[Mesa-dev] [PATCH 07/11] glsl: Add arb_cull_distance support

Timothy Arceri t_arceri at yahoo.com.au
Sun May 24 16:19:39 PDT 2015


On Mon, 2015-05-25 at 00:46 +0200, Tobias Klausmann wrote:
> hi,
> replay inline.
> 
> On 25.05.2015 00:34, Timothy Arceri wrote:
> > On Sun, 2015-05-24 at 19:58 +0200, Tobias Klausmann wrote:
> >> Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
> >> ---
> >>   src/glsl/ast_to_hir.cpp             |  14 +++++
> >>   src/glsl/builtin_variables.cpp      |  13 +++-
> >>   src/glsl/glcpp/glcpp-parse.y        |   3 +
> >>   src/glsl/glsl_parser_extras.cpp     |   1 +
> >>   src/glsl/glsl_parser_extras.h       |   3 +
> >>   src/glsl/link_varyings.cpp          |   2 +-
> >>   src/glsl/linker.cpp                 | 121 +++++++++++++++++++++++++-----------
> >>   src/glsl/standalone_scaffolding.cpp |   1 +
> >>   src/glsl/tests/varyings_test.cpp    |  27 ++++++++
> >>   9 files changed, 145 insertions(+), 40 deletions(-)
> >>
> >> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
> >> index 8aebb13..4db2b2e 100644
> >> --- a/src/glsl/ast_to_hir.cpp
> >> +++ b/src/glsl/ast_to_hir.cpp
> >> @@ -1045,6 +1045,20 @@ check_builtin_array_max_size(const char *name, unsigned size,
> >>         _mesa_glsl_error(&loc, state, "`gl_ClipDistance' array size cannot "
> >>                          "be larger than gl_MaxClipDistances (%u)",
> >>                          state->Const.MaxClipPlanes);
> >> +   } else if (strcmp("gl_CullDistance", name) == 0
> >> +              && size > state->Const.MaxClipPlanes) {
> >> +      /* From the ARB_cull_distance spec:
> >> +       *
> >> +       *   "The gl_CullDistance array is predeclared as unsized and
> >> +       *    must be sized by the shader either redeclaring it with
> >> +       *    a size or indexing it only with integral constant
> >> +       *    expressions. The size determines the number and set of
> >> +       *    enabled cull distances and can be at most
> >> +       *    gl_MaxCullDistances."
> >> +       */
> >> +      _mesa_glsl_error(&loc, state, "`gl_CullDistance' array size cannot "
> >> +                       "be larger than gl_MaxCullDistances (%u)",
> >> +                       state->Const.MaxClipPlanes);
> >>      }
> >>   }
> >>   
> >> diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
> >> index 6806aa1..78c8db2 100644
> >> --- a/src/glsl/builtin_variables.cpp
> >> +++ b/src/glsl/builtin_variables.cpp
> >> @@ -298,7 +298,7 @@ public:
> >>      const glsl_type *construct_interface_instance() const;
> >>   
> >>   private:
> >> -   glsl_struct_field fields[10];
> >> +   glsl_struct_field fields[11];
> >>      unsigned num_fields;
> >>   };
> >>   
> >> @@ -600,6 +600,12 @@ builtin_variable_generator::generate_constants()
> >>         add_const("gl_MaxVaryingComponents", state->ctx->Const.MaxVarying * 4);
> >>      }
> >>   
> >> +   if (state->is_version(450, 0) || state->ARB_cull_distance_enable) {
> >> +      add_const("gl_MaxCullDistances", state->Const.MaxClipPlanes);
> >> +      add_const("gl_MaxCombinedClipAndCullDistances",
> >> +                state->Const.MaxClipPlanes);
> >> +   }
> >> +
> >>      if (state->is_version(150, 0)) {
> >>         add_const("gl_MaxVertexOutputComponents",
> >>                   state->Const.MaxVertexOutputComponents);
> >> @@ -1029,6 +1035,11 @@ builtin_variable_generator::generate_varyings()
> >>                      "gl_ClipDistance");
> >>      }
> >>   
> >> +   if (state->is_version(450, 0) || state->ARB_cull_distance_enable) {
> >> +       ADD_VARYING(VARYING_SLOT_CULL_DIST0, array(float_t, 0),
> >> +                   "gl_CullDistance");
> >> +   }
> >> +
> >>      if (compatibility) {
> >>         ADD_VARYING(VARYING_SLOT_TEX0, array(vec4_t, 0), "gl_TexCoord");
