javax.media.j3d
Class CompressedGeometry

java.lang.Object
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  +--javax.media.j3d.SceneGraphObject
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        +--javax.media.j3d.NodeComponent
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              +--javax.media.j3d.Geometry
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                    +--javax.media.j3d.CompressedGeometry

public class CompressedGeometry

extends Geometry

The compressed geometry object is used to store geometry in a compressed format. Using compressed geometry reduces the amount of memory needed by a Java 3D application and increases the speed objects can be sent over the network. Once geometry decompression hardware support becomes available, increased rendering performance will also result from the use of compressed geometry.

Compressed geometry may be passed to this CompressedGeometry object in one of two ways: by copying the data into this object using the existing constructor, or by passing a reference to the data.

• By Copying: The existing CompressedGeometry constructor copies the buffer of compressed geometry data into this CompressedGeometry object. This is appropriate for many applications, and allows Java 3D to verify the data once and then not worry about it again.
• By Reference: A new constructor and set of methods in Java 3D version 1.2 allows compressed geometry data to be accessed by reference, directly from the user's array. To use this feature, you need to construct a CompressedGeometry object with the byReference flag set to true. In this mode, a reference to the input data is saved, but the data itself is not necessarily copied. Note that the compressed geometry header is still copied into this compressed geometry object. Data referenced by a CompressedGeometry object must not be modified after the CompressedGeometry object is constructed. Applications must exercise care not to violate this rule. If any referenced compressed geometry data is modified after construction, the results are undefined.

Field Summary

static int	ALLOW_COUNT_READ Specifies that this CompressedGeometry object allows reading its byte count information.
static int	ALLOW_GEOMETRY_READ Specifies that this CompressedGeometry object allows reading its geometry data component information.
static int	ALLOW_HEADER_READ Specifies that this CompressedGeometry object allows reading its header information.
static int	ALLOW_REF_DATA_READ Specifies that this CompressedGeometry allows reading the geometry data reference information for this object.

Fields inherited from class javax.media.j3d.Geometry

ALLOW_INTERSECT

Constructor Summary

CompressedGeometry(CompressedGeometryHeader hdr, byte[] compressedGeometry)
Creates a new CompressedGeometry NodeComponent by copying the specified compressed geometry data into this object.

CompressedGeometry(CompressedGeometryHeader hdr, byte[] compressedGeometry, boolean byReference)
Creates a new CompressedGeometry NodeComponent.

Method Summary

NodeComponent	cloneNodeComponent() Deprecated. replaced with cloneNodeComponent(boolean forceDuplicate)
Shape3D[]	decompress() Decompresses the compressed geometry.
int	getByteCount() Returns the size, in bytes, of the compressed geometry buffer.
void	getCompressedGeometry(byte[] compressedGeometry) Retrieves the compressed geometry associated with the CompressedGeometry NodeComponent object.
void	getCompressedGeometryHeader(CompressedGeometryHeader hdr) Copies the compressed geometry header from the CompressedGeometry NodeComponent into the passed in parameter.
byte[]	getCompressedGeometryRef() Gets the compressed geometry data reference.
boolean	isByReference() Retrieves the data access mode for this CompressedGeometry object.

Methods inherited from class javax.media.j3d.NodeComponent

cloneNodeComponent, duplicateNodeComponent, duplicateNodeComponent, getDuplicateOnCloneTree, setDuplicateOnCloneTree

Methods inherited from class javax.media.j3d.SceneGraphObject

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

Methods inherited from class java.lang.Object

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

Field Detail

ALLOW_COUNT_READ

public static final int ALLOW_COUNT_READ

Specifies that this CompressedGeometry object allows reading its byte count information.

ALLOW_HEADER_READ

public static final int ALLOW_HEADER_READ

Specifies that this CompressedGeometry object allows reading its header information.

ALLOW_GEOMETRY_READ

public static final int ALLOW_GEOMETRY_READ

Specifies that this CompressedGeometry object allows reading its geometry data component information.

ALLOW_REF_DATA_READ

public static final int ALLOW_REF_DATA_READ

Specifies that this CompressedGeometry allows reading the geometry data reference information for this object. This is only used in by-reference geometry mode.

