com.horstmann.violet.framework
Class Direction

java.lang.Object
  com.horstmann.violet.framework.Direction

public class Direction
extends java.lang.Object

This class describes a direction in the 2D plane. A direction is a vector of length 1 with an angle between 0 (inclusive) and 360 degrees (exclusive). There is also a degenerate direction of length 0.

Field Summary

static Direction	EAST
static Direction	NORTH
static Direction	SOUTH
static Direction	WEST

Constructor Summary

Direction(double dx, double dy)
Constructs a direction (normalized to length 1).

Direction(java.awt.geom.Point2D p, java.awt.geom.Point2D q)
Constructs a direction between two points

Method Summary

double	getX() Gets the x-component of this direction
double	getY() Gets the y-component of this direction
Direction	turn(double angle) Turns this direction by an angle.

Methods inherited from class java.lang.Object

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

Field Detail

NORTH

public static final Direction NORTH

SOUTH

public static final Direction SOUTH

EAST

public static final Direction EAST

WEST

public static final Direction WEST

Constructor Detail

Direction

public Direction(double dx,
                 double dy)

Constructs a direction (normalized to length 1).

Parameters:

dx - the x-value of the direction

dy - the corresponding y-value of the direction

Direction

public Direction(java.awt.geom.Point2D p,
                 java.awt.geom.Point2D q)

Constructs a direction between two points

Parameters:

p - the starting point

q - the ending point

Method Detail

turn

public Direction turn(double angle)

Turns this direction by an angle.

Parameters:

angle - the angle in degrees

getX

public double getX()

Gets the x-component of this direction

Returns:

the x-component (between -1 and 1)

getY

public double getY()

Gets the y-component of this direction

Returns:

the y-component (between -1 and 1)