/*

 ============================================================================
                   The Apache Software License, Version 1.1
 ============================================================================

 Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.

 Redistribution and use in source and binary forms, with or without modifica-
 tion, are permitted provided that the following conditions are met:

 1. Redistributions of  source code must  retain the above copyright  notice,
    this list of conditions and the following disclaimer.

 2. Redistributions 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.

 3. The end-user documentation included with the redistribution, if any, must
    include  the following  acknowledgment:  "This product includes  software
    developed  by the  Apache Software Foundation  (http://www.apache.org/)."
    Alternately, this  acknowledgment may  appear in the software itself,  if
    and wherever such third-party acknowledgments normally appear.

 4. The names "Batik" and  "Apache Software Foundation" must  not  be
    used to  endorse or promote  products derived from  this software without
    prior written permission. For written permission, please contact
    apache@apache.org.

 5. Products  derived from this software may not  be called "Apache", nor may
    "Apache" appear  in their name,  without prior written permission  of the
    Apache Software Foundation.

 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 FITNESS  FOR A PARTICULAR  PURPOSE ARE  DISCLAIMED.  IN NO  EVENT SHALL  THE
 APACHE SOFTWARE  FOUNDATION  OR ITS CONTRIBUTORS  BE LIABLE FOR  ANY DIRECT,
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 DING, BUT NOT LIMITED TO, PROCUREMENT  OF SUBSTITUTE GOODS OR SERVICES; LOSS
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 (INCLUDING  NEGLIGENCE OR  OTHERWISE) ARISING IN  ANY WAY OUT OF THE  USE OF
 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 This software  consists of voluntary contributions made  by many individuals
 on  behalf of the Apache Software  Foundation. For more  information on the
 Apache Software Foundation, please see <http://www.apache.org/>.

*/

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


import java.awt.Point;
import java.awt.Rectangle;
import java.awt.color.ColorSpace;
import java.awt.image.BandCombineOp;
import java.awt.image.BufferedImage;
import java.awt.image.ColorConvertOp;
import java.awt.image.ColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.Raster;
import java.awt.image.SampleModel;
import java.awt.image.SinglePixelPackedSampleModel;
import java.awt.image.WritableRaster;

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

/**
 * This function will tranform an image from any colorspace into a
 * luminance image.  The alpha channel if any will be copied to the
 * new image.
 *
 * @author <a href="mailto:Thomas.DeWeeese@Kodak.com">Thomas DeWeese</a>
 * @version $Id: Any2LsRGBRed.java,v 1.5 2003/08/09 16:58:42 deweese Exp $ */
public class Any2LsRGBRed extends AbstractRed {

    boolean srcIssRGB = false;

    /**
     * Construct a luminace image from src.
     *
     * @param src The image to convert to a luminance image
     */
    public Any2LsRGBRed(CachableRed src) {
        super(src,src.getBounds(), 
              fixColorModel(src),
              fixSampleModel(src),
              src.getTileGridXOffset(),
              src.getTileGridYOffset(),
              null);

        ColorModel srcCM = src.getColorModel();
        if (srcCM == null) return;
        ColorSpace srcCS = srcCM.getColorSpace();
        if (srcCS == ColorSpace.getInstance(ColorSpace.CS_sRGB))
            srcIssRGB = true;
    }

    /**
     * Gamma for linear to sRGB convertion
     */
    private static final double GAMMA = 2.4;
    private static final double LFACT = 1.0/12.92;


    public static final double sRGBToLsRGB(double value) {
        if(value <= 0.003928)
            return value*LFACT;
        return Math.pow((value+0.055)/1.055, GAMMA);
    }

    /**
     * Lookup tables for RGB lookups. The linearToSRGBLut is used
     * when noise values are considered to be on a linearScale. The
     * linearToLinear table is used when the values are considered to
     * be on the sRGB scale to begin with.
     */
    private static final int sRGBToLsRGBLut[] = new int[256];
    static {
        final double scale = 1.0/255;

