constify API

18 files changed, 152 insertions, 147 deletions

diff --git a/babl/babl-class.h b/babl/babl-class.h
index 4e9bbaf..47c783d 100644
--- a/babl/babl-class.h
+++ b/babl/babl-class.h
@@ -33,11 +33,11 @@ typedef int  (*BablEachFunction) (Babl *entry,
  * to be iterated over, common functionality is defined through these
  * macros.
  */
-#define BABL_CLASS_DECLARE(klass)                                    \
-                                                                     \
-BablDb * babl_##klass##_db (void);                                   \
-Babl   * babl_##klass##_from_id        (int id);                     \
-void     babl_##klass##_class_for_each (BablEachFunction  each_fun,  \
+#define BABL_CLASS_DECLARE(klass)                                          \
+                                                                           \
+BablDb       * babl_##klass##_db (void);                                   \
+const Babl   * babl_##klass##_from_id        (int id);                     \
+void           babl_##klass##_class_for_each (BablEachFunction  each_fun,  \
                                         void             *user_data)
 
 /* common header for any item inserted into database, the actual
diff --git a/babl/babl-component.c b/babl/babl-component.c
index 65e8767..a483b19 100644
--- a/babl/babl-component.c
+++ b/babl/babl-component.c
@@ -58,7 +58,7 @@ is_component_duplicate (Babl *babl, int luma, int chroma, int alpha)
 }
 
 
-Babl *
+const Babl *
 babl_component_new (void *first_arg,
                     ...)
 {
diff --git a/babl/babl-conversion.c b/babl/babl-conversion.c
index b88ab1f..15beb91 100644
--- a/babl/babl-conversion.c
+++ b/babl/babl-conversion.c
@@ -109,8 +109,8 @@ conversion_new (const char    *name,
   if (babl->class_type == BABL_CONVERSION_LINEAR &&
       BABL (babl->conversion.source)->class_type == BABL_MODEL)
     {
-      Babl *src_format = NULL;
-      Babl *dst_format = NULL;
+      const Babl *src_format = NULL;
+      const Babl *dst_format = NULL;
       if (BABL (babl->conversion.source) == babl_model_from_id (BABL_RGBA))
         {
           src_format = babl_format_from_id (BABL_RGBA_DOUBLE);
@@ -171,8 +171,8 @@ create_name (Babl *source, Babl *destination, int type)
   return buf;
 }
 
-Babl *
-babl_conversion_new (void *first_arg,
+const Babl *
+babl_conversion_new (const void *first_arg,
                      ...)
 {
   va_list        varg;
@@ -344,7 +344,7 @@ babl_conversion_planar_process (BablConversion *conversion,
 }
 
 long
-babl_conversion_process (Babl       *babl,
+babl_conversion_process (const Babl *babl,
                          const char *source,
                          char       *destination,
                          long        n)
@@ -467,13 +467,13 @@ babl_conversion_error (BablConversion *conversion)
   Babl *fmt_source;
   Babl *fmt_destination;
 
-  Babl *fmt_rgba_double = babl_format_new (babl_model ("RGBA"),
-                                           babl_type ("double"),
-                                           babl_component ("R"),
-                                           babl_component ("G"),
-                                           babl_component ("B"),
-                                           babl_component ("A"),
-                                           NULL);
+  const Babl *fmt_rgba_double = babl_format_new (babl_model ("RGBA"),
+                                                 babl_type ("double"),
+                                                 babl_component ("R"),
+                                                 babl_component ("G"),
+                                                 babl_component ("B"),
+                                                 babl_component ("A"),
+                                                 NULL);
 
   double  error       = 0.0;
   long    ticks_start = 0;
diff --git a/babl/babl-conversion.h b/babl/babl-conversion.h
index 15e34a1..902beb5 100644
--- a/babl/babl-conversion.h
+++ b/babl/babl-conversion.h
@@ -21,9 +21,7 @@
 
 BABL_CLASS_DECLARE (conversion);
 
