org.j3d.aviatrix3d
Class Fog

java.lang.Object
  org.j3d.aviatrix3d.SceneGraphObject
      org.j3d.aviatrix3d.Node
          org.j3d.aviatrix3d.Leaf
              org.j3d.aviatrix3d.Fog

All Implemented Interfaces:

java.lang.Comparable, CascadeRenderable, Cullable, EffectRenderable, LeafCullable, ObjectRenderable, Renderable

public class Fog
extends Leaf
implements LeafCullable, ObjectRenderable, EffectRenderable

Describes a fog rendering effect.

All types of fog are reprensented in a single class. If the parameter type is not useful for the fog mode, it is ignored.

Fog may act either locally or globally. If an instance of the fog node is registered with the ViewEnvironment, then it shall act as a global fog effect for the world. If it is not, then may act as a local effect, scoped the group node that contains it (like lights). Local fog effects must be explicitly enabled, otherwise only the global is used. If, during a traversal from the root of the tree down to a leaf, multiple Fog node instances are encountered, then only the closest to the Leaf is used. If multiple instances are provided in the same Group node instance, the chosen one is implementation independent.

When combined with fog coordinates on the geometry, local fog provides volumetric fog effects.

By default, fog is not enabled and global only.

Rendering Implementation Tips

See the EffectRenderable interface for definition of the scoping and effects bounds.

Internationalisation Resource Names

• invertedRangeMsg: Error message when the caller tries to set a minimum range greater than the maximum range.

Version:

$Revision: 1.25 $

Author:

Justin Couch

Field Summary

static int	EXPONENTIAL Set the fog mode to exponential curve
static int	EXPONENTIAL_2 Set the fog mode to exponential-squared curve
static int	LINEAR Set the fog mode to linear

Fields inherited from class org.j3d.aviatrix3d.Node

bounds, implicitBounds, INVALID_BOUNDS, parent

Fields inherited from class org.j3d.aviatrix3d.SceneGraphObject

alive, LISTENER_SET_TIMING_ERR_PROP, updateHandler

Fields inherited from interface org.j3d.aviatrix3d.rendering.LeafCullable

AUDIO_CULLABLE, CLIP_CULLABLE, FOG_CULLABLE, GEOMETRY_CULLABLE, LIGHT_CULLABLE, OVERRIDE_CULLABLE

Constructor Summary

Fog()
Constructs a fog node with the default mode set to linear the colour set to white and global only.

Fog(float[] c)
Construct a fog using the given colour and assumes a linear mode.

Fog(float[] c, boolean global)
Construct a fog using the given colour and choice of gloval effect, assuming a linear mode.

Fog(int mode)
Construct a fog using the given mode and with the colour set to white.

Fog(int mode, boolean global)
Construct a fog using the given mode and the option of selecting local or global effects.

Fog(int mode, float[] c)
Construct a fog using the given mode and colour.

Fog(int mode, float[] c, boolean global)
Construct a fog using the given mode and colour and selection of global state.

Method Summary

int	compareTo(Fog fog) Compares this object with the specified object for order.
int	compareTo(java.lang.Object o) Compares this object with the specified object for order.
boolean	equals(Fog fog) Compares this object with the specified object to check for equivalence.
boolean	equals(java.lang.Object o) Compare this object for equality to the given object.
void	getColor(float[] c) Get the current drawing colour
int	getCullableType() Get the type that this cullable represents.
float	getDensityRate() Get the current decay rate.
BoundingVolume	getEffectBounds() Get the current bounding volume that this light effects.
void	getLinearDistance(float[] values) Get the two distance values for the linear fog settings.
int	getMode() Get the current decay rate.
Renderable	getRenderable() Get the child renderable of this object.
boolean	isEnabled() Get the current enabled state of the light.
boolean	isGlobalOnly() Get the current setting of the global-only flag.
protected void	markBoundsDirty() Mark this node as having dirty bounds due to one of it's children having their bounds changed.
void	postRender(javax.media.opengl.GL gl) Restore all openGL state to the given drawable.
void	render(javax.media.opengl.GL gl) Issue ogl commands needed for this component
void	setColor(float[] c) Change the fog colour to the new colour.
void	setDensityRate(float rate) Set the exponential decay factor.
void	setEffectBounds(BoundingVolume bounds) Set the bounds that will effect the range of this light.
void	setEnabled(boolean state) Set the enabled state of the light.
void	setGlobalOnly(boolean enable) Set whether the fog should act in local or global mode.
void	setLinearDistance(float start, float end) Set the distance functions for the fog when in linear mode.
void	setMode(int type) Set the type of fog to be rendered.

