Hi Ferruh, On Thu, May 22, 2014 at 02:03:40PM +0300, Ferruh Yigit wrote: > Hi, > > What is the metric of ABS_MT_TOUCH_MAJOR / ABS_MT_WIDTH_MAJOR events? > > The Linux documentation > <https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt> > says: > "The length of the major axis of the contact. The length should be given > in surface units. ..." > > What does "surface units" means, is it millimeter or pixels?
It is whatever unit the device reports, similarly to ABS_MT_POSITION_X and ABS_MT_POSITION_Y. Userspace can use EVIOCGABS to map device units onto common units. >From include/uapi/linux/input.h (struct input_absinfo): * Resolution for main axes (ABS_X, ABS_Y, ABS_Z) is reported in * units per millimeter (units/mm), resolution for rotational axes * (ABS_RX, ABS_RY, ABS_RZ) is reported in units per radian. Hope this helps. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
