[gimp] app: use compositing format for fill buffer

[Ell <ell src gnome org>]

commit 245a17c79f81413a47d9df309b20af46e8f15c44
Author: Ell <ell_se yahoo com>
Date:   Wed Mar 27 12:33:21 2019 -0400

    app: use compositing format for fill buffer
    
    Add gimp_fill_options_get_format(), which returns the format to be
    used for the fill buffer; this is the same format used during
    compositing.  Use this format in gimp_fill_options_create_buffer(),
    instead of the drawable format.
    
    This fixes the result of fill operations when the fill color/
    pattern is not representable in the drawable format, and speeds up
    color fills by avoiding color-conversion for the fill buffer during
    processing.

 app/core/gimpfilloptions.c | 21 ++++++++++++++++++++-
 app/core/gimpfilloptions.h |  3 +++
 2 files changed, 23 insertions(+), 1 deletion(-)
---
diff --git a/app/core/gimpfilloptions.c b/app/core/gimpfilloptions.c
index 95398fb900..6c232ce906 100644
--- a/app/core/gimpfilloptions.c
+++ b/app/core/gimpfilloptions.c
@@ -29,6 +29,8 @@
 
 #include "core-types.h"
 
+#include "operations/layer-modes/gimp-layer-modes.h"
+
 #include "gimp.h"
 #include "gimp-palettes.h"
 #include "gimpdrawable.h"
@@ -404,6 +406,23 @@ gimp_fill_options_get_undo_desc (GimpFillOptions *options)
   g_return_val_if_reached (NULL);
 }
 
+const Babl *
+gimp_fill_options_get_format (GimpFillOptions *options,
+                              GimpDrawable    *drawable)
+{
+  GimpContext *context;
+
+  g_return_val_if_fail (GIMP_IS_FILL_OPTIONS (options), NULL);
+  g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
+
+  context = GIMP_CONTEXT (options);
+
+  return gimp_layer_mode_get_format (gimp_context_get_paint_mode (context),
+                                     GIMP_LAYER_COLOR_SPACE_AUTO,
+                                     GIMP_LAYER_COLOR_SPACE_AUTO,
+                                     gimp_drawable_get_format (drawable));
+}
+
 GeglBuffer *
 gimp_fill_options_create_buffer (GimpFillOptions     *options,
                                  GimpDrawable        *drawable,
@@ -422,7 +441,7 @@ gimp_fill_options_create_buffer (GimpFillOptions     *options,
   g_return_val_if_fail (rect != NULL, NULL);
 
   buffer = gegl_buffer_new (rect,
-                            gimp_drawable_get_format_with_alpha (drawable));
+                            gimp_fill_options_get_format (options, drawable));
 
   gimp_fill_options_fill_buffer (options, drawable, buffer,
                                  pattern_offset_x, pattern_offset_y);
diff --git a/app/core/gimpfilloptions.h b/app/core/gimpfilloptions.h
index d8dcfa4ba5..2d183a129f 100644
--- a/app/core/gimpfilloptions.h
+++ b/app/core/gimpfilloptions.h
@@ -71,6 +71,9 @@ gboolean          gimp_fill_options_set_by_fill_mode (GimpFillOptions     *optio
 
 const gchar     * gimp_fill_options_get_undo_desc    (GimpFillOptions     *options);
 
+const Babl      * gimp_fill_options_get_format       (GimpFillOptions     *options,
+                                                      GimpDrawable        *drawable);
+
 GeglBuffer      * gimp_fill_options_create_buffer    (GimpFillOptions     *options,
                                                       GimpDrawable        *drawable,
                                                       const GeglRectangle *rect,