/*
 *  Copyright (c) 1999 Matthias Elter  <me@kde.org>
 *  Copyright (c) 2003 Patrick Julien  <freak@codepimps.org>
 *  Copyright (c) 2004 Boudewijn Rempt <boud@valdyas.org>
 *  Copyright (c) 2004 Adrian Page <adrian@pagenet.plus.com>
 *  Copyright (c) 2005 Bart Coppens <kde@bartcoppens.be>
 *
 *  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; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#include <netinet/in.h>
#include <limits.h>
#include <stdlib.h>
#include <cfloat>

#include <qfile.h>
#include <qimage.h>
#include <qpoint.h>
#include <qvaluevector.h>

#include <kdebug.h>
#include <klocale.h>

#include <kis_meta_registry.h>
#include "kis_paint_device.h"
#include "kis_global.h"
#include "kis_brush.h"
#include "kis_alpha_mask.h"
#include "kis_colorspace_factory_registry.h"
#include "kis_iterators_pixel.h"
#include "kis_image.h"


namespace {
    struct GimpBrushV1Header {
        Q_UINT32 header_size;  /*  header_size = sizeof (BrushHeader) + brush name  */
        Q_UINT32 version;      /*  brush file version #  */
        Q_UINT32 width;        /*  width of brush  */
        Q_UINT32 height;       /*  height of brush  */
        Q_UINT32 bytes;        /*  depth of brush in bytes */
    };

    /// All fields are in MSB on disk!
    struct GimpBrushHeader {
        Q_UINT32 header_size;  /*  header_size = sizeof (BrushHeader) + brush name  */
        Q_UINT32 version;      /*  brush file version #  */
        Q_UINT32 width;        /*  width of brush  */
        Q_UINT32 height;       /*  height of brush  */
        Q_UINT32 bytes;        /*  depth of brush in bytes */

                       /*  The following are only defined in version 2 */
        Q_UINT32 magic_number; /*  GIMP brush magic number  */
        Q_UINT32 spacing;      /*  brush spacing as % of width & height, 0 - 1000 */
    };

    // Needed, or the GIMP won't open it!
    Q_UINT32 const GimpV2BrushMagic = ('G' << 24) + ('I' << 16) + ('M' << 8) + ('P' << 0);
}

#define DEFAULT_SPACING 0.25
#define MAXIMUM_SCALE 2

KisBrush::KisBrush(const QString& filename) : super(filename)
{
    m_brushType = INVALID;
    m_ownData = true;
    m_useColorAsMask = false;
    m_hasColor = false;
    m_spacing = DEFAULT_SPACING;
    m_boundary = 0;
}

KisBrush::KisBrush(const QString& filename,
           const QByteArray& data,
           Q_UINT32 & dataPos) : super(filename)
{
    m_brushType = INVALID;
    m_ownData = false;
    m_useColorAsMask = false;
    m_hasColor = false;
    m_spacing = DEFAULT_SPACING;
    m_boundary = 0;

    m_data.setRawData(data.data() + dataPos, data.size() - dataPos);
    init();
    m_data.resetRawData(data.data() + dataPos, data.size() - dataPos);
    dataPos += m_header_size + (width() * height() * m_bytes);
}

KisBrush::KisBrush(KisPaintDevice* image, int x, int y, int w, int h)
    : super(QString(""))
{
    m_brushType = INVALID;
    m_ownData = true;
    m_useColorAsMask = false;
    m_hasColor = true;
    m_spacing = DEFAULT_SPACING;
    m_boundary = 0;

    initFromPaintDev(image, x, y, w, h);
}

KisBrush::KisBrush(const QImage& image, const QString& name)
    : super(QString(""))
{
    m_ownData = false;
    m_useColorAsMask = false;
    m_hasColor = true;
    m_spacing = DEFAULT_SPACING;
    m_boundary = 0;

    setImage(image);
    setName(name);
    setBrushType(IMAGE);
}


KisBrush::~KisBrush()
{
    m_scaledBrushes.clear();
    delete m_boundary;
}

bool KisBrush::load()
{
    if (m_ownData) {
        QFile file(filename());
        file.open(IO_ReadOnly);
        m_data = file.readAll();
        file.close();
    }
    return init();
}

bool KisBrush::init()
{
    GimpBrushHeader bh;

    if (sizeof(GimpBrushHeader) > m_data.size()) {
        return false;
    }

    memcpy(&bh, &m_data[0], sizeof(GimpBrushHeader));
    bh.header_size = ntohl(bh.header_size);
    m_header_size = bh.header_size;

    bh.version = ntohl(bh.version);
    m_version = bh.version;

    bh.width = ntohl(bh.width);
    bh.height = ntohl(bh.height);

    bh.bytes = ntohl(bh.bytes);
    m_bytes = bh.bytes;

    bh.magic_number = ntohl(bh.magic_number);
    m_magic_number = bh.magic_number;

    if (bh.version == 1) {
        // No spacing in version 1 files so use Gimp default
        bh.spacing = static_cast<int>(DEFAULT_SPACING * 100);
    }
    else {
        bh.spacing = ntohl(bh.spacing);

        if (bh.spacing > 1000) {
            return false;
        }
    }

    setSpacing(bh.spacing / 100.0);

    if (bh.header_size > m_data.size() || bh.header_size == 0) {
        return false;
    }

