1 files changed, 150 insertions, 0 deletions
diff --git a/app/core/gimpdrawable-foreground-extract.c b/app/core/gimpdrawable-foreground-extract.c
new file mode 100644
index 0000000..5846363
--- /dev/null
+++ b/app/core/gimpdrawable-foreground-extract.c
@@ -0,0 +1,150 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gio/gio.h>
+#include <gegl.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+
+#include "libgimpbase/gimpbase.h"
+
+#include "core-types.h"
+
+#include "gegl/gimp-gegl-utils.h"
+
+#include "gimpchannel.h"
+#include "gimpdrawable.h"
+#include "gimpdrawable-foreground-extract.h"
+#include "gimpimage.h"
+#include "gimpprogress.h"
+
+#include "gimp-intl.h"
+
+
+/*  public functions  */
+
+GeglBuffer *
+gimp_drawable_foreground_extract (GimpDrawable      *drawable,
+                                  GimpMattingEngine  engine,
+                                  gint               global_iterations,
+                                  gint               levin_levels,
+                                  gint               levin_active_levels,
+                                  GeglBuffer        *trimap,
+                                  GimpProgress      *progress)
+{
+  GeglBuffer    *drawable_buffer;
+  GeglNode      *gegl;
+  GeglNode      *input_node;
+  GeglNode      *trimap_node;
+  GeglNode      *matting_node;
+  GeglNode      *output_node;
+  GeglBuffer    *buffer;
+  GeglProcessor *processor;
+  gdouble        value;
+  gint           off_x, off_y;
+
+  g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
+  g_return_val_if_fail (GEGL_IS_BUFFER (trimap), NULL);
+  g_return_val_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress), NULL);
+
+  progress = gimp_progress_start (progress, FALSE,
+                                  _("Computing alpha of unknown pixels"));
+
+  drawable_buffer = gimp_drawable_get_buffer (drawable);
+
+  gegl = gegl_node_new ();
+
+  trimap_node = gegl_node_new_child (gegl,
+                                     "operation", "gegl:buffer-source",
+                                     "buffer",    trimap,
+                                     NULL);
+  input_node = gegl_node_new_child (gegl,
+                                    "operation", "gegl:buffer-source",
+                                    "buffer",    drawable_buffer,
+                                    NULL);
+  output_node = gegl_node_new_child (gegl,
+                                     "operation", "gegl:buffer-sink",
+                                     "buffer",    &buffer,
+                                     "format",    NULL,
+                                     NULL);
+
+  if (engine == GIMP_MATTING_ENGINE_GLOBAL)
+    {
+      matting_node = gegl_node_new_child (gegl,
+                                          "operation",  "gegl:matting-global",
+                                          "iterations", global_iterations,
+                                          NULL);
+    }
+  else
+    {
+      matting_node = gegl_node_new_child (gegl,
+                                          "operation",     "gegl:matting-levin",
+                                          "levels",        levin_levels,
+                                          "active_levels", levin_active_levels,
+                                          NULL);
+    }
+
+  gimp_item_get_offset (GIMP_ITEM (drawable), &off_x, &off_y);
+
+  if (off_x || off_y)
+    {
+      GeglNode *pre;
+      GeglNode *post;
+
+      pre = gegl_node_new_child (gegl,
+                                 "operation", "gegl:translate",
+                                 "x", -1.0 * off_x,
+                                 "y", -1.0 * off_y,
+                                 NULL);
+      post = gegl_node_new_child (gegl,
+                                  "operation", "gegl:translate",
+                                  "x", 1.0 * off_x,
+                                  "y", 1.0 * off_y,
+                                  NULL);
+
+      gegl_node_connect_to (trimap_node,   "output", pre, "input");
+      gegl_node_connect_to (pre,  "output", matting_node, "aux");
+      gegl_node_link_many (input_node, matting_node, post, output_node, NULL);
+    }
+  else
+    {
+      gegl_node_connect_to (input_node,   "output",
+                            matting_node, "input");
+      gegl_node_connect_to (trimap_node,  "output",
+                            matting_node, "aux");
+      gegl_node_connect_to (matting_node, "output",
+                            output_node,  "input");
+    }
+
+  processor = gegl_node_new_processor (output_node, NULL);
+
+  while (gegl_processor_work (processor, &value))
+    {
+      if (progress)
+        gimp_progress_set_value (progress, value);
+    }
+
+  if (progress)
+    gimp_progress_end (progress);
+
+  g_object_unref (processor);
+
+  g_object_unref (gegl);
+
+  return buffer;
+}