title: How to detect if monitor is a projector?
body: <p>Is there a way to use the Windows APIs to detect if a particular monitor is a projector (beamer) rather than a screen?</p>
  
  <p>(I'm writing a projection mapping desktop application, and I'd like it to automatically detect if a projector is attached and active to allow the user to compare the reality to the preview.)</p>
  
  <p>I've used both EnumDisplayMonitors and EnumDisplayDevices to find the monitors, but I can't find any flag or other indication of the type of the display.  I've looked in the DEVMODE and the DISPLAY_DEVICE and the registry keys the latter points to.  I don't see a DeviceCapabilities or GetDeviceCaps call that can distinguish between a screen and a projector.  I also looked in the device manager to see if there was a property that distinguishes my regular monitor from the projector, but I couldn't find anything.  So maybe there's no way to do it.</p>
  
  <p>But, the Screen Resolution control panel applet identifies the projector as "PROJECTOR" while identifying my primary monitor as "Dell U3011."  Using EnumDisplayDevices, I can get the "Dell U3011" string from the DISPLAY_DEVICE, but, for the projector, I get just "Generic PnP Monitor."  Somehow, the applet must be looking somewhere else to get that "PROJECTOR" string or it shows "PROJECTOR" for any Generic PnP Monitor that seems to be a projector.  So where does it look and how does it know?</p>