    QString name;

    if (bh.version == 1) {
        // Version 1 has no magic number or spacing, so the name
        // is at a different offset. Character encoding is undefined.
        const char *text = &m_data[sizeof(GimpBrushV1Header)];
        name = QString::fromAscii(text, bh.header_size - sizeof(GimpBrushV1Header));
    } else {
        // ### Version = 3->cinepaint; may be float16 data!
        // Version >=2: UTF-8 encoding is used
        name = QString::fromUtf8(&m_data[sizeof(GimpBrushHeader)],
                                  bh.header_size - sizeof(GimpBrushHeader));
    }

    setName(i18n(name.ascii())); // Ascii? And what with real UTF-8 chars?

    if (bh.width == 0 || bh.height == 0 || !m_img.create(bh.width, bh.height, 32)) {
        return false;
    }

    Q_INT32 k = bh.header_size;

    if (bh.bytes == 1) {
        // Grayscale

        if (static_cast<Q_UINT32>(k + bh.width * bh.height) > m_data.size()) {
            return false;
        }

        m_brushType = MASK;
        m_hasColor = false;

        for (Q_UINT32 y = 0; y < bh.height; y++) {
            for (Q_UINT32 x = 0; x < bh.width; x++, k++) {
                Q_INT32 val = 255 - static_cast<uchar>(m_data[k]);
                m_img.setPixel(x, y, qRgb(val, val, val));
            }
        }
    } else if (bh.bytes == 4) {
        // RGBA

        if (static_cast<Q_UINT32>(k + (bh.width * bh.height * 4)) > m_data.size()) {
            return false;
        }

        m_brushType = IMAGE;
        m_img.setAlphaBuffer(true);
        m_hasColor = true;

        for (Q_UINT32 y = 0; y < bh.height; y++) {
            for (Q_UINT32 x = 0; x < bh.width; x++, k += 4) {
                m_img.setPixel(x, y, qRgba(m_data[k],
                               m_data[k+1],
                               m_data[k+2],
                               m_data[k+3]));
            }
        }
    } else {
        return false;
    }

    setWidth(m_img.width());
    setHeight(m_img.height());
    //createScaledBrushes();
    if (m_ownData) {
        m_data.resize(0); // Save some memory, we're using enough of it as it is.
    }


    if (m_img.width() == 0 || m_img.height() == 0)
        setValid(false);
    else
        setValid(true);

    return true;
}

bool KisBrush::initFromPaintDev(KisPaintDevice* image, int x, int y, int w, int h) {
    // Forcefully convert to RGBA8
    // XXX profile and exposure?
    setImage(image->convertToQImage(0, x, y, w, h));
    setName(image->name());

    m_brushType = IMAGE;
    m_hasColor = true;

    return true;
}

bool KisBrush::save()
{
    QFile file(filename());
    file.open(IO_WriteOnly | IO_Truncate);
    bool ok = saveToDevice(&file);
    file.close();
    return ok;
}

bool KisBrush::saveToDevice(QIODevice* dev) const
{
    GimpBrushHeader bh;
    QCString utf8Name = name().utf8(); // Names in v2 brushes are in UTF-8
    char const* name = utf8Name.data();
    int nameLength = qstrlen(name);
    int wrote;

    bh.header_size = htonl(sizeof(GimpBrushHeader) + nameLength);
    bh.version = htonl(2); // Only RGBA8 data needed atm, no cinepaint stuff
    bh.width = htonl(width());
    bh.height = htonl(height());
    // Hardcoded, 4 bytes RGBA or 1 byte GREY
    if (!hasColor())
        bh.bytes = htonl(1);
    else
        bh.bytes = htonl(4);
    bh.magic_number = htonl(GimpV2BrushMagic);
    bh.spacing = htonl(static_cast<Q_UINT32>(spacing() * 100.0));

    // Write header: first bh, then the name
    QByteArray bytes;
    bytes.setRawData(reinterpret_cast<char*>(&bh), sizeof(GimpBrushHeader));
    wrote = dev->writeBlock(bytes);
    bytes.resetRawData(reinterpret_cast<char*>(&bh), sizeof(GimpBrushHeader));

    if (wrote == -1)
        return false;

    wrote = dev->writeBlock(name, nameLength); // No +1 for the trailing NULL it seems...
    if (wrote == -1)
        return false;

    int k = 0;

    if (!hasColor()) {
        bytes.resize(width() * height());
        for (Q_INT32 y = 0; y < height(); y++) {
            for (Q_INT32 x = 0; x < width(); x++) {
                QRgb c = m_img.pixel(x, y);
                bytes[k++] = static_cast<char>(255 - qRed(c)); // red == blue == green
            }
        }
    } else {
        bytes.resize(width() * height() * 4);
        for (Q_INT32 y = 0; y < height(); y++) {
            for (Q_INT32 x = 0; x < width(); x++) {
                // order for gimp brushes, v2 is: RGBA
                QRgb pixel = m_img.pixel(x,y);
                bytes[k++] = static_cast<char>(qRed(pixel));
                bytes[k++] = static_cast<char>(qGreen(pixel));
                bytes[k++] = static_cast<char>(qBlue(pixel));
                bytes[k++] = static_cast<char>(qAlpha(pixel));
            }
        }
    }

    wrote = dev->writeBlock(bytes);
    if (wrote == -1)
        return false;

    return true;
}

QImage KisBrush::img()
{
    QImage image = m_img;

    if (hasColor() && useColorAsMask()) {
        image.detach();

        for (int x = 0; x < image.width(); x++) {
            for (int y = 0; y < image.height(); y++) {
                QRgb c = image.pixel(x, y);
                int a = (qGray(c) * qAlpha(c)) / 255;
                image.setPixel(x, y, qRgba(a, 0, a, a));
            }
        }
    }

    return image;
}

KisAlphaMaskSP KisBrush::mask(const KisPaintInformation& info, double subPixelX, double subPixelY) const
{
    if (m_scaledBrushes.isEmpty()) {
        createScaledBrushes();
    }

    double scale = scaleForPressure(info.pressure);

    const ScaledBrush *aboveBrush = 0;
    const ScaledBrush *belowBrush = 0;

    findScaledBrushes(scale, &aboveBrush,  &belowBrush);
    Q_ASSERT(aboveBrush != 0);

    KisAlphaMaskSP outputMask = 0;

    if (belowBrush != 0) {
        // We're in between two masks. Interpolate between them.

