[cogl] primitive: add missing description

[Robert Bragg <rbragg src gnome org>]

commit 643a7ba5a182a5a1652c380c4e6fc1c4eb1585b1
Author: Lionel Landwerlin <llandwerlin gmail com>
Date:   Tue Sep 3 15:39:50 2013 +0100

    primitive: add missing description
    
    Reviewed-by: Robert Bragg <robert linux intel com>
    
    (cherry picked from commit db513174f0e1a11b8dbe9689183b20183d384f9d)

 cogl/cogl-primitive.h |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)
---
diff --git a/cogl/cogl-primitive.h b/cogl/cogl-primitive.h
index 19571f6..9d79737 100644
--- a/cogl/cogl-primitive.h
+++ b/cogl/cogl-primitive.h
@@ -232,6 +232,27 @@ cogl_primitive_new (CoglVerticesMode mode,
                     int n_vertices,
                     ...);
 
+/**
+ * cogl_primitive_new_with_attributes:
+ * @mode: A #CoglVerticesMode defining how to draw the vertices
+ * @n_vertices: The number of vertices to process when drawing
+ * @attributes: An array of CoglAttribute
+ * @n_attributes: The number of attributes
+ *
+ * Combines a set of #CoglAttribute<!-- -->s with a specific draw @mode
+ * and defines a vertex count so a #CoglPrimitive object can be retained and
+ * drawn later with no addition information required.
+ *
+ * The value passed as @n_vertices will simply update the
+ * #CoglPrimitive <structfield>n_vertices</structfield> property as if
+ * cogl_primitive_set_n_vertices() were called. This property defines
+ * the number of vertices to read when drawing.
+ *
+ * Return value: (transfer full): A newly allocated #CoglPrimitive object
+ *
+ * Since: 1.6
+ * Stability: Unstable
+ */
 CoglPrimitive *
 cogl_primitive_new_with_attributes (CoglVerticesMode mode,
                                     int n_vertices,