> >>         ADD_VARYING(VARYING_SLOT_FOGC, float_t, "gl_FogFragCoord");
> >> diff --git a/src/glsl/glcpp/glcpp-parse.y b/src/glsl/glcpp/glcpp-parse.y
> >> index a11b6b2..536c17f 100644
> >> --- a/src/glsl/glcpp/glcpp-parse.y
> >> +++ b/src/glsl/glcpp/glcpp-parse.y
> >> @@ -2483,6 +2483,9 @@ _glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t versio
> >>   
> >>                 if (extensions->ARB_shader_precision)
> >>                    add_builtin_define(parser, "GL_ARB_shader_precision", 1);
> >> +
> >> +          if (extensions->ARB_cull_distance)
> >> +	         add_builtin_define(parser, "GL_ARB_cull_distance", 1);
> >>   	   }
> >>   	}
> >>   
> >> diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
> >> index 046d5d7..d1cd8ff 100644
> >> --- a/src/glsl/glsl_parser_extras.cpp
> >> +++ b/src/glsl/glsl_parser_extras.cpp
> >> @@ -554,6 +554,7 @@ static const _mesa_glsl_extension _mesa_glsl_supported_extensions[] = {
> >>      EXT(ARB_arrays_of_arrays,           true,  false,     ARB_arrays_of_arrays),
> >>      EXT(ARB_compute_shader,             true,  false,     ARB_compute_shader),
> >>      EXT(ARB_conservative_depth,         true,  false,     ARB_conservative_depth),
> >> +   EXT(ARB_cull_distance,              true,  false,     ARB_cull_distance),
> >>      EXT(ARB_derivative_control,         true,  false,     ARB_derivative_control),
> >>      EXT(ARB_draw_buffers,               true,  false,     dummy_true),
> >>      EXT(ARB_draw_instanced,             true,  false,     ARB_draw_instanced),
> >> diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
> >> index 9a0c24e..8572905 100644
> >> --- a/src/glsl/glsl_parser_extras.h
> >> +++ b/src/glsl/glsl_parser_extras.h
> >> @@ -378,6 +378,7 @@ struct _mesa_glsl_parse_state {
> >>   
> >>         /* ARB_viewport_array */
> >>         unsigned MaxViewports;
> >> +
> >>      } Const;
> >>   
> >>      /**
> >> @@ -430,6 +431,8 @@ struct _mesa_glsl_parse_state {
> >>      bool ARB_compute_shader_warn;
> >>      bool ARB_conservative_depth_enable;
> >>      bool ARB_conservative_depth_warn;
> >> +   bool ARB_cull_distance_enable;
> >> +   bool ARB_cull_distance_warn;
> >>      bool ARB_derivative_control_enable;
> >>      bool ARB_derivative_control_warn;
> >>      bool ARB_draw_buffers_enable;
> >> diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
> >> index 46f84c6..81c0dac 100644
> >> --- a/src/glsl/link_varyings.cpp
> >> +++ b/src/glsl/link_varyings.cpp
> >> @@ -404,7 +404,7 @@ tfeedback_decl::assign_location(struct gl_context *ctx,
> >>            this->matched_candidate->type->fields.array->vector_elements;
> >>         unsigned actual_array_size =
> >>            (this->is_clip_distance_mesa || this->is_cull_distance_mesa) ?
> >> -         prog->LastClipDistanceArraySize :
> >> +         prog->LastClipCullDistanceArraySize :
> >>            this->matched_candidate->type->array_size();
> >>   
> >>         if (this->is_subscripted) {
> >> diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
> >> index e616520..8bb1a5c 100644
> >> --- a/src/glsl/linker.cpp
> >> +++ b/src/glsl/linker.cpp
> >> @@ -474,49 +474,94 @@ link_invalidate_variable_locations(exec_list *ir)
> >>   }
> >>   
> >>
> >> +
> >>   /**
> >> - * Set UsesClipDistance and ClipDistanceArraySize based on the given shader.
> >> + * Set UsesClipCullDistance and ClipCullDistanceArraySize based on the given
> >> + * shader.
> >>    *
> >> - * Also check for errors based on incorrect usage of gl_ClipVertex and
> >> - * gl_ClipDistance.
> >> + * Also check for errors based on incorrect usage of gl_ClipVertex,
> >> + * gl_ClipDistance and gl_CullDistance.
> >> + *
> >> + * Additionally test whether the arrays gl_ClipDistance and gl_CullDistance
> >> + * exceed the maximum size defined by gl_MaxCombinedClipAndCullDistances.
