Windows: Is it *possible* to create a (virtual) video card driver?

Question

i want to create a virtual monitor. The way this would work is that the virtual monitor would appear in a window on my desktop. As far as Windows knows it is just another monitor.

It occurs to me that it would, as a practical matter, have to be done as video card driver (i.e. rather than the video going out a wire to an LCD panel, it would go into another window on the desktop).

Does what i'm describing sound, technically, possible? (from a DDK point of view)

Note: i can't use a virtual pc, because no virtual PC has resolutions high enough for my needs. Also because it's not what i asked for.

Note: My reasons are unimportant, but i can make some up:

• i want to test my application under high-dpi settings (288dpi)
• i want to create a monitor that my iPad can VNC to
• the family TV runs on the main monitor
• the hijacker is monitoring the bus, and he'll blow it up if he suspects we're getting the passengers off
• i'm trying to expand the limits of human knowledge and understanding, for the good of all man-kind

Answer 1

I'd say it's definitely possible, since that's what virtualization tools do for their guest utilities, but I wouldn't be able to tell you how in details. I'd suggest looking at the VirtualBox guest driver code as a starting point: http://www.virtualbox.org/browser/trunk/src/VBox/Additions/WINNT/Graphics

(This is released under GPL as far as I'm aware.)

Answer 2

It's definitely possible, see for example the UltraVNC mirror driver. But I don't know of any virtual video driver that makes source code available.

Answer 3

I have been searching for something similar and I found a nice solution: spacedesk. You can download it here: http://spacedesk.ph/ In windows, it installs an extra monitor, which you can open in a browser or a viewer. Enjoy!