Method tint

libraries/rainbow/src/rainbow.cpp:237–265

}

QColor Rainbow::tint(const QColor& base, const QColor& color, qreal amount)
{
    if (amount <= 0.0) {
        return base;
    }
    if (amount >= 1.0) {
        return color;
    }
    if (qIsNaN(amount)) {
        return base;
    }

    qreal baseLuma = luma(base);  // cache value because luma call is expensive
    double ri = contrastRatioForLuma(baseLuma, luma(color));
    double rg = 1.0 + ((ri + 1.0) * amount * amount * amount);
    double u = 1.0, l = 0.0;
    QColor result;
    for (int i = 12; i; --i) {
        double a = 0.5 * (l + u);
        result = tintHelper(base, baseLuma, color, a);
        double ra = contrastRatioForLuma(baseLuma, luma(result));
        if (ra > rg) {
            u = a;
        } else {
            l = a;
        }
    }
    return result;
}

QColor Rainbow::mix(const QColor& c1, const QColor& c2, qreal bias)
{