[gimp/soc-2011-seamless-clone2] app: sense the input format in gimp:mask-components

[Clayton Walker <claytonw src gnome org>]

commit 85c9b6c98baf4bf3ef1150bb86437afb0d3e62ac
Author: Michael Natterer <mitch gimp org>
Date:   Fri Apr 26 23:29:03 2013 +0200

    app: sense the input format in gimp:mask-components
    
    because it can work on RGBA and R'G'B'A without conversions.

 app/operations/gimpoperationmaskcomponents.c |   22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)
---
diff --git a/app/operations/gimpoperationmaskcomponents.c b/app/operations/gimpoperationmaskcomponents.c
index 1df1b58..036ad5b 100644
--- a/app/operations/gimpoperationmaskcomponents.c
+++ b/app/operations/gimpoperationmaskcomponents.c
@@ -143,9 +143,25 @@ gimp_operation_mask_components_set_property (GObject      *object,
 static void
 gimp_operation_mask_components_prepare (GeglOperation *operation)
 {
-  gegl_operation_set_format (operation, "input",  babl_format ("RGBA float"));
-  gegl_operation_set_format (operation, "aux",    babl_format ("RGBA float"));
-  gegl_operation_set_format (operation, "output", babl_format ("RGBA float"));
+  const Babl *format = gegl_operation_get_source_format (operation, "input");
+
+  if (format)
+    {
+      const Babl *model = babl_format_get_model (format);
+
+      if (model == babl_model ("R'G'B'A"))
+        format = babl_format ("R'G'B'A float");
+      else
+        format = babl_format ("RGBA float");
+    }
+  else
+    {
+      format = babl_format ("RGBA float");
+    }
+
+  gegl_operation_set_format (operation, "input",  format);
+  gegl_operation_set_format (operation, "aux",    format);
+  gegl_operation_set_format (operation, "output", format);
 }
 
 static gboolean