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458

answers:

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Hello everyone,

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.

thanks in advance, George

+3  A: 

Touch isn't hugely "there" in .NET 3.5; but the good news is that I'm pretty sure it is much better supported in the 4.0 toolset (WPF 4.0 in particular, see here).

In 3.5, the only time I've personally seen good touch support is when I was using a "surface" device and the surface SDK; note that the surface SDK is not compatible with the regular touch API (although I think they've tried to bring the two together).

Oh, and I suspect you'll need windows 7.

Marc Gravell
Marc, sorry I may not make myself understood. I think the video you show me is WPF working on some H/W (laptop in this sample) which already has multi-touch capability, correct? If yes, then I am in another situation, suppose a laptop only supports single touch, I want to program it to make it support multi-touch. Any ideas or comments for this?
George2
+4  A: 

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.

Will Bickford
Thanks Will, do you mean if the current single-touch screen expose itself as USB or PS/2 mouse "interface", I cannot programming from this interface and I need to ask for lower level interface?
George2
Yes I think so. It's an issue of whether they can provide you with raw tracking data or just the filtered point. More expensive hardware probably does the processing on-board. Cheaper hardware probably does it in software. So looking for a cheap touch device might serve you better. This is pure conjecture though.
Will Bickford
Thanks, my question is answered.
George2