[babl] babl.h: add documentation

[Øyvind "pippin" Kolås <ok src gnome org>]

commit e32a42254e085fb78421366ae95139411094f2f5
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Jul 11 22:57:59 2018 +0200

    babl.h: add documentation

 babl/babl-internal.h |  5 +++++
 babl/babl.h          | 21 +++++++++++++++------
 2 files changed, 20 insertions(+), 6 deletions(-)
---
diff --git a/babl/babl-internal.h b/babl/babl-internal.h
index 392d786..ee920ed 100644
--- a/babl/babl-internal.h
+++ b/babl/babl-internal.h
@@ -455,6 +455,11 @@ void _babl_fish_prepare_bpp (Babl *babl);
  * the result is allocated with malloc and you should free it when done.
  */
 
+typedef enum {
+  BABL_ICC_DEFAULTS = 0,
+  BABL_ICC_COMPACT_TRC_LUT = 1,
+} BablICCFlags;
+
 char *babl_space_to_icc (const Babl  *space,
                          const char  *description,
                          const char  *copyright,
diff --git a/babl/babl.h b/babl/babl.h
index c6052e7..660138f 100644
--- a/babl/babl.h
+++ b/babl/babl.h
@@ -494,13 +494,9 @@ const Babl * babl_trc_gamma (double gamma);
  */
 const Babl * babl_trc (const char *name);
 
-typedef enum {
-  BABL_ICC_DEFAULTS = 0,
-  BABL_ICC_COMPACT_TRC_LUT = 1,
-} BablICCFlags;
-
 
-/* babl_space_get:
+/**
+ * babl_space_get:
  *
  * query thechromaticities of white point and primaries as well as trcs
  * used for r g a nd b, all arguments mights be NULL.
@@ -515,6 +511,19 @@ void babl_space_get (const Babl *space,
                      const Babl **green_trc,
                      const Babl **blue_trc);
 
+/**
+ * babl_space_get_icc:
+ *
+ * Return pointer to ICC profile for space note that this is
+ * the ICC profile for R'G'B', though in formats only supporting linear
+ * like EXR GEGL chooses to load this lienar data as RGB and use the sRGB
+ * TRC.
+ *
+ * @babl: a BablSpace
+ * @length: point to an integer where length of profile in bytes is stored.
+ *
+ * Returns pointer to ICC profile data.
+ */
 const char *babl_space_get_icc (const Babl *babl, int *length);
 
 #ifdef __cplusplus