How do you retrieve stylus pressure information on windows?

Question

Is anyone aware of a sane way to get tablet/stylus pressure information on Windows?

It's possible to distinguish stylus from mouse with ::GetMessageExtraInfo, but you can't get any more information beyond that. I also found the WinTab API in a out of the way corner of the Wacom site, but that's not part of windows as far as i can tell, and has a completely distinct event/messaging system from the message queue.

Given all I want is the most basic pressure information surely there is a standard Win32/COM API, is anyone aware of what it might be?

Answer 1

does this help ? ..

Answer 2

You need to use the Tablet PC Pen/Ink API. The COM version of the API lives in InkObj.dll. Here is a starting point for documentation: http://msdn.microsoft.com/en-us/library/ms700664.aspx

If I remember correctly, InkObj.dll is available on Windows XP SP2 and all later Windows client OSes, regardless of whether the machine is a Tablet PC.

Answer 3

This is a pretty late response, but recently my wife and I purchased a Dell XT tablet PC, which as it turns out actually uses NTrig, a suite of interfaces that utilize Ink, the accepted new windows API that shipped with Windows XP Tablet edition, then SP 2 and all versions thereafter.

A lot of Wacom tablets and others use the Wintab API, which is not currently open nor really permitted to use. From what I hear the folks who maintain it are pretty sue-happy.

So it depends on what type of tablet you're using, and the drivers you have installed for it. In my biased opinion, you should work with Ink, as it provides (or at least through NTrig and Windows 7 WILL provide) multi-touch capability and will likely be the new standard for tablet interfaces. But as of now, NTrig devices do not translate their pressure and angle information to common Wintab-based applications, such as Photoshop or Corel Painter. The applications tend to require at least some support for Microsoft's Tablet API in order to function properly.