[Mesa-dev] [PATCH 2/3] glsl: Clarify and document type_compare()

[Chad Versace]

The parameters were named 'a' and 'b', but there was no documentation
indicating which was being converted to which. So rename 'a' -> 'to' and
'b' -> 'from'.

Also add a Doxygen comment.

Signed-off-by: Chad Versace <chad at chad-versace.us>
---
 src/glsl/ir_function.cpp |   27 +++++++++++++++++----------
 1 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/glsl/ir_function.cpp b/src/glsl/ir_function.cpp
index 6795988..e6ba359 100644
--- a/src/glsl/ir_function.cpp
+++ b/src/glsl/ir_function.cpp
@@ -24,29 +24,36 @@
 #include "glsl_types.h"
 #include "ir.h"
 
+/**
+ * \brief Check if an implicit type conversion is possible.
+ *
+ * Called by type_compare().
+ *
+ * \return If conversion is possible, 1. Else, -1.
+ */
 int
-type_compare(const glsl_type *a, const glsl_type *b)
+type_compare(const glsl_type *to, const glsl_type *from)
 {
    /* If the types are the same, they trivially match.
     */
-   if (a == b)
+   if (to == from)
       return 0;
 
-   switch (a->base_type) {
+   switch (to->base_type) {
    case GLSL_TYPE_UINT:
    case GLSL_TYPE_INT:
    case GLSL_TYPE_BOOL:
       /* There is no implicit conversion to or from integer types or bool.
        */
-      if ((a->is_integer() != b->is_integer())
-	  || (a->is_boolean() != b->is_boolean()))
+      if ((to->is_integer() != from->is_integer())
+	  || (to->is_boolean() != from->is_boolean()))
 	 return -1;
 
       /* FALLTHROUGH */
 
    case GLSL_TYPE_FLOAT:
-      if ((a->vector_elements != b->vector_elements)
-	  || (a->matrix_columns != b->matrix_columns))
+      if ((to->vector_elements != from->vector_elements)
+	  || (to->matrix_columns != from->matrix_columns))
 	 return -1;
 
       return 1;
@@ -58,8 +65,8 @@ type_compare(const glsl_type *a, const glsl_type *b)
       return -1;
 
    case GLSL_TYPE_ARRAY:
-      if ((b->base_type != GLSL_TYPE_ARRAY)
-	  || (a->length != b->length))
+      if ((from->base_type != GLSL_TYPE_ARRAY)
+	  || (to->length != from->length))
 	 return -1;
 
       /* From GLSL 1.50 spec, page 27 (page 33 of the PDF):
@@ -68,7 +75,7 @@ type_compare(const glsl_type *a, const glsl_type *b)
        * If the comparison of the array element types detects that a conversion
        * would be required, the array types do not match.
        */
-      return (type_compare(a->fields.array, b->fields.array) == 0) ? 0 : -1;
+      return (type_compare(to->fields.array, from->fields.array) == 0) ? 0 : -1;
 
    case GLSL_TYPE_VOID:
    case GLSL_TYPE_ERROR:
-- 
1.7.6