001/*
002 * $RCSfile: TIFFPackBitsUtil.java,v $
003 *
004 * 
005 * Copyright (c) 2005 Sun Microsystems, Inc. All  Rights Reserved.
006 * 
007 * Redistribution and use in source and binary forms, with or without
008 * modification, are permitted provided that the following conditions
009 * are met: 
010 * 
011 * - Redistribution of source code must retain the above copyright 
012 *   notice, this  list of conditions and the following disclaimer.
013 * 
014 * - Redistribution in binary form must reproduce the above copyright
015 *   notice, this list of conditions and the following disclaimer in 
016 *   the documentation and/or other materials provided with the
017 *   distribution.
018 * 
019 * Neither the name of Sun Microsystems, Inc. or the names of 
020 * contributors may be used to endorse or promote products derived 
021 * from this software without specific prior written permission.
022 * 
023 * This software is provided "AS IS," without a warranty of any 
024 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
025 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
026 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
027 * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL 
028 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF 
029 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
030 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR 
031 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
032 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
033 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
034 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
035 * POSSIBILITY OF SUCH DAMAGES. 
036 * 
037 * You acknowledge that this software is not designed or intended for 
038 * use in the design, construction, operation or maintenance of any 
039 * nuclear facility. 
040 *
041 * $Revision: 1.1 $
042 * $Date: 2005/02/11 05:01:49 $
043 * $State: Exp $
044 */
045package com.github.jaiimageio.impl.plugins.tiff;
046
047import java.io.IOException;
048
049public class TIFFPackBitsUtil {
050
051    private static final boolean debug = false;
052
053    byte[] dstData = new byte[8192];
054    int dstIndex = 0;
055
056    public TIFFPackBitsUtil() {
057    }
058
059    private void ensureCapacity(int bytesToAdd) {
060        if (dstIndex + bytesToAdd > dstData.length) {
061            byte[] newDstData = new byte[Math.max((int)(dstData.length*1.2f),
062                                                  dstIndex + bytesToAdd)];
063            System.arraycopy(dstData, 0, newDstData, 0, dstData.length);
064            dstData = newDstData;
065        }
066    }
067
068    public byte[] decode(byte[] srcData) throws IOException {
069        int inIndex = 0;
070        while (inIndex < srcData.length) {
071            byte b = srcData[inIndex++];
072            
073            if (b >= 0 && b <= 127) { // second test not needed?
074                // Literal run packet
075                
076                ensureCapacity(b + 1);
077                for (int i = 0; i < b + 1; i++) {
078                    dstData[dstIndex++] = srcData[inIndex++];
079                }
080            } else if (b <= -1 && b >= -127) {
081                // 2-byte encoded run packet
082                byte repeat = srcData[inIndex++];
083                ensureCapacity(-b + 1);
084                for (int i = 0; i < (-b + 1); i++) {
085                    dstData[dstIndex++] = repeat;
086                }
087            } else {
088                // No-op packet, do nothing
089                ++inIndex;
090            }
091        }
092        
093        byte[] newDstData = new byte[dstIndex];
094        System.arraycopy(dstData, 0, newDstData, 0, dstIndex);
095        return newDstData;
096    }
097}
098