-Babl * babl_conversion (const char *name);
-
-
+const Babl * babl_conversion (const char *name);
 
 /* Signature of functions registered for reference type
  * conversions,
diff --git a/babl/babl-extension.h b/babl/babl-extension.h
index 4c2610a..b0b8b36 100644
--- a/babl/babl-extension.h
+++ b/babl/babl-extension.h
@@ -27,8 +27,8 @@ BABL_CLASS_DECLARE (extension);
  * BablExtension objects are only used internally in babl.
  */
 
-Babl * babl_extension (const char *name);
-void   babl_extension_load_dir_list (const char *dir_list);
+const  Babl * babl_extension               (const char *name);
+void          babl_extension_load_dir_list (const char *dir_list);
 
 typedef struct
 {
diff --git a/babl/babl-fish-path.c b/babl/babl-fish-path.c
index a2d1a68..7914e0c 100644
--- a/babl/babl-fish-path.c
+++ b/babl/babl-fish-path.c
@@ -29,16 +29,16 @@ int   babl_in_fish_path = 0;
 
 typedef struct _FishPathInstrumentation
 {
-  Babl   *fmt_rgba_double;
+  const Babl   *fmt_rgba_double;
   double *test;
   void   *source;
   void   *destination;
   void   *ref_destination;
   double *destination_rgba_double;
   double *ref_destination_rgba_double;
-  Babl   *fish_rgba_to_source;
-  Babl   *fish_reference;
-  Babl   *fish_destination_to_rgba;
+  const Babl   *fish_rgba_to_source;
+  const Babl   *fish_reference;
+  const Babl   *fish_destination_to_rgba;
   double  reference_cost;
   int     init_instrumentation_done;
 } FishPathInstrumentation;
@@ -378,11 +378,12 @@ babl_fish_process (Babl       *babl,
 }
 
 long
-babl_process (Babl       *babl,
+babl_process (const Babl *cbabl,
               const void *source,
               void       *destination,
               long        n)
 {
+  Babl *babl = (Babl*)cbabl;
   babl_assert (babl);
   babl_assert (source);
   babl_assert (destination);
diff --git a/babl/babl-fish-reference.c b/babl/babl-fish-reference.c
index 4f90d12..b00d67d 100644
--- a/babl/babl-fish-reference.c
+++ b/babl/babl-fish-reference.c
@@ -20,8 +20,8 @@
 #include "babl-internal.h"
 
 static Babl *
-assert_conversion_find (void *source,
-                        void *destination)
+assert_conversion_find (const void *source,
+                        const void *destination)
 {
   Babl *ret = babl_conversion_find (source, destination);
 
@@ -276,7 +276,7 @@ ncomponent_convert_from_double (BablFormat *destination_fmt,
 
 
 static int
-process_same_model (Babl            *babl,
+process_same_model (const Babl      *babl,
                     const BablImage *source,
                     BablImage       *destination,
                     long             n)
@@ -341,7 +341,7 @@ process_same_model (Babl            *babl,
 }
 
 long
-babl_fish_reference_process (Babl            *babl,
+babl_fish_reference_process (const Babl      *babl,
                              const BablImage *source,
                              BablImage       *destination,
                              long             n)
diff --git a/babl/babl-fish-stats.c b/babl/babl-fish-stats.c
index f4893db..ccd4037 100644
--- a/babl/babl-fish-stats.c
+++ b/babl/babl-fish-stats.c
@@ -35,12 +35,12 @@ static int
 table_destination_sum_each (Babl *babl,
                             void *userdata)
 {
-  Babl *source      = userdata;
-  Babl *destination = babl;
+  const Babl *source      = userdata;
+  const Babl *destination = babl;
 
   if (source != destination)
     {
-      Babl *fish = babl_fish (source, destination);
+      const Babl *fish = babl_fish (source, destination);
       babl_assert (fish);
       sum_pixels += fish->fish.pixels;
     }
@@ -76,7 +76,7 @@ table_destination_each (Babl *babl,
     fprintf (output_file, "<td class='cell'>&nbsp;</td>");
   else
     {
-      Babl *fish = babl_fish (source, destination);
+      const Babl *fish = babl_fish (source, destination);
 
       babl_assert (fish);
 
diff --git a/babl/babl-fish.c b/babl/babl-fish.c
index 67e53fb..76cb53d 100644
--- a/babl/babl-fish.c
+++ b/babl/babl-fish.c
@@ -138,7 +138,7 @@ babl_fish_get_id (const Babl *source,
   return id;
 }
 