        KisAlphaMaskSP scaledAboveMask = scaleMask(aboveBrush, scale, subPixelX, subPixelY);
        KisAlphaMaskSP scaledBelowMask = scaleMask(belowBrush, scale, subPixelX, subPixelY);

        double t = (scale - belowBrush->scale()) / (aboveBrush->scale() - belowBrush->scale());

        outputMask = KisAlphaMask::interpolate(scaledBelowMask, scaledAboveMask, t);
    } else {
        if (fabs(scale - aboveBrush->scale()) < DBL_EPSILON) {
            // Exact match.
            outputMask = scaleMask(aboveBrush, scale, subPixelX, subPixelY);
        } else {
            // We are smaller than the smallest mask, which is always 1x1.
            double s = scale / aboveBrush->scale();
            outputMask = scaleSinglePixelMask(s, aboveBrush->mask()->alphaAt(0, 0), subPixelX, subPixelY);
        }
    }

    return outputMask;
}

KisPaintDeviceSP KisBrush::image(KisColorSpace * /*colorSpace*/, const KisPaintInformation& info, double subPixelX, double subPixelY) const
{
    if (m_scaledBrushes.isEmpty()) {
        createScaledBrushes();
    }

    double scale = scaleForPressure(info.pressure);

    const ScaledBrush *aboveBrush = 0;
    const ScaledBrush *belowBrush = 0;

    findScaledBrushes(scale, &aboveBrush,  &belowBrush);
    Q_ASSERT(aboveBrush != 0);

    QImage outputImage;

    if (belowBrush != 0) {
        // We're in between two brushes. Interpolate between them.

        QImage scaledAboveImage = scaleImage(aboveBrush, scale, subPixelX, subPixelY);
        QImage scaledBelowImage = scaleImage(belowBrush, scale, subPixelX, subPixelY);

        double t = (scale - belowBrush->scale()) / (aboveBrush->scale() - belowBrush->scale());

        outputImage = interpolate(scaledBelowImage, scaledAboveImage, t);
    } else {
        if (fabs(scale - aboveBrush->scale()) < DBL_EPSILON) {
            // Exact match.
            outputImage = scaleImage(aboveBrush, scale, subPixelX, subPixelY);
        } else {
            // We are smaller than the smallest brush, which is always 1x1.
            double s = scale / aboveBrush->scale();
            outputImage = scaleSinglePixelImage(s, aboveBrush->image().pixel(0, 0), subPixelX, subPixelY);
        }
    }

    int outputWidth = outputImage.width();
    int outputHeight = outputImage.height();

    KisPaintDevice *layer = new KisPaintDevice(KisMetaRegistry::instance()->csRegistry()->getRGB8(), "brush");

    Q_CHECK_PTR(layer);

    for (int y = 0; y < outputHeight; y++) {
        KisHLineIterator iter = layer->createHLineIterator( 0, y, outputWidth, true);
        for (int x = 0; x < outputWidth; x++) {
	    Q_UINT8 * p = iter.rawData();

            QRgb pixel = outputImage.pixel(x, y);
            int red = qRed(pixel);
            int green = qGreen(pixel);
            int blue = qBlue(pixel);
            int alpha = qAlpha(pixel);

            // Scaled images are in pre-multiplied alpha form so
            // divide by alpha.
	    // channel order is BGRA
            if (alpha != 0) {
                p[2] = (red * 255) / alpha;
                p[1] = (green * 255) / alpha;
		p[0] = (blue * 255) / alpha;
		p[3] = alpha;
            }

            ++iter;
        }
    }

    return layer;
}

void KisBrush::setHotSpot(KisPoint pt)
{
    double x = pt.x();
    double y = pt.y();

    if (x < 0)
        x = 0;
    else if (x >= width())
        x = width() - 1;

    if (y < 0)
        y = 0;
    else if (y >= height())
        y = height() - 1;

    m_hotSpot = KisPoint(x, y);
}

KisPoint KisBrush::hotSpot(const KisPaintInformation& info) const
{
    double scale = scaleForPressure(info.pressure);
    double w = width() * scale;
    double h = height() * scale;

    // The smallest brush we can produce is a single pixel.
    if (w < 1) {
        w = 1;
    }

    if (h < 1) {
        h = 1;
    }

    // XXX: This should take m_hotSpot into account, though it
    // isn't specified by gimp brushes so it would default to the centre
    // anyway.
    KisPoint p(w / 2, h / 2);
    return p;
}

enumBrushType KisBrush::brushType() const
{
    if (m_brushType == IMAGE && useColorAsMask()) {
        return MASK;
    }
    else {
        return m_brushType;
    }
}

bool KisBrush::hasColor() const
{
    return m_hasColor;
}

void KisBrush::createScaledBrushes() const
{
    if (!m_scaledBrushes.isEmpty())
        m_scaledBrushes.clear();

