Re: Need a direction to XInput support in NSEvent.

[Banlu Kemiyatorn]

On 2004-01-29 10:29:58 +0700 Adam Fedor <address@hidden> wrote:

> On Sun, 2004-01-25 at 03:24, Banlu Kemiyatorn wrote:
> > Dear Sirs,
> >         I'm about to start working on XInput support for tablets
> > and I need a direction on how to implement it. There are addition
> > information I currently need in the mouse event including current
> > device id, tilt & rotation (can be unioned?).
>
> Is that in addition to deltaX, deltaY, and deltaZ? Could you use deltaZ
> for tilt and/or rotation?

Tilts are the angles that the device do to the tablet plane in X and Y axis.
If deltas were used in a mouse event, how can application know about
original event. And there's no event on tilt angles changing. You will
know the tilt angles once on each movement event arriving.

> What is device id used for and how would the front-end deal with it?
> maybe use button number? I'd rather not overload things too much, but it
> depends on how much you need and how much is useful (and trying not to
> add new ivars).

Device id is used to specify the device that cause the event. XInput allow
many devices working at the same time. (such as cursor, stylus, eraser, mouse,
4d mouse, keyboard(s?))

> I don't see why subpixel positioning would break apps. Maybe I don't
> understand.

Since it happenned to my own image editing app. it is definitely app's fault to
assume that the mouse event are coming in integral floating point.