Methods inherited from class org.j3d.aviatrix3d.Node

boundsChanged, checkForCyclicParent, getBounds, getParent, recomputeBounds, removeParent, requestBoundsUpdate, setBounds, setParent, updateBounds, updateParentBounds

Methods inherited from class org.j3d.aviatrix3d.SceneGraphObject

checkForCyclicChild, dataChanged, getAppUpdateWriteTimingMessage, getBoundsWriteTimingMessage, getDataWriteTimingMessage, getUserData, isLive, setLive, setUpdateHandler, setUserData

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.j3d.aviatrix3d.rendering.LeafCullable

getBounds

Field Detail

EXPONENTIAL

public static final int EXPONENTIAL

Set the fog mode to exponential curve

See Also:

Constant Field Values

EXPONENTIAL_2

public static final int EXPONENTIAL_2

Set the fog mode to exponential-squared curve

See Also:

Constant Field Values

LINEAR

public static final int LINEAR

Set the fog mode to linear

See Also:

Constant Field Values

Constructor Detail

Fog

public Fog()

Constructs a fog node with the default mode set to linear the colour set to white and global only.

Fog

public Fog(int mode)

Construct a fog using the given mode and with the colour set to white.

Parameters:

mode - One of LINEAR, EXPONENTIAL or EXPONENTIAL_2

Fog

public Fog(int mode,
           boolean global)

Construct a fog using the given mode and the option of selecting local or global effects. The colour set to white.

Parameters:

mode - One of LINEAR, EXPONENTIAL or EXPONENTIAL_2

global - true if this is a global-only fog effect

Fog

public Fog(int mode,
           float[] c)

Construct a fog using the given mode and colour.

Parameters:

mode - One of LINEAR, EXPONENTIAL or EXPONENTIAL_2

c - The initial colour to use for the fog

Fog

public Fog(float[] c)

Construct a fog using the given colour and assumes a linear mode.

Parameters:

c - The initial colour to use for the fog

Fog

public Fog(float[] c,
           boolean global)

Construct a fog using the given colour and choice of gloval effect, assuming a linear mode.

Parameters:

c - The initial colour to use for the fog

global - true if this is a global-only fog effect

Fog

public Fog(int mode,
           float[] c,
           boolean global)

Construct a fog using the given mode and colour and selection of global state.

Parameters:

mode - One of LINEAR, EXPONENTIAL or EXPONENTIAL_2

c - The initial colour to use for the fog

global - true if this is a global-only fog effect

Method Detail

getCullableType

public int getCullableType()

Get the type that this cullable represents.

Specified by:

getCullableType in interface LeafCullable

Returns:

One of the _CULLABLE constants

getRenderable

public Renderable getRenderable()

Get the child renderable of this object.

Specified by:

getRenderable in interface LeafCullable

Returns:

an array of nodes

isEnabled

public boolean isEnabled()

Get the current enabled state of the light.

Specified by:

isEnabled in interface CascadeRenderable

Returns:

The current state

isGlobalOnly

public boolean isGlobalOnly()

Get the current setting of the global-only flag.

Specified by:

isGlobalOnly in interface EffectRenderable

Returns:

true if for global use only, false otherwise

getEffectBounds

public BoundingVolume getEffectBounds()

Get the current bounding volume that this light effects. If the light is to effect everything for infinite distance, then this will return null.

