Thoughts on Linux multitouch
Oct 06, 2010, 12:34 (1 Talkback[s])
(Other stories by Peter Hutterer)
"Let's start from the basics. Traditional input devices such as
mice provide one physical device to control one virtual input point
(the cursor or the keyboard focus). At it's very basic, multitouch
is the ability to use multiple input points on a single physical
device. This has some implications on technical issues but many
more implications on the UI design. It is also the main reason why
multi-pointer (which we support since server 1.7) is not a
replacement for multitouch.
"Multitouch comes in roughly two different forms: direct touch
and what I call dependent touch. Direct touch is simple, a touch
point directly relates to the position on the device, i.e. a touch
in the upper right corner of the touch device will usually result
in some action in the upper right corner of the screen.
Dependent-touch devices are e.g. multi-touch aware touchpads but
also devices like the Apple Magic Mouse. In their case, the touch
is usually interpreted relative to the pointer position of that
"The usage of such devices differs vastly too. A direct-touch
device will likely be used as such, with plenty of direct object
manipulations at their respective position."