[Mesa-dev] [PATCH 08/10] glsl: parser changes for GL_ARB_explicit_uniform_location

Tapani tapani.palli at intel.com
Wed May 21 07:43:06 PDT 2014


On 05/21/2014 01:27 AM, Ian Romanick wrote:
> On 05/19/2014 10:08 PM, Tapani wrote:
>> On 05/19/2014 08:18 PM, Ian Romanick wrote:
>>> On 04/09/2014 02:56 AM, Tapani Pälli wrote:
>>>> Patch adds a preprocessor define for the extension and stores explicit
>>>> location data for uniforms during AST->HIR conversion. It also sets
>>>> layout token to be available when having the extension in place.
>>>>
>>>> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
>>>> ---
>>>>    src/glsl/ast_to_hir.cpp       | 37
>>>> +++++++++++++++++++++++++++++++++++++
>>>>    src/glsl/glcpp/glcpp-parse.y  |  3 +++
>>>>    src/glsl/glsl_lexer.ll        |  1 +
>>>>    src/glsl/glsl_parser_extras.h | 14 ++++++++++++++
>>>>    4 files changed, 55 insertions(+)
>>>>
>>>> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
>>>> index 8d55ee3..7431ad7 100644
>>>> --- a/src/glsl/ast_to_hir.cpp
>>>> +++ b/src/glsl/ast_to_hir.cpp
>>>> @@ -2170,6 +2170,43 @@ validate_explicit_location(const struct
>>>> ast_type_qualifier *qual,
>>>>    {
>>>>       bool fail = false;
>>>>    +   /* Checks for GL_ARB_explicit_uniform_location. */
>>>> +   if (qual->flags.q.uniform) {
>>>> +
>>> Extra blank line.
>> oops
>>
>>>> +      if (!state->check_explicit_uniform_location_allowed(loc, var))
>>>> +         return;
>>>> +
>>>> +      const struct gl_context *const ctx = state->ctx;
>>>> +      unsigned max_loc = qual->location +
>>>> var->type->component_slots() - 1;
>>> I think that over counts for this purpose, and we can blame confusing
>>> nomenclature.  component_slots for a mat4 is 4, so a mat4 uniform counts
>>> 4*4 against the GL_MAX_VERTEX_UNIFORM_COMPONENTS limit.  However, it
>>> only has one "location" (as returned by glGetUniformLocation), so it
>>> only counts 1 against the GL_MAX_UNIFORM_LOCATIONS limit.
>> I see, I was considering structs and arrays when writing this part and
>> forgot about matrix. I assume matrix is the only special case here
>> though? Everything else gets correct location count value via
>> component_slots().
> Currently, it should only bee matrices and structures containing matrices
> that need different treatment.  I think dvec3 and dvec4 (when we add support
> for doubles) will also take multiple slots.

Ok, I'll add additional helper to glsl_type for this as it is needed 
when assigning locations too.