Specified by:

getEffectBounds in interface EffectRenderable

Returns:

A bounding volume if there is to be bounds, null for none.

render

public void render(javax.media.opengl.GL gl)

Issue ogl commands needed for this component

Specified by:

render in interface ObjectRenderable

Parameters:

gl - The gl context to draw with

postRender

public void postRender(javax.media.opengl.GL gl)

Restore all openGL state to the given drawable.

Specified by:

postRender in interface ObjectRenderable

Parameters:

gl - The gl context to draw with

markBoundsDirty

protected void markBoundsDirty()

Mark this node as having dirty bounds due to one of it's children having their bounds changed.

Overrides:

markBoundsDirty in class Node

compareTo

public int compareTo(java.lang.Object o)
              throws java.lang.ClassCastException

Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Specified by:

compareTo in interface java.lang.Comparable

Parameters:

o - The objec to be compared

Returns:

-1, 0 or 1 depending on order

Throws:

java.lang.ClassCastException - The specified object's type prevents it from being compared to this Object

equals

public boolean equals(java.lang.Object o)

Compare this object for equality to the given object.

Specified by:

equals in interface Renderable

Overrides:

equals in class java.lang.Object

Parameters:

o - The object to be compared

Returns:

True if these represent the same values

setEnabled

public void setEnabled(boolean state)
                throws InvalidWriteTimingException

Set the enabled state of the light. Can use this to turn it on and off in a general fashion.

Parameters:

state - The new state of the light

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the NodeUpdateListener data changed callback method

setGlobalOnly

public void setGlobalOnly(boolean enable)
                   throws InvalidWriteTimingException

Set whether the fog should act in local or global mode.

Parameters:

enable - true to force this fog to be used for global rendering only

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the NodeUpdateListener data changed callback method

setEffectBounds

public void setEffectBounds(BoundingVolume bounds)
                     throws InvalidWriteTimingException

Set the bounds that will effect the range of this light. The bounds are used as a secondary scoping capability to define which objects should or should not be effected based on whether their bounding volumes intersect with this volume. If the light is to effect everything then this value should be set to null, otherwise it defines the bounds in the local coordinate system of the light.

Parameters:

bounds - A volume to use or null to clear

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the NodeUpdateListener data changed callback method

setColor

public void setColor(float[] c)
              throws InvalidWriteTimingException

Change the fog colour to the new colour. Fog colour only takes RGB.

Parameters:

c - The colour to copy in

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the NodeUpdateListener data changed callback method

getColor

public void getColor(float[] c)

Get the current drawing colour

Parameters:

c - An array of length 3 or more to copy the colour to

setLinearDistance

public void setLinearDistance(float start,
                              float end)
                       throws InvalidWriteTimingException

Set the distance functions for the fog when in linear mode.

Parameters:

start - The closest distance that fog starts at

end - The distance that the fog is fully opaque at

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the NodeUpdateListener data changed callback method

getLinearDistance

public void getLinearDistance(float[] values)

Get the two distance values for the linear fog settings. The values are returned in the provided array with index 0 being the start and index 1 being the end.

Parameters:

values - An array to copy the values into

setDensityRate

public void setDensityRate(float rate)
                    throws InvalidWriteTimingException

Set the exponential decay factor.

Parameters:

rate - A value that should be greater than zero

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the NodeUpdateListener data changed callback method

getDensityRate

public float getDensityRate()

Get the current decay rate.

Returns:

a value > 0

setMode

public void setMode(int type)
             throws InvalidWriteTimingException

Set the type of fog to be rendered. The type is one of the 3 pre-defined modes described in the class header.

Parameters:

type - One of EXPONENTIAL, EXPONENTIAL_2, or LINEAR

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the NodeUpdateListener data changed callback method

getMode

public int getMode()

Get the current decay rate.

Returns:

One of EXPONENTIAL, EXPONENTIAL_2, or LINEAR

compareTo

public int compareTo(Fog fog)

Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Parameters:

fog - The program instance to be compared

Returns:

-1, 0 or 1 depending on order

equals

public boolean equals(Fog fog)

Compares this object with the specified object to check for equivalence.

Parameters:

fog - The program instance to be compared

Returns:

true if the objects represent identical values