[Mesa-dev] [PATCH] mesa: add missing RGB9_E5 format in _mesa_base_fbo_format

[Antia Puentes]

On 25/01/18 18:56, Roland Scheidegger wrote:

> Am 25.01.2018 um 17:56 schrieb Roland Scheidegger:
>> Am 25.01.2018 um 16:30 schrieb Michel Dänzer:
>>> On 2018-01-24 05:38 PM, Juan A. Suarez Romero wrote:
>>>> This fixes KHR-GL45.internalformat.renderbuffer.rgb9_e5.
>>>> ---
>>>>   src/mesa/main/fbobject.c | 3 +++
>>>>   1 file changed, 3 insertions(+)
>>>>
>>>> diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
>>>> index d23916d1ad7..c72204e11a0 100644
>>>> --- a/src/mesa/main/fbobject.c
>>>> +++ b/src/mesa/main/fbobject.c
>>>> @@ -1976,6 +1976,9 @@ _mesa_base_fbo_format(const struct gl_context *ctx, GLenum internalFormat)
>>>>                  ctx->Extensions.ARB_texture_float) ||
>>>>                 _mesa_is_gles3(ctx) /* EXT_color_buffer_float */ )
>>>>            ? GL_RGBA : 0;
>>>> +   case GL_RGB9_E5:
>>>> +      return (_mesa_is_desktop_gl(ctx) && ctx->Extensions.EXT_texture_shared_exponent)
>>>> +         ? GL_RGB: 0;
>>>>      case GL_ALPHA16F_ARB:
>>>>      case GL_ALPHA32F_ARB:
>>>>         return ctx->API == API_OPENGL_COMPAT &&
>>>>
>>> Unfortunately, this broke the "spec at arb_internalformat_query2@samples
>>> and num_sample_counts pname checks" piglit tests with radeonsi and
>>> llvmpipe, see below.
>>>
>>> Any idea what might need to be done in Gallium to fix this?
>>>
>>>
>>>      32 bit failing case: pname = GL_NUM_SAMPLE_COUNTS, target = GL_RENDERBUFFER, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      32 bit failing case: pname = GL_NUM_SAMPLE_COUNTS, target = GL_TEXTURE_2D_MULTISAMPLE, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      32 bit failing case: pname = GL_NUM_SAMPLE_COUNTS, target = GL_TEXTURE_2D_MULTISAMPLE_ARRAY, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      64 bit failing case: pname = GL_NUM_SAMPLE_COUNTS, target = GL_RENDERBUFFER, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      64 bit failing case: pname = GL_NUM_SAMPLE_COUNTS, target = GL_TEXTURE_2D_MULTISAMPLE, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      64 bit failing case: pname = GL_NUM_SAMPLE_COUNTS, target = GL_TEXTURE_2D_MULTISAMPLE_ARRAY, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>> PIGLIT: {"subtest": {"GL_NUM_SAMPLE_COUNTS" : "fail"}}
>>>      32 bit failing case: pname = GL_SAMPLES, target = GL_RENDERBUFFER, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      32 bit failing case: pname = GL_SAMPLES, target = GL_TEXTURE_2D_MULTISAMPLE, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      32 bit failing case: pname = GL_SAMPLES, target = GL_TEXTURE_2D_MULTISAMPLE_ARRAY, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      64 bit failing case: pname = GL_SAMPLES, target = GL_RENDERBUFFER, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      64 bit failing case: pname = GL_SAMPLES, target = GL_TEXTURE_2D_MULTISAMPLE, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>>      64 bit failing case: pname = GL_SAMPLES, target = GL_TEXTURE_2D_MULTISAMPLE_ARRAY, internalformat = GL_RGB9_E5, params[0] = (1,GL_TRUE), supported=1
>>> PIGLIT: {"subtest": {"GL_SAMPLES" : "fail"}}
>>> PIGLIT: {"result": "fail" }
>>>
>>>
>> Purely coincidentally, I was trying to clean up the formatquery code
>> recently (should help some failures with r600 too), and I think these
>> cleanups would fix it.
>> Basically outright say "no" to target/pname combinations which don't
>> make sense rather than trying to find a format suitable for another
>> target and then asking the driver for the nonsense combination, plus
>> some other small bits like not validating things again (sometimes, a
>> third time...).
>> Albeit it will cause some breakage with the piglit test, which I believe
>> is a test error, but that might be open for debate...
>> (For TEXTURE_BUFFER and the internalformat size/type queries, do you
>> return valid values or unsupported? The problem here is ARB_tbo says you
>> can't get these values via the equivalent GetTexLevelParameter queries,
>> whereas with GL 3.1 you can. And internalformat_query2 says it returns
>> "the same information" as GetTexLevelParameter, albeit it's not entirely
>> true in any case since the equivalent of the internalformat stencil type
>> doesn't even exist. My stance would be that valid values should be
>> reported even without GL 3.1, but the piglit test thinks differently.)
>>
> Err, actually this won't fix it I suppose - because rgb9e5 now is a
> valid fbo format. Was that commit really correct? It does not make sense
> to me, rgb9e5 cannot be a fbo/renderable format. Or was this just
> working around issues in formatquery.c (which I try to address with this
> patch)?
>
I believe the commit is wrong, _mesa_base_fbo_format_ is used to 
validate the internalformat
passed to RenderbufferStorage, which in the OpenGL 4.6 is said that 
needs to be:

An INVALID_ENUM error is generated if internalformat is not one of the
color-renderable, depth-renderable, or stencil-renderable formats defined in
section 9.4.

and that's exactly the error returned by the "renderbuffer_storage" 
function if _mesa_base_fbo_format
returns 0.

RGB9_E5 is not renderable, that is stated in the same specification (Bug 
9338). Juan, I believe the CTS test is
wrong and this commit should be reverted.