-Babl *
+const Babl *
 babl_fish (const void *source,
            const void *destination)
 {
diff --git a/babl/babl-format.c b/babl/babl-format.c
index ef56431..7f43911 100644
--- a/babl/babl-format.c
+++ b/babl/babl-format.c
@@ -48,7 +48,7 @@ format_new (const char     *name,
             BablModel      *model,
             BablComponent **component,
             BablSampling  **sampling,
-            BablType      **type)
+            const BablType **type)
 {
   Babl *babl;
 
@@ -121,17 +121,17 @@ format_new (const char     *name,
 
 
 static char *
-create_name (BablModel      *model,
-             int             components,
-             BablComponent **component,
-             BablType      **type)
+create_name (const BablModel *model,
+             int              components,
+             BablComponent  **component,
+             const BablType **type)
 {
   char            buf[512] = "";
   char           *p = &buf[0];
   int             i;
   int             same_types = 1;
-  BablType      **t          = type;
-  BablType       *first_type = *type;
+  const BablType**t          = type;
+  const BablType *first_type = *type;
   BablComponent **c1         = component;
   BablComponent **c2         = model->component;
 
@@ -190,8 +190,8 @@ create_name (BablModel      *model,
 
 
 static char *
-ncomponents_create_name (Babl *type,
-                         int   components)
+ncomponents_create_name (const Babl *type,
+                         int         components)
 {
   char buf[512];
   sprintf (buf, "%s[%i] ", type->instance.name, components);
@@ -207,8 +207,8 @@ babl_format_set_is_format_n (Babl *format)
     }
 }
 
-Babl *
-babl_format_n (Babl *btype,
+const Babl *
+babl_format_n (const Babl *btype,
                int   components)
 {
   int            i;
@@ -218,7 +218,7 @@ babl_format_n (Babl *btype,
   BablModel     *model      = (BablModel *)babl_model ("Y");
   BablComponent *component [components];
   BablSampling  *sampling  [components];
-  BablType      *type      [components];
+  const BablType *type      [components];
   char          *name       = NULL;
 
   for (i = 0; i<components; i++)
@@ -252,7 +252,7 @@ babl_format_n (Babl *btype,
 }
 
 int
-babl_format_is_format_n (Babl *format)
+babl_format_is_format_n (const Babl *format)
 {
   if (format->class_type == BABL_FORMAT)
     {
@@ -264,13 +264,13 @@ babl_format_is_format_n (Babl *format)
 
 
 static int
-is_format_duplicate (Babl           *babl,
-                     int             planar,
-                     int             components,
-                     BablModel      *model,
-                     BablComponent **component,
-                     BablSampling  **sampling,
-                     BablType      **type)
+is_format_duplicate (Babl            *babl,
+                     int              planar,
+                     int              components,
+                     BablModel       *model,
+                     BablComponent  **component,
+                     BablSampling   **sampling,
+                     const BablType **type)
 {
   int i;
 
@@ -289,8 +289,8 @@ is_format_duplicate (Babl           *babl,
   return 1;
 }
 
-Babl *
-babl_format_new (void *first_arg,
+const Babl *
+babl_format_new (const void *first_arg,
                  ...)
 {
   va_list        varg;
@@ -301,12 +301,12 @@ babl_format_new (void *first_arg,
   BablModel     *model      = NULL;
   BablComponent *component [BABL_MAX_COMPONENTS];
   BablSampling  *sampling  [BABL_MAX_COMPONENTS];
-  BablType      *type      [BABL_MAX_COMPONENTS];
+  const BablType*type      [BABL_MAX_COMPONENTS];
 
