componentsamplemodel.java

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/*
 * @(#)ComponentSampleModel.java	1.43 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 *** As  an unpublished  work pursuant to Title 17 of the United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;

import java.util.Arrays;

/**
 *  This class represents image data which is stored such that each sample
 *  of a pixel occupies one data element of the DataBuffer.  It stores the
 *  N samples which make up a pixel in N separate data array elements.
 *  Different bands may be in different banks of the DataBuffer.
 *  Accessor methods are provided so that image data can be manipulated
 *  directly. This class can support different kinds of interleaving, e.g.
 *  band interleaving, scanline interleaving, and pixel interleaving.
 *  Pixel stride is the number of data array elements between two samples
 *  for the same band on the same scanline. 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.  This class can represent image
 *  data for which each sample is an unsigned integral number which can be
 *  stored in 8, 16, or 32 bits (using <code>DataBuffer.TYPE_BYTE</code>,
 *  <code>DataBuffer.TYPE_USHORT</code>, or <code>DataBuffer.TYPE_INT</code>,
 *  respectively), data for which each sample is a signed integral number
 *  which can be stored in 16 bits (using <code>DataBuffer.TYPE_SHORT</code>),
 *  or data for which each sample is a signed float or double quantity
 *  (using <code>DataBuffer.TYPE_FLOAT</code> or
 *  <code>DataBuffer.TYPE_DOUBLE</code>, respectively).
 *  All samples of a given ComponentSampleModel
 *  are stored with the same precision.  All strides and offsets must be
 *  non-negative.  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}, 
 *  {@link DataBuffer#TYPE_DOUBLE TYPE_DOUBLE}, 
 *  @see java.awt.image.PixelInterleavedSampleModel
 *  @see java.awt.image.BandedSampleModel
 */

public class ComponentSampleModel extends SampleModel
{
    /** Offsets for all bands in data array elements. */
    protected int bandOffsets[];

    /** Index for each bank storing a band of image data. */
    protected int[] bankIndices;

    /** 
     * The number of bands in this 
     * <code>ComponentSampleModel</code>.
     */
    protected int numBands = 1;

    /**
     * The number of banks in this 
     * <code>ComponentSampleModel</code>.
     */
    protected int numBanks = 1;

    /**
     *  Line stride (in data array elements) of the region of image
     *  data described by this ComponentSampleModel.
     */
    protected int scanlineStride;

    /** Pixel stride (in data array elements) of the region of image
     *  data described by this ComponentSampleModel.
     */
    protected int pixelStride;

    static private native void initIDs();
    static {
        ColorModel.loadLibraries();
        initIDs();
    }

    /**
     * Constructs a ComponentSampleModel with the specified parameters.
     * The number of bands will be given by the length of the bandOffsets array.
     * All bands will be stored in the first bank of the DataBuffer.
     * @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 pixelStride the pixel stride of the region of image
     *     data described
     * @param scanlineStride the line stride of the region of image
     *     data described
     * @param bandOffsets the offsets of all bands
     * @throws IllegalArgumentException if <code>w</code> or
     *         <code>h</code> is not greater than 0
     * @throws IllegalArgumentException if <code>pixelStride</code>
     *         is less than 0
     * @throws IllegalArgumentException if <code>scanlineStride</code>
     *         is less than 0
     * @throws IllegalArgumentException if <code>numBands</code>
     *         is less than 1
     * @throws IllegalArgumentException if the product of <code>w</code>
     *         and <code>h</code> is greater than
     *         <code>Integer.MAX_VALUE</code>
     * @throws IllegalArgumentException if <code>dataType</code> is not
     *         one of the supported data types
     */
    public ComponentSampleModel(int dataType,
                                int w, int h,
                                int pixelStride,
                                int scanlineStride,
                                int bandOffsets[]) {
	super(dataType, w, h, bandOffsets.length);
	this.dataType = dataType;
	this.pixelStride = pixelStride;
	this.scanlineStride  = scanlineStride;
	this.bandOffsets = (int[])bandOffsets.clone();
        numBands = bandOffsets.length;
        if (pixelStride < 0) {
            throw new IllegalArgumentException("Pixel stride must be >= 0");
        }
        // TODO - bug 4296691 - remove this check
        if (scanlineStride < 0) {
            throw new IllegalArgumentException("Scanline stride must be >= 0");
        }
        if (numBands < 1) {
            throw new IllegalArgumentException("Must have at least one band.");
        }
        if ((dataType < DataBuffer.TYPE_BYTE) ||
            (dataType > DataBuffer.TYPE_DOUBLE)) {
            throw new IllegalArgumentException("Unsupported dataType.");
        }
	bankIndices = new int[numBands];
	for (int i=0; i<numBands; i++) {
	    bankIndices[i] = 0;
        }
    }


