javax.media.j3d
Class Background

java.lang.Object
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  +--javax.media.j3d.SceneGraphObject
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        +--javax.media.j3d.Node
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              +--javax.media.j3d.Leaf
                    |
                    +--javax.media.j3d.Background

public class Background

extends Leaf

The Background leaf node defines either a solid background color or a background image that is used to fill the window at the beginning of each new frame. It optionally allows background geometry---which is pre-tessellated onto a unit sphere and is drawn at infinity---to be referenced. It also specifies an application region in which this background is active. A Background node is active when its application region intersects the ViewPlatform's activation volume. If multiple Background nodes are active, the Background node that is "closest" to the eye will be used. If no Background nodes are active, then the window is cleared to black.

The set of nodes that can be added to a BranchGroup associated with a Background node is limited. All Group nodes (except SharedGroup, which must not have any parents) are legal in a background geometry branch graph. The only Leaf nodes that are legal are Shape3D and Morph. The presence of any other Leaf nodes will cause an IllegalSharingException to be thrown. Note that Link nodes are not allowed; a background geometry branch graph must not reference shared subgraphs.

Field Summary

static int	ALLOW_APPLICATION_BOUNDS_READ Specifies that the Background allows read access to its application bounds and bounding leaf at runtime.
static int	ALLOW_APPLICATION_BOUNDS_WRITE Specifies that the Background allows write access to its application bounds and bounding leaf at runtime.
static int	ALLOW_COLOR_READ Specifies that the Background allows read access to its color at runtime.
static int	ALLOW_COLOR_WRITE Specifies that the Background allows write access to its color at runtime.
static int	ALLOW_GEOMETRY_READ Specifies that the Background allows read access to its background geometry at runtime.
static int	ALLOW_GEOMETRY_WRITE Specifies that the Background allows write access to its background geometry at runtime.
static int	ALLOW_IMAGE_READ Specifies that the Background allows read access to its image at runtime.
static int	ALLOW_IMAGE_WRITE Specifies that the Background allows write access to its image at runtime.

Fields inherited from class javax.media.j3d.Node

ALLOW_AUTO_COMPUTE_BOUNDS_READ, ALLOW_AUTO_COMPUTE_BOUNDS_WRITE, ALLOW_BOUNDS_READ, ALLOW_BOUNDS_WRITE, ALLOW_COLLIDABLE_READ, ALLOW_COLLIDABLE_WRITE, ALLOW_LOCAL_TO_VWORLD_READ, ALLOW_PICKABLE_READ, ALLOW_PICKABLE_WRITE, ENABLE_COLLISION_REPORTING, ENABLE_PICK_REPORTING

Constructor Summary

Background()
Constructs a Background node with default parameters.

Background(BranchGroup branch)
Constructs a Background node with the specified geometry.

Background(Color3f color)
Constructs a Background node with the specified color.

Background(float r, float g, float b)
Constructs a Background node with the specified color.

Background(ImageComponent2D image)
Constructs a Background node with the specified image.

Method Summary

Node	cloneNode(boolean forceDuplicate) Creates a new instance of the node.
void	duplicateNode(Node originalNode, boolean forceDuplicate) Copies all node information from originalNode into the current node.
BoundingLeaf	getApplicationBoundingLeaf() Retrieves the Background node's application bounding leaf.
Bounds	getApplicationBounds() Retrieves the Background node's application bounds.
void	getColor(Color3f color) Retrieves the background color.
BranchGroup	getGeometry() Retrieves the background geometry.
ImageComponent2D	getImage() Retrieves the background image.
void	setApplicationBoundingLeaf(BoundingLeaf region) Set the Background's application region to the specified bounding leaf.
void	setApplicationBounds(Bounds region) Set the Background's application region to the specified bounds.
void	setColor(Color3f color) Sets the background color to the specified color.
void	setColor(float r, float g, float b) Sets the background color to the specified color.
void	setGeometry(BranchGroup branch) Sets the background geometry to the specified BranchGroup node.
void	setImage(ImageComponent2D image) Sets the background image to the specified image.
void	updateNodeReferences(NodeReferenceTable referenceTable) Callback used to allow a node to check if any scene graph objects referenced by that node have been duplicated via a call to cloneTree.

