src/gui/painting/qcolor.cpp

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/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qcolor.h"
#include "qcolor_p.h"
#include "qnamespace.h"
#include "qcolormap.h"
#include "qdatastream.h"
#include "qvariant.h"
#include "qdebug.h"

#include <math.h>
#include <stdio.h>
#include <limits.h>


#define QCOLOR_INT_RANGE_CHECK(fn, var) \
    do { \
        if (var < 0 || var > 255) { \
            qWarning(#fn": invalid value %d", var); \
            var = qMax(0, qMin(var, 255)); \
        } \
    } while (0)

#define QCOLOR_REAL_RANGE_CHECK(fn, var) \
    do { \
        if (var < qreal(0.0) || var > qreal(1.0)) { \
            qWarning(#fn": invalid value %g", var); \
            var = qMax(qreal(0.0), qMin(var, qreal(1.0)));      \
        } \
    } while (0)

/*****************************************************************************
  QColor member functions
 *****************************************************************************/

QColor::QColor(Qt::GlobalColor color)
{
#define QRGB(r, g, b) \
    QRgb(((0xff << 24) | ((r & 0xff) << 16) | ((g & 0xff) << 8) | (b & 0xff)))
#define QRGBA(r, g, b, a) \
    QRgb(((a & 0xff) << 24) | ((r & 0xff) << 16) | ((g & 0xff) << 8) | (b & 0xff))

    static const QRgb global_colors[] = {
        QRGB(255, 255, 255), // Qt::color0
        QRGB(  0,   0,   0), // Qt::color1
        QRGB(  0,   0,   0), // black
        QRGB(255, 255, 255), // white
        /*
         * From the "The Palette Manager: How and Why" by Ron Gery,
         * March 23, 1992, archived on MSDN:
         *
         *     The Windows system palette is broken up into two
         *     sections, one with fixed colors and one with colors
         *     that can be changed by applications. The system palette
         *     predefines 20 entries; these colors are known as the
         *     static or reserved colors and consist of the 16 colors
         *     found in the Windows version 3.0 VGA driver and 4
         *     additional colors chosen for their visual appeal.  The
         *     DEFAULT_PALETTE stock object is, as the name implies,
         *     the default palette selected into a device context (DC)
         *     and consists of these static colors. Applications can
         *     set the remaining 236 colors using the Palette Manager.
         *
         * The 20 reserved entries have indices in [0,9] and
         * [246,255]. We reuse 17 of them.
         */
        QRGB(128, 128, 128), // index 248   medium gray
        QRGB(160, 160, 164), // index 247   light gray
        QRGB(192, 192, 192), // index 7     light gray
        QRGB(255,   0,   0), // index 249   red
        QRGB(  0, 255,   0), // index 250   green
        QRGB(  0,   0, 255), // index 252   blue
        QRGB(  0, 255, 255), // index 254   cyan
        QRGB(255,   0, 255), // index 253   magenta
        QRGB(255, 255,   0), // index 251   yellow
        QRGB(128,   0,   0), // index 1     dark red
        QRGB(  0, 128,   0), // index 2     dark green
        QRGB(  0,   0, 128), // index 4     dark blue
        QRGB(  0, 128, 128), // index 6     dark cyan
        QRGB(128,   0, 128), // index 5     dark magenta
        QRGB(128, 128,   0), // index 3     dark yellow
        QRGBA(0, 0, 0, 0)    //             transparent
    };
#undef QRGB
#undef QRGBA

    setRgb(qRed(global_colors[color]),
           qGreen(global_colors[color]),
           qBlue(global_colors[color]),
           qAlpha(global_colors[color]));
}

QColor::QColor(QRgb color)
{
    cspec = Rgb;
    ct.argb.alpha = 0xffff;
    ct.argb.red   = qRed(color)   * 0x101;
    ct.argb.green = qGreen(color) * 0x101;
    ct.argb.blue  = qBlue(color)  * 0x101;
    ct.argb.pad   = 0;
}


QColor::QColor(Spec spec)
{
    switch (spec) {
    case Invalid:
        invalidate();
        break;
    case Rgb:
        setRgb(0, 0, 0);
        break;
    case Hsv:
        setHsv(0, 0, 0);
        break;
    case Cmyk:
        setCmyk(0, 0, 0, 0);
        break;
    }
}

QString QColor::name() const
{
    QString s;
    s.sprintf("#%02x%02x%02x", red(), green(), blue());
    return s;
}

void QColor::setNamedColor(const QString &name)
{
    if (name.isEmpty()) {
        invalidate();
        return;
    }