    // Construct a series of brushes where each one's dimensions are
    // half the size of the previous one.
    int width = m_img.width() * MAXIMUM_SCALE;
    int height = m_img.height() * MAXIMUM_SCALE;

    QImage scaledImage;

    while (true) {

        if (width >= m_img.width() && height >= m_img.height()) {
            scaledImage = scaleImage(m_img, width, height);
        }
        else {
            // Scale down the previous image once we're below 1:1.
            scaledImage = scaleImage(scaledImage, width, height);
        }

        KisAlphaMaskSP scaledMask = new KisAlphaMask(scaledImage, hasColor());
        Q_CHECK_PTR(scaledMask);

        double xScale = static_cast<double>(width) / m_img.width();
        double yScale = static_cast<double>(height) / m_img.height();
        double scale = xScale;

        m_scaledBrushes.append(ScaledBrush(scaledMask, hasColor() ? scaledImage : QImage(), scale, xScale, yScale));

        if (width == 1 && height == 1) {
            break;
        }

        // Round up so that we never have to scale an image by less than 1/2.
        width = (width + 1) / 2;
        height = (height + 1) / 2;

    }

}

double KisBrush::xSpacing(double pressure) const
{
    return width() * scaleForPressure(pressure) * m_spacing;
}

double KisBrush::ySpacing(double pressure) const
{
    return height() * scaleForPressure(pressure) * m_spacing;
}

double KisBrush::scaleForPressure(double pressure)
{
    double scale = pressure / PRESSURE_DEFAULT;

    if (scale < 0) {
        scale = 0;
    }

    if (scale > MAXIMUM_SCALE) {
        scale = MAXIMUM_SCALE;
    }

    return scale;
}

Q_INT32 KisBrush::maskWidth(const KisPaintInformation& info) const
{
    // Add one for sub-pixel shift
    return static_cast<Q_INT32>(ceil(width() * scaleForPressure(info.pressure)) + 1);
}

Q_INT32 KisBrush::maskHeight(const KisPaintInformation& info) const
{
    // Add one for sub-pixel shift
    return static_cast<Q_INT32>(ceil(height() * scaleForPressure(info.pressure)) + 1);
}

KisAlphaMaskSP KisBrush::scaleMask(const ScaledBrush *srcBrush, double scale, double subPixelX, double subPixelY) const
{
    // Add one pixel for sub-pixel shifting
    int dstWidth = static_cast<int>(ceil(scale * width())) + 1;
    int dstHeight = static_cast<int>(ceil(scale * height())) + 1;

    KisAlphaMaskSP dstMask = new KisAlphaMask(dstWidth, dstHeight);
    Q_CHECK_PTR(dstMask);

    KisAlphaMaskSP srcMask = srcBrush->mask();

    // Compute scales to map the scaled brush onto the required scale.
    double xScale = srcBrush->xScale() / scale;
    double yScale = srcBrush->yScale() / scale;

    int srcWidth = srcMask->width();
    int srcHeight = srcMask->height();

    for (int dstY = 0; dstY < dstHeight; dstY++) {
        for (int dstX = 0; dstX < dstWidth; dstX++) {

            double srcX = (dstX - subPixelX + 0.5) * xScale;
            double srcY = (dstY - subPixelY + 0.5) * yScale;

            srcX -= 0.5;
            srcY -= 0.5;

            int leftX = static_cast<int>(srcX);

            if (srcX < 0) {
                leftX--;
            }

            double xInterp = srcX - leftX;

            int topY = static_cast<int>(srcY);

            if (srcY < 0) {
                topY--;
            }

            double yInterp = srcY - topY;

            Q_UINT8 topLeft = (leftX >= 0 && leftX < srcWidth && topY >= 0 && topY < srcHeight) ? srcMask->alphaAt(leftX, topY) : OPACITY_TRANSPARENT;
            Q_UINT8 bottomLeft = (leftX >= 0 && leftX < srcWidth && topY + 1 >= 0 && topY + 1 < srcHeight) ? srcMask->alphaAt(leftX, topY + 1) : OPACITY_TRANSPARENT;
            Q_UINT8 topRight = (leftX + 1 >= 0 && leftX + 1 < srcWidth && topY >= 0 && topY < srcHeight) ? srcMask->alphaAt(leftX + 1, topY) : OPACITY_TRANSPARENT;
            Q_UINT8 bottomRight = (leftX + 1 >= 0 && leftX + 1 < srcWidth && topY + 1 >= 0 && topY + 1 < srcHeight) ? srcMask->alphaAt(leftX + 1, topY + 1) : OPACITY_TRANSPARENT;

            double a = 1 - xInterp;
            double b = 1 - yInterp;

            // Bi-linear interpolation
            int d = static_cast<int>(a * b * topLeft
                + a * (1 - b) * bottomLeft
                + (1 - a) * b * topRight
                + (1 - a) * (1 - b) * bottomRight + 0.5);

            if (d < OPACITY_TRANSPARENT) {
                d = OPACITY_TRANSPARENT;
            }
            else
            if (d > OPACITY_OPAQUE) {
                d = OPACITY_OPAQUE;
            }

            dstMask->setAlphaAt(dstX, dstY, static_cast<Q_UINT8>(d));
        }
    }

    return dstMask;
}

QImage KisBrush::scaleImage(const ScaledBrush *srcBrush, double scale, double subPixelX, double subPixelY) const
{
    // Add one pixel for sub-pixel shifting
    int dstWidth = static_cast<int>(ceil(scale * width())) + 1;
    int dstHeight = static_cast<int>(ceil(scale * height())) + 1;

