compressedgeometrydata.java

JAVA3D矩陈的相关类

	//
	// Using TriangleArray output is currently the fastest, given the
	// strip sizes observed from various compressed geometry objects, but
	// produces about twice as many vertices.  TriangleStripArray produces
	// the same number of Shape3D objects as TriangleArray using 1/2
	// to 2/3 of the vertices, with only a marginal performance penalty.
	//
	return decompressor.toTriangleStripArrays(cgr);
    }


    /**
     * Retrieves the data access mode for this CompressedGeometryData object.
     * 
     * @return <code>true</code> if the data access mode for this
     * CompressedGeometryData object is by-reference;
     * <code>false</code> if the data access mode is by-copying.
     */
    public boolean isByReference() {
	return this.retained.isByReference();
    }


    /**
     * Gets the compressed geometry data reference.
     *
     * @return the current compressed geometry data reference.
     *
     * @exception IllegalStateException if the data access mode for this
     * object is not by-reference.
     */
    public byte[] getCompressedGeometryRef() {
	if (!isByReference()) {
	    throw new IllegalStateException(
                    J3dUtilsI18N.getString("CompressedGeometry8"));
        }

	return this.retained.getReference();
    }


    /**
     * Gets the compressed geometry data buffer reference, which is
     * always null since NIO buffers are not supported for
     * CompressedGeometryData objects.
     * 
     * @return null
     */
    public J3DBuffer getCompressedGeometryBuffer() {
        return null;
    }


    /**
     * The Header class is a data container for the header information,
     * used in conjunction with a CompressedGeometryData object.
     * This information is used to aid the decompression of the compressed geometry.
     *
     * <p>
     * All instance data is declared public and no get or set methods are
     * provided.
     *
     * @since Java 3D 1.5
     */
    public static class Header extends Object {

        /**
         * bufferType: compressed geometry is made up of individual points.
         */
        public static final int POINT_BUFFER = 0;

        /**
         * bufferType: compressed geometry is made up of line segments.
         */
        public static final int LINE_BUFFER = 1;

        /**
         * bufferType: compressed geometry is made up of triangles.
         */
        public static final int TRIANGLE_BUFFER = 2;

        // Valid values for the bufferDataPresent field.

        /**
         * bufferDataPresent: bit indicating that normal information is
         * bundled with the vertices in the compressed geometry buffer.
         */
        public static final int NORMAL_IN_BUFFER = 1;

        /**
         * bufferDataPresent: bit indicating that RGB color information is
         * bundled with the vertices in the compressed geometry buffer.
         */
        public static final int COLOR_IN_BUFFER = 2;

        /**
         * bufferDataPresent: bit indicating that alpha information is
         * bundled with the vertices in the compressed geometry buffer.
         */
        public static final int ALPHA_IN_BUFFER = 4;

        /**
         * The major version number for the compressed geometry format that
         * was used to compress the geometry.
         * If the version number of compressed geometry is incompatible
         * with the supported version of compressed geometry in the
         * current version of Java 3D, the compressed geometry obejct will
         * not be rendered.
         *
         * @see Canvas3D#queryProperties
         */
        public int majorVersionNumber;

        /**
         * The minor version number for the compressed geometry format that
         * was used to compress the geometry.
         * If the version number of compressed geometry is incompatible
         * with the supported version of compressed geometry in the
         * current version of Java 3D, the compressed geometry obejct will
         * not be rendered.
         *
         * @see Canvas3D#queryProperties
         */
        public int minorVersionNumber;

        /**
         * The minor-minor version number for the compressed geometry format
         * that was used to compress the geometry.
         * If the version number of compressed geometry is incompatible
         * with the supported version of compressed geometry in the
         * current version of Java 3D, the compressed geometry obejct will
         * not be rendered.
         *
         * @see Canvas3D#queryProperties
         */
        public int minorMinorVersionNumber;

        /**
         * Describes the type of data in the compressed geometry buffer.
         * Only one type may be present in any given compressed geometry
         * buffer.
         */
        public int bufferType;

        /**
         * Contains bits indicating what data is bundled with the vertices in the
         * compressed geometry buffer.  If this data is not present (e.g. color)
         * then this info will be inherited from the Appearance node.
         */
        public int bufferDataPresent;

        /**
         * Size of the compressed geometry in bytes.
         */
        public int size;

