we wrote a virtual HID multi touch driver for different displays (different sizes, different resolutions) and are experiencing problems since Windows 8 in connection with Display Scaling options.
When we select a display scaling in "Intel HD Graphics Control Panel" to anything else than "Maintain Display Scaling", the touch input always has some offset on the screen. For example selecting "Maintain Aspect Ratio" on a display where actual screen is 16:9, but the resolution is 1280x1024 would result in having black bars left and right and the touch driver's touch points would be offset from the actual location.
I couldn't find much about this problem on the internet.
Is there some solution for this or can anybody provide more details, so we could build an workaround?
We could for example make a workaround, if we could programmatically or through command line find out what the actual scaling is. Or is there something specific which needs to be set in the driver's HID descriptors?
The right place to ask question about developing solutions would be here Intel® Software, this team might help you with the issue you are dealing with. Please, try posting there and let me know how it goes.
You may also refer to the following link Intel® Processor Graphics | Intel® Software where you will find Developer Documents for Intel® Processor Graphics.