    QImage dstImage(dstWidth, dstHeight, 32);
    dstImage.setAlphaBuffer(true);

    const QImage srcImage = srcBrush->image();

    // Compute scales to map the scaled brush onto the required scale.
    double xScale = srcBrush->xScale() / scale;
    double yScale = srcBrush->yScale() / scale;

    int srcWidth = srcImage.width();
    int srcHeight = srcImage.height();

    for (int dstY = 0; dstY < dstHeight; dstY++) {
        for (int dstX = 0; dstX < dstWidth; dstX++) {

            double srcX = (dstX - subPixelX + 0.5) * xScale;
            double srcY = (dstY - subPixelY + 0.5) * yScale;

            srcX -= 0.5;
            srcY -= 0.5;

            int leftX = static_cast<int>(srcX);

            if (srcX < 0) {
                leftX--;
            }

            double xInterp = srcX - leftX;

            int topY = static_cast<int>(srcY);

            if (srcY < 0) {
                topY--;
            }

            double yInterp = srcY - topY;

            QRgb topLeft = (leftX >= 0 && leftX < srcWidth && topY >= 0 && topY < srcHeight) ? srcImage.pixel(leftX, topY) : qRgba(0, 0, 0, 0);
            QRgb bottomLeft = (leftX >= 0 && leftX < srcWidth && topY + 1 >= 0 && topY + 1 < srcHeight) ? srcImage.pixel(leftX, topY + 1) : qRgba(0, 0, 0, 0);
            QRgb topRight = (leftX + 1 >= 0 && leftX + 1 < srcWidth && topY >= 0 && topY < srcHeight) ? srcImage.pixel(leftX + 1, topY) : qRgba(0, 0, 0, 0);
            QRgb bottomRight = (leftX + 1 >= 0 && leftX + 1 < srcWidth && topY + 1 >= 0 && topY + 1 < srcHeight) ? srcImage.pixel(leftX + 1, topY + 1) : qRgba(0, 0, 0, 0);

            double a = 1 - xInterp;
            double b = 1 - yInterp;

            // Bi-linear interpolation. Image is pre-multiplied by alpha.
            int red = static_cast<int>(a * b * qRed(topLeft)
                + a * (1 - b) * qRed(bottomLeft)
                + (1 - a) * b * qRed(topRight)
                + (1 - a) * (1 - b) * qRed(bottomRight) + 0.5);
            int green = static_cast<int>(a * b * qGreen(topLeft)
                + a * (1 - b) * qGreen(bottomLeft)
                + (1 - a) * b * qGreen(topRight)
                + (1 - a) * (1 - b) * qGreen(bottomRight) + 0.5);
            int blue = static_cast<int>(a * b * qBlue(topLeft)
                + a * (1 - b) * qBlue(bottomLeft)
                + (1 - a) * b * qBlue(topRight)
                + (1 - a) * (1 - b) * qBlue(bottomRight) + 0.5);
            int alpha = static_cast<int>(a * b * qAlpha(topLeft)
                + a * (1 - b) * qAlpha(bottomLeft)
                + (1 - a) * b * qAlpha(topRight)
                + (1 - a) * (1 - b) * qAlpha(bottomRight) + 0.5);

            if (red < 0) {
                red = 0;
            }
            else
            if (red > 255) {
                red = 255;
            }

            if (green < 0) {
                green = 0;
            }
            else
            if (green > 255) {
                green = 255;
            }

            if (blue < 0) {
                blue = 0;
            }
            else
            if (blue > 255) {
                blue = 255;
            }

            if (alpha < 0) {
                alpha = 0;
            }
            else
            if (alpha > 255) {
                alpha = 255;
            }

            dstImage.setPixel(dstX, dstY, qRgba(red, green, blue, alpha));
        }
    }

    return dstImage;
}

QImage KisBrush::scaleImage(const QImage& srcImage, int width, int height)
{
    QImage scaledImage;
    //QString filename;

    int srcWidth = srcImage.width();
    int srcHeight = srcImage.height();

    double xScale = static_cast<double>(srcWidth) / width;
    double yScale = static_cast<double>(srcHeight) / height;

    if (xScale > 2 + DBL_EPSILON || yScale > 2 + DBL_EPSILON || xScale < 1 - DBL_EPSILON || yScale < 1 - DBL_EPSILON) {
        // smoothScale gives better results when scaling an image up
        // or scaling it to less than half size.
        scaledImage = srcImage.smoothScale(width, height);

        //filename = QString("smoothScale_%1x%2.png").arg(width).arg(height);
    }
    else {
        scaledImage.create(width, height, 32);
        scaledImage.setAlphaBuffer(srcImage.hasAlphaBuffer());

        for (int dstY = 0; dstY < height; dstY++) {
            for (int dstX = 0; dstX < width; dstX++) {

                double srcX = (dstX + 0.5) * xScale;
                double srcY = (dstY + 0.5) * yScale;

                srcX -= 0.5;
                srcY -= 0.5;

                int leftX = static_cast<int>(srcX);

                if (srcX < 0) {
                    leftX--;
                }

                double xInterp = srcX - leftX;

                int topY = static_cast<int>(srcY);

                if (srcY < 0) {
                    topY--;
                }

                double yInterp = srcY - topY;

