- From: Rick Byers via GitHub <sysbot+gh@w3.org>
- Date: Mon, 01 May 2017 18:53:17 +0000
- To: public-touchevents@w3.org
> am i right in assuming that the Apple Pencil has no concept of "twist" (i.e. that both the altitudeAngle and azimuthAngle remain unchanged if i simply spin the Pencil along its lengthwise/z axis while keeping its overall position/attitude towards the digitizer surface the same)? Sorry for the delay. Yes, AFAIK there's no notion of twist (I think that's the same as MS Surface, right?). But Twist is entirely separate I think (unless you're thinking about the special case of the stylus pointing straight up and down). altitudeAngle/azimuthAngle are mathematically just an alternate representation of tiltX/tiltY. Android has basically the same thing with [AXIS_TILT](https://developer.android.com/reference/android/view/MotionEvent.html#AXIS_TILT) (altitudeAngle) and [AXIS_ORIENTATION](https://developer.android.com/reference/android/view/MotionEvent.html#AXIS_ORIENTATION) (for stylus only, equivalent of azimuthAngle). In Chrome we just do some trigonometry to convert between the [one](https://cs.chromium.org/chromium/src/ui/events/blink/blink_event_util.cc?sq=package:chromium&dr=CSs&l=907) representation and [the other](https://cs.chromium.org/chromium/src/content/browser/renderer_host/input/motion_event_web.cc?sq=package:chromium&dr=CSs&l=143). -- GitHub Notification of comment by RByers Please view or discuss this issue at https://github.com/w3c/touch-events/pull/81#issuecomment-298401520 using your GitHub account
Received on Monday, 1 May 2017 18:53:26 UTC