    QByteArray n = name.toLatin1();
    if (n.startsWith('#')) {
        QRgb rgb;
        if (qt_get_hex_rgb(n, &rgb)) {
            setRgb(rgb);
        } else {
            qWarning("QColor::setNamedColor: Could not parse color '%s'", n.constData());
            invalidate();
        }
        return;
    }

    QRgb rgb;
    if (qt_get_named_rgb(n, &rgb)) {
        setRgb(rgb);
    } else {
        qWarning("QColor::setNamedColor: Unknown color name '%s'", n.constData());
        invalidate();
    }
}

QStringList QColor::colorNames()
{
    return qt_get_colornames();
}

void QColor::getHsvF(qreal *h, qreal *s, qreal *v, qreal *a) const
{
        if (!h || !s || !v)
        return;

    if (cspec != Invalid && cspec != Hsv) {
        toHsv().getHsvF(h, s, v, a);
        return;
    }

    *h = ct.ahsv.hue == USHRT_MAX ? -1.0 : ct.ahsv.hue / 36000.0;
    *s = ct.ahsv.saturation / qreal(USHRT_MAX);
    *v = ct.ahsv.value / qreal(USHRT_MAX);

    if (a)
        *a = ct.ahsv.alpha / qreal(USHRT_MAX);
}

void QColor::getHsv(int *h, int *s, int *v, int *a) const
{
    if (!h || !s || !v)
        return;

    if (cspec != Invalid && cspec != Hsv) {
        toHsv().getHsv(h, s, v, a);
        return;
    }

    *h = ct.ahsv.hue == USHRT_MAX ? -1 : ct.ahsv.hue / 100;
    *s = ct.ahsv.saturation >> 8;
    *v = ct.ahsv.value      >> 8;

    if (a)
        *a = ct.ahsv.alpha >> 8;
}

void QColor::setHsvF(qreal h, qreal s, qreal v, qreal a)
{
    if (((h < 0.0 || h > 1.0) && h != -1.0)
        || (s < 0.0 || s > 1.0)
        || (v < 0.0 || v > 1.0)
        || (a < 0.0 || a > 1.0)) {
        qWarning("QColor::setHsvF: HSV parameters out of range");
        return;
    }

    cspec = Hsv;
    ct.ahsv.alpha      = qRound(a * USHRT_MAX);
    ct.ahsv.hue        = h == -1.0 ? USHRT_MAX : qRound(h * 36000);
    ct.ahsv.saturation = qRound(s * USHRT_MAX);
    ct.ahsv.value      = qRound(v * USHRT_MAX);
    ct.ahsv.pad        = 0;
}

void QColor::setHsv(int h, int s, int v, int a)
{
    if (h < -1 || (uint)s > 255 || (uint)v > 255 || (uint)a > 255) {
        qWarning("QColor::setHsv: HSV parameters out of range");
        invalidate();
        return;
    }

    cspec = Hsv;
    ct.ahsv.alpha      = a * 0x101;
    ct.ahsv.hue        = h == -1 ? USHRT_MAX : (h % 360) * 100;
    ct.ahsv.saturation = s * 0x101;
    ct.ahsv.value      = v * 0x101;
    ct.ahsv.pad        = 0;
}

void QColor::getRgbF(qreal *r, qreal *g, qreal *b, qreal *a) const
{
    if (!r || !g || !b)
        return;

    if (cspec != Invalid && cspec != Rgb) {
        toRgb().getRgbF(r, g, b, a);
        return;
    }

    *r = ct.argb.red   / qreal(USHRT_MAX);
    *g = ct.argb.green / qreal(USHRT_MAX);
    *b = ct.argb.blue  / qreal(USHRT_MAX);

    if (a)
        *a = ct.argb.alpha / qreal(USHRT_MAX);

}

void QColor::getRgb(int *r, int *g, int *b, int *a) const
{
    if (!r || !g || !b)
        return;

    if (cspec != Invalid && cspec != Rgb) {
        toRgb().getRgb(r, g, b, a);
        return;
    }

