Suppose I have a touch screen which supports single finger touch, is it very hard to use software based solution (e.g. programming to detect multi-finger touch and movement) to make the touch screen support multi-touch?
Just like I bought a cheap single finger touch cell phone and through programming I make it work as iPhone, Gphone or what so ever cool (supporting multi-touch). :-)
I am using VSTS 2008 + C# + .Net 3.5. I am asking seriously, not joking. Please correct me if I am stupid and on a wrong direction.
It would likely depend upon what sort of information the driver for your device receives. If raw data from the touch panel is available, then you might be able to get some extra information and do some pseudo multi-touch.
My gut feeling, however, is that a single-touch interface will configure itself like a standard USB or PS/2 mouse. This would be done to simplify the driver interface - the manufacturer would be able to expose the hardware via already-established protocols.
If you have a device in mind you could always contact the manufacturer and ask them what sort of additional information they might be able to feed to you.