[gimp/gimp-2-10] app: with recent gegl:watershed-transform, no need for intermediate...

[Jehan <jehanp src gnome org>]

commit 687d058416f0e10f09e2dd4e4403d2ec0b80cc6c
Author: Jehan <jehan girinstud io>
Date:   Fri Oct 26 13:15:50 2018 +0200

    app: with recent gegl:watershed-transform, no need for intermediate...
    
    ... labels buffer.
    We can watershed directly the mask buffer being correctly flagged.
    This commit relies on merge request gegl!8 being accepted and merged.
    
    (cherry picked from commit e905ea7ba2c348515816c28747f1c8008cf6b143)

 app/core/gimppickable-contiguous-region.c | 73 ++++++++++++-------------------
 1 file changed, 28 insertions(+), 45 deletions(-)
---
diff --git a/app/core/gimppickable-contiguous-region.c b/app/core/gimppickable-contiguous-region.c
index 7ad4b78716..193b661b83 100644
--- a/app/core/gimppickable-contiguous-region.c
+++ b/app/core/gimppickable-contiguous-region.c
@@ -116,6 +116,7 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable        *pickable,
   gboolean       has_alpha;
   gfloat         start_col[MAX_CHANNELS];
   gboolean       smart_line_art = FALSE;
+  gfloat         flag = 2.0;
 
   g_return_val_if_fail (GIMP_IS_PICKABLE (pickable), NULL);
 
@@ -225,7 +226,6 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable        *pickable,
        * unknown pixels be labelled by flooding through watershed.
        */
       GeglBufferIterator *gi;
-      GeglBuffer         *labels;
       GeglBuffer         *distmap;
       GeglBuffer         *tmp;
       GeglNode           *graph;
@@ -235,47 +235,6 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable        *pickable,
       GeglNode           *sink;
 
       GIMP_TIMER_START();
-      labels = gegl_buffer_new (&extent, babl_format ("YA u32"));
-
-      gi = gegl_buffer_iterator_new (src_buffer, NULL, 0, NULL,
-                                     GEGL_ACCESS_READ, GEGL_ABYSS_NONE, 3);
-      gegl_buffer_iterator_add (gi, mask_buffer, NULL, 0,
-                                babl_format ("Y float"),
-                                GEGL_ACCESS_READ, GEGL_ABYSS_NONE);
-      gegl_buffer_iterator_add (gi, labels, NULL, 0,
-                                babl_format ("YA u32"),
-                                GEGL_ACCESS_WRITE, GEGL_ABYSS_NONE);
-
-      while (gegl_buffer_iterator_next (gi))
-        {
-          guchar  *lineart = (guchar*) gi->items[0].data;
-          gfloat  *mask    = (gfloat*) gi->items[1].data;
-          guint32 *label   = (guint32*) gi->items[2].data;
-          gint    k;
-
-          for (k = 0; k < gi->length; k++)
-            {
-              if (*mask)
-                {
-                  label[0] = G_MAXUINT32;
-                  label[1] = 1;
-                }
-              else if (*lineart)
-                {
-                  label[0] = 0;
-                  label[1] = 0;
-                }
-              else
-                {
-                  label[0] = 0;
-                  label[1] = 1;
-                }
-              lineart++;
-              mask++;
-              label += 2;
-            }
-        }
-      g_object_unref (src_buffer);
 
       /* Compute a distance map for the labels. */
       graph = gegl_node_new ();
@@ -325,11 +284,34 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable        *pickable,
       g_object_unref (distmap);
       distmap = tmp;
 
-      /* Watershed the labels. */
+      /* Flag the mask on the line art. */
+      gi = gegl_buffer_iterator_new (src_buffer, NULL, 0, NULL,
+                                     GEGL_ACCESS_READ, GEGL_ABYSS_NONE, 2);
+      gegl_buffer_iterator_add (gi, mask_buffer, NULL, 0,
+                                babl_format ("Y float"),
+                                GEGL_ACCESS_READWRITE, GEGL_ABYSS_NONE);
+
+      while (gegl_buffer_iterator_next (gi))
+        {
+          guchar  *lineart = (guchar*) gi->items[0].data;
+          gfloat  *mask    = (gfloat*) gi->items[1].data;
+          gint    k;
+
+          for (k = 0; k < gi->length; k++)
+            {
+              if (*lineart && ! *mask)
+                *mask = flag;
+              lineart++;
+              mask++;
+            }
+        }
+      g_object_unref (src_buffer);
+
+      /* Watershed the line art. */
       graph = gegl_node_new ();
       input = gegl_node_new_child (graph,
                                    "operation", "gegl:buffer-source",
-                                   "buffer", labels,
+                                   "buffer", mask_buffer,
                                    NULL);
       aux = gegl_node_new_child (graph,
                                  "operation", "gegl:buffer-source",
@@ -337,6 +319,8 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable        *pickable,
                                  NULL);
       op  = gegl_node_new_child (graph,
                                  "operation", "gegl:watershed-transform",
+                                 "flag-component", 0,
+                                 "flag", &flag,
                                  NULL);
       sink  = gegl_node_new_child (graph,
                                    "operation", "gegl:buffer-sink",
@@ -354,7 +338,6 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable        *pickable,
 
       gegl_buffer_copy (tmp, NULL, GEGL_ABYSS_NONE, mask_buffer, NULL);
       g_object_unref (tmp);
-      g_object_unref (labels);
 
       GIMP_TIMER_END("watershed line art");
     }