org.deepsymmetry.beatlink

Class Util

java.lang.Object

org.deepsymmetry.beatlink.Util

public class Util
extends Object

Provides utility functions.

Author:

James Elliott

Method Summary

Modifier and Type	Method and Description
static long	addressToLong(InetAddress address) Converts the bytes that make up an internet address into the corresponding integer value to make it easier to perform bit-masking operations on them.
static long	bytesToNumber(byte[] buffer, int start, int length) Reconstructs a number that is represented by more than one byte in a network packet in big-endian order.
static double	pitchToMultiplier(long pitch) Convert a pitch value reported by a device to the corresponding multiplier (0.0 to 2.0, where normal, unadjusted pitch has the multiplier 1.0).
static double	pitchToPercentage(long pitch) Convert a pitch value reported by a device to the corresponding percentage (-100% to +100%, where normal, unadjusted pitch has the value 0%).
static boolean	sameNetwork(int prefixLength, InetAddress address1, InetAddress address2) Checks whether two internet addresses are on the same subnet.
static int	unsign(byte b) Converts a signed byte to its unsigned int equivalent in the range 0-255.
static boolean	validateHeader(DatagramPacket packet, int kind, String name) Check to see whether a packet starts with the standard header bytes, followed by a byte identifying it as the kind of packet that is expected.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

validateHeader

public static boolean validateHeader(DatagramPacket packet,
                                     int kind,
                                     String name)

Check to see whether a packet starts with the standard header bytes, followed by a byte identifying it as the kind of packet that is expected.

Parameters:

packet - a packet that has just been received

kind - the expected value of the eleventh byte, which seems to identify the packet type

name - the name of the kind of packet expected, for use in logging warnings if a mismatch is found

Returns:

true if the packet has the right header

unsign

public static int unsign(byte b)

Converts a signed byte to its unsigned int equivalent in the range 0-255.

Parameters:

b - a byte value to be considered an unsigned integer

Returns:

the unsigned version of the byte

bytesToNumber

public static long bytesToNumber(byte[] buffer,
                                 int start,
                                 int length)

Reconstructs a number that is represented by more than one byte in a network packet in big-endian order.

Parameters:

buffer - the byte array containing the packet data

start - the index of the first byte containing a numeric value

length - the number of bytes making up the value

Returns:

the reconstructed number

addressToLong

public static long addressToLong(InetAddress address)

Converts the bytes that make up an internet address into the corresponding integer value to make it easier to perform bit-masking operations on them.

Parameters:

address - an address whose integer equivalent is desired

Returns:

the integer corresponding to that address

sameNetwork

public static boolean sameNetwork(int prefixLength,
                                  InetAddress address1,
                                  InetAddress address2)

Checks whether two internet addresses are on the same subnet.

Parameters:

prefixLength - the number of bits within an address that identify the network

address1 - the first address to be compared

address2 - the second address to be compared

Returns:

true if both addresses share the same network bits

pitchToPercentage

public static double pitchToPercentage(long pitch)

Convert a pitch value reported by a device to the corresponding percentage (-100% to +100%, where normal, unadjusted pitch has the value 0%).

Parameters:

pitch - the reported device pitch

Returns:

the pitch as a percentage

pitchToMultiplier

public static double pitchToMultiplier(long pitch)

Convert a pitch value reported by a device to the corresponding multiplier (0.0 to 2.0, where normal, unadjusted pitch has the multiplier 1.0).

Parameters:

pitch - the reported device pitch

Returns:

the implied pitch multiplier