   BablSampling  *current_sampling = (BablSampling *) babl_sampling (1, 1);
   BablType      *current_type     = (BablType *) babl_type_from_id (BABL_DOUBLE);
   char          *name             = NULL;
-  void          *arg              = first_arg;
+  const void    *arg              = first_arg;
 
   va_start (varg, first_arg);
 
@@ -498,7 +498,7 @@ babl_format_get_n_components (const Babl *format)
   return 0;
 }
 
-Babl *
+const Babl *
 babl_format_get_type (const Babl *format,
                       int         component_index)
 {
@@ -512,9 +512,9 @@ babl_format_get_type (const Babl *format,
   return NULL;
 }
 
-Babl *
-babl_format_with_model_as_type (Babl *model,
-                                Babl *type)
+const Babl *
+babl_format_with_model_as_type (const Babl *model,
+                                const Babl *type)
 {
   BablComponent *component[10];
   int            i;
@@ -561,7 +561,7 @@ test_create (void)
 }
 
 double
-babl_format_loss (Babl *babl)
+babl_format_loss (const Babl *babl)
 {
   double  loss = 0.0;
   double *test;
@@ -570,10 +570,10 @@ babl_format_loss (Babl *babl)
   void   *destination;
   double *transformed;
 
-  Babl   *ref_fmt;
-  Babl   *fmt;
-  Babl   *fish_to;
-  Babl   *fish_from;
+  const Babl *ref_fmt;
+  const Babl *fmt;
+  Babl       *fish_to;
+  Babl       *fish_from;
 
   ref_fmt = babl_format_new (
     babl_model ("RGBA"),
@@ -615,13 +615,13 @@ babl_format_loss (Babl *babl)
   babl_free (transformed);
   babl_free (test);
 
-  babl->format.loss = loss;
+  ((Babl*)babl)->format.loss = loss;
   return loss;
 }
 
 
 void *
-babl_get_user_data (Babl *babl)
+babl_get_user_data (const Babl *babl)
 {
   switch (babl->instance.class_type)
     {
@@ -637,9 +637,10 @@ babl_get_user_data (Babl *babl)
 }
 
 void
-babl_set_user_data (Babl *babl, void *data)
+babl_set_user_data (const Babl *cbabl, void *data)
 {
-  switch (babl->instance.class_type)
+  Babl *babl = (Babl*) cbabl;
+  switch (cbabl->instance.class_type)
     {
       case BABL_MODEL:
         babl->model.data = data;
diff --git a/babl/babl-image.c b/babl/babl-image.c
index 631fe6d..a5d4e1f 100644
--- a/babl/babl-image.c
+++ b/babl/babl-image.c
@@ -79,9 +79,10 @@ image_new (BablFormat     *format,
 }
 
 Babl *
-babl_image_from_linear (char *buffer,
-                        Babl *format)
+babl_image_from_linear (char       *buffer,
+                        const Babl *cformat)
 {
+  Babl          *format = (Babl*) cformat;
   Babl          *babl;
   BablModel     *model      = NULL;
   int            components = 0;
@@ -169,7 +170,7 @@ babl_image_from_linear (char *buffer,
 }
 
 Babl *
-babl_image_new (void *first,
+babl_image_new (const void *first,
                 ...)
 {
   va_list        varg;
diff --git a/babl/babl-image.h b/babl/babl-image.h
index 2b7a2a8..0c93f49 100644
--- a/babl/babl-image.h
+++ b/babl/babl-image.h
@@ -41,7 +41,7 @@ BABL_CLASS_DECLARE (image);
  *                        ...]
  *                        NULL);
  */
-Babl * babl_image_new  (void *first_component,
+Babl * babl_image_new  (const void *first_component,
                         ...) BABL_ARG_NULL_TERMINATED;
 
