Flagging Support for Nonlocal Display Memory

A driver must inform DirectDraw (and DirectDraw applications) that it is AGP-compatible. This is accomplished by specifying the capability bit DDCAPS2_NONLOCALVIDMEM in the dwCaps2 member of the DDCORECAPS structure, which is part of the DD_HALINFO structure passed to DirectDraw.

If running on an operating system that does not support AGP services, DirectDraw turns off the DDCAPS2_NONLOCALVIDMEM capability bit and all associated nonlocal heaps.