polyfrombytes function
Deserializes a polynomial from a byte array using 12-bit encoding.
Implementation
Poly polyfrombytes(Uint8List r) {
Poly a = Poly();
for (int i = 0; i < KYBER_N ~/ 2; i++) {
int t0 = r[3 * i + 0] | ((r[3 * i + 1] & 0x0F) << 8);
int t1 = (r[3 * i + 1] >> 4) | (r[3 * i + 2] << 4);
a.coeffs[2 * i] = t0;
a.coeffs[2 * i + 1] = t1;
}
return a;
}