        // System.out.print("S2L: ");
        for(int i=0; i<256; i++){
            double value = sRGBToLsRGB(i*scale);
            sRGBToLsRGBLut[i] = (int)Math.round(value*255.0);
            // System.out.print(sRGBToLsRGBLut[i] + ",");
        }
        // System.out.println("");
    }

    public WritableRaster copyData(WritableRaster wr) {
        // Get my source.
        CachableRed src   = (CachableRed)getSources().get(0);
        ColorModel  srcCM = src.getColorModel();
        SampleModel srcSM = src.getSampleModel();

        // Fast case, SRGB source, INT Pack writable raster...
        if (srcIssRGB && 
            Any2sRGBRed.is_INT_PACK_COMP(wr.getSampleModel())) {
            src.copyData(wr);
            if (srcCM.hasAlpha())
                GraphicsUtil.coerceData(wr, srcCM, false);
            Any2sRGBRed.applyLut_INT(wr, sRGBToLsRGBLut);
            return wr;
        }

        if (srcCM == null) {
            // We don't really know much about this source, let's
            // guess based on the number of bands...

            float [][] matrix = null;
            switch (srcSM.getNumBands()) {
            case 1:
                matrix = new float[1][3];
                matrix[0][0] = 1; // Red
                matrix[0][1] = 1; // Grn
                matrix[0][2] = 1; // Blu
                break;
            case 2:
                matrix = new float[2][4];
                matrix[0][0] = 1; // Red
                matrix[0][1] = 1; // Grn
                matrix[0][2] = 1; // Blu
                matrix[1][3] = 1; // Alpha
                break;
            case 3:
                matrix = new float[3][3];
                matrix[0][0] = 1; // Red
                matrix[1][1] = 1; // Grn
                matrix[2][2] = 1; // Blu
                break;
            default:
                matrix = new float[srcSM.getNumBands()][4];
                matrix[0][0] = 1; // Red
                matrix[1][1] = 1; // Grn
                matrix[2][2] = 1; // Blu
                matrix[3][3] = 1; // Alpha
                break;
            }

            Raster srcRas = src.getData(wr.getBounds());
            BandCombineOp op = new BandCombineOp(matrix, null);
            op.filter(srcRas, wr);
        } else {
            ColorModel dstCM = getColorModel();
            BufferedImage dstBI;

            if (!dstCM.hasAlpha()) {
                // No alpha ao we don't have to work around the bug
                // in the color convert op.
                dstBI = new BufferedImage
                    (dstCM, wr.createWritableTranslatedChild(0,0),
                     dstCM.isAlphaPremultiplied(), null);
            } else {
                // All this nonsense is to work around the fact that
                // the Color convert op doesn't properly copy the
                // Alpha from src to dst.
                SinglePixelPackedSampleModel dstSM;
                dstSM = (SinglePixelPackedSampleModel)wr.getSampleModel();
                int [] masks = dstSM.getBitMasks();
                SampleModel dstSMNoA = new SinglePixelPackedSampleModel
                    (dstSM.getDataType(), dstSM.getWidth(), dstSM.getHeight(), 
                     dstSM.getScanlineStride(), 
                     new int[] {masks[0], masks[1], masks[2]});
                ColorModel dstCMNoA = GraphicsUtil.Linear_sRGB;

