Reporting DirectDraw Capabilities for DMA Model Nonlocal Display Memory
A DMA model driver has different capabilities for nonlocal display memory than for local display memory. For example, a display card may be able to stretch blit local display memory surfaces but not nonlocal display memory surfaces. If the driver specifies the DDCAPS2_NONLOCALVIDMEMCAPS flag, the driver is probed for the DirectDraw capabilities of nonlocal display memory surface by the DdGetDriverInfo driver entry point. The GUID that identifies this probe is GUID_NonLocalVidMemCaps.
It is important to note that for this release of DirectDraw, a driver can only specify the capabilities for blts from nonlocal display memory to local display memory. Transfers from local display memory to nonlocal display memory, and from nonlocal display memory to nonlocal display memory, are always emulated by the DirectDraw HEL. This restriction may be relaxed in a future release.