qglcolormap.cpp

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#include "qglcolormap.h"

QT_BEGIN_NAMESPACE

QGLColormap::QGLColormapData QGLColormap::shared_null = { Q_BASIC_ATOMIC_INITIALIZER(1), 0, 0 };

QGLColormap::QGLColormap()
    : d(&shared_null)
{
    d->ref.ref();
}


QGLColormap::QGLColormap(const QGLColormap &map)
    : d(map.d)
{
    d->ref.ref();
}

QGLColormap::~QGLColormap()
{
    if (!d->ref.deref())
        cleanup(d);
}

void QGLColormap::cleanup(QGLColormap::QGLColormapData *x)
{
    delete x->cells;
    x->cells = 0;
    delete x;
}

QGLColormap & QGLColormap::operator=(const QGLColormap &map)
{
    map.d->ref.ref();
    if (!d->ref.deref())
        cleanup(d);
    d = map.d;
    return *this;
}

void QGLColormap::detach_helper()
{
    QGLColormapData *x = new QGLColormapData;
    x->ref = 1;
    x->cmapHandle = 0;
    x->cells = 0;
    if (d->cells) {
        x->cells = new QVector<QRgb>(256);
        *x->cells = *d->cells;
    }
    if (!d->ref.deref())
        cleanup(d);
    d = x;
}

void QGLColormap::setEntry(int idx, QRgb color)
{
    detach();
    if (!d->cells)
        d->cells = new QVector<QRgb>(256);
    d->cells->replace(idx, color);
}

void QGLColormap::setEntries(int count, const QRgb *colors, int base)
{
    detach();
    if (!d->cells)
        d->cells = new QVector<QRgb>(256);

    Q_ASSERT_X(colors && base >= 0 && (base + count) <= d->cells->size(), "QGLColormap::setEntries",
               "preconditions not met");
    for (int i = 0; i < count; ++i)
        setEntry(base + i, colors[i]);
}

QRgb QGLColormap::entryRgb(int idx) const
{
    if (d == &shared_null || !d->cells)
        return 0;
    else
        return d->cells->at(idx);
}

void QGLColormap::setEntry(int idx, const QColor &color)
{
    setEntry(idx, color.rgb());
}

QColor QGLColormap::entryColor(int idx) const
{
    if (d == &shared_null || !d->cells)
        return QColor();
    else
        return QColor(d->cells->at(idx));
}

bool QGLColormap::isEmpty() const
{
    return d == &shared_null || d->cells == 0 || d->cells->size() == 0 || d->cmapHandle == 0;
}


int QGLColormap::size() const
{
    return d->cells ? d->cells->size() : 0;
}

int QGLColormap::find(QRgb color) const
{
    if (d->cells)
        return d->cells->indexOf(color);
    return -1;
}

int QGLColormap::findNearest(QRgb color) const
{
    int idx = find(color);
    if (idx >= 0)
        return idx;
    int mapSize = size();
    int mindist = 200000;
    int r = qRed(color);
    int g = qGreen(color);
    int b = qBlue(color);
    int rx, gx, bx, dist;
    for (int i = 0; i < mapSize; ++i) {
        QRgb ci = d->cells->at(i);
        rx = r - qRed(ci);
        gx = g - qGreen(ci);
        bx = b - qBlue(ci);
        dist = rx * rx + gx * gx + bx * bx;        // calculate distance
        if (dist < mindist) {                // minimal?
            mindist = dist;
            idx = i;
        }
    }
    return idx;
}

QT_END_NAMESPACE