    *r = ct.argb.red   >> 8;
    *g = ct.argb.green >> 8;
    *b = ct.argb.blue  >> 8;

    if (a)
        *a = ct.argb.alpha >> 8;
}

void QColor::setRgbF(qreal r, qreal g, qreal b, qreal a)
{
    if (r < 0.0 || r > 1.0
        || g < 0.0 || g > 1.0
        || b < 0.0 || b > 1.0
        || a < 0.0 || a > 1.0) {
        qWarning("QColor::setRgbF: RGB parameters out of range");
        invalidate();
        return;
    }

    cspec = Rgb;
    ct.argb.alpha = qRound(a * USHRT_MAX);
    ct.argb.red   = qRound(r * USHRT_MAX);
    ct.argb.green = qRound(g * USHRT_MAX);
    ct.argb.blue  = qRound(b * USHRT_MAX);
    ct.argb.pad   = 0;
}

void QColor::setRgb(int r, int g, int b, int a)
{
    if ((uint)r > 255 || (uint)g > 255 || (uint)b > 255 || (uint)a > 255) {
        qWarning("QColor::setRgb: RGB parameters out of range");
        invalidate();
        return;
    }

    cspec = Rgb;
    ct.argb.alpha = a * 0x101;
    ct.argb.red   = r * 0x101;
    ct.argb.green = g * 0x101;
    ct.argb.blue  = b * 0x101;
    ct.argb.pad   = 0;
}

QRgb QColor::rgba() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().rgba();
    return qRgba(ct.argb.red >> 8, ct.argb.green >> 8, ct.argb.blue >> 8, ct.argb.alpha >> 8);
}

void QColor::setRgba(QRgb rgba)
{
    cspec = Rgb;
    ct.argb.alpha = qAlpha(rgba) * 0x101;
    ct.argb.red   = qRed(rgba)   * 0x101;
    ct.argb.green = qGreen(rgba) * 0x101;
    ct.argb.blue  = qBlue(rgba)  * 0x101;
    ct.argb.pad   = 0;
}

QRgb QColor::rgb() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().rgb();
    return qRgb(ct.argb.red >> 8, ct.argb.green >> 8, ct.argb.blue >> 8);
}

void QColor::setRgb(QRgb rgb)
{
    cspec = Rgb;
    ct.argb.alpha = 0xffff;
    ct.argb.red   = qRed(rgb)   * 0x101;
    ct.argb.green = qGreen(rgb) * 0x101;
    ct.argb.blue  = qBlue(rgb)  * 0x101;
    ct.argb.pad   = 0;
}

int QColor::alpha() const
{ return ct.argb.alpha >> 8; }


void QColor::setAlpha(int alpha)
{
    QCOLOR_INT_RANGE_CHECK("QColor::setAlpha", alpha);
    ct.argb.alpha = alpha * 0x101;
}

qreal QColor::alphaF() const
{ return ct.argb.alpha / qreal(USHRT_MAX); }

void QColor::setAlphaF(qreal alpha)
{
    QCOLOR_REAL_RANGE_CHECK("QColor::setAlphaF", alpha);
    qreal tmp = alpha * USHRT_MAX;
    ct.argb.alpha = qRound(tmp);
}


int QColor::red() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().red();
    return ct.argb.red >> 8;
}

void QColor::setRed(int red)
{
    QCOLOR_INT_RANGE_CHECK("QColor::setRed", red);
    if (cspec != Rgb)
        setRgb(red, green(), blue(), alpha());
    else
        ct.argb.red = red * 0x101;
}

int QColor::green() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().green();
    return ct.argb.green >> 8;
}

void QColor::setGreen(int green)
{
    QCOLOR_INT_RANGE_CHECK("QColor::setGreen", green);
    if (cspec != Rgb)
        setRgb(red(), green, blue(), alpha());
    else
        ct.argb.green = green * 0x101;
}


int QColor::blue() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().blue();
    return ct.argb.blue >> 8;
}


void QColor::setBlue(int blue)
{
    QCOLOR_INT_RANGE_CHECK("QColor::setBlue", blue);
    if (cspec != Rgb)
        setRgb(red(), green(), blue, alpha());
    else
        ct.argb.blue = blue * 0x101;
}

qreal QColor::redF() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().redF();
    return ct.argb.red / qreal(USHRT_MAX);
}


void QColor::setRedF(qreal red)
{
    QCOLOR_REAL_RANGE_CHECK("QColor::setRedF", red);
    if (cspec != Rgb)
        setRgbF(red, greenF(), blueF(), alphaF());
    else
        ct.argb.red = qRound(red * USHRT_MAX);
}

qreal QColor::greenF() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().greenF();
    return ct.argb.green / qreal(USHRT_MAX);
}


