Thumbnail destinations with page structure

config.php

<?php

c::set('thumbs.destination', function($thumb) {

  $page     = $thumb->source->page();
  $filename = $thumb->source->name() . '-' . $thumb->settingsIdentifier() . '.' . $thumb->source->extension();
  $root     = $thumb->options['root'] . DS . str_replace('/', DS, $page->uri()) . DS . $filename;
  $url      = $thumb->options['url'] . '/' . $page->uri() . '/' . $filename;

  // create the directory
  dir::make(dirname($root));

  return new Obj(array(
    'url'  => $url,
    'root' => $root
  ));

});