javax.media.j3d

Class Background

java.lang.Object

javax.media.j3d.SceneGraphObject

javax.media.j3d.Node

javax.media.j3d.Leaf

javax.media.j3d.Background

public class Background
extends Leaf

The Background leaf node defines a solid background color and a background image that are used to fill the window at the beginning of each new frame. The background image may be null. 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 ViewSpecificGroup are legal in a background geometry branch graph. The only Leaf nodes that are legal are Shape3D (except OrientedShape3D), Morph, Light, and Fog. The presence of any other Leaf node, including OrientedShape3D, or of a ViewSpecificGroup node will cause an IllegalSceneGraphException to be thrown. Note that Link nodes are not allowed; a background geometry branch graph must not reference shared subgraphs. NodeComponent objects can be shared between background branches and ordinary (non-background) branches or among different background branches, however.

Light and Fog nodes in a background geometry branch graph do not affect nodes outside of the background geometry branch graph, and vice versa. Light and Fog nodes that appear in a background geometry branch graph must not be hierarchically scoped to any group node outside of that background geometry branch graph. Conversely, Light and Fog nodes that appear outside of a particular background geometry branch graph must not be hierarchically scoped to any group node in that background geometry branch graph. Any attempt to do so will be ignored.

The influencing bounds of any Light or Fog node in a background geometry branch graph is effectively infinite (meaning that all lights can affect all geometry objects nodes within the background geometry graph, and that an arbitrary fog is selected). An application wishing to limit the scope of a Light or Fog node must use hierarchical scoping.

Picking and collision is ignored for nodes inside a background geometry branch graph.

Field Summary

Fields

Modifier and Type	Field and Description
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_SCALE_MODE_READ Specifies that the Background allows read access to its image scale mode at runtime.
static int	ALLOW_IMAGE_SCALE_MODE_WRITE Specifies that the Background allows write access to its image scale mode at runtime.
static int	ALLOW_IMAGE_WRITE Specifies that the Background allows write access to its image at runtime.
static int	SCALE_FIT_ALL Indicates that the background image is scaled to fit the window.
static int	SCALE_FIT_MAX Indicates that the background image is uniformly scaled to fit the window such that the entire window is filled.
static int	SCALE_FIT_MIN Indicates that the background image is uniformly scaled to fit the window such that the entire image is visible.
static int	SCALE_NONE Indicates that no scaling of the background image is done.
static int	SCALE_NONE_CENTER Indicates that the background image is centered in the window and that no scaling of the image is done.
static int	SCALE_REPEAT Indicates that the background image is tiled to fill the entire window.

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_LOCALE_READ, ALLOW_PARENT_READ, ALLOW_PICKABLE_READ, ALLOW_PICKABLE_WRITE, ENABLE_COLLISION_REPORTING, ENABLE_PICK_REPORTING

Constructor Summary

Constructors

Constructor and Description
Background() Constructs a Background node with default parameters.
Background(BranchGroup branch) Constructs a Background node with the specified geometry.
Background(javax.vecmath.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

Methods

Modifier and Type	Method and Description
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(javax.vecmath.Color3f color) Retrieves the background color.
BranchGroup	getGeometry() Retrieves the background geometry.
ImageComponent2D	getImage() Retrieves the background image.
int	getImageScaleMode() Retrieves the current image scale mode.
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(javax.vecmath.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	setImageScaleMode(int imageScaleMode) Sets the image scale mode for this Background node.
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, getLocale, getLocalToVworld, getLocalToVworld, getParent, getPickable, setBounds, setBoundsAutoCompute, setCollidable, setPickable

Methods inherited from class javax.media.j3d.SceneGraphObject

clearCapability, clearCapabilityIsFrequent, duplicateSceneGraphObject, getCapability, getCapabilityIsFrequent, getName, getUserData, isCompiled, isLive, setCapability, setCapabilityIsFrequent, setName, setUserData, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, 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.

See Also:

Constant Field Values

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.

See Also:

Constant Field Values

ALLOW_IMAGE_READ

public static final int ALLOW_IMAGE_READ

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

See Also:

Constant Field Values

ALLOW_IMAGE_WRITE

public static final int ALLOW_IMAGE_WRITE

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

See Also:

Constant Field Values

ALLOW_COLOR_READ

public static final int ALLOW_COLOR_READ

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

See Also:

Constant Field Values

ALLOW_COLOR_WRITE

public static final int ALLOW_COLOR_WRITE

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

See Also:

Constant Field Values

ALLOW_GEOMETRY_READ

public static final int ALLOW_GEOMETRY_READ

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

See Also:

Constant Field Values

ALLOW_GEOMETRY_WRITE

public static final int ALLOW_GEOMETRY_WRITE

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

See Also:

Constant Field Values

ALLOW_IMAGE_SCALE_MODE_READ

public static final int ALLOW_IMAGE_SCALE_MODE_READ

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

Since:

Java 3D 1.3

See Also:

Constant Field Values

ALLOW_IMAGE_SCALE_MODE_WRITE

public static final int ALLOW_IMAGE_SCALE_MODE_WRITE

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

Since:

Java 3D 1.3

See Also:

Constant Field Values

SCALE_NONE

public static final int SCALE_NONE

Indicates that no scaling of the background image is done. The image will be drawn in its actual size. If the window is smaller than the image, the image will be clipped. If the window is larger than the image, the portion of the window not filled by the image will be filled with the background color. In all cases, the upper left corner of the image is anchored at the upper-left corner of the window. This is the default mode.

