[Mesa-dev] [PATCH 04/25] glsl: Add support for linking uniform arrays of arrays

[Timothy Arceri]

V2: Handle arrays of arrays in the same way structures are handled

The ARB_arrays_of_arrays spec doesn't give very many details on how
AoA uniforms are intended to be implemented. However in the
ARB_program_interface_query spec there are details that show AoA are
intended to be handled in a similar way to structs.

Issues 7 from the ARB_program_interface_query spec:

 We define rules consistent with our enumeration rules for
 other complex types.  For existing one-dimensional arrays, we enumerate
 a single entry if the array is an array of basic types, or separate
 entries for each array element if the array is an array of structures.
 We follow similar rules here.  For a uniform array such as:

   uniform vec4 a[5][4][3];

 we enumerate twenty different entries ("a[0][0][0]" through
 "a[4][3][0]"), each of which is treated as an array with three elements.
 This is morally equivalent to what you'd get if you worked around the
 limitation in current GLSL via:

    struct ArrayBottom { vec4 c[3]; };
    struct ArrayMid    { ArrayBottom b[3]; };
    uniform ArrayMid   a[5];

 which would enumerate "a[0].b[0].c[0]" through "a[4].b[3].c[0]".
---
 src/glsl/link_uniform_initializers.cpp |  4 +++-
 src/glsl/link_uniforms.cpp             | 13 +++++++++----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/glsl/link_uniform_initializers.cpp b/src/glsl/link_uniform_initializers.cpp
index d61ae91..0cc79d9 100644
--- a/src/glsl/link_uniform_initializers.cpp
+++ b/src/glsl/link_uniform_initializers.cpp
@@ -165,6 +165,7 @@ set_uniform_initializer(void *mem_ctx, gl_shader_program *prog,
 			const char *name, const glsl_type *type,
                         ir_constant *val, unsigned int boolean_true)
 {
+   const glsl_type *t_without_array = type->without_array();
    if (type->is_record()) {
       ir_constant *field_constant;
 
@@ -179,7 +180,8 @@ set_uniform_initializer(void *mem_ctx, gl_shader_program *prog,
 	 field_constant = (ir_constant *)field_constant->next;
       }
       return;
-   } else if (type->is_array() && type->fields.array->is_record()) {
+   } else if (t_without_array->is_record() ||
+              (type->is_array() && type->fields.array->is_array())) {
       const glsl_type *const element_type = type->fields.array;
 
       for (unsigned int i = 0; i < type->length; i++) {
diff --git a/src/glsl/link_uniforms.cpp b/src/glsl/link_uniforms.cpp
index 42f75e9..61b47c9 100644
--- a/src/glsl/link_uniforms.cpp
+++ b/src/glsl/link_uniforms.cpp
@@ -138,7 +138,8 @@ program_resource_visitor::process(ir_variable *var)
        */
       recursion(var->type, &name, strlen(name), row_major, NULL, false);
       ralloc_free(name);
-   } else if (t->without_array()->is_record()) {
+   } else if (t_without_array->is_record() ||
+              (t->is_array() && t->fields.array->is_array())) {
       char *name = ralloc_strdup(NULL, var->name);
       recursion(var->type, &name, strlen(name), row_major, NULL, false);
       ralloc_free(name);
@@ -215,7 +216,8 @@ program_resource_visitor::recursion(const glsl_type *t, char **name,
          this->leave_record(t, *name, row_major);
       }
    } else if (t->without_array()->is_record()
-              || t->without_array()->is_interface()) {
+              || t->without_array()->is_interface()
+              || (t->is_array() && t->fields.array->is_array())) {
       if (record_type == NULL && t->fields.array->is_record())
          record_type = t->fields.array;
 
@@ -344,6 +346,7 @@ private:
    {
       assert(!type->without_array()->is_record());
       assert(!type->without_array()->is_interface());
+      assert(!(type->is_array() && type->fields.array->is_array()));
 
       (void) row_major;
 
@@ -594,6 +597,7 @@ private:
    {
       assert(!type->without_array()->is_record());
       assert(!type->without_array()->is_interface());
+      assert(!(type->is_array() && type->fields.array->is_array()));
 
       unsigned id;
       bool found = this->map->get(id, name);
@@ -666,7 +670,7 @@ private:
 
 	 if (type->is_array()) {
 	    this->uniforms[id].array_stride =
-	       glsl_align(type->fields.array->std140_size(row_major), 16);
+	       glsl_align(type->without_array()->std140_size(row_major), 16);
 	 } else {
 	    this->uniforms[id].array_stride = 0;
 	 }
@@ -807,7 +811,8 @@ link_update_uniform_buffer_variables(struct gl_shader *shader)
 
       if (var->type->is_record()) {
          sentinel = '.';
-      } else if (var->type->without_array()->is_record()) {
+      } else if (var->type->is_array() && (var->type->fields.array->is_array()
+                 || var->type->fields.array->is_record())) {
          sentinel = '[';
       }
 
-- 
2.4.3