[Mesa-dev] [PATCH v5 0/3] Add and enable extension EXT_sRGB_write_control

[Ilia Mirkin]

On Mon, Nov 5, 2018 at 7:12 AM Gert Wollny <gert.wollny at collabora.com> wrote:
>
> Am Donnerstag, den 01.11.2018, 12:32 -0400 schrieb Ilia Mirkin:
> >
> >
> > EXT_framebuffer_sRGB is a desktop GL ext. EXT_sRGB_write_control is a
> > GLES ext that was meant to provide the same functionality in GLES
> > (have a glance at Issue #1 in that spec). You could have hardware
> > that  supports neither, or hardware that supports both.
> BTW: why is it so hard to imagine that there is some GLES only hardware
> out there that supports sRGB textures as framebuffer attachment, but
> doesn't have a proper hardware interface to turn off encoding to sRGB
> on write and allows changing this only by changing the attached texture
> to a non-sRGB one?

There's no difference between the two extensions at the driver level
-- the differences end at the GL API level. At the mesa driver level,
it's a promise to look at ctx->Color.sRGBEnabled. At the gallium
level, it's a promise that some PIPE_FORMAT_*_SRGB is supported for
rendering and that you can use a non-srgb format in the surface even
if the resource was originally allocated with an srgb format (and
vice-versa). The latter bit is always a requirement for gallium
drivers, of course.

  -ilia