Since:

Java 3D 1.3

See Also:

setImageScaleMode(int), Constant Field Values

SCALE_FIT_MIN

public static final int SCALE_FIT_MIN

Indicates that the background image is uniformly scaled to fit the window such that the entire image is visible. The image is scaled by the smaller of window.width/image.width and window.height/image.height. The image will exactly fill either the width or height of the window, but not necessarily both. The portion of the window not filled by the image will be filled with the background color. The upper left corner of the image is anchored at the upper-left corner of the window.

Since:

Java 3D 1.3

See Also:

setImageScaleMode(int), Constant Field Values

SCALE_FIT_MAX

public static final int SCALE_FIT_MAX

Indicates that the background image is uniformly scaled to fit the window such that the entire window is filled. The image is scaled by the larger of window.width/image.width and window.height/image.height. The image will entirely fill the window, but may by clipped either in X or Y. The upper left corner of the image is anchored at the upper-left corner of the window.

Since:

Java 3D 1.3

See Also:

setImageScaleMode(int), Constant Field Values

SCALE_FIT_ALL

public static final int SCALE_FIT_ALL

Indicates that the background image is scaled to fit the window. The image is scaled non-uniformly in x and y by window.width/image.width and and window.height/image.height, respectively. The image will entirely fill the window.

Since:

Java 3D 1.3

See Also:

setImageScaleMode(int), Constant Field Values

SCALE_REPEAT

public static final int SCALE_REPEAT

Indicates that the background image is tiled to fill the entire window. The image is not scaled. The upper left corner of the image is anchored at the upper-left corner of the window.

Since:

Java 3D 1.3

See Also:

setImageScaleMode(int), Constant Field Values

SCALE_NONE_CENTER

public static final int SCALE_NONE_CENTER

Indicates that the background image is centered in the window and that no scaling of the image is done. The image will be drawn in its actual size. If the window is smaller than the image, the image will be clipped. If the window is larger than the image, the portion of the window not filled by the image will be filled with the background color.

Since:

Java 3D 1.3

See Also:

setImageScaleMode(int), Constant Field Values

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
image scale mode : SCALE_NONE
application bounds : null
application bounding leaf : null

Background

public Background(javax.vecmath.Color3f color)

Constructs a Background node with the specified color. This color is used to fill the window prior to drawing any objects in the scene.

Background

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

Constructs a Background node with the specified color. This color is used to fill the window prior to drawing any objects in the scene.

Background

public Background(ImageComponent2D image)

Constructs a Background node with the specified image. If this image is non-null, it is rendered to the window prior to drawing any objects in the scene. If the image is smaller than the window, then that portion of the window not covered by the image is filled with the background color.

Parameters:

image - pixel array object used as the background image

Throws:

IllegalArgumentException - if the image class of the specified ImageComponent2D is ImageClass.NIO_IMAGE_BUFFER.

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 and 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.

IllegalSceneGraphException - if specified branch graph contains an illegal node.

Method Detail

setColor

public void setColor(javax.vecmath.Color3f color)

Sets the background color to the specified color. This color is used to fill the window prior to drawing any objects in the scene.

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 to fill the window prior to drawing any objects in the scene.

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(javax.vecmath.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, it is rendered to the window prior to drawing any objects in the scene. If the image is smaller than the window, then that portion of the window not covered by the image is filled with the background color.

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

IllegalSharingException - if this Background is live and the specified image is being used by a Canvas3D as an off-screen buffer.

IllegalSharingException - if this Background is being used by an immediate mode context and the specified image is being used by a Canvas3D as an off-screen buffer.

IllegalArgumentException - if the image class of the specified ImageComponent2D is ImageClass.NIO_IMAGE_BUFFER.

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

setImageScaleMode

public void setImageScaleMode(int imageScaleMode)

Sets the image scale mode for this Background node.

Parameters:

imageScaleMode - the new image scale mode, one of: SCALE_NONE, SCALE_FIT_MIN, SCALE_FIT_MAX, SCALE_FIT_ALL, SCALE_REPEAT, or SCALE_NONE_CENTER.

Throws:

IllegalArgumentException - if imageScaleMode is a value other than SCALE_NONE, SCALE_FIT_MIN, SCALE_FIT_MAX, SCALE_FIT_ALL, SCALE_REPEAT, or SCALE_NONE_CENTER.

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

Since:

Java 3D 1.3

getImageScaleMode

public int getImageScaleMode()

Retrieves the current image scale mode.

Returns:

the current image scale mode, one of: SCALE_NONE, SCALE_FIT_MIN, SCALE_FIT_MAX, SCALE_FIT_ALL, SCALE_REPEAT, or SCALE_NONE_CENTER.

Throws:

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

Since:

Java 3D 1.3

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 and 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.

IllegalSceneGraphException - if specified branch graph contains an illegal 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