Messages in this thread | | | From | "Henrik Rydberg" <> | Date | Fri, 4 May 2012 15:48:31 +0200 | Subject | Re: [PATCH 4/5] input: Introduce MT_CENTER_X and MT_CENTER_Y |
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Hi Benjamin, Stephane,
> Microsoft published a new version of their multitouch specification. > They introduced a new multitouch field: MT_CENTER_X|Y.
I would like a bit of elaboration here, since I am not convinced the mapping should be directly translated to the MT protocol.
Clearly, the basic idea to be able to model an assymmetric tool is good. Without an angle description, however, there seems to be a mismatch in the degrees of freedom. In win8, one can place the hot spot in a corner of the rectangle, but one cannot make the rectangle into an ellipse in that direction. In linux, one can put the ellipse in the wanted direction, but the hot spot is always in the center. To first order, both models allow for finger-rotation information, but in different ways. Adding more parameters requires a bit more thought. Perhaps one should use the newly found win8 parameters to reshape the pointing ellipse to start with.
Thanks, Henrik
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