Gesture challenge

[Biterider]

Hi
I want to implement a zoom gesture that acts on a window, but selectively in the x and y directions. 

The idea is to analyze the 2-finger pinch gesture and get the line connecting the 2 contact points and break it down into delta x and delta y to calculate the zoom factors in each direction.

Has anyone done something like that?

Biterider

[hutch--]

The only way I have even zoomed a window is with MoveWindow(). Primitive but fast and smooth if the steps are not too large.

[jj2007]

I don't have a touch screen, but these messages could be helpful:
WM_GESTURE
WM_TOUCH
WM_POINTER

You are certainly aware of RegisterTouchWindow & friends. Sounds like a nice project

[hutch--]

If you can track the two finger positions, the rest should be easy. You would probably need to write both a left hand and right hand resizer but they are not all that hard to do.

[raymond]

You could consider trying the Windows BitBlt function. I've never tried using it to stretch only in one direction but it could work.

[Biterider]

Hi
Thanks for your replays. 

AFAIK, there are 2 ways to get touch information: WM_TOUCH/WM_POINTER or WM_GESTURE and they are mutually exclusive.
WM_TOUCH is more of the raw approach, while WM_GESTURE gives a more elaborate result that can be used right away if you want the standard gestures.

In this case, WM_GESTURE returns a zoom gesture, but does not distinguish in which direction.
On the other hand, if we want to use WM_TOUCH we have to write a full gesture recognition algorithm, which is a huge undertaking.

Zooming the window contents is another topic that is not relevant right now.

Biterider