 typedef struct
diff --git a/babl/babl-internal.h b/babl/babl-internal.h
index bf85727..6f821cd 100644
--- a/babl/babl-internal.h
+++ b/babl/babl-internal.h
@@ -69,7 +69,7 @@ Babl *   babl_conversion_find           (const void     *source,
                                          const void     *destination);
 double   babl_conversion_error          (BablConversion *conversion);
 long     babl_conversion_cost           (BablConversion *conversion);
-long     babl_conversion_process        (Babl           *conversion,
+long     babl_conversion_process        (const Babl     *conversion,
                                          const char     *source,
                                          char           *destination,
                                          long            n);
@@ -82,7 +82,7 @@ void     babl_set_extender              (Babl           *new_extender);
 Babl   * babl_extension_quiet_log       (void);
 void     babl_extension_deinit          (void);
 
-long     babl_fish_reference_process    (Babl           *babl,
+long     babl_fish_reference_process    (const Babl     *babl,
                                          const BablImage*source,
                                          BablImage      *destination,
                                          long            n);
@@ -97,20 +97,20 @@ Babl   * babl_fish_path                 (const Babl     *source,
 int      babl_fish_get_id               (const Babl     *source,
                                          const Babl     *destination);
 
-double   babl_format_loss               (Babl           *babl);
+double   babl_format_loss               (const Babl     *babl);
 Babl   * babl_image_from_linear         (char           *buffer,
-                                         Babl           *format);
-Babl   * babl_image_double_from_image   (Babl           *source);
+                                         const Babl     *format);
+Babl   * babl_image_double_from_image   (const Babl     *source);
 
-double   babl_model_is_symmetric        (Babl           *babl);
+double   babl_model_is_symmetric        (const Babl     *babl);
 void     babl_die                       (void);
 int      babl_sanity                    (void);
 
 void     babl_core_init                 (void);
-Babl   * babl_format_with_model_as_type (Babl           *model,
-                                         Babl           *type);
+const Babl *babl_format_with_model_as_type (const Babl     *model,
+                                         const Babl     *type);
 int      babl_formats_count             (void);                                     /* should maybe be templated? */
-int      babl_type_is_symmetric         (Babl           *babl);
+int      babl_type_is_symmetric         (const Babl     *babl);
 
 /**** LOGGER ****/
 #include <stdarg.h>
@@ -259,7 +259,7 @@ babl_##klass##_class_for_each (BablEachFunction  each_fun,    \
 #define BABL_CLASS_IMPLEMENT(klass)                           \
 BABL_CLASS_MINIMAL_IMPLEMENT(klass)                           \
                                                               \
-Babl *                                                        \
+const Babl *                                                  \
 babl_##klass (const char *name)                               \
 {                                                             \
   Babl *babl;                                                 \
@@ -277,7 +277,7 @@ babl_##klass (const char *name)                               \
   return babl;                                                \
 }                                                             \
                                                               \
-Babl *                                                        \
+const Babl *                                                  \
 babl_##klass##_from_id (int id)                               \
 {                                                             \
   Babl *babl;                                                 \
diff --git a/babl/babl-model.c b/babl/babl-model.c
index f35e1a3..1f77076 100644
--- a/babl/babl-model.c
+++ b/babl/babl-model.c
@@ -24,7 +24,7 @@
 #include "babl-internal.h"
 #include "babl-db.h"
 
-static Babl *construct_double_format (Babl *model);
+static const Babl *construct_double_format (const Babl *model);
 
 static int
 babl_model_destroy (void *data)
@@ -93,7 +93,7 @@ is_model_duplicate (Babl *babl, int components, BablComponent **component)
 }
 
 
-Babl *
+const Babl *
 babl_model_new (void *first_argument,
                 ...)
 {
@@ -234,9 +234,9 @@ test_create (void)
   return test;
 }
 
