bandedsamplemodel.java

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/*
 * @(#)BandedSampleModel.java	1.33 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

/* ****************************************************************
 ******************************************************************
 ******************************************************************
 *** COPYRIGHT (c) Eastman Kodak Company, 1997
 *** As  an unpublished  work pursuant to Title 17 of the United
 *** States Code.  All rights reserved.
 ******************************************************************
 ******************************************************************
 ******************************************************************/

package java.awt.image;

/** 
 *  This class represents image data which is stored in a band interleaved
 *  fashion and for
 *  which each sample of a pixel occupies one data element of the DataBuffer.
 *  It subclasses ComponentSampleModel but provides a more efficent
 *  implementation for accessing band interleaved image data than is provided
 *  by ComponentSampleModel.  This class should typically be used when working
 *  with images which store sample data for each band in a different bank of the
 *  DataBuffer. Accessor methods are provided so that image data can be
 *  manipulated directly. Pixel stride is the number of
 *  data array elements between two samples for the same band on the same
 *  scanline. The pixel stride for a BandedSampleModel is one.
 *  Scanline stride is the number of data array elements between
 *  a given sample and the corresponding sample in the same column of the next
 *  scanline.  Band offsets denote the number
 *  of data array elements from the first data array element of the bank
 *  of the DataBuffer holding each band to the first sample of the band.
 *  The bands are numbered from 0 to N-1.
 *  Bank indices denote the correspondence between a bank of the data buffer
 *  and a band of image data.  This class supports 
 *  {@link DataBuffer#TYPE_BYTE TYPE_BYTE},
 *  {@link DataBuffer#TYPE_USHORT TYPE_USHORT},
 *  {@link DataBuffer#TYPE_SHORT TYPE_SHORT},
 *  {@link DataBuffer#TYPE_INT TYPE_INT},
 *  {@link DataBuffer#TYPE_FLOAT TYPE_FLOAT}, and
 *  {@link DataBuffer#TYPE_DOUBLE TYPE_DOUBLE} datatypes
 */


public final class BandedSampleModel extends ComponentSampleModel
{

    /**
     * Constructs a BandedSampleModel with the specified parameters.
     * The pixel stride will be one data element.  The scanline stride
     * will be the same as the width.  Each band will be stored in
     * a separate bank and all band offsets will be zero.
     * @param dataType  The data type for storing samples.
     * @param w 	The width (in pixels) of the region of
     *                  image data described. 
     * @param h 	The height (in pixels) of the region of image
     *                  data described.
     * @param numBands  The number of bands for the image data.
     * @throws IllegalArgumentException if <code>dataType</code> is not
     *         one of the supported data types
     */
    public BandedSampleModel(int dataType, int w, int h, int numBands) {
	super(dataType, w, h, 1, w,
              BandedSampleModel.createIndicesArray(numBands),
              BandedSampleModel.createOffsetArray(numBands));
    }

    /**
     * Constructs a BandedSampleModel with the specified parameters. 
     * The number of bands will be inferred from the lengths of the
     * bandOffsets bankIndices arrays, which must be equal.  The pixel
     * stride will be one data element.
     * @param dataType  The data type for storing samples.
     * @param w 	The width (in pixels) of the region of
     *                  image data described.
     * @param h 	The height (in pixels) of the region of
     *                  image data described.
     * @param scanlineStride The line stride of the of the image data.
     * @param bankIndices The bank index for each band.
     * @param bandOffsets The band offset for each band.
     * @throws IllegalArgumentException if <code>dataType</code> is not
     *         one of the supported data types
     */
    public BandedSampleModel(int dataType,
			     int w, int h,
			     int scanlineStride,
			     int bankIndices[],
                             int bandOffsets[]) {

	super(dataType, w, h, 1,scanlineStride, bankIndices, bandOffsets);
    }

    /**
     * Creates a new BandedSampleModel with the specified
     * width and height.  The new BandedSampleModel will have the same
     * number of bands, storage data type, and bank indices
     * as this BandedSampleModel.  The band offsets will be compressed
     * such that the offset between bands will be w*pixelStride and
     * the minimum of all of the band offsets is zero.
     * @param w the width of the resulting <code>BandedSampleModel</code>
     * @param h the height of the resulting <code>BandedSampleModel</code>
     * @return a new <code>BandedSampleModel</code> with the specified
     *         width and height.
     * @throws IllegalArgumentException if <code>w</code> or 
     *         <code>h</code> equals either
     *         <code>Integer.MAX_VALUE</code> or
     *         <code>Integer.MIN_VALUE</code>
     * @throws IllegalArgumentException if <code>dataType</code> is not
     *         one of the supported data types
     */
    public SampleModel createCompatibleSampleModel(int w, int h) {
        int[] bandOffs;

        if (numBanks == 1) {
            bandOffs = orderBands(bandOffsets, w*h);
        }
        else {
            bandOffs = new int[bandOffsets.length];
        }

        SampleModel sampleModel = 
            new BandedSampleModel(dataType, w, h, w, bankIndices, bandOffs);
	return sampleModel;
    }

