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

Tobias Klausmann tobias.johannes.klausmann at mni.thm.de
Sun May 24 10:58:05 PDT 2015


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;
+
+      /* 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 =
-- 
2.4.1



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