> On 11 Feb 2016, at 11:35, Александр Волков <[email protected]> wrote:
> Angle is not enough, because for compatibility with older apps 
> TouchPoint::rect() should be as close as possible to the rotated rect.
> See https://codereview.qt-project.org/#/c/114238/
> In other words it should be a projection of the rotated rect, so you should 
> introduce a separate method to get the rotated rect.

TUIO models the touchpoint as a rotated ellipse though, right?  
http://www.tuio.org/?specification  And I think that’s nice, for finger 
touchpoints at least (although markers could be any shape).  It can be assumed 
to be the ellipse inscribed in a rect; but I don’t think for the next-gen API 
that it makes sense to change the dimensions just because it’s rotated, because 
that makes it hard to visualize the ellipse, and hard to turn the size of the 
contact patch into a pressure (if you have hardware which gives you the contact 
patch but not the pressure).

Typical capacitive touchscreens (or window-system APIs) don’t provide the 
contact patch either, do they?  I’m not sure why it’s not more common.
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