[gimp] app: add gimp_babl_component_format() and use it in GimpImage

[Michael Natterer <mitch src gnome org>]

commit 8a55b13577462667130ca86bd53f1bf9e0a5b0cb
Author: Michael Natterer <mitch gimp org>
Date:   Sun Apr 22 19:47:46 2012 +0200

    app: add gimp_babl_component_format() and use it in GimpImage

 app/core/gimpimage.c |   40 ++++++++++++++++++++++++++++++++------
 app/gegl/gimp-babl.c |   51 ++++++++++++++++++++++++++++++++++++++++++++++++++
 app/gegl/gimp-babl.h |    3 ++
 3 files changed, 87 insertions(+), 7 deletions(-)
---
diff --git a/app/core/gimpimage.c b/app/core/gimpimage.c
index 9ef7bbf..868c04e 100644
--- a/app/core/gimpimage.c
+++ b/app/core/gimpimage.c
@@ -1551,7 +1551,12 @@ gimp_image_get_mask_format (const GimpImage *image)
 {
   g_return_val_if_fail (GIMP_IS_IMAGE (image), NULL);
 
-  return babl_format ("Y u8");
+  switch (gimp_image_get_precision (image))
+    {
+    case GIMP_PRECISION_U8: return babl_format ("Y u8");
+    }
+
+  g_return_val_if_reached (NULL);
 }
 
 gint
@@ -2061,12 +2066,33 @@ gimp_image_get_component_format (const GimpImage *image,
 
   switch (channel)
     {
-    case GIMP_RED_CHANNEL:     return babl_format ("R' u8");
-    case GIMP_GREEN_CHANNEL:   return babl_format ("G' u8");
-    case GIMP_BLUE_CHANNEL:    return babl_format ("B' u8");
-    case GIMP_GRAY_CHANNEL:    return babl_format ("Y' u8");
-    case GIMP_INDEXED_CHANNEL: return babl_format ("Y' u8"); /* XXX: seems wrong */
-    case GIMP_ALPHA_CHANNEL:   return babl_format ("A u8");
+    case GIMP_RED_CHANNEL:
+      return gimp_babl_component_format (GIMP_RGB,
+                                         gimp_image_get_precision (image),
+                                         RED);
+
+    case GIMP_GREEN_CHANNEL:
+      return gimp_babl_component_format (GIMP_RGB,
+                                         gimp_image_get_precision (image),
+                                         GREEN);
+
+    case GIMP_BLUE_CHANNEL:
+      return gimp_babl_component_format (GIMP_RGB,
+                                         gimp_image_get_precision (image),
+                                         BLUE);
+
+    case GIMP_ALPHA_CHANNEL:
+      return gimp_babl_component_format (GIMP_RGB,
+                                         gimp_image_get_precision (image),
+                                         ALPHA);
+
+    case GIMP_GRAY_CHANNEL:
+      return gimp_babl_component_format (GIMP_GRAY,
+                                         gimp_image_get_precision (image),
+                                         GRAY);
+
+    case GIMP_INDEXED_CHANNEL:
+      return babl_format ("Y' u8"); /* XXX: seems wrong */
     }
 
   return NULL;
diff --git a/app/gegl/gimp-babl.c b/app/gegl/gimp-babl.c
index f7d3b1f..78a0717 100644
--- a/app/gegl/gimp-babl.c
+++ b/app/gegl/gimp-babl.c
@@ -206,3 +206,54 @@ gimp_babl_format (GimpImageBaseType  base_type,
 
   g_return_val_if_reached (NULL);
 }
+
+const Babl *
+gimp_babl_component_format (GimpImageBaseType base_type,
+                            GimpPrecision     precision,
+                            gint              index)
+{
+  switch (base_type)
+    {
+    case GIMP_RGB:
+      switch (precision)
+        {
+        case GIMP_PRECISION_U8:
+          switch (index)
+            {
+            case 0: return babl_format ("R' u8");
+            case 1: return babl_format ("G' u8");
+            case 2: return babl_format ("B' u8");
+            case 3: return babl_format ("A u8");
+            default:
+              break;
+            }
+
+        default:
+          break;
+        }
+      break;
+
+    case GIMP_GRAY:
+      switch (precision)
+        {
+        case GIMP_PRECISION_U8:
+          switch (index)
+            {
+            case 0: return babl_format ("Y' u8");
+            case 1: return babl_format ("A u8");
+            default:
+              break;
+            }
+
+        default:
+          break;
+        }
+      break;
+
+    case GIMP_INDEXED:
+      /* need to use the image's api for this */
+      break;
+    }
+
+  g_return_val_if_reached (NULL);
+}
diff --git a/app/gegl/gimp-babl.h b/app/gegl/gimp-babl.h
index 1a50b1d..efadeae 100644
--- a/app/gegl/gimp-babl.h
+++ b/app/gegl/gimp-babl.h
@@ -32,6 +32,9 @@ GimpPrecision       gimp_babl_format_get_precision  (const Babl        *format);
 const Babl        * gimp_babl_format                (GimpImageBaseType  base_type,
                                                      GimpPrecision      precision,
                                                      gboolean           with_alpha);
+const Babl        * gimp_babl_component_format      (GimpImageBaseType  base_type,
+                                                     GimpPrecision      precision,
+                                                     gint               index);
 
 
 #endif /* __GIMP_BABL_H__ */