> >>    *
> >>    * Return false if an error was reported.
> >>    */
> >>   static void
> >> -analyze_clip_usage(struct gl_shader_program *prog,
> >> -                   struct gl_shader *shader, GLboolean *UsesClipDistance,
> >> -                   GLuint *ClipDistanceArraySize)
> >> +analyze_clip_cull_usage(struct gl_shader_program *prog,
> >> +                        struct gl_shader *shader,
> >> +                        struct gl_context *ctx,
> >> +                        GLboolean *UsesClipCullDistance,
> >> +                        GLuint *ClipCullDistanceArraySize)
> >>   {
> >> -   *ClipDistanceArraySize = 0;
> >> +   *ClipCullDistanceArraySize = 0;
> >>   
> >> -   if (!prog->IsES && prog->Version >= 130) {
> >> -      /* From section 7.1 (Vertex Shader Special Variables) of the
> >> -       * GLSL 1.30 spec:
> >> -       *
> >> -       *   "It is an error for a shader to statically write both
> >> -       *   gl_ClipVertex and gl_ClipDistance."
> >> -       *
> >> -       * This does not apply to GLSL ES shaders, since GLSL ES defines neither
> >> -       * gl_ClipVertex nor gl_ClipDistance.
> >> -       */
> >> +   if (prog->IsES && prog->Version < 130) {
> >> +      *UsesClipCullDistance = false;
> >> +   } else {
> >>         find_assignment_visitor clip_vertex("gl_ClipVertex");
> >>         find_assignment_visitor clip_distance("gl_ClipDistance");
> >> +      find_assignment_visitor cull_distance("gl_CullDistance");
> >>   
> >>         clip_vertex.run(shader->ir);
> >>         clip_distance.run(shader->ir);
> >> +      cull_distance.run(shader->ir);
> >> +
> >> +      /* From the ARB_cull_distance spec:
> >> +       *
> >> +       * It is a compile-time or link-time error for the set of shaders forming
> >> +       * a program to statically read or write both gl_ClipVertex and either
> >> +       * gl_ClipDistance or gl_CullDistance.
> >> +       *
> >> +       * This does not apply to GLSL ES shaders, since GLSL ES defines neither
> >> +       * gl_ClipVertex, gl_ClipDistance or gl_CullDistance.
> >> +       */
> >>         if (clip_vertex.variable_found() && clip_distance.variable_found()) {
> >>            linker_error(prog, "%s shader writes to both `gl_ClipVertex' "
> >>                         "and `gl_ClipDistance'\n",
> >>                         _mesa_shader_stage_to_string(shader->Stage));
> >>            return;
> >>         }
> >> -      *UsesClipDistance = clip_distance.variable_found();
> >> +      if (clip_vertex.variable_found() && cull_distance.variable_found()) {
> >> +         linker_error(prog, "%s shader writes to both `gl_ClipVertex' "
> >> +                      "and `gl_CullDistance'\n",
> >> +                      _mesa_shader_stage_to_string(shader->Stage));
> >> +         return;
> >> +      }
> >> +
> >> +      *UsesClipCullDistance = clip_distance.variable_found() |
> >> +                              cull_distance.variable_found();
> >> +
> >>         ir_variable *clip_distance_var =
> >>            shader->symbols->get_variable("gl_ClipDistance");
> >> +      ir_variable *cull_distance_var =
> >> +         shader->symbols->get_variable("gl_CullDistance");
> >> +
> >>         if (clip_distance_var)
> >> -         *ClipDistanceArraySize = clip_distance_var->type->length;
> >> -   } else {
> >> -      *UsesClipDistance = false;
> >> +         *ClipCullDistanceArraySize = clip_distance_var->type->was_unsized ?
> >> +               clip_distance_var->type->length  -1 :
> >> +               clip_distance_var->type->length;
> >> +
> >> +      if (cull_distance_var)
> >> +         *ClipCullDistanceArraySize+= cull_distance_var->type->was_unsized ?
> >> +               cull_distance_var->type->length -1 :
> >> +               cull_distance_var->type->length;
> >
> > How come this needs to be done for former unsized arrays?
> >
> 
> We replace an unsized array with a default size of 1 ( fixup_type() ) , 
> so with either cull or clip set to max (8) and the other array left 
> unsized we would end up with a total of 9 reported, that would trigger 
> the error below.

I see. Is there a piglit test for this? I couldn't find it but I may be
blind. I take it the Nvidia driver passes in this case? 

