[gegl] point-coposer3: skip some multi-threading for opaque buffers

[Øyvind Kolås <ok src gnome org>]

commit 32949ae63ed2f1361782d8088a277f854603865c
Author: Massimo Valentini <mvalentini src gnome org>
Date:   Sat Jan 9 20:07:32 2016 +0100

    point-coposer3: skip some multi-threading for opaque buffers
    
    Patch from:
      https://bugzilla.gnome.org/show_bug.cgi?id=760372

 gegl/operation/gegl-operation-point-composer3.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/gegl/operation/gegl-operation-point-composer3.c b/gegl/operation/gegl-operation-point-composer3.c
index 1c6242e..450a888 100644
--- a/gegl/operation/gegl-operation-point-composer3.c
+++ b/gegl/operation/gegl-operation-point-composer3.c
@@ -257,6 +257,12 @@ gegl_operation_point_composer3_process (GeglOperation       *operation,
 
         if (input)
         {
+          if (! babl_format_has_alpha (in_buf_format))
+            {
+              in_buf_format = in_format;
+              in_buf_bpp = in_bpp;
+            }
+
           read = gegl_buffer_iterator_add (i, input, result, level, in_buf_format, GEGL_ACCESS_READ, 
GEGL_ABYSS_NONE);
           for (gint j = 0; j < threads; j ++)
           {
@@ -276,6 +282,12 @@ gegl_operation_point_composer3_process (GeglOperation       *operation,
             thread_data[j].input_fish = NULL;
         if (aux)
         {
+          if (! babl_format_has_alpha (aux_buf_format))
+            {
+              aux_buf_format = aux_format;
+              aux_buf_bpp = aux_bpp;
+            }
+
           foo = gegl_buffer_iterator_add (i, aux, result, level, aux_buf_format,
                                           GEGL_ACCESS_READ, GEGL_ABYSS_NONE);
           for (gint j = 0; j < threads; j ++)
@@ -298,6 +310,12 @@ gegl_operation_point_composer3_process (GeglOperation       *operation,
         }
         if (aux2)
         {
+          if (! babl_format_has_alpha (aux2_buf_format))
+            {
+              aux2_buf_format = aux2_format;
+              aux2_buf_bpp = aux2_bpp;
+            }
+
           bar = gegl_buffer_iterator_add (i, aux2, result, level, aux2_buf_format,
                                           GEGL_ACCESS_READ, GEGL_ABYSS_NONE);
           for (gint j = 0; j < threads; j ++)