Monday, January 10, 2011

SoC Multitouch Directory - The Making Of

You may have noticed that GermaniumWeb does not natively support multitouch yet. Today, Kent and Torin Nguyen, the two School of Computing students who brought you the SoC Multitouch Directory share with us how they managed to enable multitouch in their web application.

TUIO (Tangible User Interface Objects) was used as the core of the touch processing, as it is "a common protocol and API for tangible multitouch surfaces" (tuio.org). Essentially, TUIO is a set of XML-based messages broadcast through UDP socket connections, which gives a clean separation between the touchscreen hardware and the user interface application.

This allowed them to develop their application once and be able to integrate with a wide variety of touchscreens. For screens which support Windows 7 Touch like the 3M M2256PW, PQ Labs and NextWindow touchscreens, bridges like Touch2Tuio and WM_TOUCH to TUIO were used to convert Windows Touch messages to TUIO messages. These were then sent to the Firefox web browser, where the npTuioClient plugin received them, converted them to JavaScript callbacks and allowed their web application to convert them to GermaniumWeb Eye calls.

For touchscreens which support TUIO directly like some PQ Labs touchscreens and DIY screens based on the Community Core Vision (CCV) or Touchlib libraries, the bridge was unnecessary and the touchscreen directly sent TUIO messages to the npTuioClient plugin.

I hope you found this information useful. Thanks to Kent and Torin for sharing it with us!

Ian Loh

No comments:

Post a Comment