uk.ac.starlink.ttools.plot

Class Fogger

java.lang.Object

uk.ac.starlink.ttools.plot.Fogger

public class Fogger
extends Object

Defines how colours are changed at different depths (distances away from the viewer) by interposing a 'fog' which makes the colours gloomier the further away you go.

Various methods are provided to fog colours at a given Z coordinate. For reasonable rendering, z should be greater than or equal to zero, and of order of this renderer's scale distance.

Instances of this class are not thread safe.

The fogging algorithm comes from Eric Dumont's fog FAQ.

Since:

18 Jan 2006

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
Fogger(double scale) Constructs a new depth tweaker for rendering distances of the order of a given scale.

Method Summary

Modifier and Type	Method and Description
DataColorTweaker	createTweaker(int ifog, DataColorTweaker base) Constructs a DataColorTweaker based on an existing one which appends the affect of this fogger.
DataColorTweaker	createTweaker(int ifog, int ncoord) Constructs a DataColorTweaker corresponding to this fogger which just takes care of fogging.
Color	fogAt(double z, Color color) Returns a fogged version of a given colour at a given depth.
void	fogAt(double z, float[] rgba) Returns a fogged version of a given colour at a given depth using normalised components.
int	fogAt(double z, int argb) Returns a fogged version of a given colour at a given depth.
void	fogAt(double z, int[] rgba) Returns a fogged version of a given colour at a given depth.
double	getFogginess() Returns the thickness of the fog.
double	getScale() Returns the depth scale distance.
void	setFogginess(double fogginess) Sets the thickness of the fog.

Methods inherited from class java.lang.Object

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

Constructor Detail

Fogger

public Fogger(double scale)

Constructs a new depth tweaker for rendering distances of the order of a given scale.

Parameters:

scale - depth scale distance

Method Detail

getScale

public double getScale()

Returns the depth scale distance.

Returns:

depth scale distance

setFogginess

public void setFogginess(double fogginess)

Sets the thickness of the fog. A given value of fogginess corresponds to a given amount of obscuration of a mark at a depth of the given multiple of the scale distance. Default value is zero (no fog).

Parameters:

fogginess - intensity of fog per scale distance

getFogginess

public double getFogginess()

Returns the thickness of the fog.

Returns:

intensity of fog per scale distance

fogAt

public Color fogAt(double z,
                   Color color)

Returns a fogged version of a given colour at a given depth.

Parameters:

z - distance at which the colour is being viewed

color - original colour

Returns:

fogged colour

fogAt

public void fogAt(double z,
                  int[] rgba)

Returns a fogged version of a given colour at a given depth.

Parameters:

z - distance at which the colour is being viewed

rgba - rgba colour components; these will be modified on exit to represent the fogged value

fogAt

public void fogAt(double z,
                  float[] rgba)

Returns a fogged version of a given colour at a given depth using normalised components.

Parameters:

z - distance at which the colour is being viewed

rgba - normalised rgba colour components; these will be modified on exit to represent the fogged value

fogAt

public int fogAt(double z,
                 int argb)

Returns a fogged version of a given colour at a given depth.

Parameters:

z - distance at which the colour is being viewed

Returns:

argb packed colour value for the fogged colour

createTweaker

public DataColorTweaker createTweaker(int ifog,
                                      int ncoord)

Constructs a DataColorTweaker corresponding to this fogger which just takes care of fogging.

Parameters:

ifog - index in coordinate array of Z coordinate

ncoord - size of coordinate array

createTweaker

public DataColorTweaker createTweaker(int ifog,
                                      DataColorTweaker base)

Constructs a DataColorTweaker based on an existing one which appends the affect of this fogger.

Parameters:

ifog - index in coordinate array of Z coordinate

base - color tweaker to be additionally fogged