package us.bannister.encoders;

public class EncoderUTF8 {
    public byte[] buffer;
    public int size;
    public EncoderUTF8(int n) {
        buffer = new byte[n];
    }
    public void encode(String s) {
        int i = size;
        for (char c : s.toCharArray()) {
            int v = 255 & c;
            if (v < 0x80) {
                buffer[i++] = (byte) v;
            } else if (v < 0x800) {
                buffer[i++] = (byte) (0xC0 | (v >> 6));
                buffer[i++] = (byte) (0x80 | (63 & v));
            } else if (v < 0x10000) {
                buffer[i++] = (byte) (0xE0 | (v >> 12));
                buffer[i++] = (byte) (0x80 | (63 & (v >> 6)));
                buffer[i++] = (byte) (0x80 | (63 & v));
            } else {
                buffer[i++] = (byte) (0xF0 | (v >> 18));
                buffer[i++] = (byte) (0x80 | (63 & (v >> 12)));
                buffer[i++] = (byte) (0x80 | (63 & (v >> 6)));
                buffer[i++] = (byte) (0x80 | (63 & v));
            }
        }
        size = i;
    }
}