Windows 8 Getting Absolute X Y Coordinates of Touchscreen (regardless of window) [duplicate]

Question

This question already has an answer here:

How to detect tapping (touch input) globally instead of mouse clicking? (1 answer)

Closed 9 years ago.

I've scowered MSDN/Google for the past few days and I've been unable to find the answer to this question.

I'm looking to get the X Y coordinates of a touch/multiple touches on a touchscreen device powered by Windows 8. There are tons of guides on how to add a touch handle to a specific window, but I would like to create an app that relies on touch input, regardless of which window/app is the one in focus/being touched.

Basically, I'm looking for the lowest level touch API out there. Anyone got any ideas? Thanks!

Answer 1

The easy way would be to use the "legacy" (Windows 7) API. With this, you receive the touch input as a WM_TOUCH message.

You use the lParam of that message in a call to GetTouchInputInfo.

That returns an array of TOUCHINPUT structures, each of which includes an x and y coordinate (which, in what seems like it may be a record for useless/illusory precision, is given to a precision of a one-hundredth of a pixel).

For new apps, Microsoft recommends using the Pointer Input API. With this, you'd receive messages like WM_POINTERDOWN, WM_POINTERUP, and WM_POINTERUPDATE. With these, the lParam of the message contains a single x/y point for the input. For more complete information about the location, you'd call GetPointerInfo to retrieve the coordinates of the input in POINTER_INFO structures.