fprintf(stderr, "extends: %d %d -> %d %d (%d rects)\n",
region.extends.left(), region.extends.top(),
region.extends.right(), region.extends.bottom(), region.rects.size());
fprintf(stderr, "extends: %d %d -> %d %d (%d rects)\n",
region.extends.left(), region.extends.top(),
region.extends.right(), region.extends.bottom(), region.rects.size());