void QColor::setGreenF(qreal green)
{
    QCOLOR_REAL_RANGE_CHECK("QColor::setGreenF", green);
    if (cspec != Rgb)
        setRgbF(redF(), green, blueF(), alphaF());
    else
        ct.argb.green = qRound(green * USHRT_MAX);
}

qreal QColor::blueF() const
{
    if (cspec != Invalid && cspec != Rgb)
        return toRgb().blueF();
    return ct.argb.blue / qreal(USHRT_MAX);
}

void QColor::setBlueF(qreal blue)
{
    QCOLOR_REAL_RANGE_CHECK("QColor::setBlueF", blue);
    if (cspec != Rgb)
        setRgbF(redF(), greenF(), blue, alphaF());
    else
        ct.argb.blue = qRound(blue * USHRT_MAX);
}

int QColor::hue() const
{
    if (cspec != Invalid && cspec != Hsv)
        return toHsv().hue();
    return ct.ahsv.hue == USHRT_MAX ? -1 : ct.ahsv.hue / 100;
}

int QColor::saturation() const
{
    if (cspec != Invalid && cspec != Hsv)
        return toHsv().saturation();
    return ct.ahsv.saturation >> 8;
}

int QColor::value() const
{
    if (cspec != Invalid && cspec != Hsv)
        return toHsv().value();
    return ct.ahsv.value >> 8;
}

qreal QColor::hueF() const
{
    if (cspec != Invalid && cspec != Hsv)
        return toHsv().hueF();
    return ct.ahsv.hue == USHRT_MAX ? -1.0 : ct.ahsv.hue / 36000.0;
}

qreal QColor::saturationF() const
{
    if (cspec != Invalid && cspec != Hsv)
        return toHsv().saturationF();
    return ct.ahsv.saturation / qreal(USHRT_MAX);
}

qreal QColor::valueF() const
{
    if (cspec != Invalid && cspec != Hsv)
        return toHsv().valueF();
    return ct.ahsv.value / qreal(USHRT_MAX);
}

int QColor::cyan() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().cyan();
    return ct.acmyk.cyan >> 8;
}

int QColor::magenta() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().magenta();
    return ct.acmyk.magenta >> 8;
}

int QColor::yellow() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().yellow();
    return ct.acmyk.yellow >> 8;
}

int QColor::black() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().black();
    return ct.acmyk.black >> 8;
}

qreal QColor::cyanF() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().cyanF();
    return ct.acmyk.cyan / qreal(USHRT_MAX);
}

qreal QColor::magentaF() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().magentaF();
    return ct.acmyk.magenta / qreal(USHRT_MAX);
}

qreal QColor::yellowF() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().yellowF();
    return ct.acmyk.yellow / qreal(USHRT_MAX);
}

qreal QColor::blackF() const
{
    if (cspec != Invalid && cspec != Cmyk)
        return toCmyk().blackF();
    return ct.acmyk.black / qreal(USHRT_MAX);
}

QColor QColor::toRgb() const
{
    if (!isValid() || cspec == Rgb)
        return *this;

    QColor color;
    color.cspec = Rgb;
    color.ct.argb.alpha = ct.argb.alpha;
    color.ct.argb.pad = 0;

    switch (cspec) {
    case Hsv:
        {
            if (ct.ahsv.saturation == 0 || ct.ahsv.hue == USHRT_MAX) {
                // achromatic case
                color.ct.argb.red = color.ct.argb.green = color.ct.argb.blue = ct.ahsv.value;
                break;
            }

            // chromatic case
            const qreal h = ct.ahsv.hue / 6000.;
            const qreal s = ct.ahsv.saturation / qreal(USHRT_MAX);
            const qreal v = ct.ahsv.value / qreal(USHRT_MAX);
            const int i = int(h);
            const qreal f = h - i;
            const qreal p = v * (1.0 - s);

            if (i & 1) {
                const qreal q = v * (1.0 - (s * f));

                switch (i) {
                case 1:
                    color.ct.argb.red   = qRound(q * USHRT_MAX);
                    color.ct.argb.green = qRound(v * USHRT_MAX);
                    color.ct.argb.blue  = qRound(p * USHRT_MAX);
                    break;
                case 3:
                    color.ct.argb.red   = qRound(p * USHRT_MAX);
                    color.ct.argb.green = qRound(q * USHRT_MAX);
                    color.ct.argb.blue  = qRound(v * USHRT_MAX);
                    break;
                case 5:
                    color.ct.argb.red   = qRound(v * USHRT_MAX);
                    color.ct.argb.green = qRound(p * USHRT_MAX);
                    color.ct.argb.blue  = qRound(q * USHRT_MAX);
                    break;
                }
            } else {
                const qreal t = v * (1.0 - (s * (1.0 - f)));

