. */ /** |