[gnome-photos/wip/rishi/double-buffering: 3/12] utils: Add photos_utils_dup_buffer_from_node

[Debarshi Ray <debarshir src gnome org>]

commit ca8d50a9f4461994f69822ebf51540eb480e1f45
Author: Debarshi Ray <debarshir gnome org>
Date:   Tue Jan 17 12:31:19 2017 +0100

    utils: Add photos_utils_dup_buffer_from_node
    
    Unlike photos_utils_get_buffer_from_node, this won't just return a new
    reference on the GeglNode's output buffer. Instead, the buffer will be
    copied and have copy-on-write tiles.

 src/photos-utils.c |   24 ++++++++++++++++++++++++
 src/photos-utils.h |    3 +++
 2 files changed, 27 insertions(+), 0 deletions(-)
---
diff --git a/src/photos-utils.c b/src/photos-utils.c
index 86db6c4..dbee5cb 100644
--- a/src/photos-utils.c
+++ b/src/photos-utils.c
@@ -843,6 +843,30 @@ photos_utils_draw_rectangle_thirds (cairo_t *cr, gdouble x, gdouble y, gdouble w
 }
 
 
+GeglBuffer *
+photos_utils_dup_buffer_from_node (GeglNode *node, const Babl *format)
+{
+  GeglBuffer *buffer;
+  GeglRectangle bbox;
+  gint64 end;
+  gint64 start;
+
+  g_return_val_if_fail (GEGL_IS_NODE (node), NULL);
+
+  bbox = gegl_node_get_bounding_box (node);
+  buffer = gegl_buffer_new (&bbox, format);
+
+  start = g_get_monotonic_time ();
+
+  gegl_node_blit_buffer (node, buffer, &bbox, 0, GEGL_ABYSS_NONE);
+
+  end = g_get_monotonic_time ();
+  photos_debug (PHOTOS_DEBUG_GEGL, "Utils: Dup Buffer from Node: %" G_GINT64_FORMAT, end - start);
+
+  return buffer;
+}
+
+
 void
 photos_utils_ensure_builtins (void)
 {
diff --git a/src/photos-utils.h b/src/photos-utils.h
index 26a5db1..a9810f5 100644
--- a/src/photos-utils.h
+++ b/src/photos-utils.h
@@ -28,6 +28,7 @@
 #ifndef PHOTOS_UTILS_H
 #define PHOTOS_UTILS_H
 
+#include <babl/babl.h>
 #include <cairo.h>
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <gegl.h>
@@ -117,6 +118,8 @@ void             photos_utils_draw_rectangle_thirds       (cairo_t *cr,
                                                            gdouble width,
                                                            gdouble height);
 
+GeglBuffer      *photos_utils_dup_buffer_from_node        (GeglNode *node, const Babl *format);
+
 void             photos_utils_ensure_builtins             (void);
 
 void             photos_utils_ensure_extension_points     (void);