How can I calculate the public address if I only have the private key with PHP only?

For example I have
5K2YUVmWfxbmvsNxCsfvArXdGXm7d5DC9pn4yD75k2UaSYgkXTh
and want
1HKqKTMpBTZZ8H5zcqYEWYBaaWELrDEXeE

Does anyone have a working PHP code without using bitcoind or any other API/tools?