D3D9Ex uses different driver paths. This helps with "headless"
configurations when no user logs in. Plain D3D9 device creation will
fail if no user is logged in, while it works with D3D9Ex.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Just the presence of a hw frames context is not enough to detect whether
the transfer is an upload or a download, because hw frames mapped to
system memory will have a hw frames context attached.
D3DLOCK_READONLY properly corresponds to the absence of the write flag,
not to the presence of the read flag, while D3DLOCK_DISCARD is
equivalent to the overwrite flag.