Wouldn't you only want the test below to pass if the unsized cull or
clip is unused? If it defaults to 1 (or is resized to 1) and its used
then isn't it valid for this to fail? 



> 
> >
> >> +
> >> +      /* From the ARB_cull_distance spec:
> >> +       *
> >> +       * It is a compile-time or link-time error for the set of shaders forming
> >> +       * a program to have the sum of the sizes of the gl_ClipDistance and
> >> +       * gl_CullDistance arrays to be larger than
> >> +       * gl_MaxCombinedClipAndCullDistances.
> >> +       */
> >> +      if (*ClipCullDistanceArraySize > ctx->Const.MaxClipPlanes) {
> >> +          linker_error(prog, "%s shader: the combined size of "
> >> +                       "'gl_ClipDistance' and 'gl_CullDistance' size cannot "
> >> +                       "be larger than "
> >> +                       "gl_MaxCombinedClipAndCullDistances (%u)",
> >> +                       _mesa_shader_stage_to_string(shader->Stage),
> >> +                       ctx->Const.MaxClipPlanes);
> >> +      }
> >>      }
> >>   }
> >>   
> >> @@ -524,14 +569,14 @@ analyze_clip_usage(struct gl_shader_program *prog,
> >>   /**
> >>    * Verify that a vertex shader executable meets all semantic requirements.
> >>    *
> >> - * Also sets prog->Vert.UsesClipDistance and prog->Vert.ClipDistanceArraySize
> >> - * as a side effect.
> >> + * Also sets prog->Vert.UsesClipCullDistance and
> >> + * prog->Vert.ClipCullDistanceArraySize as a side effect.
> >>    *
> >>    * \param shader  Vertex shader executable to be verified
> >>    */
> >>   void
> >>   validate_vertex_shader_executable(struct gl_shader_program *prog,
> >> -				  struct gl_shader *shader)
> >> +				  struct gl_shader *shader, struct gl_context *ctx)
> >>   {
> >>      if (shader == NULL)
> >>         return;
> >> @@ -578,8 +623,8 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
> >>         }
> >>      }
> >>   
> >> -   analyze_clip_usage(prog, shader, &prog->Vert.UsesClipDistance,
> >> -                      &prog->Vert.ClipDistanceArraySize);
> >> +   analyze_clip_cull_usage(prog, shader, ctx, &prog->Vert.UsesClipCullDistance,
> >> +                           &prog->Vert.ClipCullDistanceArraySize);
> >>   }
> >>   
> >>
> >> @@ -590,7 +635,7 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
> >>    */
> >>   void
> >>   validate_fragment_shader_executable(struct gl_shader_program *prog,
> >> -				    struct gl_shader *shader)
> >> +				    struct gl_shader *shader, struct gl_context *ctx)
> >>   {
> >>      if (shader == NULL)
> >>         return;
> >> @@ -610,14 +655,14 @@ validate_fragment_shader_executable(struct gl_shader_program *prog,
> >>   /**
> >>    * Verify that a geometry shader executable meets all semantic requirements
> >>    *
> >> - * Also sets prog->Geom.VerticesIn, prog->Geom.UsesClipDistance, and
> >> - * prog->Geom.ClipDistanceArraySize as a side effect.
> >> + * Also sets prog->Geom.VerticesIn, prog->Geom.UsesClipCullDistance, and
> >> + * prog->Geom.ClipCullDistanceArraySize as a side effect.