                WritableRaster dstWr;
                dstWr = Raster.createWritableRaster(dstSMNoA,
                                                    wr.getDataBuffer(),
                                                    new Point(0,0));
                dstWr = dstWr.createWritableChild
                    (wr.getMinX()-wr.getSampleModelTranslateX(),
                     wr.getMinY()-wr.getSampleModelTranslateY(),
                     wr.getWidth(), wr.getHeight(),
                     0, 0, null);
                
                dstBI = new BufferedImage(dstCMNoA, dstWr, false, null);
            }

            // Divide out alpha if we have it.  We need to do this since
            // the color convert may not be a linear operation which may 
            // lead to out of range values.
            ColorModel srcBICM = srcCM;
            WritableRaster srcWr;
            if ((srcCM.hasAlpha() == true) && 
                (srcCM.isAlphaPremultiplied() != false)) {
                Rectangle wrR = wr.getBounds();
                SampleModel sm = srcCM.createCompatibleSampleModel
                    (wrR.width, wrR.height);
                
                srcWr = Raster.createWritableRaster
                    (sm, new Point(wrR.x, wrR.y));
                src.copyData(srcWr);
                srcBICM = GraphicsUtil.coerceData(srcWr, srcCM, false);
            } else {
                Raster srcRas = src.getData(wr.getBounds());
                srcWr = GraphicsUtil.makeRasterWritable(srcRas);
            }

            BufferedImage srcBI;
            srcBI = new BufferedImage(srcBICM, 
                                      srcWr.createWritableTranslatedChild(0,0),
                                      false, 
                                      null);

            /*
             * System.out.println("src: " + srcBI.getWidth() + "x" + 
             *                    srcBI.getHeight());
             * System.out.println("dst: " + dstBI.getWidth() + "x" + 
             *                    dstBI.getHeight());
             */

            ColorConvertOp op = new ColorConvertOp(null);
            op.filter(srcBI, dstBI);

            if (dstCM.hasAlpha())
                copyBand(srcWr, srcSM.getNumBands()-1,
                         wr,    getSampleModel().getNumBands()-1);
        }
        return wr;
    }

        /**
         * This function 'fixes' the source's color model.  Right now
         * it just selects if it should have one or two bands based on
         * if the source had an alpha channel.
         */
    protected static ColorModel fixColorModel(CachableRed src) {
        ColorModel  cm = src.getColorModel();
        if (cm != null) {
            if (cm.hasAlpha())
                return GraphicsUtil.Linear_sRGB_Unpre;

            return GraphicsUtil.Linear_sRGB;
        }
        else {
            // No ColorModel so try to make some intelligent
            // decisions based just on the number of bands...
            // 1 bands -> replicated into RGB
            // 2 bands -> Band 0 replicated into RGB & Band 1 -> alpha premult
            // 3 bands -> sRGB (not-linear?)
            // 4 bands -> sRGB premult (not-linear?)
            SampleModel sm = src.getSampleModel();

            switch (sm.getNumBands()) {
            case 1:
                return GraphicsUtil.Linear_sRGB;
            case 2:
                return GraphicsUtil.Linear_sRGB_Unpre;
            case 3:
                return GraphicsUtil.Linear_sRGB;
            }
            return GraphicsUtil.Linear_sRGB_Unpre;
        }
    }

    /**
     * This function 'fixes' the source's sample model.
     * Right now it just selects if it should have 3 or 4 bands
     * based on if the source had an alpha channel.
     */
    protected static SampleModel fixSampleModel(CachableRed src) {
        SampleModel sm = src.getSampleModel();
        ColorModel  cm = src.getColorModel();

        boolean alpha = false;

        if (cm != null)
            alpha = cm.hasAlpha();
        else {
            switch (sm.getNumBands()) {
            case 1: case 3:
                alpha = false;
                break;
            default:
                alpha = true;
                break;
            }
        }
        if (alpha)
            return new SinglePixelPackedSampleModel
                (DataBuffer.TYPE_INT,
                 sm.getWidth(),
                 sm.getHeight(),
                 new int [] {0xFF0000, 0xFF00, 0xFF, 0xFF000000});
        else
            return new SinglePixelPackedSampleModel
                (DataBuffer.TYPE_INT,
                 sm.getWidth(),
                 sm.getHeight(),
                 new int [] {0xFF0000, 0xFF00, 0xFF});
    }
}
