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

[Tapani]

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().

>> +
>> +      /* 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.

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