                QRgb topLeft = (leftX >= 0 && leftX < srcWidth && topY >= 0 && topY < srcHeight) ? srcImage.pixel(leftX, topY) : qRgba(0, 0, 0, 0);
                QRgb bottomLeft = (leftX >= 0 && leftX < srcWidth && topY + 1 >= 0 && topY + 1 < srcHeight) ? srcImage.pixel(leftX, topY + 1) : qRgba(0, 0, 0, 0);
                QRgb topRight = (leftX + 1 >= 0 && leftX + 1 < srcWidth && topY >= 0 && topY < srcHeight) ? srcImage.pixel(leftX + 1, topY) : qRgba(0, 0, 0, 0);
                QRgb bottomRight = (leftX + 1 >= 0 && leftX + 1 < srcWidth && topY + 1 >= 0 && topY + 1 < srcHeight) ? srcImage.pixel(leftX + 1, topY + 1) : qRgba(0, 0, 0, 0);

                double a = 1 - xInterp;
                double b = 1 - yInterp;

                int red;
                int green;
                int blue;
                int alpha;

                if (srcImage.hasAlphaBuffer()) {
                    red = static_cast<int>(a * b * qRed(topLeft)         * qAlpha(topLeft)
                        + a * (1 - b) * qRed(bottomLeft)             * qAlpha(bottomLeft)
                        + (1 - a) * b * qRed(topRight)               * qAlpha(topRight)
                        + (1 - a) * (1 - b) * qRed(bottomRight)      * qAlpha(bottomRight) + 0.5);
                    green = static_cast<int>(a * b * qGreen(topLeft)     * qAlpha(topLeft)
                        + a * (1 - b) * qGreen(bottomLeft)           * qAlpha(bottomLeft)
                        + (1 - a) * b * qGreen(topRight)             * qAlpha(topRight)
                        + (1 - a) * (1 - b) * qGreen(bottomRight)    * qAlpha(bottomRight) + 0.5);
                    blue = static_cast<int>(a * b * qBlue(topLeft)       * qAlpha(topLeft)
                        + a * (1 - b) * qBlue(bottomLeft)            * qAlpha(bottomLeft)
                        + (1 - a) * b * qBlue(topRight)              * qAlpha(topRight)
                        + (1 - a) * (1 - b) * qBlue(bottomRight)     * qAlpha(bottomRight) + 0.5);
                    alpha = static_cast<int>(a * b * qAlpha(topLeft)
                        + a * (1 - b) * qAlpha(bottomLeft)
                        + (1 - a) * b * qAlpha(topRight)
                        + (1 - a) * (1 - b) * qAlpha(bottomRight) + 0.5);

                    if (alpha != 0) {
                        red /= alpha;
                        green /= alpha;
                        blue /= alpha;
                    }
                }
                else {
                    red = static_cast<int>(a * b * qRed(topLeft)
                        + a * (1 - b) * qRed(bottomLeft)
                        + (1 - a) * b * qRed(topRight)
                        + (1 - a) * (1 - b) * qRed(bottomRight) + 0.5);
                    green = static_cast<int>(a * b * qGreen(topLeft)
                        + a * (1 - b) * qGreen(bottomLeft)
                        + (1 - a) * b * qGreen(topRight)
                        + (1 - a) * (1 - b) * qGreen(bottomRight) + 0.5);
                    blue = static_cast<int>(a * b * qBlue(topLeft)
                        + a * (1 - b) * qBlue(bottomLeft)
                        + (1 - a) * b * qBlue(topRight)
                        + (1 - a) * (1 - b) * qBlue(bottomRight) + 0.5);
                    alpha = 255;
                }

                if (red < 0) {
                    red = 0;
                }
                else
                if (red > 255) {
                    red = 255;
                }

                if (green < 0) {
                    green = 0;
                }
                else
                if (green > 255) {
                    green = 255;
                }

                if (blue < 0) {
                    blue = 0;
                }
                else
                if (blue > 255) {
                    blue = 255;
                }

                if (alpha < 0) {
                    alpha = 0;
                }
                else
                if (alpha > 255) {
                    alpha = 255;
                }

                scaledImage.setPixel(dstX, dstY, qRgba(red, green, blue, alpha));
            }
        }

        //filename = QString("bilinear_%1x%2.png").arg(width).arg(height);
    }

    //scaledImage.save(filename, "PNG");

    return scaledImage;
}

void KisBrush::findScaledBrushes(double scale, const ScaledBrush **aboveBrush, const ScaledBrush **belowBrush) const
{
    uint current = 0;

    while (true) {
        *aboveBrush = &(m_scaledBrushes[current]);

        if (fabs((*aboveBrush)->scale() - scale) < DBL_EPSILON) {
            // Scale matches exactly
            break;
        }

        if (current == m_scaledBrushes.count() - 1) {
            // This is the last one
            break;
        }

        if (scale > m_scaledBrushes[current + 1].scale() + DBL_EPSILON) {
            // We fit in between the two.
            *belowBrush = &(m_scaledBrushes[current + 1]);
            break;
        }

        current++;
    }
}

KisAlphaMaskSP KisBrush::scaleSinglePixelMask(double scale, Q_UINT8 maskValue, double subPixelX, double subPixelY)
{
    int srcWidth = 1;
    int srcHeight = 1;
    int dstWidth = 2;
    int dstHeight = 2;
    KisAlphaMaskSP outputMask = new KisAlphaMask(dstWidth, dstHeight);
    Q_CHECK_PTR(outputMask);

    double a = subPixelX;
    double b = subPixelY;

    for (int y = 0; y < dstHeight; y++) {
        for (int x = 0; x < dstWidth; x++) {

