/*

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */
package org.apache.batik.ext.awt.image.rendered;

import java.awt.RenderingHints;
import java.awt.image.ByteLookupTable;
import java.awt.image.LookupOp;
import java.awt.image.WritableRaster;

import org.apache.batik.ext.awt.image.GraphicsUtil;
import org.apache.batik.ext.awt.image.TransferFunction;

/**
 *
 * @author <a href="mailto:thomas.deweese@kodak.com">Thomas DeWeese</a>
 * @version $Id$
 */
public class ComponentTransferRed extends AbstractRed {
    LookupOp operation;

    /**
     * The constructor will instantiate a LookupOp instance using
     * a LookupOp, which is built using the four LUT
     * data obtained by the TransferFunction objects
     * funcs[0] : Alpha component transfer function
     * funcs[1] : Red component transfer function
     * funcs[2] : Green component transfer function
     * funcs[3] : Blue component transfer function
     */
    public ComponentTransferRed(CachableRed src,
                                TransferFunction [] funcs,
                                RenderingHints hints) {
        super(src, src.getBounds(),
              GraphicsUtil.coerceColorModel(src.getColorModel(), false),
              src.getSampleModel(),
              null);

        byte [][] tableData = {funcs[1].getLookupTable(),
                               funcs[2].getLookupTable(),
                               funcs[3].getLookupTable(),
                               funcs[0].getLookupTable()};

        // Note that we create an anonymous subclass here.
        // For what ever reason this makes the Op work correctly.
        // If you remove this, it seems to get the color channels messed
        // up.  The downside is that I suspect that this means we are
        // falling into a more general, and hence slower case, but
        // at least it works....
        operation  =  new LookupOp(new ByteLookupTable(0, tableData), hints)
            { };
    }

    public WritableRaster copyData(WritableRaster wr){
        CachableRed src = (CachableRed)getSources().get(0);

        wr = src.copyData(wr);
        GraphicsUtil.coerceData(wr, src.getColorModel(), false);

        WritableRaster srcWR = wr.createWritableTranslatedChild(0,0);

        operation.filter(srcWR, srcWR);

        return wr;
    }
}