    /**
     * Constructs a ComponentSampleModel with the specified parameters.
     * The number of bands will be given by the length of the bandOffsets array.
     * Different bands may be stored in different banks of the DataBuffer.
     *
     * @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 pixelStride the pixel stride of the region of image
     *     data described
     * @param scanlineStride The line stride of the region of image
     *     data described
     * @param bankIndices the bank indices of all bands
     * @param bandOffsets the band offsets of all bands
     * @throws IllegalArgumentException if <code>w</code> or
     *         <code>h</code> is not greater than 0
     * @throws IllegalArgumentException if <code>pixelStride</code>
     *         is less than 0
     * @throws IllegalArgumentException if <code>scanlineStride</code>
     *         is less than 0
     * @throws IllegalArgumentException if the length of 
     *         <code>bankIndices</code> does not equal the length of 
     *         <code>bankOffsets</code>
     * @throws IllegalArgumentException if any of the bank indices 
     *         of <code>bandIndices</code> is less than 0
     * @throws IllegalArgumentException if <code>dataType</code> is not
     *         one of the supported data types
     */
    public ComponentSampleModel(int dataType,
                                int w, int h,
                                int pixelStride,
                                int scanlineStride,
                                int bankIndices[],
                                int bandOffsets[]) {
        super(dataType, w, h, bandOffsets.length);
	this.dataType = dataType;
	this.pixelStride = pixelStride;
	this.scanlineStride  = scanlineStride;
	this.bandOffsets = (int[])bandOffsets.clone();
        this.bankIndices = (int[]) bankIndices.clone();
        if (pixelStride < 0) {
            throw new IllegalArgumentException("Pixel stride must be >= 0");
        }
        // TODO - bug 4296691 - remove this check
        if (scanlineStride < 0) {
            throw new IllegalArgumentException("Scanline stride must be >= 0");
        }
        if ((dataType < DataBuffer.TYPE_BYTE) ||
            (dataType > DataBuffer.TYPE_DOUBLE)) {
            throw new IllegalArgumentException("Unsupported dataType.");
        }
        int maxBank = bankIndices[0];
        if (maxBank < 0) {
            throw new IllegalArgumentException("Index of bank 0 is less than "+
                                               "0 ("+maxBank+")");
        }
        for (int i=1; i < bankIndices.length; i++) {
            if (bankIndices[i] > maxBank) {
                maxBank = bankIndices[i];
            }
            else if (bankIndices[i] < 0) {
                throw new IllegalArgumentException("Index of bank "+i+
                                                   " is less than 0 ("+
                                                   maxBank+")");
            }
        }
        numBanks         = maxBank+1;
        numBands         = bandOffsets.length;
        if (bandOffsets.length != bankIndices.length) {
            throw new IllegalArgumentException("Length of bandOffsets must "+
                                               "equal length of bankIndices.");
        }
    }

    /**
     * Returns the size of the data buffer (in data elements) needed
     * for a data buffer that matches this ComponentSampleModel.
     */
     private long getBufferSize() {
         int maxBandOff=bandOffsets[0];
         for (int i=1; i<bandOffsets.length; i++)
             maxBandOff = Math.max(maxBandOff,bandOffsets[i]);

         long size = 0;
         if (maxBandOff >= 0)
             size += maxBandOff+1;
         if (pixelStride > 0)
             size += pixelStride * (width-1);
         if (scanlineStride > 0)
             size += scanlineStride*(height-1);
         return size;
     }

     /**
      * Preserves band ordering with new step factor...
      */
    int []orderBands(int orig[], int step) {
        int map[] = new int[orig.length];
        int ret[] = new int[orig.length];

        for (int i=0; i<map.length; i++) map[i] = i;

        for (int i = 0; i < ret.length; i++) {
            int index = i;
            for (int j = i+1; j < ret.length; j++) {
                if (orig[map[index]] > orig[map[j]]) {
                    index = j;
                }
            }
            ret[map[index]] = i*step;
            map[index]  = map[i];
        }
        return ret;
    }