-static Babl *reference_format (void)
+static const Babl *reference_format (void)
 {
-  static Babl *self = NULL;
+  static const Babl *self = NULL;
 
   if (!self)
     self = babl_format_new (
@@ -250,9 +250,9 @@ static Babl *reference_format (void)
   return self;
 }
 
-static Babl *construct_double_format (Babl *model)
+static const Babl *construct_double_format (const Babl *model)
 {
-  void *argument[44 + 1];
+  const void *argument[44 + 1];
   int   args = 0;
   int   i;
 
@@ -286,8 +286,9 @@ static Babl *construct_double_format (Babl *model)
 }
 
 double
-babl_model_is_symmetric (Babl *babl)
+babl_model_is_symmetric (const Babl *cbabl)
 {
+  Babl *babl = (Babl*)cbabl;
   double *test;
   void   *original;
   double *clipped;
@@ -295,10 +296,10 @@ babl_model_is_symmetric (Babl *babl)
   double *transformed;
   int     symmetric = 1;
 
-  Babl   *ref_fmt;
-  Babl   *fmt;
-  Babl   *fish_to;
-  Babl   *fish_from;
+  const Babl *ref_fmt;
+  const Babl *fmt;
+  Babl *fish_to;
+  Babl *fish_from;
 
   test      = test_create ();
   ref_fmt   = reference_format ();
diff --git a/babl/babl-palette.c b/babl/babl-palette.c
index c2340db..29a0ae4 100644
--- a/babl/babl-palette.c
+++ b/babl/babl-palette.c
@@ -35,7 +35,7 @@ typedef struct BablPalette
 } BablPalette;
 
 
-static BablPalette *make_pal (Babl *format, void *data, int count)
+static BablPalette *make_pal (const Babl *format, const void *data, int count)
 {
   BablPalette *pal = NULL;
   int bpp = babl_format_get_bytes_per_pixel (format);
@@ -315,13 +315,13 @@ copy_strip_1 (int    src_bands,
 /* should return the BablModel, permitting to fetch
  * other formats out of it?
  */
-void babl_new_palette (const char *name, Babl **format_u8,
-                                         Babl **format_u8_with_alpha)
+void babl_new_palette (const char *name, const Babl **format_u8,
+                                         const Babl **format_u8_with_alpha)
 {
-  Babl *model;
-  Babl *model_no_alpha;
-  Babl *f_pal_u8;
-  Babl *f_pal_a_u8;
+  const Babl *model;
+  const Babl *model_no_alpha;
+  const Babl *f_pal_u8;
+  const Babl *f_pal_a_u8;
   BablPalette **palptr;
 
   char  cname[64];
@@ -432,10 +432,10 @@ void babl_new_palette (const char *name, Babl **format_u8,
 }
 
 void
-babl_palette_set_palette (Babl *babl,
-                          Babl *format,
-                          void *data,
-                          int   count)
+babl_palette_set_palette (const Babl *babl,
+                          const Babl *format,
+                          void       *data,
+                          int         count)
 {
   BablPalette **palptr = babl_get_user_data (babl);
   babl_palette_reset (babl);
@@ -443,7 +443,7 @@ babl_palette_set_palette (Babl *babl,
 }
 
 void
-babl_palette_reset (Babl *babl)
+babl_palette_reset (const Babl *babl)
 {
   BablPalette **palptr = babl_get_user_data (babl);
   if (*palptr != default_palette ())
diff --git a/babl/babl-sampling.c b/babl/babl-sampling.c
index d2e43d6..15b6532 100644
--- a/babl/babl-sampling.c
+++ b/babl/babl-sampling.c
@@ -27,7 +27,7 @@
 static BablSampling sampling_db[(HORIZONTAL_MAX - HORIZONTAL_MIN + 1) *
                                 (VERTICAL_MAX - VERTICAL_MIN + 1)];
 
-Babl *
+const Babl *
 babl_sampling (int horizontal,
                int vertical)
 {
diff --git a/babl/babl-type.c b/babl/babl-type.c
index b838860..9c3a3e8 100644
--- a/babl/babl-type.c
+++ b/babl/babl-type.c
@@ -65,7 +65,7 @@ is_type_duplicate (Babl *babl, int bits)
   return 1;
 }
 