            Q_UINT8 topLeft = (x > 0 && y > 0) ? maskValue : OPACITY_TRANSPARENT;
            Q_UINT8 bottomLeft = (x > 0 && y < srcHeight) ? maskValue : OPACITY_TRANSPARENT;
            Q_UINT8 topRight = (x < srcWidth && y > 0) ? maskValue : OPACITY_TRANSPARENT;
            Q_UINT8 bottomRight = (x < srcWidth && y < srcHeight) ? maskValue : OPACITY_TRANSPARENT;

            // Bi-linear interpolation
            int d = static_cast<int>(a * b * topLeft
                + a * (1 - b) * bottomLeft
                + (1 - a) * b * topRight
                + (1 - a) * (1 - b) * bottomRight + 0.5);

            // Multiply by the square of the scale because a 0.5x0.5 pixel
            // has 0.25 the value of the 1x1.
            d = static_cast<int>(d * scale * scale + 0.5);

            if (d < OPACITY_TRANSPARENT) {
                d = OPACITY_TRANSPARENT;
            }
            else
            if (d > OPACITY_OPAQUE) {
                d = OPACITY_OPAQUE;
            }

            outputMask->setAlphaAt(x, y, static_cast<Q_UINT8>(d));
        }
    }

    return outputMask;
}

QImage KisBrush::scaleSinglePixelImage(double scale, QRgb pixel, double subPixelX, double subPixelY)
{
    int srcWidth = 1;
    int srcHeight = 1;
    int dstWidth = 2;
    int dstHeight = 2;

    QImage outputImage(dstWidth, dstHeight, 32);
    outputImage.setAlphaBuffer(true);

    double a = subPixelX;
    double b = subPixelY;

    for (int y = 0; y < dstHeight; y++) {
        for (int x = 0; x < dstWidth; x++) {

            QRgb topLeft = (x > 0 && y > 0) ? pixel : qRgba(0, 0, 0, 0);
            QRgb bottomLeft = (x > 0 && y < srcHeight) ? pixel : qRgba(0, 0, 0, 0);
            QRgb topRight = (x < srcWidth && y > 0) ? pixel : qRgba(0, 0, 0, 0);
            QRgb bottomRight = (x < srcWidth && y < srcHeight) ? pixel : qRgba(0, 0, 0, 0);

            // Bi-linear interpolation. Images are in pre-multiplied form.
            int red = static_cast<int>(a * b * qRed(topLeft)
                + a * (1 - b) * qRed(bottomLeft)
                + (1 - a) * b * qRed(topRight)
                + (1 - a) * (1 - b) * qRed(bottomRight) + 0.5);
            int green = static_cast<int>(a * b * qGreen(topLeft)
                + a * (1 - b) * qGreen(bottomLeft)
                + (1 - a) * b * qGreen(topRight)
                + (1 - a) * (1 - b) * qGreen(bottomRight) + 0.5);
            int blue = static_cast<int>(a * b * qBlue(topLeft)
                + a * (1 - b) * qBlue(bottomLeft)
                + (1 - a) * b * qBlue(topRight)
                + (1 - a) * (1 - b) * qBlue(bottomRight) + 0.5);
            int alpha = static_cast<int>(a * b * qAlpha(topLeft)
                + a * (1 - b) * qAlpha(bottomLeft)
                + (1 - a) * b * qAlpha(topRight)
                + (1 - a) * (1 - b) * qAlpha(bottomRight) + 0.5);

            // Multiply by the square of the scale because a 0.5x0.5 pixel
            // has 0.25 the value of the 1x1.
            alpha = static_cast<int>(alpha * scale * scale + 0.5);

            // Apply to the colour channels too since we are
            // storing pre-multiplied by alpha.
            red = static_cast<int>(red * scale * scale + 0.5);
            green = static_cast<int>(green * scale * scale + 0.5);
            blue = static_cast<int>(blue * scale * scale + 0.5);

            if (red < 0) {
                red = 0;
            }
            else
            if (red > 255) {
                red = 255;
            }

            if (green < 0) {
                green = 0;
            }
            else
            if (green > 255) {
                green = 255;
            }

            if (blue < 0) {
                blue = 0;
            }
            else
            if (blue > 255) {
                blue = 255;
            }

            if (alpha < 0) {
                alpha = 0;
            }
            else
            if (alpha > 255) {
                alpha = 255;
            }

            outputImage.setPixel(x, y, qRgba(red, green, blue, alpha));
        }
    }

    return outputImage;
}

QImage KisBrush::interpolate(const QImage& image1, const QImage& image2, double t)
{
    Q_ASSERT((image1.width() == image2.width()) && (image1.height() == image2.height()));
    Q_ASSERT(t > -DBL_EPSILON && t < 1 + DBL_EPSILON);

    int width = image1.width();
    int height = image1.height();

    QImage outputImage(width, height, 32);
    outputImage.setAlphaBuffer(true);

    for (int x = 0; x < width; x++) {
        for (int y = 0; y < height; y++) {
            QRgb image1pixel = image1.pixel(x, y);
            QRgb image2pixel = image2.pixel(x, y);