    /**
     * Creates a new <code>ComponentSampleModel</code> with the specified
     * width and height.  The new <code>SampleModel</code> will have the same
     * number of bands, storage data type, interleaving scheme, and
     * pixel stride as this <code>SampleModel</code>.
     * @param w the width of the resulting <code>SampleModel</code>
     * @param h the height of the resulting <code>SampleModel</code>
     * @return a new <code>ComponentSampleModel</code> with the specified size
     * @throws IllegalArgumentException if <code>w</code> or
     *         <code>h</code> is not greater than 0
     */
    public SampleModel createCompatibleSampleModel(int w, int h) {
        SampleModel ret=null;
        long size;
        int minBandOff=bandOffsets[0];
        int maxBandOff=bandOffsets[0];
        for (int i=1; i<bandOffsets.length; i++) {
            minBandOff = Math.min(minBandOff,bandOffsets[i]);
            maxBandOff = Math.max(maxBandOff,bandOffsets[i]);
        }
        maxBandOff -= minBandOff;

        int bands   = bandOffsets.length;
        int bandOff[];
        int pStride = Math.abs(pixelStride);
        int lStride = Math.abs(scanlineStride);
        int bStride = Math.abs(maxBandOff);

        if (pStride > lStride) {
            if (pStride > bStride) {
                if (lStride > bStride) { // pix > line > band
                    bandOff = new int[bandOffsets.length];
                    for (int i=0; i<bands; i++)
                        bandOff[i] = bandOffsets[i]-minBandOff;
                    lStride = bStride+1;
                    pStride = lStride*h;
                } else { // pix > band > line
                    bandOff = orderBands(bandOffsets,lStride*h);
                    pStride = bands*lStride*h;
                }
            } else { // band > pix > line
                pStride = lStride*h;
                bandOff = orderBands(bandOffsets,pStride*w);
            }
        } else {
            if (pStride > bStride) { // line > pix > band
                bandOff = new int[bandOffsets.length];
                for (int i=0; i<bands; i++)
                    bandOff[i] = bandOffsets[i]-minBandOff;
                pStride = bStride+1;
                lStride = pStride*w;
            } else {
                if (lStride > bStride) { // line > band > pix
                    bandOff = orderBands(bandOffsets,pStride*w);
                    lStride = bands*pStride*w;
                } else { // band > line > pix
                    lStride = pStride*w;
                    bandOff = orderBands(bandOffsets,lStride*h);
                }
            }
        }

        // make sure we make room for negative offsets...
        int base = 0;
        if (scanlineStride < 0) {
            base += lStride*h;
            lStride *= -1;
        }
        if (pixelStride    < 0) {
            base += pStride*w;
            pStride *= -1;
        }

        for (int i=0; i<bands; i++)
            bandOff[i] += base;
        return new ComponentSampleModel(dataType, w, h, pStride,
                                        lStride, bankIndices, bandOff);
    }

    /**
     * Creates a new ComponentSampleModel with a subset of the bands
     * of this ComponentSampleModel.  The new ComponentSampleModel can be
     * used with any DataBuffer that the existing ComponentSampleModel
     * can be used with.  The new ComponentSampleModel/DataBuffer
     * combination will represent an image with a subset of the bands
     * of the original ComponentSampleModel/DataBuffer combination.
     * @param bands a subset of bands from this 
     *              <code>ComponentSampleModel</code>
     * @return a <code>ComponentSampleModel</code> created with a subset
     *          of bands from this <code>ComponentSampleModel</code>.
     */
    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 ComponentSampleModel(this.dataType, width, height,
                                        this.pixelStride,
                                        this.scanlineStride,
                                        newBankIndices, newBandOffsets);
    }

    /**
     * Creates a <code>DataBuffer</code> that corresponds to this 
     * <code>ComponentSampleModel</code>.
     * The <code>DataBuffer</code> object's data type, number of banks, 
     * and size are be consistent with this <code>ComponentSampleModel</code>.
     * @return a <code>DataBuffer</code> whose data type, number of banks
     *         and size are consistent with this 
     *         <code>ComponentSampleModel</code>.
     */