com.levigo.jadice.document.util
Class GradationCurve

java.lang.Object
  com.levigo.jadice.document.util.ControlCurve
      com.levigo.jadice.document.util.NaturalCubicSpline1D
          com.levigo.jadice.document.util.GradationCurve

All Implemented Interfaces:

Serializable, Cloneable

public class GradationCurve
extends NaturalCubicSpline1D
implements Cloneable

This class represents a gradation curve which can be used to map pixel intensity values to rendered intensities. Like its ancestor, NaturalCubicSpline1D, the GradationCurve is defined by a set of control points which may be set, removed and modified. However, the control points are subject to certain restrictions which are due to the nature of a GradationCurve:

• x and y values of the control points must be in the range [0..255]
• with x1 being the x value of control point p and x2 the one of p+1, the condition x2>x1 must hold.
• the curve may be evaluated in the range [0..255]
• for x values within two control points x1, x2, the value is calculated by fitting the natural cubic spline which achieves a smooth transition at the points (first derivatives left and right of the control point are equal and second derivatives are zero)
• with n0 being the first control point and pn being the last one, y=y0 for x<x0 and y=yn for x>xn
• there are at least two control points

See Also:

Serialized Form

Field Summary

Fields inherited from class com.levigo.jadice.document.util.ControlCurve

curveChanged, points

Constructor Summary

GradationCurve()
Create a new GradationCurve which is initialised as a linear identity curve.

GradationCurve(GradationCurve gradCurve)
Create a new GradationCurve as clone of a given gradation curve.

Method Summary

int	addControlPoint(Point p) Add a control point to the end of the list.
protected GradationCurve	clone()
protected void	computeCurve()
boolean	equals(Object obj)
Point	getControlPoint(int n) Get a specified control point.
byte[]	getLookupTable(int size) Return a lookup table based on the curve in the range 0...size.
int	getValueAt(int x) Get the intensity value for a given point.
int	hashCode() Calculate a hash code based on all points on the curve.
int	insertControlPoint(int n, Point p) Insert a control point at a given location
boolean	isLinearIdentity() Returns whether this curve is a identity curve
void	load(Properties properties, String curveName) Load the curve from the given properties object.
void	removeControlPoint(int n) Remove the specified control point
void	reset() Removes all intermediate controls points and keeps just a start and end point for this curve.
void	save(Properties properties, String curveName) Save the curve into the given properties object.
void	setControlPoint(int n, Point p) Set the specified control point
String	toString()

Methods inherited from class com.levigo.jadice.document.util.NaturalCubicSpline1D

getCurve, getValueAt

Methods inherited from class com.levigo.jadice.document.util.ControlCurve

getControlPoints, getPointCount

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

GradationCurve

public GradationCurve()

Create a new GradationCurve which is initialised as a linear identity curve.

GradationCurve

public GradationCurve(GradationCurve gradCurve)

Create a new GradationCurve as clone of a given gradation curve.

Method Detail

addControlPoint

public int addControlPoint(Point p)

Description copied from class: ControlCurve

Add a control point to the end of the list.

Overrides:

addControlPoint in class ControlCurve

Parameters:

p - the Pointto add

See Also:

The addition makes sure that the x values of the points are ascending.

getControlPoint

public Point getControlPoint(int n)

Description copied from class: ControlCurve

Get a specified control point.

Overrides:

getControlPoint in class ControlCurve

See Also:

ControlCurve.getControlPoint(int)

insertControlPoint

public int insertControlPoint(int n,
                              Point p)

Description copied from class: ControlCurve

Insert a control point at a given location

Overrides:

insertControlPoint in class ControlCurve

Parameters:

n - the position to insert at

p - the Pointto insert

See Also:

The insertion makes sure that the x values of the points are ascending, if necessary, the x value is modified.

removeControlPoint

public void removeControlPoint(int n)

Description copied from class: ControlCurve

Remove the specified control point

Overrides:

removeControlPoint in class ControlCurve

Parameters:

n - the index of the point to remove

See Also:

ControlCurve.removeControlPoint(int)

reset

public void reset()

Removes all intermediate controls points and keeps just a start and end point for this curve.

setControlPoint

public void setControlPoint(int n,
                            Point p)

Description copied from class: ControlCurve

Set the specified control point

Overrides:

setControlPoint in class ControlCurve

Parameters:

n - the index of the point to modify

p - the Pointto set

See Also:

The modification makes sure that the x values of the points are ascending, if necessary, the x value is modified.

load

public void load(Properties properties,
                 String curveName)

Load the curve from the given properties object. The points must be defined in the properties object by keys of the style [curveName.]point.i.x and [curveName.]point.i.y with curveName being the supplied curve name and i being an index from 0 to n-1.

Parameters:

properties - the Propertiesfrom which to load the curve

curveName - the optional name of the curve. If non- null, the name is prepended to the keys with a separating dot.

save

public void save(Properties properties,
                 String curveName)

Save the curve into the given properties object. The points are defined in the properties object by keys of the style [curveName.]point.i.x and [curveName.]point.i.y with curveName being the supplied curve name and i being an index from 0 to n-1.

Parameters:

properties - the Propertiesfrom which to load the curve

curveName - the optional name of the curve. If non- null, the name is prepended to the keys with a separating dot.

getValueAt

public int getValueAt(int x)

Get the intensity value for a given point. The curve is automatically mirrored around the zero point.

clone

protected GradationCurve clone()
                        throws CloneNotSupportedException

Overrides:

clone in class Object

Throws:

CloneNotSupportedException

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

See Also:

Object.equals(Object)

isLinearIdentity

public boolean isLinearIdentity()

Returns whether this curve is a identity curve

Returns:

boolean flag

hashCode

public int hashCode()

Calculate a hash code based on all points on the curve.

Overrides:

hashCode in class Object

See Also:

Object.hashCode()

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()

getLookupTable

public byte[] getLookupTable(int size)

Return a lookup table based on the curve in the range 0...size. Lookup value interpretation: x=0 - black, x=255 - white.

Returns:

a lookup table

computeCurve

protected void computeCurve()

Overrides:

computeCurve in class NaturalCubicSpline1D