Dual-Touch SDK for Resistive Screens V1.0 Beta

**Hypnotic2010** · #1 (**permalink**) 04-19-2010, 11:03 AM

Interesting.........
http://www.windowsphoneme.com/?p=386

Here is something for developers, Adel Al Zubeir have recently released a SDK which promises to bring MultiTouch ( detects up to 2 touches ) to Resistive screen. I am no developer and have no idea how this works but if you are a developer and want to add multitouch gestures to your windows mobile apps then this might be worth a look. This SDK allows developers to build Dual-Touch enabled applications. Features:
* Pinch to Zoom Support
* Drag (swipe) support.
* Replacement events for the mouse move fires only when a single finger detected.
* Multiple events based on gestures.
* Performance optimized, memory footprint is minimal.
To use this SDK you will need Visual Studio Professional or better. start a new Smart Device Project, and add the SDK to your references.
The SDK is consists of only one object, which is DualTouchSDK. We will need one instance of this class for every control that supports pinch to zoom or drag in your application.

**pixelpower** · #2 (**permalink**) 04-19-2010, 11:16 AM

Thanks for the info !!

hamagc · #3 (**permalink**) 04-19-2010, 12:25 PM

can't wait to see something come of this. are there any sample applications with this implemented?

inertone · #4 (**permalink**) 04-19-2010, 06:47 PM

theres more info on the XDA thread:
http://forum.xda-developers.com/showthread.php?t=655830

**orangekid** · #5 (**permalink**) 04-26-2010, 10:30 AM

quoted from post #47 to explain how this works.

Just tested on the touch pro. Works.

But, there are limitations.
It can only detect motion of the second point pressed.
If both are pressed at nearly the exact time, it does not work.
If you do move the first finger pressed, the position of the second point is not calculted correctly. I don't really see a way to calculate it correctly, since it isn't really detecting both pressed points.

It's detecting the 2 points were pressed in a very short amount of time.
So, it uses the coordinates of the 1st press, and the registered point of the second press, to calculate where the second finger is based on the first point.

If you draw a line between the 2, the registered point is half way.
So the algorithm is pretty simple.
Something like:

2 * (2nd registerd point(xM,yM) - 1st press (x1,y1) ) + (x1, y1) = (x2,y2)

where (x1,y1) is actual position of finger 1
where (x2,y2) is actual position of finger 2
where (xM,yM) is actual position regsitered when the 2nd finger is added.