        /**
         * Offset in bytes of the start of the compressed geometry from the
         * beginning of the compressed geometry byte array passed to the
         * CompressedGeometryData constructor. <p>
         *
         * If the CompressedGeometryData is created with reference access semantics,
         * then this allow external compressors or file readers to embed several
         * blocks of compressed geometry in a single large byte array, possibly
         * interspersed with metadata that is not specific to Java 3D, without
         * having to copy each block to a separate byte array. <p>
         *
         * If the CompressedGeometryData is created with copy access semantics, then
         * <code>size</code> bytes of compressed geometry data are copied from the
         * offset indicated by <code>start</code> instead of copying the entire
         * byte array.  The getCompressedGeometry() method will return only the
         * bytes used to construct the object, and the getCompressedGeometryHeader()
         * method will return a header with the <code>start</code> field set to 0.
         */
        public int start;

        /**
         * A point that defines the lower bound of the <i>x</i>,
         * <i>y</i>, and <i>z</i> components for all positions in the
         * compressed geometry buffer.  If null, a lower bound of
         * (-1,-1,-1) is assumed.  Java 3D will use this information to
         * construct a bounding box around compressed geometry objects
         * that are used in nodes for which the auto compute bounds flag
         * is true.  The default value for this point is null.
         */
        public Point3d lowerBound = null;

        /**
         * A point that defines the upper bound of the <i>x</i>,
         * <i>y</i>, and <i>z</i> components for all positions in the
         * compressed geometry buffer.  If null, an upper bound of (1,1,1)
         * is assumed.  Java 3D will use this information to construct a
         * bounding box around compressed geometry objects that are used
         * in nodes for which the auto compute bounds flag is true.  The
         * default value for this point is null.
         */
        public Point3d upperBound = null;

        /**
         * Creates a new Header object used for the
         * creation of a CompressedGeometryData object.
         * All instance data is declared public and no get or set methods are
         * provided.  All values are set to 0 by default and must be filled
         * in by the application.
         *
         * @see CompressedGeometryData
         */
        public Header() {
        }

        /**
         * Package-scoped method to copy current Header object
         * to the passed-in Header object.
         *
         * @param hdr the Header object into which to copy the
         * current Header.
         */
        void copy(Header hdr) {
            hdr.majorVersionNumber = this.majorVersionNumber;
            hdr.minorVersionNumber = this.minorVersionNumber;
            hdr.minorMinorVersionNumber = this.minorMinorVersionNumber;
            hdr.bufferType = this.bufferType;
            hdr.bufferDataPresent = this.bufferDataPresent;
            hdr.size = this.size;
            hdr.start = this.start;
            hdr.lowerBound = this.lowerBound;
            hdr.upperBound = this.upperBound;
        }

        /**
         * Returns a String describing the contents of the
         * Header object.
         *
         * @return a String describing contents of the compressed geometry header
         */
        public String toString() {
            String type = "UNKNOWN";
            switch (bufferType) {
                case POINT_BUFFER:    type = "POINT_BUFFER";    break;
                case LINE_BUFFER:     type = "LINE_BUFFER";     break;
                case TRIANGLE_BUFFER: type = "TRIANGLE_BUFFER"; break;
            }

            String data = "";
            if ((bufferDataPresent & NORMAL_IN_BUFFER) != 0)
                data = data + "NORMALS ";
            if ((bufferDataPresent & COLOR_IN_BUFFER) != 0)
                data = data + "COLORS ";
            if ((bufferDataPresent & ALPHA_IN_BUFFER) != 0)
                data = data + "ALPHA ";

            String lbound = "null";
            if (lowerBound != null)
                lbound = lowerBound.toString();

            String ubound = "null";
            if (upperBound != null)
                ubound = upperBound.toString();

            return
                    "majorVersionNumber: "      + majorVersionNumber      + "  " +
                    "minorVersionNumber: "      + minorVersionNumber      + "  " +
                    "minorMinorVersionNumber: " + minorMinorVersionNumber + "\n" +
                    "bufferType: "              + type                    + "  " +
                    "bufferDataPresent: "       + data                    + "\n" +
                    "size: "                    + size                    + "  " +
                    "start: "                   + start                   + "\n" +
                    "lower bound: "             + lbound                  + "\n" +
                    "upper bound: "             + ubound                  + "  ";
        }
    }
}