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Application to set clone mode to an Indirect Display Driver Display RRS feed

  • Question

  • I  implement an Indirect Display Driver (IDDM), it will create a virtual display monitor, and I want to write an application to control it to switch it to extended desktop or clone with primary display.

    I wrote it with Connecting and Configuring Displays (DDC) API to implement. The extended desktop mode is OK, but I can't call SetDisplayConfig () function to change it to clone mode.  The IDDM graphic adapter and the primary adapter have different adapter LUID, only the paths belong to the same adapter can be clone.  But the "Display Settings" control panel can do it, it can clone two different adapter's display.

    Does any one know how to implement it?

    Thanks.

    Tristan Yu 

    Thursday, January 18, 2018 6:58 AM

Answers

  • This is still a limitation/problem/bug of the WDDM IddCx Indirect Display driver model.

    Indirect Displays can mirror/clone display monitors on other graphics adapters ONLY IF the other graphics adapter driver is WDDM 2.0 and above. IF the other graphics adapter driver is e.g. WDDM 1.3, then the Indirect Display CAN NOT mirror/clone display monitors on this graphics adapter.

    This seems due to the fact that Indirect Display mirroring relies on Windows 10 graphics adapter "Virtual Modes". "Virtual Modes" are only supported on WDDM 2.0 and above.
    It would be very nice to see this limitation eventually being fixed. But I have very little hope for this to happen...
    Thursday, January 18, 2018 6:08 PM

All replies

  • This is still a limitation/problem/bug of the WDDM IddCx Indirect Display driver model.

    Indirect Displays can mirror/clone display monitors on other graphics adapters ONLY IF the other graphics adapter driver is WDDM 2.0 and above. IF the other graphics adapter driver is e.g. WDDM 1.3, then the Indirect Display CAN NOT mirror/clone display monitors on this graphics adapter.

    This seems due to the fact that Indirect Display mirroring relies on Windows 10 graphics adapter "Virtual Modes". "Virtual Modes" are only supported on WDDM 2.0 and above.
    It would be very nice to see this limitation eventually being fixed. But I have very little hope for this to happen...
    Thursday, January 18, 2018 6:08 PM
  • Thanks for your reply. I can set the clone mode with IDDM display by changing the setting in display setting dialog manually, and I notice there are some new members in DISPLAYCONFIG_PATH_INFO structure, ex :

    cloneGroupIdsourceModeInfoIdx, desktopModeInfoIdx and targetModeInfoIdx. I have done many tests in my application, the return value of SetDisplayConfig () is always ERROR_INVALID_PARAMETER. Do you have any sample code or guideline about setting clone mode with IDDM display?

    Many thanks.

    Tristan Yu

    Friday, January 19, 2018 6:56 AM