Since:

Java 3D 1.2

Constructor Detail

CompressedGeometry

public CompressedGeometry(CompressedGeometryHeader hdr,
                          byte[] compressedGeometry)

Creates a new CompressedGeometry NodeComponent by copying the specified compressed geometry data into this object. If the version number of compressed geometry, as specified by the CompressedGeometryHeader, is incompatible with the supported version of compressed geometry in the current version of Java 3D, then the compressed geometry object will not be rendered.

Parameters:

hdr - the compressed geometry header. This is copied into the CompressedGeometry NodeComponent.

compressedGeometry - the compressed geometry data. The geometry must conform to the format described in Appendix B of the Java 3D API Specification.

Throws:

java.lang.IllegalArgumentException - if a problem is detected with the header

See Also:

CompressedGeometryHeader, Canvas3D.queryProperties()

CompressedGeometry

public CompressedGeometry(CompressedGeometryHeader hdr,
                          byte[] compressedGeometry,
                          boolean byReference)

Creates a new CompressedGeometry NodeComponent. The specified compressed geometry data is either copied into this object or is accessed by reference. If the version number of compressed geometry, as specified by the CompressedGeometryHeader, is incompatible with the supported version of compressed geometry in the current version of Java 3D, the compressed geometry object will not be rendered.

Parameters:

hdr - the compressed geometry header. This is copied into the CompressedGeometry NodeComponent.

compressedGeometry - the compressed geometry data. The geometry must conform to the format described in Appendix B of the Java 3D API Specification.

byReference - a flag that indicates whether the data is copied into this compressed geometry object or is accessed by reference.

Throws:

java.lang.IllegalArgumentException - if a problem is detected with the header

Since:

Java 3D 1.2

See Also:

CompressedGeometryHeader, Canvas3D.queryProperties()

Method Detail

getByteCount

public int getByteCount()

Returns the size, in bytes, of the compressed geometry buffer. The size of the compressed geometry header is not included.

Returns:

the size, in bytes, of the compressed geometry buffer.

Throws:

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

getCompressedGeometryHeader

public void getCompressedGeometryHeader(CompressedGeometryHeader hdr)

Copies the compressed geometry header from the CompressedGeometry NodeComponent into the passed in parameter.

Parameters:

hdr - the CompressedGeometryHeader object into which to copy the CompressedGeometry NodeComponent's header; the offset field may differ from that which was originally specified if a copy of the original compressed geometry byte array was created.

Throws:

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

See Also:

CompressedGeometryHeader

getCompressedGeometry

public void getCompressedGeometry(byte[] compressedGeometry)

Retrieves the compressed geometry associated with the CompressedGeometry NodeComponent object. Copies the compressed geometry from the CompressedGeometry node into the given array. The array must be large enough to hold all of the bytes. The individual array elements must be allocated by the caller.

Parameters:

compressedGeometry - the array into which to copy the compressed geometry.

Throws:

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

java.lang.IllegalStateException - if the data access mode for this object is by-reference.

ArrayIndexOutOfBoundsException - if compressedGeometry byte array is not large enough to receive the compressed geometry

decompress

public Shape3D[] decompress()

Decompresses the compressed geometry. Returns an array of Shape nodes containing the decompressed geometry objects, or null if the version number of the compressed geometry is incompatible with the decompressor in the current version of Java 3D.

Returns:

an array of Shape nodes containing the geometry decompressed from this CompressedGeometry NodeComponent object, or null if its version is incompatible

Throws:

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

isByReference

public boolean isByReference()

Retrieves the data access mode for this CompressedGeometry object.

Returns:

true if the data access mode for this CompressedGeometry object is by-reference; false if the data access mode is by-copying.

Since:

Java 3D 1.2

getCompressedGeometryRef

public byte[] getCompressedGeometryRef()

Gets the compressed geometry data reference.

Returns:

the current compressed geometry data reference.

Throws:

java.lang.IllegalStateException - if the data access mode for this object is not by-reference.

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

Since:

Java 3D 1.2

cloneNodeComponent

public NodeComponent cloneNodeComponent()

Deprecated. replaced with cloneNodeComponent(boolean forceDuplicate)

Overrides:

cloneNodeComponent in class NodeComponent