1 files changed, 110 insertions, 0 deletions
diff --git a/app/core/gimpdrawable-shadow.c b/app/core/gimpdrawable-shadow.c
new file mode 100644
index 0000000..4c42655
--- /dev/null
+++ b/app/core/gimpdrawable-shadow.c
@@ -0,0 +1,110 @@
+/* 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 <gdk-pixbuf/gdk-pixbuf.h>
+#include <gegl.h>
+#include <cairo.h>
+
+#include "core-types.h"
+
+#include "gegl/gimp-gegl-utils.h"
+
+#include "gimpdrawable.h"
+#include "gimpdrawable-private.h"
+#include "gimpdrawable-shadow.h"
+
+
+GeglBuffer *
+gimp_drawable_get_shadow_buffer (GimpDrawable *drawable)
+{
+  GimpItem   *item;
+  gint        width;
+  gint        height;
+  const Babl *format;
+
+  g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
+
+  item = GIMP_ITEM (drawable);
+
+  width  = gimp_item_get_width  (item);
+  height = gimp_item_get_height (item);
+  format = gimp_drawable_get_format (drawable);
+
+  if (drawable->private->shadow)
+    {
+      if ((width  != gegl_buffer_get_width  (drawable->private->shadow)) ||
+          (height != gegl_buffer_get_height (drawable->private->shadow)) ||
+          (format != gegl_buffer_get_format (drawable->private->shadow)))
+        {
+          gimp_drawable_free_shadow_buffer (drawable);
+        }
+      else
+        {
+          return drawable->private->shadow;
+        }
+    }
+
+  drawable->private->shadow = gegl_buffer_new (GEGL_RECTANGLE (0, 0,
+                                                               width, height),
+                                               format);
+
+  return drawable->private->shadow;
+}
+
+void
+gimp_drawable_free_shadow_buffer (GimpDrawable *drawable)
+{
+  g_return_if_fail (GIMP_IS_DRAWABLE (drawable));
+
+  g_clear_object (&drawable->private->shadow);
+}
+
+void
+gimp_drawable_merge_shadow_buffer (GimpDrawable *drawable,
+                                   gboolean      push_undo,
+                                   const gchar  *undo_desc)
+{
+  gint x, y;
+  gint width, height;
+
+  g_return_if_fail (GIMP_IS_DRAWABLE (drawable));
+  g_return_if_fail (gimp_item_is_attached (GIMP_ITEM (drawable)));
+  g_return_if_fail (GEGL_IS_BUFFER (drawable->private->shadow));
+
+  /*  A useful optimization here is to limit the update to the
+   *  extents of the selection mask, as it cannot extend beyond
+   *  them.
+   */
+  if (gimp_item_mask_intersect (GIMP_ITEM (drawable), &x, &y, &width, &height))
+    {
+      GeglBuffer *buffer = g_object_ref (drawable->private->shadow);
+
+      gimp_drawable_apply_buffer (drawable, buffer,
+                                  GEGL_RECTANGLE (x, y, width, height),
+                                  push_undo, undo_desc,
+                                  GIMP_OPACITY_OPAQUE,
+                                  GIMP_LAYER_MODE_REPLACE,
+                                  GIMP_LAYER_COLOR_SPACE_AUTO,
+                                  GIMP_LAYER_COLOR_SPACE_AUTO,
+                                  GIMP_LAYER_COMPOSITE_AUTO,
+                                  NULL, x, y);
+
+      g_object_unref (buffer);
+    }
+}