public function appendPaddingBit(&$bstream)
{
$bits = $bstream->size();
$maxwords = weixin_qrcode_QRspec::getDataLength($this->version, $this->level);
$maxbits = $maxwords * 8;
if ($maxbits == $bits) {
return 0;
}
if ($maxbits - $bits < 5) {
return $bstream->appendNum($maxbits - $bits, 0);
}
$bits += 4;
$words = (int) (($bits + 7) / 8);
$padding = new weixin_qrcode_QRbitstream();
$ret = $padding->appendNum($words * 8 - $bits + 4, 0);
if ($ret < 0) {
return $ret;
}
$padlen = $maxwords - $words;
if ($padlen > 0) {
$padbuf = array();
for ($i = 0; $i < $padlen; $i++) {
$padbuf[$i] = $i & 1 ? 0x11 : 0xec;
}
$ret = $padding->appendBytes($padlen, $padbuf);
if ($ret < 0) {
return $ret;
}
}
$ret = $bstream->append($padding);
return $ret;
}
