BarcodeGenerator::codabar_encode

private function codabar_encode($data) {
	$data = strtoupper(preg_replace(
		'/[^0-9ABCDENTabcdent*./:+$-]/', '', $data
	));
	$blocks = array();
	for ($i = 0, $n = strlen($data); $i < $n; $i++) {
		if ($blocks) {
			$blocks[] = array(
				'm' => array(array(0, 1, 3))
			);
		}
		$char = substr($data, $i, 1);
		$block = $this->codabar_alphabet[$char];
		$blocks[] = array(
			'm' => array(
				array(1, 1, $block[0]),
				array(0, 1, $block[1]),
				array(1, 1, $block[2]),
				array(0, 1, $block[3]),
				array(1, 1, $block[4]),
				array(0, 1, $block[5]),
				array(1, 1, $block[6]),
			),
			'l' => array($char)
		);
	}
	return array('g' => 'l', 'b' => $blocks);
}