                switch (i) {
                case 0:
                    color.ct.argb.red   = qRound(v * USHRT_MAX);
                    color.ct.argb.green = qRound(t * USHRT_MAX);
                    color.ct.argb.blue  = qRound(p * USHRT_MAX);
                    break;
                case 2:
                    color.ct.argb.red   = qRound(p * USHRT_MAX);
                    color.ct.argb.green = qRound(v * USHRT_MAX);
                    color.ct.argb.blue  = qRound(t * USHRT_MAX);
                    break;
                case 4:
                    color.ct.argb.red   = qRound(t * USHRT_MAX);
                    color.ct.argb.green = qRound(p * USHRT_MAX);
                    color.ct.argb.blue  = qRound(v * USHRT_MAX);
                    break;
                }
            }
            break;
        }
    case Cmyk:
        {
            const qreal c = ct.acmyk.cyan / qreal(USHRT_MAX);
            const qreal m = ct.acmyk.magenta / qreal(USHRT_MAX);
            const qreal y = ct.acmyk.yellow / qreal(USHRT_MAX);
            const qreal k = ct.acmyk.black / qreal(USHRT_MAX);

            color.ct.argb.red   = qRound((1.0 - (c * (1.0 - k) + k)) * USHRT_MAX);
            color.ct.argb.green = qRound((1.0 - (m * (1.0 - k) + k)) * USHRT_MAX);
            color.ct.argb.blue  = qRound((1.0 - (y * (1.0 - k) + k)) * USHRT_MAX);
            break;
        }
    default:
        break;
    }

    return color;
}


#define Q_MAX_3(a, b, c) ( ( a > b && a > c) ? a : (b > c ? b : c) )
#define Q_MIN_3(a, b, c) ( ( a < b && a < c) ? a : (b < c ? b : c) )


QColor QColor::toHsv() const
{
    if (!isValid())
        return *this;

    if (cspec != Rgb)
        return toRgb().toHsv();

    QColor color;
    color.cspec = Hsv;
    color.ct.ahsv.alpha = ct.argb.alpha;
    color.ct.ahsv.pad = 0;

    const qreal r = ct.argb.red   / qreal(USHRT_MAX);
    const qreal g = ct.argb.green / qreal(USHRT_MAX);
    const qreal b = ct.argb.blue  / qreal(USHRT_MAX);
    const qreal max = Q_MAX_3(r, g, b);
    const qreal min = Q_MIN_3(r, g, b);
    const qreal delta = max - min;
    color.ct.ahsv.value = qRound(max * USHRT_MAX);
    if (delta == 0.0) {
        // achromatic case, hue is undefined
        color.ct.ahsv.hue = USHRT_MAX;
        color.ct.ahsv.saturation = 0;
    } else {
        // chromatic case
        qreal hue = 0;
        color.ct.ahsv.saturation = qRound((delta / max) * USHRT_MAX);
        if (r == max) {
            hue = ((g - b) /delta);
        } else if (g == max) {
            hue = (2.0 + (b - r) / delta);
        } else if (b == max) {
            hue = (4.0 + (r - g) / delta);
        } else {
            Q_ASSERT_X(false, "QColor::toHsv", "internal error");
        }
        hue *= 60.0;
        if (hue < 0.0)
            hue += 360.0;
        color.ct.ahsv.hue = qRound(hue * 100);
    }

    return color;
}

QColor QColor::toCmyk() const
{
    if (!isValid())
        return *this;
    if (cspec != Rgb)
        return toRgb().toCmyk();

    QColor color;
    color.cspec = Cmyk;
    color.ct.acmyk.alpha = ct.argb.alpha;

    // rgb -> cmy
    const qreal r = ct.argb.red   / qreal(USHRT_MAX);
    const qreal g = ct.argb.green / qreal(USHRT_MAX);
    const qreal b = ct.argb.blue  / qreal(USHRT_MAX);
    qreal c = 1.0 - r;
    qreal m = 1.0 - g;
    qreal y = 1.0 - b;