Methods inherited from class javax.media.j3d.Node

cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, getBounds, getBoundsAutoCompute, getCollidable, getLocalToVworld, getLocalToVworld, getParent, getPickable, setBounds, setBoundsAutoCompute, setCollidable, setPickable

Methods inherited from class javax.media.j3d.SceneGraphObject

clearCapability, duplicateSceneGraphObject, getCapability, getUserData, isCompiled, isLive, setCapability, setUserData

Methods inherited from class java.lang.Object

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

Field Detail

ALLOW_APPLICATION_BOUNDS_READ

public static final int ALLOW_APPLICATION_BOUNDS_READ

Specifies that the Background allows read access to its application bounds and bounding leaf at runtime.

ALLOW_APPLICATION_BOUNDS_WRITE

public static final int ALLOW_APPLICATION_BOUNDS_WRITE

Specifies that the Background allows write access to its application bounds and bounding leaf at runtime.

ALLOW_IMAGE_READ

public static final int ALLOW_IMAGE_READ

Specifies that the Background allows read access to its image at runtime.

ALLOW_IMAGE_WRITE

public static final int ALLOW_IMAGE_WRITE

Specifies that the Background allows write access to its image at runtime.

ALLOW_COLOR_READ

public static final int ALLOW_COLOR_READ

Specifies that the Background allows read access to its color at runtime.

ALLOW_COLOR_WRITE

public static final int ALLOW_COLOR_WRITE

Specifies that the Background allows write access to its color at runtime.

ALLOW_GEOMETRY_READ

public static final int ALLOW_GEOMETRY_READ

Specifies that the Background allows read access to its background geometry at runtime.

ALLOW_GEOMETRY_WRITE

public static final int ALLOW_GEOMETRY_WRITE

Specifies that the Background allows write access to its background geometry at runtime.

Constructor Detail

Background

public Background()

Constructs a Background node with default parameters. The default values are as follows:

color : black (0,0,0)
image : null
geometry : null
application bounds : null
application bounding leaf : null

Background

public Background(Color3f color)

Constructs a Background node with the specified color.

Background

public Background(float r,
                  float g,
                  float b)

Constructs a Background node with the specified color.

Background

public Background(ImageComponent2D image)

Constructs a Background node with the specified image. If this image is non-null, the color is ignored.

Parameters:

image - pixel array object used as the background image

Background

public Background(BranchGroup branch)

Constructs a Background node with the specified geometry. If non-null, this background geometry is drawn on top of the background color or image using a projection matrix that essentially puts the geometry at infinity. The geometry should be pre-tessellated onto a unit sphere.

Parameters:

branch - the root of the background geometry

Throws:

IllegalSharingException - if the BranchGroup node is a child of any Group node, or is already attached to a Locale, or is already referenced by another Background node.

Method Detail

setColor

public void setColor(Color3f color)

Sets the background color to the specified color. This color is used if the image is null.

Parameters:

color - the new background color

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setColor

public void setColor(float r,
                     float g,
                     float b)

Sets the background color to the specified color. This color is used if the image is null.

Parameters:

r - the red component of the background color

g - the green component of the background color

b - the blue component of the background color

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

getColor

public void getColor(Color3f color)

Retrieves the background color.

Parameters:

color - the vector that will receive the current background color

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setImage

public void setImage(ImageComponent2D image)

Sets the background image to the specified image. If this image is non-null, the color is ignored.

Parameters:

image - new pixel array object used as the background image

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

getImage

public ImageComponent2D getImage()

Retrieves the background image.

Returns:

the current background image

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setGeometry

public void setGeometry(BranchGroup branch)

Sets the background geometry to the specified BranchGroup node. If non-null, this background geometry is drawn on top of the background color or image using a projection matrix that essentially puts the geometry at infinity. The geometry should be pre-tessellated onto a unit sphere.

