/*
 * Created on Feb 5, 2008
 * Created by Olivier Chalouhi
 * 
 * Copyright 2008 Vuze, Inc.  All rights reserved.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License only.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

package com.aelitis.azureus.core.util.png;

import java.io.ByteArrayOutputStream;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;

public class IDATChunk extends CRCedChunk {
	private static final byte[] type = {(byte) 73, (byte) 68, (byte) 65, (byte) 84 };
	
	private int width;
	private int height;
	
	public IDATChunk(int width, int height) {
		super(type);
		this.width = width;
		this.height = height;
	}
	
	
	public byte[] getContentPayload() {
		byte[] payload = new byte[(width+1)*height];
		for(int i = 0; i<height ; i++) {
			int offset = i * (width+1);
			//NO filter on this line
			payload[offset++] = 0;
			for(int j = 0 ; j<width ; j++) {
				payload[offset+j] = (byte)(127);
			}
		}
		
		Deflater deflater = new Deflater( Deflater.DEFAULT_COMPRESSION );
	    ByteArrayOutputStream outBytes = new ByteArrayOutputStream((width+1)*height);
	            
	    DeflaterOutputStream compBytes = new DeflaterOutputStream( outBytes, deflater );
	    try {
	    	compBytes.write(payload);
	    	compBytes.close();
	    } catch(Exception e) {
	    	e.printStackTrace();
	    }
	    byte[] compPayload = outBytes.toByteArray();
	    		
		return compPayload;
	}

}