    /**
     * Creates a new BandedSampleModel with a subset of the bands of this
     * BandedSampleModel.  The new BandedSampleModel can be
     * used with any DataBuffer that the existing BandedSampleModel
     * can be used with.  The new BandedSampleModel/DataBuffer
     * combination will represent an image with a subset of the bands
     * of the original BandedSampleModel/DataBuffer combination.
     * @throws RasterFormatException if the number of bands is greater than
     *                               the number of banks in this sample model.
     * @throws IllegalArgumentException if <code>dataType</code> is not
     *         one of the supported data types 
     */
    public SampleModel createSubsetSampleModel(int bands[]) {
	if (bands.length > bankIndices.length)
	    throw new RasterFormatException("There are only " +
					    bankIndices.length +
					    " bands");
	int newBankIndices[] = new int[bands.length];
	int newBandOffsets[] = new int[bands.length];

	for (int i=0; i<bands.length; i++) {
	    newBankIndices[i] = bankIndices[bands[i]];
	    newBandOffsets[i] = bandOffsets[bands[i]];
        }

        return new BandedSampleModel(this.dataType, width, height,
				     this.scanlineStride,
				     newBankIndices, newBandOffsets);
    }

    /**
     * Creates a DataBuffer that corresponds to this BandedSampleModel,
     * The DataBuffer's data type, number of banks, and size
     * will be consistent with this BandedSampleModel.
     * @throws IllegalArgumentException if <code>dataType</code> is not
     *         one of the supported types.
     */
    public DataBuffer createDataBuffer() {
        DataBuffer dataBuffer = null;

	int size = scanlineStride * height;
        switch (dataType) {
        case DataBuffer.TYPE_BYTE:
            dataBuffer = new DataBufferByte(size, numBands);
            break;
        case DataBuffer.TYPE_USHORT:
            dataBuffer = new DataBufferUShort(size, numBands);
            break;
        case DataBuffer.TYPE_SHORT:
            dataBuffer = new DataBufferShort(size, numBands);
            break;
        case DataBuffer.TYPE_INT:
            dataBuffer = new DataBufferInt(size, numBands);
            break;
        case DataBuffer.TYPE_FLOAT:
            dataBuffer = new DataBufferFloat(size, numBands);
            break;
        case DataBuffer.TYPE_DOUBLE:
            dataBuffer = new DataBufferDouble(size, numBands);
            break;
        default:
            throw new IllegalArgumentException("dataType is not one " +
                "of the supported types.");
        }

        return dataBuffer;
    }


    /** 
     * Returns data for a single pixel in a primitive array of type
     * TransferType.  For a BandedSampleModel, this will be the same
     * as the data type, and samples will be returned one per array
     * element.  Generally, obj
     * should be passed in as null, so that the Object will be created
     * automatically and will be of the right primitive data type.
     * <p>
     * The following code illustrates transferring data for one pixel from
     * DataBuffer <code>db1</code>, whose storage layout is described by
     * BandedSampleModel <code>bsm1</code>, to DataBuffer <code>db2</code>,
     * whose storage layout is described by
     * BandedSampleModel <code>bsm2</code>.
     * The transfer will generally be more efficient than using
     * getPixel/setPixel.
     * <pre>
     * 	     BandedSampleModel bsm1, bsm2;
     *	     DataBufferInt db1, db2;
     * 	     bsm2.setDataElements(x, y, bsm1.getDataElements(x, y, null, db1),
     *                            db2);
     * </pre>
     * Using getDataElements/setDataElements to transfer between two
     * DataBuffer/SampleModel pairs is legitimate if the SampleModels have
     * the same number of bands, corresponding bands have the same number of
     * bits per sample, and the TransferTypes are the same.
     * <p>
     * If obj is non-null, it should be a primitive array of type TransferType.
     * Otherwise, a ClassCastException is thrown.  An
     * ArrayIndexOutOfBoundsException may be thrown if the coordinates are
     * not in bounds, or if obj is non-null and is not large enough to hold
     * the pixel data.
     * @param x,&nbsp;y The coordinates of the pixel location
     * @param obj       If non-null, a primitive array in which to return
     *                  the pixel data.
     * @param data      The DataBuffer containing the image data.
     * @return the data for the specified pixel.
     * @see #setDataElements(int, int, Object, DataBuffer)
     */
    public Object getDataElements(int x, int y, Object obj, DataBuffer data) {
        if ((x < 0) || (y < 0) || (x >= width) || (y >= height)) {
            throw new ArrayIndexOutOfBoundsException
                ("Coordinate out of bounds!");
        }
	int type = getTransferType();
	int numDataElems = getNumDataElements();
	int pixelOffset = y*scanlineStride + x;

	switch(type) {

	case DataBuffer.TYPE_BYTE:

	    byte[] bdata;

	    if (obj == null) {
		bdata = new byte[numDataElems];
            } else {
		bdata = (byte[])obj;
            }

	    for (int i=0; i<numDataElems; i++) {
		bdata[i] = (byte)data.getElem(bankIndices[i],
                                              pixelOffset + bandOffsets[i]);
	    }

	    obj = (Object)bdata;
	    break;

	case DataBuffer.TYPE_USHORT:
        case DataBuffer.TYPE_SHORT:
            
	    short[] sdata;