x property

@override BigInt get x

Get the x-coordinate of this point in the projective elliptic curve coordinates.

Implementation

@override
BigInt get x {
  /// Extract the x-coordinate and z-coordinate from the point's coordinates.
  final xCoordinate = _coords[0];
  final zCoordinate = _coords[2];

  /// If z-coordinate is one, return the x-coordinate as it is.
  if (zCoordinate == BigInt.one) {
    return xCoordinate;
  }

  /// Get the prime field modulus from the curve.
  final p = curve.p;

  /// Calculate the inverse of z-coordinate modulo p.
  final zInverse = BigintUtils.inverseMod(zCoordinate, p);

  /// Compute and return the x-coordinate in projective coordinates.
  final result = (xCoordinate * zInverse * zInverse) % p;
  return result;
}