[Mesa-dev] [PATCH 1/2] glsl: always enable OES_standard_derivatives features if supported

[Timothy Arceri]

On 16/05/18 22:29, Ilia Mirkin wrote:
> On Wed, May 16, 2018 at 8:26 AM, Timothy Arceri <tarceri at itsqueeze.com> wrote:
>>
>>
>> On 16/05/18 22:09, Ilia Mirkin wrote:
>>>
>>> On Wed, May 16, 2018 at 8:04 AM, Timothy Arceri <tarceri at itsqueeze.com>
>>> wrote:
>>>>
>>>>
>>>>
>>>> On 16/05/18 21:12, Ilia Mirkin wrote:
>>>>>
>>>>>
>>>>>    From the spec,
>>>>>
>>>>> """
>>>>>        The built-in derivative functions dFdx, dFdy, and fwidth are
>>>>> optional, and
>>>>>        must be enabled by
>>>>>
>>>>>        #extension GL_OES_standard_derivatives : enable
>>>>>
>>>>>        before being used.
>>>>> """
>>>>>
>>>>> Sounds like you need an application override?
>>>>
>>>>
>>>>
>>>> The ES spec has no such wording is simply states:
>>>>
>>>> "dFdx(), dFdy(), and fwidth() are made optional."
>>>
>>>
>>> That is under the heading of "Changes from Revision 59 of the OpenGL
>>> Shading Language specification:", i.e. desktop GLSL.
>>>
>>> There isn't a single other reference to those functions anywhere else
>>> in https://www.khronos.org/files/opengles_shading_language.pdf . The
>>> "optional" is in reference to it being moved out to an extension
>>> rather than being part of the core language.
>>
>>
>> It also says noise is optional but there is no spec for it that I can see.
> 
> Yeah, the function just doesn't exist in ES. Those comments sections
> at the top of "how does this differ from X" aren't normative. Look at
> the list of functions -- is it in there? If not, it doesn't exist.

Ok, well I guess I'll submit a CTS test since I don't think we can do 
application overrides with wine apps.