/* gcc gegl-sampler-demystify.c $(pkg-config --cflags --libs gegl-0.4) */

#include <gegl.h>

gint
main (void)
{
  GeglBuffer *buffer;
  GeglNode *crop;
  GeglNode *graph;
  GeglNode *scale;
  GeglNode *src;
  GeglNode *sink;
  GeglRectangle bbox;

  gegl_init (NULL, NULL);

  graph = gegl_node_new ();
  src = gegl_node_new_child (graph,
                             "operation", "gegl:checkerboard",
                             "x", 8,
                             "y", 8,
                             NULL);
  crop = gegl_node_new_child (graph,
                              "operation", "gegl:crop",
                              "height", 16.0,
                              "width", 16.0,
                              NULL);
  scale = gegl_node_new_child (graph,
                               "operation", "gegl:scale-ratio",
                               "x", 0.5,
                               "y", 0.5,
                               NULL);
  sink = gegl_node_new_child (graph,
                              "operation", "gegl:buffer-sink",
                              NULL);

  gegl_node_link_many (src, crop, scale, sink, NULL);
  gegl_node_set (sink, "buffer", &buffer, NULL);

  gegl_node_process (sink);

  bbox = *gegl_buffer_get_extent (buffer);
  g_message ("buffer: (%d, %d), %dx%d", bbox.x, bbox.y, bbox.width, bbox.height);

  g_object_unref (buffer);
  g_object_unref (graph);
  gegl_exit ();

  return 0;
}