            // Images are in pre-multiplied alpha format.
            int red = static_cast<int>((1 - t) * qRed(image1pixel) + t * qRed(image2pixel) + 0.5);
            int green = static_cast<int>((1 - t) * qGreen(image1pixel) + t * qGreen(image2pixel) + 0.5);
            int blue = static_cast<int>((1 - t) * qBlue(image1pixel) + t * qBlue(image2pixel) + 0.5);
            int alpha = static_cast<int>((1 - t) * qAlpha(image1pixel) + t * qAlpha(image2pixel) + 0.5);

            if (red < 0) {
                red = 0;
            }
            else
            if (red > 255) {
                red = 255;
            }

            if (green < 0) {
                green = 0;
            }
            else
            if (green > 255) {
                green = 255;
            }

            if (blue < 0) {
                blue = 0;
            }
            else
            if (blue > 255) {
                blue = 255;
            }

            if (alpha < 0) {
                alpha = 0;
            }
            else
            if (alpha > 255) {
                alpha = 255;
            }

            outputImage.setPixel(x, y, qRgba(red, green, blue, alpha));
        }
    }

    return outputImage;
}

KisBrush::ScaledBrush::ScaledBrush()
{
    m_mask = 0;
    m_image = QImage();
    m_scale = 1;
    m_xScale = 1;
    m_yScale = 1;
}

KisBrush::ScaledBrush::ScaledBrush(KisAlphaMaskSP scaledMask, const QImage& scaledImage, double scale, double xScale, double yScale)
{
    m_mask = scaledMask;
    m_image = scaledImage;
    m_scale = scale;
    m_xScale = xScale;
    m_yScale = yScale;

    if (!m_image.isNull()) {
        // Convert image to pre-multiplied by alpha.

        m_image.detach();

        for (int y = 0; y < m_image.height(); y++) {
            for (int x = 0; x < m_image.width(); x++) {

                QRgb pixel = m_image.pixel(x, y);

                int red = qRed(pixel);
                int green = qGreen(pixel);
                int blue = qBlue(pixel);
                int alpha = qAlpha(pixel);

                red = (red * alpha) / 255;
                green = (green * alpha) / 255;
                blue = (blue * alpha) / 255;

                m_image.setPixel(x, y, qRgba(red, green, blue, alpha));
            }
        }
    }
}

void KisBrush::setImage(const QImage& img)
{
    m_img = img;
    m_img.detach();

    setWidth(img.width());
    setHeight(img.height());

    m_scaledBrushes.clear();

    setValid(true);
}

Q_INT32 KisBrush::width() const
{
    return m_width;
}

void KisBrush::setWidth(Q_INT32 w)
{
    m_width = w;
}

Q_INT32 KisBrush::height() const
{
    return m_height;
}

void KisBrush::setHeight(Q_INT32 h)
{
    m_height = h;
}

/*QImage KisBrush::outline(double pressure) {
    KisLayerSP layer = image(KisMetaRegistry::instance()->csRegistry()->getColorSpace(KisID("RGBA",""),""),
                             KisPaintInformation(pressure));
    KisBoundary bounds(layer.data());
    int w = maskWidth(pressure);
    int h = maskHeight(pressure);

    bounds.generateBoundary(w, h);
    QPixmap pix(bounds.pixmap(w, h));
    QImage result;
    result = pix;
    return result;
}*/

void KisBrush::generateBoundary() {
    KisPaintDeviceSP dev;
    int w = maskWidth(KisPaintInformation());
    int h = maskHeight(KisPaintInformation());

    if (brushType() == IMAGE || brushType() == PIPE_IMAGE) {
        dev = image(KisMetaRegistry::instance()->csRegistry() ->getColorSpace(KisID("RGBA",""),""), KisPaintInformation());
    } else {
        KisAlphaMaskSP amask = mask(KisPaintInformation());
        KisColorSpace* cs = KisMetaRegistry::instance()->csRegistry()->getColorSpace(KisID("RGBA",""),"");
        dev = new KisPaintDevice(cs, "tmp for generateBoundary");
        for (int y = 0; y < h; y++) {
            KisHLineIteratorPixel it = dev->createHLineIterator(0, y, w, true);
            int x = 0;

            while(!it.isDone()) {
                cs->setAlpha(it.rawData(), amask->alphaAt(x++, y), 1);
                ++it;
            }
        }
    }

    m_boundary = new KisBoundary(dev);
    m_boundary->generateBoundary(w, h);
}

KisBoundary KisBrush::boundary() {
    if (!m_boundary)
        generateBoundary();
    return *m_boundary;
}

void KisBrush::makeMaskImage() {
    if (!hasColor())
        return;

    QImage img;
    img.create(width(), height(), 32);

    if (m_img.width() == img.width() && m_img.height() == img.height()) {
        for (int x = 0; x < width(); x++) {
            for (int y = 0; y < height(); y++) {
                QRgb c = m_img.pixel(x, y);
                int a = (qGray(c) * qAlpha(c)) / 255; // qGray(black) = 0
                img.setPixel(x, y, qRgba(a, a, a, 255));
            }
        }

        m_img = img;
    }

    m_brushType = MASK;
    m_hasColor = false;
    m_useColorAsMask = false;
    delete m_boundary;
    m_boundary = 0;
    m_scaledBrushes.clear();
}

KisBrush* KisBrush::clone() const {
    KisBrush* c = new KisBrush("");
    c->m_spacing = m_spacing;
    c->m_useColorAsMask = m_useColorAsMask;
    c->m_hasColor = m_useColorAsMask;
    c->m_img = m_img;
    c->m_width = m_width;
    c->m_height = m_height;
    c->m_ownData = false;
    c->m_hotSpot = m_hotSpot;
    c->m_brushType = m_brushType;
    c->setValid(true);

    return c;
}

#include "kis_brush.moc"