-Babl *
+const Babl *
 babl_type_new (void *first_arg,
                ...)
 {
@@ -162,6 +162,9 @@ babl_type_new (void *first_arg,
    */
   babl_db_insert (db, babl);
   return babl;
+
+  if (min || max || is_integer || max_val || min_val)
+    return NULL;
 }
 
 
@@ -193,9 +196,9 @@ static void test_init (double min, double max)
 }
 
 
-static Babl *double_vector_format (void)
+static const Babl *double_vector_format (void)
 {
-  static Babl *self = NULL;
+  static const Babl *self = NULL;
 
   if (!self)
     self = babl_format_new (
@@ -207,7 +210,7 @@ static Babl *double_vector_format (void)
 }
 
 int
-babl_type_is_symmetric (Babl *babl)
+babl_type_is_symmetric (const Babl *babl)
 {
   int     is_symmetrical = 1;
   void   *original;
@@ -215,10 +218,10 @@ babl_type_is_symmetric (Babl *babl)
   void   *destination;
   double *transformed;
 
-  Babl   *ref_fmt;
-  Babl   *fmt;
-  Babl   *fish_to;
-  Babl   *fish_from;
+  const Babl *ref_fmt;
+  const Babl *fmt;
+  Babl       *fish_to;
+  Babl       *fish_from;
 
   test_init (0.0, 182.0);
 
diff --git a/babl/babl.h b/babl/babl.h
index 0a11e72..be629a2 100644
--- a/babl/babl.h
+++ b/babl/babl.h
@@ -45,45 +45,45 @@ void         babl_exit      (void);
  * Returns the babl object representing the data type given by @name
  * such as for example "u8", "u16" or "float".
  */
-Babl *       babl_type      (const char *name);
+const Babl * babl_type      (const char *name);
 
 /**
  * Returns the babl object representing the @horizontal and @vertical
  * sampling such as for example 2, 2 for the chroma components in
  * YCbCr.
  */
-Babl *       babl_sampling  (int horizontal,
+const Babl * babl_sampling  (int horizontal,
                              int vertical);
 
 /**
  * Returns the babl object representing the color component given by
  * @name such as for example "R", "cyan" or "CIE L".
  */
-Babl *       babl_component (const char *name);
+const Babl * babl_component (const char *name);
 
 /**
  * Returns the babl object representing the color model given by @name
  * such as for example "RGB", "CMYK" or "CIE Lab".
  */
-Babl *       babl_model     (const char *name);
+const Babl * babl_model     (const char *name);
 
 /**
  * Returns the babl object representing the color format given by
  * @name such as for example "RGB u8", "CMYK float" or "CIE Lab u16".
  */
-Babl *       babl_format    (const char *name);
+const Babl * babl_format    (const char *name);
 
 /*  Create a babl fish capable of converting from source_format to
  *  destination_format, source and destination can be either strings
  *  with the names of the formats or Babl-format objects.
  */
-Babl *       babl_fish      (const void *source_format,
+const Babl * babl_fish      (const void *source_format,
                              const void *destination_format);
 
 /** Process n pixels from source to destination using babl_fish,
  *  returns number of pixels converted.
  */
-long         babl_process   (Babl *babl_fish,
+long         babl_process   (const Babl *babl_fish,
                              const void *source,
                              void *destination,
                              long  n);
@@ -113,7 +113,7 @@ int          babl_format_get_n_components      (const Babl *format);
  * Returns the type in the given @format for the given
  * @component_index.
  */
-Babl *       babl_format_get_type              (const Babl *format,
+const Babl * babl_format_get_type              (const Babl *format,
                                                 int         component_index);
 