> >>    *
> >>    * \param shader Geometry shader executable to be verified
> >>    */
> >>   void
> >>   validate_geometry_shader_executable(struct gl_shader_program *prog,
> >> -				    struct gl_shader *shader)
> >> +				    struct gl_shader *shader, struct gl_context *ctx)
> >>   {
> >>      if (shader == NULL)
> >>         return;
> >> @@ -625,8 +670,8 @@ validate_geometry_shader_executable(struct gl_shader_program *prog,
> >>      unsigned num_vertices = vertices_per_prim(prog->Geom.InputType);
> >>      prog->Geom.VerticesIn = num_vertices;
> >>   
> >> -   analyze_clip_usage(prog, shader, &prog->Geom.UsesClipDistance,
> >> -                      &prog->Geom.ClipDistanceArraySize);
> >> +   analyze_clip_cull_usage(prog, shader, ctx, &prog->Geom.UsesClipCullDistance,
> >> +                           &prog->Geom.ClipCullDistanceArraySize);
> >>   }
> >>   
> >>   /**
> >> @@ -2834,13 +2879,13 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
> >>   
> >>            switch (stage) {
> >>            case MESA_SHADER_VERTEX:
> >> -            validate_vertex_shader_executable(prog, sh);
> >> +            validate_vertex_shader_executable(prog, sh, ctx);
> >>               break;
> >>            case MESA_SHADER_GEOMETRY:
> >> -            validate_geometry_shader_executable(prog, sh);
> >> +            validate_geometry_shader_executable(prog, sh, ctx);
> >>               break;
> >>            case MESA_SHADER_FRAGMENT:
> >> -            validate_fragment_shader_executable(prog, sh);
> >> +            validate_fragment_shader_executable(prog, sh, ctx);
> >>               break;
> >>            }
> >>            if (!prog->LinkStatus)
> >> @@ -2851,11 +2896,11 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
> >>      }
> >>   
> >>      if (num_shaders[MESA_SHADER_GEOMETRY] > 0)
> >> -      prog->LastClipDistanceArraySize = prog->Geom.ClipDistanceArraySize;
> >> +      prog->LastClipCullDistanceArraySize = prog->Geom.ClipCullDistanceArraySize;
> >>      else if (num_shaders[MESA_SHADER_VERTEX] > 0)
> >> -      prog->LastClipDistanceArraySize = prog->Vert.ClipDistanceArraySize;
> >> +      prog->LastClipCullDistanceArraySize = prog->Vert.ClipCullDistanceArraySize;
> >>      else
> >> -      prog->LastClipDistanceArraySize = 0; /* Not used */
> >> +      prog->LastClipCullDistanceArraySize = 0; /* Not used */
> >>   
> >>      /* Here begins the inter-stage linking phase.  Some initial validation is
> >>       * performed, then locations are assigned for uniforms, attributes, and
> >> diff --git a/src/glsl/standalone_scaffolding.cpp b/src/glsl/standalone_scaffolding.cpp
> >> index a109c4e..0ac16bb 100644
> >> --- a/src/glsl/standalone_scaffolding.cpp
> >> +++ b/src/glsl/standalone_scaffolding.cpp
> >> @@ -142,6 +142,7 @@ void initialize_context_to_defaults(struct gl_context *ctx, gl_api api)
> >>      ctx->Extensions.ARB_texture_query_lod = true;
> >>      ctx->Extensions.ARB_uniform_buffer_object = true;
> >>      ctx->Extensions.ARB_viewport_array = true;
> >> +   ctx->Extensions.ARB_cull_distance = true;
> >>   
> >>      ctx->Extensions.OES_EGL_image_external = true;
> >>      ctx->Extensions.OES_standard_derivatives = true;
> >> diff --git a/src/glsl/tests/varyings_test.cpp b/src/glsl/tests/varyings_test.cpp
> >> index 4573529..7a962c5 100644
> >> --- a/src/glsl/tests/varyings_test.cpp
> >> +++ b/src/glsl/tests/varyings_test.cpp
> >> @@ -202,6 +202,33 @@ TEST_F(link_varyings, gl_ClipDistance)
> >>      EXPECT_TRUE(is_empty(consumer_interface_inputs));
> >>   }
> >>   
> >> +TEST_F(link_varyings, gl_CullDistance)
> >> +{
> >> +   const glsl_type *const array_8_of_float =
> >> +      glsl_type::get_array_instance(glsl_type::vec(1), 8);
> >> +
> >> +   ir_variable *const culldistance =
> >> +      new(mem_ctx) ir_variable(array_8_of_float,
> >> +                               "gl_CullDistance",
> >> +                               ir_var_shader_in);
> >> +
> >> +   culldistance->data.explicit_location = true;
> >> +   culldistance->data.location = VARYING_SLOT_CULL_DIST0;
> >> +   culldistance->data.explicit_index = 0;
> >> +
> >> +   ir.push_tail(culldistance);
> >> +
> >> +   ASSERT_TRUE(linker::populate_consumer_input_sets(mem_ctx,
> >> +                                                    &ir,
> >> +                                                    consumer_inputs,
> >> +                                                    consumer_interface_inputs,
> >> +                                                    junk));
> >> +
> >> +   EXPECT_EQ(culldistance, junk[VARYING_SLOT_CULL_DIST0]);
> >> +   EXPECT_TRUE(is_empty(consumer_inputs));
> >> +   EXPECT_TRUE(is_empty(consumer_interface_inputs));
> >> +}
> >> +
> >>   TEST_F(link_varyings, single_interface_input)
> >>   {
> >>      ir_variable *const v =
> >
> 




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