render
Class Vec

java.lang.Object
  render.Vec

public class Vec

extends java.lang.Object

Provides functionality to manipulate vectors.

Constructor Summary

Vec()

Method Summary

static void	capLength(double[] vector, double maxLength) If vector's length is greater than maxLength, reduces it to that.
static void	copy(double[] src, double[] dst) Copies contents of the src vector to the dst vector.
static void	cross(double[] a, double[] b, double[] dst) Computes the cross-product of two vectors a and b and stores the result in dst.
static double	distance(double[] a, double[] b, double[] difference)
static double	dot(double[] a, double[] b) Computes the dot product of vectors a and b.
static boolean	equals(double[] a, double[] b)
static double	length(double[] vector)
static double	norm(double[] v) Computes the magnitude of the vector.
static void	normalize(double[] v) Normalizes vector v to unit-length.
static void	rotate(double[] dst, int axis, double angle) Rotates a vector about x or y or z axis
static void	scale(double[] vector, double length) Resizes vector to given length
static void	set(double[] dst, double x, double y, double z) Populates the dst vector with values x, y, z.
static void	zero(double[] a) Set all the entries to 0

Methods inherited from class java.lang.Object

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

Constructor Detail

Vec

public Vec()

Method Detail

normalize

public static void normalize(double[] v)

Normalizes vector v to unit-length.

Parameters:

v - a vector

norm

public static double norm(double[] v)

Computes the magnitude of the vector.

Parameters:

v - a vector

Returns:

the magnitude of vector v

dot

public static double dot(double[] a,
                         double[] b)

Computes the dot product of vectors a and b. Vectors a and b must be of the same length.

Parameters:

a - source vector

b - source vector

Returns:

the result of a dot b

cross

public static void cross(double[] a,
                         double[] b,
                         double[] dst)

Computes the cross-product of two vectors a and b and stores the result in dst. a, b, and dst must be 3 dimensional vectors.

Parameters:

a - source vector 1

b - source vector 2

dst - resulting vector from a cross b

copy

public static void copy(double[] src,
                        double[] dst)

Copies contents of the src vector to the dst vector. Both vectors must be of the same length.

Parameters:

src - original vector

dst - copy of original vector

equals

public static boolean equals(double[] a,
                             double[] b)

Returns:

true if entries are the same

set

public static void set(double[] dst,
                       double x,
                       double y,
                       double z)

Populates the dst vector with values x, y, z.

Parameters:

dst - vector to be populated

x - component 0

y - component 1

z - component 2

rotate

public static void rotate(double[] dst,
                          int axis,
                          double angle)

Rotates a vector about x or y or z axis

Parameters:

dst - vector to be rotated

axis - of rotation: 0=x, 1=y, 2=z

angle - in radians

capLength

public static void capLength(double[] vector,
                             double maxLength)

If vector's length is greater than maxLength, reduces it to that.

Parameters:

vector - vector to resize

maxLength - if vector is longer than this, resizes it to this.

scale

public static void scale(double[] vector,
                         double length)

Resizes vector to given length

Parameters:

vector - vector to resize

length - desired length

length

public static double length(double[] vector)

zero

public static void zero(double[] a)

Set all the entries to 0

distance

public static double distance(double[] a,
                              double[] b,
                              double[] difference)

Parameters:

difference - a temp array of the same size as a and b to work with (its contents will be modified). This can be null, which will cause the code to dynamically allocate an array to be used.

Returns:

length of difference or Double.NaN if a and b do not have the same # of dimensions