Package com.jhlabs.image

Class Gradient

java.lang.Object

com.jhlabs.image.ArrayColormap

com.jhlabs.image.Gradient

All Implemented Interfaces:

Colormap, java.lang.Cloneable

public class Gradient
extends ArrayColormap
implements java.lang.Cloneable

A Colormap implemented using Catmull-Rom colour splines. The map has a variable number of knots with a minimum of four. The first and last knots give the tangent at the end of the spline, and colours are interpolated from the second to the second-last knots. Each knot can be given a type of interpolation. These are:

• LINEAR - linear interpolation to next knot
• SPLINE - spline interpolation to next knot
• CONSTANT - no interpolation - the colour is constant to the next knot
• HUE_CW - interpolation of hue clockwise to next knot
• HUE_CCW - interpolation of hue counter-clockwise to next knot

Field Summary

Fields

Modifier and Type	Field	Description
static int	CIRCLE_DOWN	Interpolate with a falling circle shape curve.
static int	CIRCLE_UP	Interpolate with a rising circle shape curve.
static int	CONSTANT	Don't tnterpolate - just use the starting value.
static int	HUE_CCW	Interpolate hue counter clockwise.
static int	HUE_CW	Interpolate hue clockwise.
static int	LINEAR	Interpolate linearly.
static int	RGB	Interpolate in RGB space.
static int	SPLINE	Interpolate using a spline.

Fields inherited from class com.jhlabs.image.ArrayColormap

map

Constructor Summary

Constructors

Constructor	Description
Gradient()	Construct a Gradient.
Gradient(int[] rgb)	Construct a Gradient with the given colors.
Gradient(int[] x, int[] rgb)	Construct a Gradient with the given colors and knot positions.
Gradient(int[] x, int[] rgb, byte[] types)	Construct a Gradient with the given colors, knot positions and interpolation types.

Method Summary

Modifier and Type	Method	Description
void	addKnot(int x, int color, int type)	Add a new knot.
java.lang.Object	clone()
void	copyTo(Gradient g)	Copy one Gradient into another.
int	getKnot(int n)	Get a knot color.
byte	getKnotBlend(int n)	Get a knot blend type.
int	getKnotPosition(int n)	Get a knot position.
int	getKnotType(int n)	Get a knot type.
int	getNumKnots()	Get the number of knots in the gradient.
int	knotAt(int x)	Return the knot at a given position.
void	mutate(float amount)	Mutate the gradient.
static Gradient	randomGradient()	Build a random gradient.
void	randomize()	Randomize the gradient.
void	removeKnot(int n)	Remove a knot.
void	setColor(int n, int color)	Set a knot color.
void	setKnot(int n, int color)	Set a knot color.
void	setKnotBlend(int n, int type)	Set a knot blend type.
void	setKnotPosition(int n, int x)	Set a knot position.
void	setKnots(int[] x, int[] rgb, byte[] types)	Set the values of all the knots.
void	setKnots(int[] x, int[] y, byte[] types, int offset, int count)	Set the values of a set of knots.
void	setKnotType(int n, int type)	Set a knot type.
void	splitSpan(int n)	Split a span into two by adding a knot in the middle.

Methods inherited from class com.jhlabs.image.ArrayColormap

getColor, getMap, setColorInterpolated, setColorRange, setColorRange, setMap

Methods inherited from class java.lang.Object

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

Field Detail

RGB

public static final int RGB

Interpolate in RGB space.

See Also:

Constant Field Values

HUE_CW

public static final int HUE_CW

Interpolate hue clockwise.

See Also:

Constant Field Values

HUE_CCW

public static final int HUE_CCW

Interpolate hue counter clockwise.

See Also:

Constant Field Values

LINEAR

public static final int LINEAR

Interpolate linearly.

See Also:

Constant Field Values

SPLINE

public static final int SPLINE

Interpolate using a spline.

See Also:

Constant Field Values

CIRCLE_UP

public static final int CIRCLE_UP

Interpolate with a rising circle shape curve.

See Also:

Constant Field Values

CIRCLE_DOWN

public static final int CIRCLE_DOWN

Interpolate with a falling circle shape curve.

