Am 27.01.2018 um 09:52 schrieb Alejandro Piñeiro:
> On 27/01/18 01:59, srol...@vmware.com wrote:
>> From: Roland Scheidegger <srol...@vmware.com>
>>
>> The size/type query is always legal (if we made it that far).
>> This causes a difference for GL_TEXTURE_BUFFER - the reason is that these
>> parameters are valid only with GetTexLevelParameter() if gl 3.1 is supported,
>> but not if only ARB_texture_buffer_object is supported.
>> However, while the spec says that these queries return "the same information
>> as querying GetTexLevelParameter" I believe we're not expected to return just
>> zeros here. By definition, these pnames are always valid (unlike for the
>> GetTexLevelParameter() function which would return an error without GL 3.1),
>> so returning 0 but no error makes no sense to me.
>
> But in general, AFAIU, this is how GetInternalFormat works. The
> extension only raises an error if their API is not used properly. But
> not if the combination being requested doesn't make sense.
>
> For example, the pname GET_TEXTURE_IMAGE_FORMAT, would return the same
> value that using GetTexImage. But if the resource is not supported by
> GetTextImage, it should return NONE, but not raising an error. So for
> example, you could use as target GL_RENDERBUFFER for
> GET_TEXTURE_IMAGE_FORMAT query, and just get a GL_NONE, but no an
> error. While that one would raise an error on GetTexImage.
This is correct, but I don't think that's really comparable. The case
you cited is if something isn't supported - this is not the case here at
all, if some format with TEXTURE_BUFFER is supported, we're just lying
about the size/type because ARB_tbo made these properties non-queryable.
Nevertheless, the properties exist.
Roland
>
>>
>> This breaks some piglit arb_internalformat_query2 tests (which I belive to
>> be wrong).
>> ---
>> src/mesa/main/formatquery.c | 3 ---
>> 1 file changed, 3 deletions(-)
>>
>> diff --git a/src/mesa/main/formatquery.c b/src/mesa/main/formatquery.c
>> index 2214f97e67..f345140518 100644
>> --- a/src/mesa/main/formatquery.c
>> +++ b/src/mesa/main/formatquery.c
>> @@ -960,9 +960,6 @@ _mesa_GetInternalformativ(GLenum target, GLenum
>> internalformat, GLenum pname,
>> mesa_format texformat;
>>
>> if (target != GL_RENDERBUFFER) {
>> - if (!_mesa_legal_get_tex_level_parameter_target(ctx, target, true))
>> - goto end;
>> -
>> baseformat = _mesa_base_tex_format(ctx, internalformat);
>> } else {
>> baseformat = _mesa_base_fbo_format(ctx, internalformat);
>
>
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