[Mesa-dev] [PATCH] gallium: unify transfer functions

[Marek Olšák]

On Thu, Oct 11, 2012 at 10:05 PM, Stéphane Marchesin
<stephane.marchesin at gmail.com> wrote:
> On Tue, Oct 9, 2012 at 6:04 PM, Marek Olšák <maraeo at gmail.com> wrote:
>> Hi,
>>
>> this is actually a very small cleanup that got unexpectedly big. I
>> really underestimated the size of gallium.
>>
>> It's part of the plan discussed here:
>> http://www.mail-archive.com/mesa-dev@lists.freedesktop.org/msg17930.html
>>
>> The idea is that get_transfer+transfer_map is folded into
>> transfer_map, and transfer_unmap+transfer_destroy is folded into
>> transfer_unmap. transfer_map must create and return the transfer
>> object and transfer_unmap must destroy it. transfer_map is successful
>> if the returned buffer pointer is not NULL. If transfer_map fails, the
>> pointer to the transfer object remains unchanged (i.e. doesn't have to
>> be NULL).
>>
>> I couldn't send the patch to mesa-dev, because it's too big. It's here:
>> http://cgit.freedesktop.org/~mareko/mesa/commit/?h=transfer&id=7a102748a1240c4b2624c6727b480078d2905012
>>
>> 103 files changed, 1204 insertions, 2014 deletions
>>
>> There are no piglit regressions on r600g, softpipe, and llvmpipe. I
>> haven't tested the other drivers nor have I tested the state trackers
>> not covered by piglit.
>>
>
> So is the long term goal to get rid of the map/unmap completely and
> use inline_write instead? That could save a copy for texture uploads
> in cases where map() is also a copy.

No, we don't plan to get rid of map/unmap.

You can skip the GPU->CPU copy in "map" if one of the
PIPE_TRANSFER_DISCARD_* flags is set.

Marek