/*
 * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
 * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
 * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"

#if ENABLE(FILTERS)
#include "FEColorMatrix.h"

#include "Filter.h"
#include "GraphicsContext.h"
#include "RenderTreeAsText.h"
#include "TextStream.h"

#include <wtf/ByteArray.h>
#include <wtf/MathExtras.h>

namespace WebCore {

FEColorMatrix::FEColorMatrix(Filter* filter, ColorMatrixType type, const Vector<float>& values)
    : FilterEffect(filter)
    , m_type(type)
    , m_values(values)
{
}

PassRefPtr<FEColorMatrix> FEColorMatrix::create(Filter* filter, ColorMatrixType type, const Vector<float>& values)
{
    return adoptRef(new FEColorMatrix(filter, type, values));
}

ColorMatrixType FEColorMatrix::type() const
{
    return m_type;
}

bool FEColorMatrix::setType(ColorMatrixType type)
{
    if (m_type == type)
        return false;
    m_type = type;
    return true;
}

const Vector<float>& FEColorMatrix::values() const
{
    return m_values;
}

bool FEColorMatrix::setValues(const Vector<float> &values)
{
    if (m_values == values)
        return false;
    m_values = values;
    return true;
}

inline void matrix(double& red, double& green, double& blue, double& alpha, const Vector<float>& values)
{
    double r = values[0]  * red + values[1]  * green + values[2]  * blue + values[3]  * alpha + values[4] * 255;
    double g = values[5]  * red + values[6]  * green + values[7]  * blue + values[8]  * alpha + values[9] * 255;
    double b = values[10]  * red + values[11]  * green + values[12] * blue + values[13] * alpha + values[14] * 255;
    double a = values[15] * red + values[16] * green + values[17] * blue + values[18] * alpha + values[19] * 255;

    red = r;
    green = g;
    blue = b;
    alpha = a;
}

inline void saturate(double& red, double& green, double& blue, const float& s)
{
    double r = (0.213 + 0.787 * s) * red + (0.715 - 0.715 * s) * green + (0.072 - 0.072 * s) * blue;
    double g = (0.213 - 0.213 * s) * red + (0.715 + 0.285 * s) * green + (0.072 - 0.072 * s) * blue;
    double b = (0.213 - 0.213 * s) * red + (0.715 - 0.715 * s) * green + (0.072 + 0.928 * s) * blue;

    red = r;
    green = g;
    blue = b;
}

inline void huerotate(double& red, double& green, double& blue, const float& hue)
{
    double cosHue = cos(hue * piDouble / 180); 
    double sinHue = sin(hue * piDouble / 180); 
    double r = red   * (0.213 + cosHue * 0.787 - sinHue * 0.213) +
               green * (0.715 - cosHue * 0.715 - sinHue * 0.715) +
               blue  * (0.072 - cosHue * 0.072 + sinHue * 0.928);
    double g = red   * (0.213 - cosHue * 0.213 + sinHue * 0.143) +
               green * (0.715 + cosHue * 0.285 + sinHue * 0.140) +
               blue  * (0.072 - cosHue * 0.072 - sinHue * 0.283);
    double b = red   * (0.213 - cosHue * 0.213 - sinHue * 0.787) +
               green * (0.715 - cosHue * 0.715 + sinHue * 0.715) +
               blue  * (0.072 + cosHue * 0.928 + sinHue * 0.072);

    red = r;
    green = g;
    blue = b;
}

inline void luminance(double& red, double& green, double& blue, double& alpha)
{
    alpha = 0.2125 * red + 0.7154 * green + 0.0721 * blue;
    red = 0;
    green = 0;
    blue = 0;
}

template<ColorMatrixType filterType>
void effectType(ByteArray* pixelArray, const Vector<float>& values)
{
    unsigned pixelArrayLength = pixelArray->length();
    for (unsigned pixelByteOffset = 0; pixelByteOffset < pixelArrayLength; pixelByteOffset += 4) {
        double red = pixelArray->get(pixelByteOffset);
        double green = pixelArray->get(pixelByteOffset + 1);
        double blue = pixelArray->get(pixelByteOffset + 2);
        double alpha = pixelArray->get(pixelByteOffset + 3);