>>>> +
>>>> +      /* ARB_explicit_uniform_location specification states:
>>>> +       *
>>>> +       *     "The explicitly defined locations and the generated
>>>> locations
>>>> +       *     must be in the range of 0 to MAX_UNIFORM_LOCATIONS
>>>> minus one."
>>>> +       *
>>>> +       *     "Valid locations for default-block uniform variable
>>>> locations
>>>> +       *     are in the range of 0 to the implementation-defined
>>>> maximum
>>>> +       *     number of uniform locations."
>>>> +       */
>>>> +      if (qual->location < 0) {
>>>> +         _mesa_glsl_error(loc, state,
>>>> +                          "explicit location < 0 for uniform %s",
>>>> var->name);
>>>> +         return;
>>>> +      }
>>>> +
>>>> +      if (max_loc >= ctx->Const.MaxUserAssignableUniformLocations) {
>>>> +         _mesa_glsl_error(loc, state, "location qualifier for
>>>> uniform %s "
>>>> +                          ">= MAX_UNIFORM_LOCATIONS (%u)",
>>>> +                          var->name,
>>>> +
>>>> ctx->Const.MaxUserAssignableUniformLocations);
>>>> +         return;
>>>> +      }
>>>> +
>>>> +      var->data.explicit_location = true;
>>>> +      var->data.location = qual->location;
>>>> +      return;
>>>> +   }
>>>> +
>>>>       /* Between GL_ARB_explicit_attrib_location an
>>>>        * GL_ARB_separate_shader_objects, the inputs and outputs of any
>>>> shader
>>>>        * stage can be assigned explicit locations.  The checking here
>>>> associates
>>>> diff --git a/src/glsl/glcpp/glcpp-parse.y b/src/glsl/glcpp/glcpp-parse.y
>>>> index f28d853..6d42138 100644
>>>> --- a/src/glsl/glcpp/glcpp-parse.y
>>>> +++ b/src/glsl/glcpp/glcpp-parse.y
>>>> @@ -2087,6 +2087,9 @@
>>>> _glcpp_parser_handle_version_declaration(glcpp_parser_t *parser,
>>>> intmax_t versio
>>>>              if (extensions->ARB_explicit_attrib_location)
>>>>                 add_builtin_define(parser,
>>>> "GL_ARB_explicit_attrib_location", 1);
>>>>    +          if (extensions->ARB_explicit_uniform_location)
>>>> +             add_builtin_define(parser,
>>>> "GL_ARB_explicit_uniform_location", 1);
>>>> +
>>>>              if (extensions->ARB_shader_texture_lod)
>>>>                 add_builtin_define(parser,
>>>> "GL_ARB_shader_texture_lod", 1);
>>>>    diff --git a/src/glsl/glsl_lexer.ll b/src/glsl/glsl_lexer.ll
>>>> index 7602351..83f0b6d 100644
>>>> --- a/src/glsl/glsl_lexer.ll
>>>> +++ b/src/glsl/glsl_lexer.ll
>>>> @@ -393,6 +393,7 @@ layout        {
>>>>                  || yyextra->AMD_conservative_depth_enable
>>>>                  || yyextra->ARB_conservative_depth_enable
>>>>                  || yyextra->ARB_explicit_attrib_location_enable
>>>> +              || yyextra->ARB_explicit_uniform_location_enable
>>>>                          || yyextra->has_separate_shader_objects()
>>>>                  || yyextra->ARB_uniform_buffer_object_enable
>>>>                  || yyextra->ARB_fragment_coord_conventions_enable
>>>> diff --git a/src/glsl/glsl_parser_extras.h
>>>> b/src/glsl/glsl_parser_extras.h
>>>> index c53c583..20879a0 100644
>>>> --- a/src/glsl/glsl_parser_extras.h
>>>> +++ b/src/glsl/glsl_parser_extras.h
>>>> @@ -152,6 +152,20 @@ struct _mesa_glsl_parse_state {
>>>>          return true;
>>>>       }
>>>>    +   bool check_explicit_uniform_location_allowed(YYLTYPE *locp,
>>>> +                                                const ir_variable *var)
>>>> +   {
>>>> +      /* Requires OpenGL 3.3 or ARB_explicit_attrib_location. */
>>>> +      if (ctx->Version < 33 &&
>>>> !ctx->Extensions.ARB_explicit_attrib_location) {
>>>> +         _mesa_glsl_error(locp, this, "%s explicit location requires "
>>>> +                          "GL_ARB_explicit_attrib_location extension "
>>>> +                          "or OpenGL 3.3", mode_string(var));
>>> Many copy-and-paste bugs. :) Explicit uniform locations aren't added
>>> until 4.3.
>> It may look copy-paste but the specification states that "Requires
>> OpenGL 3.3 or ARB_explicit_attrib_location":
>>
>> https://www.opengl.org/registry/specs/ARB/explicit_uniform_location.txt
>>
>> Using 4.3 capable driver will pass this check correctly.
> Oh right, because it relies on 3.3 or ARB_explicit_attib_location to
> add the layout keyword.  Some comments explaining that this isn't a
> copy-and-paste bug will prevent the next person from also thinking that
> it is. :)
>
> But this code should check the version (and extension) bits set in the
> shader, not what's enabled in the context. How about:
>
>     bool check_explicit_attrib_location_allowed(YYLTYPE *locp,
>                                                 const ir_variable *var)
>     {
>        if (!this->has_explicit_attrib_location() ||
>            !this->ARB_explicit_uniform_location_enable) {
>           _mesa_glsl_error(locp, this,
>                            "uniform explicit location requires
>                            "GL_ARB_explicit_uniform_location and either "
>                            "GL_ARB_explicit_attrib_location or GLSL 330.");
>           return false;
>        }
>
>        return true;
>     }

Sure, this is fine by me. I'll send new patches soon.

>>>> +         return false;
>>>> +      }
>>>> +
>>>> +      return true;
>>>> +   }
>>>> +
>>>>       bool has_explicit_attrib_location() const
>>>>       {
>>>>          return ARB_explicit_attrib_location_enable || is_version(330,
>>>> 300);
>>>>



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