    // cmy -> cmyk
    const qreal k = qMin(c, qMin(m, y));

    if (!qFuzzyCompare(k,1)) {
        c = (c - k) / (1.0 - k);
        m = (m - k) / (1.0 - k);
        y = (y - k) / (1.0 - k);
    }

    color.ct.acmyk.cyan    = qRound(c * USHRT_MAX);
    color.ct.acmyk.magenta = qRound(m * USHRT_MAX);
    color.ct.acmyk.yellow  = qRound(y * USHRT_MAX);
    color.ct.acmyk.black   = qRound(k * USHRT_MAX);

    return color;
}

QColor QColor::convertTo(QColor::Spec colorSpec) const
{
    if (colorSpec == cspec)
        return *this;
    switch (colorSpec) {
    case Rgb:
        return toRgb();
    case Hsv:
        return toHsv();
    case Cmyk:
        return toCmyk();
    case Invalid:
        break;
    }
    return QColor(); // must be invalid
}


QColor QColor::fromRgb(QRgb rgb)
{
    return fromRgb(qRed(rgb), qGreen(rgb), qBlue(rgb));
}


QColor QColor::fromRgba(QRgb rgba)
{
    return fromRgb(qRed(rgba), qGreen(rgba), qBlue(rgba), qAlpha(rgba));
}

QColor QColor::fromRgb(int r, int g, int b, int a)
{
    if (r < 0 || r > 255
        || g < 0 || g > 255
        || b < 0 || b > 255
        || a < 0 || a > 255) {
        qWarning("QColor::fromRgb: RGB parameters out of range");
        return QColor();
    }

    QColor color;
    color.cspec = Rgb;
    color.ct.argb.alpha = a * 0x101;
    color.ct.argb.red   = r * 0x101;
    color.ct.argb.green = g * 0x101;
    color.ct.argb.blue  = b * 0x101;
    color.ct.argb.pad   = 0;
    return color;
}

QColor QColor::fromRgbF(qreal r, qreal g, qreal b, qreal a)
{
    if (r < 0.0 || r > 1.0
        || g < 0.0 || g > 1.0
        || b < 0.0 || b > 1.0
        || a < 0.0 || a > 1.0) {
        qWarning("QColor::fromRgbF: RGB parameters out of range");
        return QColor();
    }

    QColor color;
    color.cspec = Rgb;
    color.ct.argb.alpha = qRound(a * USHRT_MAX);
    color.ct.argb.red   = qRound(r * USHRT_MAX);
    color.ct.argb.green = qRound(g * USHRT_MAX);
    color.ct.argb.blue  = qRound(b * USHRT_MAX);
    color.ct.argb.pad   = 0;
    return color;
}

QColor QColor::fromHsv(int h, int s, int v, int a)
{
    if (((h < 0 || h >= 360) && h != -1)
        || s < 0 || s > 255
        || v < 0 || v > 255
        || a < 0 || a > 255) {
        qWarning("QColor::fromHsv: HSV parameters out of range");
        return QColor();
    }

    QColor color;
    color.cspec = Hsv;
    color.ct.ahsv.alpha      = a * 0x101;
    color.ct.ahsv.hue        = h == -1 ? USHRT_MAX : (h % 360) * 100;
    color.ct.ahsv.saturation = s * 0x101;
    color.ct.ahsv.value      = v * 0x101;
    color.ct.ahsv.pad        = 0;
    return color;
}

QColor QColor::fromHsvF(qreal h, qreal s, qreal v, qreal a)
{
    if (((h < 0.0 || h > 1.0) && h != -1.0)
        || (s < 0.0 || s > 1.0)
        || (v < 0.0 || v > 1.0)
        || (a < 0.0 || a > 1.0)) {
        qWarning("QColor::fromHsvF: HSV parameters out of range");
        return QColor();
    }

    QColor color;
    color.cspec = Hsv;
    color.ct.ahsv.alpha      = qRound(a * USHRT_MAX);
    color.ct.ahsv.hue        = h == -1.0 ? USHRT_MAX : qRound(h * 36000);
    color.ct.ahsv.saturation = qRound(s * USHRT_MAX);
    color.ct.ahsv.value      = qRound(v * USHRT_MAX);
    color.ct.ahsv.pad        = 0;
    return color;
}

void QColor::getCmyk(int *c, int *m, int *y, int *k, int *a)
{
    if (!c || !m || !y || !k)
        return;

    if (cspec != Invalid && cspec != Cmyk) {
        toCmyk().getCmyk(c, m, y, k, a);
        return;
    }

    *c = ct.acmyk.cyan >> 8;
    *m = ct.acmyk.magenta >> 8;
    *y = ct.acmyk.yellow >> 8;
    *k = ct.acmyk.black >> 8;

    if (a)
        *a = ct.acmyk.alpha >> 8;
}

void QColor::getCmykF(qreal *c, qreal *m, qreal *y, qreal *k, qreal *a)
{
    if (!c || !m || !y || !k)
        return;

    if (cspec != Invalid && cspec != Cmyk) {
        toCmyk().getCmykF(c, m, y, k, a);
        return;
    }

