Assumption of 96 DPI?

Nov 9, 2010 at 1:56 AM

I'm seeing some funny results on surfaces with DPI settings other than 96 DPI. I haven't looked at the source code yet, so I thought that I'd ask ... does the code assume 96 DPI surfaces?

Nov 13, 2010 at 10:54 PM

I have more information on the problem and how it might be replicated on a Windows 7 system. Here is how you can reproduce the problem:

  1. Open the "Display" control panel applet from the Windows 7 Control Panel.
  2. Select the "100%" radio button.
  3. Close the "Display" control panel applet.
  4. Notice correct coordinate behavior from the MultipointTUIO code.
  5. Open the "Display" control panel applet from the Windows 7 Control Panel.
  6. Select the a radio button other than "100%" radio button.
  7. Close the "Display" control panel applet.
  8. Notice incorrect coordinate behavior from the MultipointTUIO code.

Thank you.

Nov 13, 2010 at 10:58 PM

If you need information on how to calculate screen heights and widths while taking various DPI settings into account, please see this article:

http://geekswithblogs.net/JeffFerguson/archive/2010/06/14/calculating-screen-resolutions-using-wpf.aspx