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Drawing Tablets

From: Florian Bösch <pyalot@gmail.com>
Date: Wed, 1 Aug 2012 13:13:26 +0200
Message-ID: <CAOK8ODhymfmwzQOZ5kW+WnbH4rBOghTgLrp4LJj7hC-DV_KNtA@mail.gmail.com>
To: Webapps WG <public-webapps@w3.org>
I'm interested in drawing tablets and I wonder how that might appear in
browsers.

Typically drawing tablets have these properties:

- PenID: The current pen ID being used
- Tool type: the classification of the pen
- Proximity: in range of the magnet-resonance sensors
- Distance: distance over the surface
- X Position: absolute position from the left
- Y Position: absolute position from the top
- Z rotation: rotation of the pen around its axis (roll)
- Pressure: when the pen contacts the tablet surface, amount of pressure
excerted
- Tilt X: the tilting of the pen relative to the X axis of the tablet
- Tilt Y: the tilting of the pen relative to the Y axis of the tablet
- Wheel: the wheel on the pen mouse
- Throttle: the throttle lever on airbrush pens
- Pen buttons (stylus, stylus2)
- Tablet buttons (left, middle, right)
- Touch: touch sensitive slide bars on the tablet

The tablets do sport fairly good resolutions of 5080 LPI in the case of
Wacom Intuous tablets which translates to a precision of +- 0.02mm. A
tablet having a size of 18.2" by 12.0" has therefore a total of 92'456 x
60'960 (5.6 gigapixels)  positions to serve up. If mapped onto a full-hd
display (1920x1080) that would be 48x56 (2688) positions per pixel on
screen. Every square inch of a tablet has a higher resolution than our
highest resolution displays have to date.

The resolution is put into these tablets in order to facilitate accurate
drawing. It is in fact, one of the major tablet performance metrics
advancing in every generation. It's therefore important not to clamp tablet
movement to pixels, because that would defeat the purpose.

>From a usability point of view, it often desirable to be able to setup a
transform and switch "mode" as in pointerlock for the tablet (if mapped to
a pointer in the first place) for certain states (like engaging with the
drawing surface). Pointer mapping is not always preferred, some users which
are ambidextrous prefer using a pen and mouse at the same time.

Another aspect that might be troublesome is that drivers for these devices
typically deliver correlated events separately (such as X/Y axes events)
which would be unusable to an application that way (it would result in
drawing stairs). It's therefore important to correlate some individual
events before passing them on to the application.

More modern tablets do also support multiple simultaneous pens and some
also have multitouch support.

Is there any specification that would be suitable to serve these devices?
Received on Friday, 3 August 2012 01:33:05 GMT

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