/*
 * $RCSfile: TIFFPackBitsUtil.java,v $
 *
 * 
 * Copyright (c) 2005 Sun Microsystems, Inc. All  Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met: 
 * 
 * - Redistribution of source code must retain the above copyright 
 *   notice, this  list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in 
 *   the documentation and/or other materials provided with the
 *   distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL 
 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF 
 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR 
 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES. 
 * 
 * You acknowledge that this software is not designed or intended for 
 * use in the design, construction, operation or maintenance of any 
 * nuclear facility. 
 *
 * $Revision: 1.1 $
 * $Date: 2005-02-11 05:01:49 $
 * $State: Exp $
 */
package com.sun.media.imageioimpl.plugins.tiff;

import java.awt.Rectangle;
import java.io.IOException;
import javax.imageio.ImageReader;
import com.sun.media.imageio.plugins.tiff.BaselineTIFFTagSet;
import com.sun.media.imageio.plugins.tiff.TIFFTag;

public class TIFFPackBitsUtil {

    private static final boolean debug = false;

    byte[] dstData = new byte[8192];
    int dstIndex = 0;

    public TIFFPackBitsUtil() {
    }

    private void ensureCapacity(int bytesToAdd) {
        if (dstIndex + bytesToAdd > dstData.length) {
            byte[] newDstData = new byte[Math.max((int)(dstData.length*1.2f),
                                                  dstIndex + bytesToAdd)];
            System.arraycopy(dstData, 0, newDstData, 0, dstData.length);
            dstData = newDstData;
        }
    }

    public byte[] decode(byte[] srcData) throws IOException {
	int inIndex = 0;
        while (inIndex < srcData.length) {
            byte b = srcData[inIndex++];
            
            if (b >= 0 && b <= 127) { // second test not needed?
                // Literal run packet
                
                ensureCapacity(b + 1);
                for (int i = 0; i < b + 1; i++) {
                    dstData[dstIndex++] = srcData[inIndex++];
                }
            } else if (b <= -1 && b >= -127) {
                // 2-byte encoded run packet
                byte repeat = srcData[inIndex++];
                ensureCapacity(-b + 1);
                for (int i = 0; i < (-b + 1); i++) {
                    dstData[dstIndex++] = repeat;
                }
            } else {
                // No-op packet, do nothing
                ++inIndex;
            }
        }
        
        byte[] newDstData = new byte[dstIndex];
        System.arraycopy(dstData, 0, newDstData, 0, dstIndex);
        return newDstData;
    }
}

