ParagonIE_Sodium_Core_Ristretto255::ristretto255_add( string $p, string $q ): string

378    public static function ristretto255_add($p, $q)379    {380        $p_res = self::ristretto255_frombytes($p);381        $q_res = self::ristretto255_frombytes($q);382        if ($p_res['res'] !== 0 || $q_res['res'] !== 0) {383            throw new SodiumException('Could not add points');384        }385        $p_p3 = $p_res['h'];386        $q_p3 = $q_res['h'];387        $q_cached = self::ge_p3_to_cached($q_p3);388        $r_p1p1 = self::ge_add($p_p3, $q_cached);389        $r_p3 = self::ge_p1p1_to_p3($r_p1p1);390        return self::ristretto255_p3_tobytes($r_p3);391    }