[Mesa-dev] [PATCH 1/3] mesa: restrict ES2 from 32-bit blending, add GL_EXT_float_blend

[Marek Olšák]

On Tue, Nov 3, 2015 at 2:14 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Mon, Nov 2, 2015 at 8:07 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> On 11/02/2015 04:50 PM, Ilia Mirkin wrote:
>>> GL_EXT_color_buffer_float adds support for float buffers in ES3.0+, but
>>> explicitly disallows 32-bit blending. However this restriction was never
>>> implemented in mesa.
>>>
>>> Add the restriction, and also allow a driver to expose
>>> GL_EXT_float_blend which re-enables the functionality.
>>>
>>> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
>>> ---
>>>
>>> Untested... looking for confirmation that this is the right thing to
>>> do. Will write a piglit if it is.
>>
>> Some flavor of this probably is the right thing to do.  The question is
>> whether or not any hardware supported by Mesa can do
>> GL_EXT_color_buffer_float but not GL_EXT_float_blend... if everyone can
>> do both or neither, this patch series could be even simpler. :)
>
> Adreno A3xx can't do 32-bit blending, only 16-bit. Sorry!

r500 (r300g) can't do 32-bit blending either.

Marek