Parameters:

branch - the root of the background geometry

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

IllegalSharingException - if the BranchGroup node is a child of any Group node, or is already attached to a Locale, or is already referenced by another Background node.

getGeometry

public BranchGroup getGeometry()

Retrieves the background geometry.

Returns:

the BranchGroup node that is the root of the background geometry

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setApplicationBounds

public void setApplicationBounds(Bounds region)

Set the Background's application region to the specified bounds. This is used when the application bounding leaf is set to null.

Parameters:

region - the bounds that contains the Background's new application region.

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

getApplicationBounds

public Bounds getApplicationBounds()

Retrieves the Background node's application bounds.

Returns:

this Background's application bounds information

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setApplicationBoundingLeaf

public void setApplicationBoundingLeaf(BoundingLeaf region)

Set the Background's application region to the specified bounding leaf. When set to a value other than null, this overrides the application bounds object.

Parameters:

region - the bounding leaf node used to specify the Background node's new application region.

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

getApplicationBoundingLeaf

public BoundingLeaf getApplicationBoundingLeaf()

Retrieves the Background node's application bounding leaf.

Returns:

this Background's application bounding leaf information

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

cloneNode

public Node cloneNode(boolean forceDuplicate)

Creates a new instance of the node. This routine is called by cloneTree to duplicate the current node.

Overrides:

cloneNode in class Node

Parameters:

forceDuplicate - when set to true, causes the duplicateOnCloneTree flag to be ignored. When false, the value of each node's duplicateOnCloneTree variable determines whether NodeComponent data is duplicated or copied.
Background geometry will not clone in this operation. It is the user's responsibility to call cloneTree on that branchGroup.

See Also:

Node.cloneTree(), Node.cloneNode(boolean), Node.duplicateNode(javax.media.j3d.Node, boolean), NodeComponent.setDuplicateOnCloneTree(boolean)

duplicateNode

public void duplicateNode(Node originalNode,
                          boolean forceDuplicate)

Copies all node information from originalNode into the current node. This method is called from the cloneNode method which is, in turn, called by the cloneTree method.

For any NodeComponent objects contained by the object being duplicated, each NodeComponent object's duplicateOnCloneTree value is used to determine whether the NodeComponent should be duplicated in the new node or if just a reference to the current node should be placed in the new node. This flag can be overridden by setting the forceDuplicate parameter in the cloneTree method to true.
NOTE: Applications should not call this method directly. It should only be called by the cloneNode method.

Overrides:

duplicateNode in class Node

Parameters:

originalNode - the original node to duplicate.

forceDuplicate - when set to true, causes the duplicateOnCloneTree flag to be ignored. When false, the value of each node's duplicateOnCloneTree variable determines whether NodeComponent data is duplicated or copied.

Throws:

ClassCastException - if originalNode is not an instance of Background

See Also:

Node.cloneTree(), Node.cloneNode(boolean), NodeComponent.setDuplicateOnCloneTree(boolean)

updateNodeReferences

public void updateNodeReferences(NodeReferenceTable referenceTable)

Callback used to allow a node to check if any scene graph objects referenced by that node have been duplicated via a call to cloneTree. This method is called by cloneTree after all nodes in the sub-graph have been duplicated. The cloned Leaf node's method will be called and the Leaf node can then look up any object references by using the getNewObjectReference method found in the NodeReferenceTable object. If a match is found, a reference to the corresponding object in the newly cloned sub-graph is returned. If no corresponding reference is found, either a DanglingReferenceException is thrown or a reference to the original object is returned depending on the value of the allowDanglingReferences parameter passed in the cloneTree call.

NOTE: Applications should not call this method directly. It should only be called by the cloneTree method.

Overrides:

updateNodeReferences in class SceneGraphObject

Parameters:

referenceTable - a NodeReferenceTableObject that contains the getNewObjectReference method needed to search for new object instances

See Also:

NodeReferenceTable, Node.cloneTree(), DanglingReferenceException