        switch (filterType) {
            case FECOLORMATRIX_TYPE_MATRIX:
                matrix(red, green, blue, alpha, values);
                break;
            case FECOLORMATRIX_TYPE_SATURATE: 
                saturate(red, green, blue, values[0]);
                break;
            case FECOLORMATRIX_TYPE_HUEROTATE:
                huerotate(red, green, blue, values[0]);
                break;
            case FECOLORMATRIX_TYPE_LUMINANCETOALPHA:
                luminance(red, green, blue, alpha);
                break;
        }

        pixelArray->set(pixelByteOffset, red);
        pixelArray->set(pixelByteOffset + 1, green);
        pixelArray->set(pixelByteOffset + 2, blue);
        pixelArray->set(pixelByteOffset + 3, alpha);
    }
}

void FEColorMatrix::apply()
{
    if (hasResult())
        return;
    FilterEffect* in = inputEffect(0);
    in->apply();
    if (!in->hasResult())
        return;

    ImageBuffer* resultImage = createImageBufferResult();
    if (!resultImage)
        return;

    resultImage->context()->drawImageBuffer(in->asImageBuffer(), ColorSpaceDeviceRGB, drawingRegionOfInputImage(in->absolutePaintRect()));

    IntRect imageRect(IntPoint(), absolutePaintRect().size());
    RefPtr<ByteArray> pixelArray = resultImage->getUnmultipliedImageData(imageRect);

    switch (m_type) {
    case FECOLORMATRIX_TYPE_UNKNOWN:
        break;
    case FECOLORMATRIX_TYPE_MATRIX:
        effectType<FECOLORMATRIX_TYPE_MATRIX>(pixelArray.get(), m_values);
        break;
    case FECOLORMATRIX_TYPE_SATURATE: 
        effectType<FECOLORMATRIX_TYPE_SATURATE>(pixelArray.get(), m_values);
        break;
    case FECOLORMATRIX_TYPE_HUEROTATE:
        effectType<FECOLORMATRIX_TYPE_HUEROTATE>(pixelArray.get(), m_values);
        break;
    case FECOLORMATRIX_TYPE_LUMINANCETOALPHA:
        effectType<FECOLORMATRIX_TYPE_LUMINANCETOALPHA>(pixelArray.get(), m_values);
        setIsAlphaImage(true);
        break;
    }

    resultImage->putUnmultipliedImageData(pixelArray.get(), imageRect.size(), imageRect, IntPoint());
}

void FEColorMatrix::dump()
{
}

static TextStream& operator<<(TextStream& ts, const ColorMatrixType& type)
{
    switch (type) {
    case FECOLORMATRIX_TYPE_UNKNOWN:
        ts << "UNKNOWN";
        break;
    case FECOLORMATRIX_TYPE_MATRIX:
        ts << "MATRIX";
        break;
    case FECOLORMATRIX_TYPE_SATURATE:
        ts << "SATURATE";
        break;
    case FECOLORMATRIX_TYPE_HUEROTATE:
        ts << "HUEROTATE";
        break;
    case FECOLORMATRIX_TYPE_LUMINANCETOALPHA:
        ts << "LUMINANCETOALPHA";
        break;
    }
    return ts;
}

TextStream& FEColorMatrix::externalRepresentation(TextStream& ts, int indent) const
{
    writeIndent(ts, indent);
    ts << "[feColorMatrix";
    FilterEffect::externalRepresentation(ts);
    ts << " type=\"" << m_type << "\"";
    if (!m_values.isEmpty()) {
        ts << " values=\"";
        Vector<float>::const_iterator ptr = m_values.begin();
        const Vector<float>::const_iterator end = m_values.end();
        while (ptr < end) {
            ts << *ptr;
            ++ptr;
            if (ptr < end) 
                ts << " ";
        }
        ts << "\"";
    }
    ts << "]\n";
    inputEffect(0)->externalRepresentation(ts, indent + 1);
    return ts;
}

} // namespace WebCore

#endif // ENABLE(FILTERS)