See Also:

Constant Field Values

CONSTANT

public static final int CONSTANT

Don't tnterpolate - just use the starting value.

See Also:

Constant Field Values

Constructor Detail

Gradient

public Gradient()

Construct a Gradient.

Gradient

public Gradient(int[] rgb)

Construct a Gradient with the given colors.

Parameters:

rgb - the colors

Gradient

public Gradient(int[] x,
                int[] rgb)

Construct a Gradient with the given colors and knot positions.

Parameters:

x - the knot positions

rgb - the colors

Gradient

public Gradient(int[] x,
                int[] rgb,
                byte[] types)

Construct a Gradient with the given colors, knot positions and interpolation types.

Parameters:

x - the knot positions

rgb - the colors

types - interpolation types

Method Detail

clone

public java.lang.Object clone()

Overrides:

clone in class ArrayColormap

copyTo

public void copyTo(Gradient g)

Copy one Gradient into another.

Parameters:

g - the Gradient to copy into

setColor

public void setColor(int n,
                     int color)

Set a knot color.

Overrides:

setColor in class ArrayColormap

Parameters:

n - the knot index

color - the color

See Also:

ArrayColormap.getColor(float)

getNumKnots

public int getNumKnots()

Get the number of knots in the gradient.

Returns:

the number of knots.

setKnot

public void setKnot(int n,
                    int color)

Set a knot color.

Parameters:

n - the knot index

color - the color

See Also:

getKnot(int)

getKnot

public int getKnot(int n)

Get a knot color.

Parameters:

n - the knot index

Returns:

the knot color

See Also:

setKnot(int, int)

setKnotType

public void setKnotType(int n,
                        int type)

Set a knot type.

Parameters:

n - the knot index

type - the type

See Also:

getKnotType(int)

getKnotType

public int getKnotType(int n)

Get a knot type.

Parameters:

n - the knot index

Returns:

the knot type

See Also:

setKnotType(int, int)

setKnotBlend

public void setKnotBlend(int n,
                         int type)

Set a knot blend type.

Parameters:

n - the knot index

type - the knot blend type

See Also:

getKnotBlend(int)

getKnotBlend

public byte getKnotBlend(int n)

Get a knot blend type.

Parameters:

n - the knot index

Returns:

the knot blend type

See Also:

setKnotBlend(int, int)

addKnot

public void addKnot(int x,
                    int color,
                    int type)

Add a new knot.

Parameters:

x - the knot position

color - the color

type - the knot type

See Also:

removeKnot(int)

removeKnot

public void removeKnot(int n)

Remove a knot.

Parameters:

n - the knot index

See Also:

addKnot(int, int, int)

setKnots

public void setKnots(int[] x,
                     int[] rgb,
                     byte[] types)

Set the values of all the knots. This version does not require the "extra" knots at -1 and 256

Parameters:

x - the knot positions

rgb - the knot colors

types - the knot types

setKnots

public void setKnots(int[] x,
                     int[] y,
                     byte[] types,
                     int offset,
                     int count)

Set the values of a set of knots.

Parameters:

x - the knot positions

y - the knot colors

types - the knot types

offset - the first knot to set

count - the number of knots

splitSpan

public void splitSpan(int n)

Split a span into two by adding a knot in the middle.

Parameters:

n - the span index

setKnotPosition

public void setKnotPosition(int n,
                            int x)

Set a knot position.

Parameters:

n - the knot index

x - the knot position

See Also:

setKnotPosition(int, int)

getKnotPosition

public int getKnotPosition(int n)

Get a knot position.

Parameters:

n - the knot index

Returns:

the knot position

See Also:

setKnotPosition(int, int)

knotAt

public int knotAt(int x)

Return the knot at a given position.

Parameters:

x - the position

Returns:

the knot number, or 1 if no knot found

randomize

public void randomize()

Randomize the gradient.

mutate

public void mutate(float amount)

Mutate the gradient.

Parameters:

amount - the amount in the range zero to one

randomGradient

public static Gradient randomGradient()

Build a random gradient.

Returns:

the new Gradient