[PATCH 6/6] wined3d: Do not warn about WINED3DUSAGE_WRITEONLY.

[Henri Verbeet]

On 4 June 2014 18:35, Stefan Dösinger <stefandoesinger at gmail.com> wrote:
> Am 04.06.2014 um 16:02 schrieb Henri Verbeet <hverbeet at gmail.com>:
>> Sort of. It may make sense to set WINED3D_BUFFER_DOUBLEBUFFER if
>> WINED3DUSAGE_WRITEONLY isn't set.
> Why would we want to do that? The only thing I can think of is if there's a GL driver where reading back the buffer object has the same performance characteristics as reading back a WRITEONLY resource on Windows. So far I haven't seen an application / driver combination with such an issue, but I didn't really look for one either.
>
I could imagine buffers being moved from VRAM to GART when they're
mapped, which would then make subsequent draws potentially slower.
Dynamic buffers are more or less expected to be in GART, but we want
static buffers to be in VRAM as much as possible. I could also perhaps
imagine the driver keeping a copy in CPU memory instead, but that
would then use up address space.