sink = gegl_node_new_child (ptn,"operation","gegl:buffer-sink","buffer", &sink_buffer,"format",NULL,NULL); gegl_node_link_many (src, opacity, sink,NULL); gegl_node_blit_buffer (sink,NULL,NULL,0, GEGL_ABYSS_NONE);if(out_format !=gegl_buffer_get_format(sink_buffer)) {printf("Go...