Re: Questions about Multi-touch Protocal

[Florian Echtler <floe@butterbrot.org>]

> The TOUCH and WIDTH parameters have a geometrical interpretation; imagine
> looking through a window at someone gently holding a finger against the glass.
> You will see two regions, one inner region consisting of the part of the finger
> actually touching the glass, and one outer region formed by the perimeter of the
> finger. The diameter of the inner region is the ABS_MT_TOUCH_MAJOR, the diameter
> of the outer region is ABS_MT_WIDTH_MAJOR. Now imagine the person pressing the
> finger harder against the glass. The inner region will increase, and in general,
> the ratio ABS_MT_TOUCH_MAJOR / ABS_MT_WIDTH_MAJOR, which is always smaller than
> unity, is related to the finger pressure.

> In addition to the MAJOR parameters, the oval shape of the finger can be
> described by adding the MINOR parameters, such that MAJOR and MINOR are the
> major and minor axis of an ellipse. Finally, the orientation of the oval shape
> can be describe with the ORIENTATION parameter.

> Hope this explains it a bit further.
Very interesting writeup, thanks a lot. Is there any currently any
hardware which is available to end-users and does support these
features? AFAIR most capacitive touchscreens don't have high enough
resolution to actually detect, e.g., twisting. If there's a commercial
option, I'd like to hear about it..

Florian
-- 
0666 - Filemode of the Beast