WP Get terms by post type

wp-get-terms-by-post-type

function ff_get_terms_by_post_type( $taxonomies, $args=array() ){
	$args = wp_parse_args($args);
	if( !empty($args['post_types']) ){
		$args['post_types'] = (array) $args['post_types'];
		add_filter( 'terms_clauses', 'ff_get_terms_by_post_type_filter',10,3);
	}
	return get_terms($taxonomies, $args);           
}
function ff_get_terms_by_post_type_filter($pieces, $tax, $args) {
	global $wpdb;
	$pieces['fields'] .=", COUNT(*) " ;
	// Join extra tables to restrict by post type
	$pieces['join'] .=" INNER JOIN $wpdb->term_relationships AS r ON r.term_taxonomy_id = tt.term_taxonomy_id INNER JOIN $wpdb->posts AS p ON p.ID = r.object_id ";

	// Restrict by post type and group by term_id
	$post_types_str = implode(',',$args['post_types']);
	$pieces['where'].= $wpdb->prepare(" AND p.post_type IN(%s) GROUP BY t.term_id", $post_types_str);

	remove_filter( current_filter(), __FUNCTION__ );
	return $pieces;
}

usage:
$regions = ff_get_terms_by_post_type('region', array(
'orderby' => 'name',
'post_types' =>array('post_type_1', 'post_type_2'),
));