[gimp/goat-invasion] app: add gimp_bpp_to_babl_format_with_alpha()

[Michael Natterer <mitch src gnome org>]

commit 70229d93fb5ed2de11c2fd9a2366d7d3fc15c69d
Author: Michael Natterer <mitch gimp org>
Date:   Sun Mar 18 15:00:08 2012 +0100

    app: add gimp_bpp_to_babl_format_with_alpha()

 app/gegl/gimp-gegl-utils.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 app/gegl/gimp-gegl-utils.h |   24 +++++++++++++-----------
 2 files changed, 57 insertions(+), 11 deletions(-)
---
diff --git a/app/gegl/gimp-gegl-utils.c b/app/gegl/gimp-gegl-utils.c
index f34eeeb..616e111 100644
--- a/app/gegl/gimp-gegl-utils.c
+++ b/app/gegl/gimp-gegl-utils.c
@@ -78,6 +78,50 @@ gimp_bpp_to_babl_format (guint    bpp,
   return NULL;
 }
 
+/**
+ * gimp_bpp_to_babl_format_with_alpha:
+ * @bpp: bytes per pixel
+ * @linear: whether the pixels are linear or gamma-corrected.
+ *
+ * Return the Babl format to use for a given number of bytes per pixel.
+ * This function assumes that the data is 8bit.
+ *
+ * Return value: the Babl format to use
+ **/
+const Babl *
+gimp_bpp_to_babl_format_with_alpha (guint    bpp,
+                                    gboolean linear)
+{
+  g_return_val_if_fail (bpp > 0 && bpp <= 4, NULL);
+
+  if (linear)
+    {
+      switch (bpp)
+        {
+        case 1:
+        case 2:
+          return babl_format ("YA u8");
+        case 3:
+        case 4:
+          return babl_format ("RGBA u8");
+        }
+    }
+  else
+    {
+      switch (bpp)
+        {
+        case 1:
+        case 2:
+          return babl_format ("Y'A u8");
+        case 3:
+        case 4:
+          return babl_format ("R'G'B'A u8");
+        }
+    }
+
+  return NULL;
+}
+
 const gchar *
 gimp_layer_mode_to_gegl_operation (GimpLayerModeEffects mode)
 {
diff --git a/app/gegl/gimp-gegl-utils.h b/app/gegl/gimp-gegl-utils.h
index ba69f65..4956fbe 100644
--- a/app/gegl/gimp-gegl-utils.h
+++ b/app/gegl/gimp-gegl-utils.h
@@ -25,21 +25,23 @@
 #include <gdk-pixbuf/gdk-pixbuf.h> /* temp hack */
 
 
-const Babl  * gimp_bpp_to_babl_format           (guint                  bpp,
-                                                 gboolean               linear) G_GNUC_CONST;
+const Babl  * gimp_bpp_to_babl_format            (guint                  bpp,
+                                                  gboolean               linear) G_GNUC_CONST;
+const Babl  * gimp_bpp_to_babl_format_with_alpha (guint                  bpp,
+                                                  gboolean               linear) G_GNUC_CONST;
 
-const gchar * gimp_layer_mode_to_gegl_operation (GimpLayerModeEffects   mode) G_GNUC_CONST;
-const gchar * gimp_interpolation_to_gegl_filter (GimpInterpolationType  interpolation) G_GNUC_CONST;
+const gchar * gimp_layer_mode_to_gegl_operation  (GimpLayerModeEffects   mode) G_GNUC_CONST;
+const gchar * gimp_interpolation_to_gegl_filter  (GimpInterpolationType  interpolation) G_GNUC_CONST;
 
-GeglBuffer  * gimp_tile_manager_create_buffer   (TileManager           *tm,
-                                                 const Babl            *format,
-                                                 gboolean               write);
-GeglBuffer  * gimp_pixbuf_create_buffer         (GdkPixbuf             *pixbuf);
+GeglBuffer  * gimp_tile_manager_create_buffer    (TileManager           *tm,
+                                                  const Babl            *format,
+                                                  gboolean               write);
+GeglBuffer  * gimp_pixbuf_create_buffer          (GdkPixbuf             *pixbuf);
 
-void          gimp_gegl_buffer_refetch_tiles    (GeglBuffer            *buffer);
+void          gimp_gegl_buffer_refetch_tiles     (GeglBuffer            *buffer);
 
-void          gimp_gegl_color_set_rgba          (GeglColor     *color,
-                                                 const GimpRGB *rgb);
+void          gimp_gegl_color_set_rgba           (GeglColor             *color,
+                                                  const GimpRGB         *rgb);
 
 
 #endif /* __GIMP_GEGL_UTILS_H__ */