On 08/27/2013 12:52 PM, Anuj Phogat wrote: > On Tue, Aug 27, 2013 at 11:53 AM, Ian Romanick <i...@freedesktop.org> wrote: >> On 08/27/2013 10:45 AM, Anuj Phogat wrote: >>> >>> GLSL 1.30 doesn't allow precision qualifiers on sampler types, >>> but in GLSL ES, sampler types are also allowed. This seems like >>> an oversight (since the intention of including these in GLSL 1.30 >>> is to allow compatibility with ES shaders). >>> >>> Currently, Mesa allows "default" precision qualifiers to be set for >>> sampler types in GLSL (commit d5948f2). This patch makes it follow >>> GLSL ES rules and also allow declaring sampler variables with a >>> precision qualifier in GLSL. >> >> >> I think our current behavior is incorrect even in the ES case. GLSL ES 3.30 > You mean to say GLSL ES 3.00?
Yes. That's about the fifth time I've made that typo in the last week...
>> and desktop GLSL 4.40 say the following in section 4.5.3 (Precision
>> Qualifiers):
>>
>>
>> "Any floating point or any integer declaration can have the type
>> preceded by one of these precision qualifiers..."
>>
> Yes, samplers are now allowed in GLSL 4.4. They were not in GLSL 4.3.
>
>> The also both say the following in section 4.5.4 (Default Precision
>> Qualifiers):
>>
>> "The precision statement...can be used to establish a default
>> precision qualifier. The type field can be either int or float
>> or any of the sampler types..."
>>
>> So I believe
>>
>> precision mediump sampler2D;
>>
>> should be legal in all versions, but
>>
>> uniform mediump sampler2D s;
>>
>> should not.
>>
> Yes, there is no clear statement in GLSL spec which allows:
> uniform mediump sampler2D s;
>
>> Which syntax is the test using?
>>
> test uses:
> uniform mediump sampler2D s;
>
> I haven't yet tested if it is accepted by NVIDIA.
There is an example in section 8 (Built-in Functions) that uses this syntax:
uniform lowp sampler2D sampler;
highp vec2 coord;
...
lowp vec4 col = texture (sampler, coord); // texture() returns lowp
It seems that this syntax should be legal. I've submitted a spec bug to
clarify the language in section 4.5.
I have also attached a patch to fix up the comment in that piece of
code. Go ahead and combine my patch (with my Signed-off-by) with your
code changes.
With the one other change suggested below,
Reviewed-by: Ian Romanick <ian.d.roman...@intel.com>
>>> This fixes a shader compilation error in Khronos OpenGL conformance
>>> test "depth_texture_mipmap".
>>>
>>> Signed-off-by: Anuj Phogat <anuj.pho...@gmail.com
>>> ---
>>> src/glsl/ast_to_hir.cpp | 14 +++++++++-----
>>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
>>> index 192130a..b3d6d8c 100644
>>> --- a/src/glsl/ast_to_hir.cpp
>>> +++ b/src/glsl/ast_to_hir.cpp
>>> @@ -3131,8 +3131,8 @@ ast_declarator_list::hir(exec_list *instructions,
>>> state->check_precision_qualifiers_allowed(&loc);
>>> }
>>>
>>> -
>>> - /* Precision qualifiers only apply to floating point and integer
>>> types.
>>> + /* Precision qualifiers apply to floating point, integer and
>>> sampler
>>> + * types.
>>> *
>>> * From section 4.5.2 of the GLSL 1.30 spec:
>>> * "Any floating point or any integer declaration can have the
>>> type
>>> @@ -3144,20 +3144,24 @@ ast_declarator_list::hir(exec_list *instructions,
>>> *
>>> * From page 87 of the GLSL ES spec:
>>> * "RESOLUTION: Allow sampler types to take a precision
>>> qualifier."
>>> + *
>>> + * GLSL 1.30 doesn't allow precision qualifiers on sampler types,
>>> but
>>> + * this seems like an oversight (since the intention of including
>>> these
>>> + * in GLSL 1.30 is to allow compatibility with ES shaders). So we
>>> allow
>>> + * int, float, and all sampler types regardless of GLSL version.
>>> */
>>> if (this->type->qualifier.precision != ast_precision_none
>>> && !var->type->is_float()
>>> && !var->type->is_integer()
>>> && !var->type->is_record()
>>> - && !(var->type->is_sampler() && state->es_shader)
>>> + && !(var->type->is_sampler())
You can delete the extra ( and ).
>>> && !(var->type->is_array()
>>> && (var->type->fields.array->is_float()
>>> || var->type->fields.array->is_integer()))) {
>>>
>>> _mesa_glsl_error(&loc, state,
>>> "precision qualifiers apply only to floating
>>> point"
>>> - "%s types", state->es_shader ? ", integer, and
>>> sampler"
>>> - : "and integer");
>>> + ", integer and sampler types");
>>> }
>>>
>>> /* From page 17 (page 23 of the PDF) of the GLSL 1.20 spec:
comment-fix-up.patch
Description: application/pgp-keys
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