[Mesa-dev] [PATCH v2 2/2] st/mesa: provide GL_OES_copy_image support by caching the original ETC data

[Ilia Mirkin]

On Sat, Jul 16, 2016 at 4:29 PM, Matt Turner <mattst88 at gmail.com> wrote:
> On Sat, Jul 16, 2016 at 9:21 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> The additional provision of GL_OES_copy_image is that it work for ETC.
>> However many desktop GPUs don't have native ETC support, so st/mesa does
>> the decoding by hand. Instead of discarding the compressed data, keep it
>> around in CPU memory. Use it when performing image copies.
>>
>> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
>
> Although the bug is filed against i965 specifically, there is
> https://bugs.freedesktop.org/show_bug.cgi?id=81843

Not 100% sure what would happen in this case before my patch on
st/mesa. I think it would also be broken.

With this patch, that sort of thing should be fixed, in addition to
making OES_copy_image work. A similar workaround is necessary for i965
if it's to support such use-cases on gen7.

  -ilia