    *c = ct.acmyk.cyan    / qreal(USHRT_MAX);
    *m = ct.acmyk.magenta / qreal(USHRT_MAX);
    *y = ct.acmyk.yellow  / qreal(USHRT_MAX);
    *k = ct.acmyk.black   / qreal(USHRT_MAX);

    if (a)
        *a = ct.acmyk.alpha / qreal(USHRT_MAX);
}

void QColor::setCmyk(int c, int m, int y, int k, int a)
{
    if (c < 0 || c > 255
        || m < 0 || m > 255
        || y < 0 || y > 255
        || k < 0 || k > 255
        || a < 0 || a > 255) {
        qWarning("QColor::setCmyk: CMYK parameters out of range");
        return;
    }

    cspec = Cmyk;
    ct.acmyk.alpha   = a * 0x101;
    ct.acmyk.cyan    = c * 0x101;
    ct.acmyk.magenta = m * 0x101;
    ct.acmyk.yellow  = y * 0x101;
    ct.acmyk.black   = k * 0x101;
}

void QColor::setCmykF(qreal c, qreal m, qreal y, qreal k, qreal a)
{
    if (c < 0.0 || c > 1.0
        || m < 0.0 || m > 1.0
        || y < 0.0 || y > 1.0
        || k < 0.0 || k > 1.0
        || a < 0.0 || a > 1.0) {
        qWarning("QColor::setCmykF: CMYK parameters out of range");
        return;
    }

    cspec = Cmyk;
    ct.acmyk.alpha   = qRound(a * USHRT_MAX);
    ct.acmyk.cyan    = qRound(c * USHRT_MAX);
    ct.acmyk.magenta = qRound(m * USHRT_MAX);
    ct.acmyk.yellow  = qRound(y * USHRT_MAX);
    ct.acmyk.black   = qRound(k * USHRT_MAX);
}

QColor QColor::fromCmyk(int c, int m, int y, int k, int a)
{
    if (c < 0 || c > 255
        || m < 0 || m > 255
        || y < 0 || y > 255
        || k < 0 || k > 255
        || a < 0 || a > 255) {
        qWarning("QColor::fromCmyk: CMYK parameters out of range");
        return QColor();
    }

    QColor color;
    color.cspec = Cmyk;
    color.ct.acmyk.alpha   = a * 0x101;
    color.ct.acmyk.cyan    = c * 0x101;
    color.ct.acmyk.magenta = m * 0x101;
    color.ct.acmyk.yellow  = y * 0x101;
    color.ct.acmyk.black   = k * 0x101;
    return color;
}

QColor QColor::fromCmykF(qreal c, qreal m, qreal y, qreal k, qreal a)
{
    if (c < 0.0 || c > 1.0
        || m < 0.0 || m > 1.0
        || y < 0.0 || y > 1.0
        || k < 0.0 || k > 1.0
        || a < 0.0 || a > 1.0) {
        qWarning("QColor::fromCmykF: CMYK parameters out of range");
        return QColor();
    }

    QColor color;
    color.cspec = Cmyk;
    color.ct.acmyk.alpha   = qRound(a * USHRT_MAX);
    color.ct.acmyk.cyan    = qRound(c * USHRT_MAX);
    color.ct.acmyk.magenta = qRound(m * USHRT_MAX);
    color.ct.acmyk.yellow  = qRound(y * USHRT_MAX);
    color.ct.acmyk.black   = qRound(k * USHRT_MAX);
    return color;
}

QColor QColor::light(int factor) const
{
    if (factor <= 0)                                // invalid lightness factor
        return *this;
    else if (factor < 100)                        // makes color darker
        return dark(10000/factor);

    QColor hsv = toHsv();
    int s = hsv.ct.ahsv.saturation;
    int v = hsv.ct.ahsv.value;

    v = (factor*v)/100;
    if (v > USHRT_MAX) {
        // overflow... adjust saturation
        s -= v - USHRT_MAX;
        if (s < 0)
            s = 0;
        v = USHRT_MAX;
    }

    hsv.ct.ahsv.saturation = s;
    hsv.ct.ahsv.value = v;

    // convert back to same color spec as original color
    return hsv.convertTo(cspec);
}

