[Sugar-devel] Multi-touch test activity

[Bert Freudenberg]

Ah, thanks. I wasn't even going to file a bug report about the aliasing because that is a limitation inherent to the kind of sensor we have.

Thinking about this a little bit more, only pinch/zoom will be fine. Rotation can still go in the wrong direction if the driver guesses the intersections wrongly.

- Bert -

On 2012-11-05, at 01:55, forster at ozonline.com.au wrote:

> See also http://dev.laptop.org/ticket/12161
> 
> Tony
> 
>> Hi folks,
>> 
>> I made a simple Sugar activity to test the XO-4's multi-touch screen:
>> 
>> 	http://activities.sugarlabs.org/en-US/sugar/addon/4611/
>> 
>> It works fine most of the time. Sometimes the touch contact ends unexpectedly without lifting the finger.
>> 
>> It also demonstrates that the Neonode sensor's two touch points are not independent: If you put down two fingers simultaneously, it does not know in which of the 4 possible positions the two fingers are (it only knows that 2 horizontal and 2 vertical beams got obstructed) and so it has to guess. Also, the tracking sometimes "switches over", e.g. when doing a pinch-zoom using your right hand.
>> 
>> For activity developers this means that pinch/zoom and rotation gestures will work fine, but we cannot rely on truly independent touch tracking.
>> 
>> Also, two-finger sweeps are not always recognized as two fingers if they are held close together.
>> 
>> Nonetheless, it is fun to play with if you happen to have an XO-4 Touch :)
>> 
>> Source code:
>> 
>> 	http://git.sugarlabs.org/testmultitouch/mainline
>> 
>> Patches welcome, but I want to keep the source simple, this is not going to become another Paint activity.
>> 
>> - Bert -
>> 
>> PS: Could some admin please delete the accidental non-mainline repo in http://git.sugarlabs.org/testmultitouch/ ? Keep "mainline", remove "testmultitouch". Thanks.
>