/*

   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.renderable;

import java.awt.image.RenderedImage;
import java.awt.image.renderable.RenderContext;

import org.apache.batik.ext.awt.image.rendered.ColorMatrixRed;

/**
 * Implements the interface expected from a color matrix
 * operation
 *
 * @author <a href="mailto:vincent.hardy@eng.sun.com">Vincent Hardy</a>
 * @version $Id: ColorMatrixRable8Bit.java 478276 2006-11-22 18:33:37Z dvholten $
 */
public class ColorMatrixRable8Bit
    extends    AbstractColorInterpolationRable
    implements ColorMatrixRable {
    /**
     * Predefined luminanceToAlpha matrix
     */
    private static float[][] MATRIX_LUMINANCE_TO_ALPHA
        = {
            {0,       0,       0,       0, 0},
            {0,       0,       0,       0, 0},
            {0,       0,       0,       0, 0},
            {0.2125f, 0.7154f, 0.0721f, 0, 0}
        };

    /**
     * This matrix type
     */
    private int type;

    /**
     * The matrix
     */
    private float[][] matrix;

    /**
     * Sets the source of the blur operation
     */
    public void setSource(Filter src){
        init(src, null);
    }

    /**
     * Returns the source of the blur operation
     */
    public Filter getSource(){
        return (Filter)getSources().get(0);
    }

    /**
     * Returns the type of this color matrix.
     * @return one of TYPE_MATRIX, TYPE_SATURATE, TYPE_HUE_ROTATE,
     *         TYPE_LUMINANCE_TO_ALPHA
     */
    public int getType(){
        return type;
    }

    /**
     * Returns the rows of the color matrix. This uses
     * the same convention as BandCombineOp.
     */
    public float[][] getMatrix(){
        return matrix;
    }

    /**
     * Instances should be built through the static
     * factory methods
     */
    private ColorMatrixRable8Bit(){
    }

    /**
     * Builds a TYPE_MATRIX instance
     */
    public static ColorMatrixRable buildMatrix(float[][] matrix){
        if(matrix == null){
            throw new IllegalArgumentException();
        }

        if(matrix.length != 4){
            throw new IllegalArgumentException();
        }

        float[][] newMatrix = new float[4][];

        for(int i=0; i<4; i++){
            float[] m = matrix[i];
            if(m == null){
                throw new IllegalArgumentException();
            }
            if(m.length != 5){
                throw new IllegalArgumentException();
            }
            newMatrix[i] = new float[5];
            for(int j=0; j<5; j++){
                newMatrix[i][j] = m[j];
            }
        }

        /*for(int i=0; i<4; i++){
            for(int j=0; j<5; j++)
                System.out.print(newMatrix[i][j] + " ");
            System.out.println();
            }*/

        ColorMatrixRable8Bit filter
            = new ColorMatrixRable8Bit();
        filter.type = TYPE_MATRIX;
        filter.matrix = newMatrix;
        return filter;
    }

    /**
     * Builds a TYPE_SATURATE instance
     */
    public static ColorMatrixRable buildSaturate(float s){
        ColorMatrixRable8Bit filter
            = new ColorMatrixRable8Bit();
        filter.type = TYPE_SATURATE;
        filter.matrix = new float[][] {
            { 0.213f+0.787f*s,  0.715f-0.715f*s, 0.072f-0.072f*s, 0, 0 },
            { 0.213f-0.213f*s,  0.715f+0.285f*s, 0.072f-0.072f*s, 0, 0 },
            { 0.213f-0.213f*s,  0.715f-0.715f*s, 0.072f+0.928f*s, 0, 0 },
            { 0,                0,               0,               1, 0 }
        };
        return filter;
    }

    /**
     * Builds a TYPE_HUE_ROTATE instance.
     * @param a angle, in radian
     */
    public static ColorMatrixRable buildHueRotate(float a){
        ColorMatrixRable8Bit filter
            = new ColorMatrixRable8Bit();
        filter.type = TYPE_HUE_ROTATE;

        float cos = (float)Math.cos(a);
        float sin = (float)Math.sin(a);

        // System.out.println("sin : " + sin + " cos : " + cos);

        float a00 = 0.213f + cos*0.787f - sin*0.213f;
        float a10 = 0.213f - cos*0.212f + sin*0.143f;
        float a20 = 0.213f - cos*0.213f - sin*0.787f;

        float a01 = 0.715f - cos*0.715f - sin*0.715f;
        float a11 = 0.715f + cos*0.285f + sin*0.140f;
        float a21 = 0.715f - cos*0.715f + sin*0.715f;

        float a02 = 0.072f - cos*0.072f + sin*0.928f;
        float a12 = 0.072f - cos*0.072f - sin*0.283f;
        float a22 = 0.072f + cos*0.928f + sin*0.072f;

        filter.matrix = new float[][] {
            { a00, a01, a02, 0, 0 },
            { a10, a11, a12, 0, 0 },
            { a20, a21, a22, 0, 0 },
            { 0,   0,   0,   1, 0 }};

        /*for(int i=0; i<4; i++){
            for(int j=0; j<5; j++)
                System.out.print(filter.matrix[i][j] + " ");
            System.out.println();
            }*/

        return filter;
    }

    /**
     * Builds a TYPE_LUMINANCE_TO_ALPHA instance
     */
    public static ColorMatrixRable buildLuminanceToAlpha(){
        ColorMatrixRable8Bit filter
            = new ColorMatrixRable8Bit();
        filter.type = TYPE_LUMINANCE_TO_ALPHA;
        filter.matrix = MATRIX_LUMINANCE_TO_ALPHA;
        return filter;
    }

    public RenderedImage createRendering(RenderContext rc) {
        //
        // Get source's rendered image
        //
        RenderedImage srcRI = getSource().createRendering(rc);

        if(srcRI == null)
            return null;

        return new ColorMatrixRed(convertSourceCS(srcRI), matrix);
    }
}