QColor QColor::dark(int factor) const
{
    if (factor <= 0)                                // invalid darkness factor
        return *this;
    else if (factor < 100)                        // makes color lighter
        return light(10000/factor);

    QColor hsv = toHsv();
    hsv.ct.ahsv.value = (hsv.ct.ahsv.value * 100) / factor;

    // convert back to same color spec as original color
    return hsv.convertTo(cspec);
}

QColor &QColor::operator=(const QColor &color)
{
    cspec = color.cspec;
    ct.argb = color.ct.argb;
    return *this;
}

QColor &QColor::operator=(Qt::GlobalColor color)
{
    return operator=(QColor(color));
}

bool QColor::operator==(const QColor &color) const
{
    return (cspec == color.cspec
            && ct.argb.alpha == color.ct.argb.alpha
            && ct.argb.red   == color.ct.argb.red
            && ct.argb.green == color.ct.argb.green
            && ct.argb.blue  == color.ct.argb.blue
            && ct.argb.pad   == color.ct.argb.pad);
}

bool QColor::operator!=(const QColor &color) const
{ return !operator==(color); }


QColor::operator QVariant() const
{
    return QVariant(QVariant::Color, this);
}

void QColor::invalidate()
{
    cspec = Invalid;
    ct.argb.alpha = USHRT_MAX;
    ct.argb.red = 0;
    ct.argb.green = 0;
    ct.argb.blue = 0;
    ct.argb.pad = 0;
}

#ifdef QT3_SUPPORT

uint QColor::pixel(int screen) const
{
    QColormap cmap = QColormap::instance(screen);
    return cmap.pixel(*this);
}

#endif // QT3_SUPPORT

/*****************************************************************************
  QColor stream functions
 *****************************************************************************/

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QColor &c)
{
#ifndef Q_BROKEN_DEBUG_STREAM
    if (!c.isValid())
        dbg.nospace() << "QColor(Invalid)";
    else if (c.spec() == QColor::Rgb)
        dbg.nospace() << "QColor(ARGB " << c.alphaF() << ", " << c.redF() << ", " << c.greenF() << ", " << c.blueF() << ")";
    else if (c.spec() == QColor::Hsv)
        dbg.nospace() << "QColor(AHSV " << c.alphaF() << ", " << c.hueF() << ", " << c.saturationF() << ", " << c.valueF() << ")";
    else if (c.spec() == QColor::Cmyk)
        dbg.nospace() << "QColor(ACMYK " << c.alphaF() << ", " << c.cyanF() << ", " << c.magentaF() << ", " << c.yellowF() << ", "
                      << c.blackF()<< ")";

    return dbg.space();
#else
    qWarning("This compiler doesn't support streaming QColor to QDebug");
    return dbg;
    Q_UNUSED(c);
#endif
}
#endif

#ifndef QT_NO_DATASTREAM

QDataStream &operator<<(QDataStream &stream, const QColor &color)
{
    if (stream.version() < 7) {
        quint32 p = (quint32)color.rgb();
        if (stream.version() == 1) // Swap red and blue
            p = ((p << 16) & 0xff0000) | ((p >> 16) & 0xff) | (p & 0xff00ff00);
        return stream << p;
    }

    qint8   s = color.cspec;
    quint16 a = color.ct.argb.alpha;
    quint16 r = color.ct.argb.red;
    quint16 g = color.ct.argb.green;
    quint16 b = color.ct.argb.blue;
    quint16 p = color.ct.argb.pad;

    stream << s;
    stream << a;
    stream << r;
    stream << g;
    stream << b;
    stream << p;

    return stream;
}

QDataStream &operator>>(QDataStream &stream, QColor &color)
{
    if (stream.version() < 7) {
        quint32 p;
        stream >> p;
        if (stream.version() == 1) // Swap red and blue
            p = ((p << 16) & 0xff0000) | ((p >> 16) & 0xff) | (p & 0xff00ff00);
        color.setRgb(p);
        return stream;
    }

    qint8 s;
    quint16 a, r, g, b, p;
    stream >> s;
    stream >> a;
    stream >> r;
    stream >> g;
    stream >> b;
    stream >> p;

    color.cspec = QColor::Spec(s);
    color.ct.argb.alpha = a;
    color.ct.argb.red   = r;
    color.ct.argb.green = g;
    color.ct.argb.blue  = b;
    color.ct.argb.pad   = p;

    return stream;
}
#endif




/*****************************************************************************
  QColor global functions (documentation only)
 *****************************************************************************/

---