 
@@ -128,7 +128,7 @@ Babl *       babl_format_get_type              (const Babl *format,
  *                          ["max_val", double max_val,]
  *                          NULL);
  */
-Babl * babl_type_new       (void *first_arg,
+const Babl * babl_type_new (void *first_arg,
                             ...) BABL_ARG_NULL_TERMINATED;
 
 /**
@@ -137,8 +137,8 @@ Babl * babl_type_new       (void *first_arg,
  *     babl_component_new  (const char *name,
  *                          NULL);
  */
-Babl * babl_component_new  (void *first_arg,
-                            ...) BABL_ARG_NULL_TERMINATED;
+const Babl * babl_component_new  (void *first_arg,
+                                  ...) BABL_ARG_NULL_TERMINATED;
 
 /**
  * Defines a new color model in babl. If no name is provided a name is
@@ -149,7 +149,7 @@ Babl * babl_component_new  (void *first_arg,
  *                          [BablComponent *componentN, ...]
  *                          NULL);
  */
-Babl * babl_model_new      (void *first_arg,
+const Babl * babl_model_new (void *first_arg,
                             ...) BABL_ARG_NULL_TERMINATED;
 
 /**
@@ -169,8 +169,8 @@ Babl * babl_model_new      (void *first_arg,
  *                          ["planar",]
  *                          NULL);
  */
-Babl * babl_format_new     (void *first_arg,
-                            ...) BABL_ARG_NULL_TERMINATED;
+const Babl * babl_format_new (const void *first_arg,
+                              ...) BABL_ARG_NULL_TERMINATED;
 
 /*
  * Defines a new pixel format in babl. With the specified data storage
@@ -178,14 +178,14 @@ Babl * babl_format_new     (void *first_arg,
  * conversions are only well defined to other babl_format_n derived formats
  * with the same number of components.
  */
-Babl *
-babl_format_n (Babl *type,
+const Babl *
+babl_format_n (const Babl *type,
                int   components);
 
 /**
  * Returns whether the @format is a format_n type.
  */
-int babl_format_is_format_n (Babl *format);
+int babl_format_is_format_n (const Babl *format);
 
 /**
  * Defines a new conversion between either two formats, two models or
@@ -197,30 +197,30 @@ int babl_format_is_format_n (Babl *format);
  *                          <"linear"|"planar">, <BablFuncLinear | BablFuncPlanar> conv_func,
  *                          NULL);
  */
-Babl * babl_conversion_new (void *first_arg,
-                            ...) BABL_ARG_NULL_TERMINATED;
+const Babl * babl_conversion_new (const void *first_arg,
+                                  ...) BABL_ARG_NULL_TERMINATED;
 
 /**
  * create a new palette based format, name is optional pass in NULL to get
  * an anonymous format. If you pass in with_alpha the format also gets
  * an 8bit alpha channel.
  */
-void babl_new_palette (const char *name, Babl **format_u8,
-                                         Babl **format_u8_with_alpha);
+void babl_new_palette (const char *name, const Babl **format_u8,
+                                         const Babl **format_u8_with_alpha);
 
 /**
  * Assign a palette to a palette format, the data is a single span of pixels
  * representing the colors of the palette.
  */
-void  babl_palette_set_palette (Babl              *babl,
-                                Babl              *format,
+void  babl_palette_set_palette (const Babl        *babl,
+                                const Babl        *format,
                                 void              *data,
                                 int                count);
 
 /**
  * reset a palette to initial state.
  */
-void  babl_palette_reset       (Babl              *babl);
+void  babl_palette_reset       (const Babl        *babl);
 
 
 /**
@@ -228,12 +228,12 @@ void  babl_palette_reset       (Babl              *babl);
  * used from the conversion functions, encoding color profiles, palettes or
  * similar with the data.
  */
-void   babl_set_user_data     (Babl *babl, void *data);
+void   babl_set_user_data     (const Babl *babl, void *data);
 
 /**
  * get data set with babl_set_user_data
  */
-void * babl_get_user_data     (Babl *babl);
+void * babl_get_user_data     (const Babl *babl);