[Development] Function to merge two QColor?

[Kai Uwe Broulik]

Hi,

Qt Quick has Qt.tint but I don’t see an equivalent in QColor. Perhaps a 
C++ API should be added. In any case, it’s trivial, just doing alpha 
blending:

QColor QQuickColorValueType::tint(const QColor &tintColor) const
{
     int tintAlpha = tintColor.alpha();
     if (tintAlpha == 0xFF)
         return tintColor;
     else if (tintAlpha == 0x00)
         return *this;

     // tint the base color and return the final color
     const QColor baseColor = QColor::toRgb();
     const qreal a = tintColor.alphaF();
     const qreal inv_a = 1.0 - a;

     const qreal r = tintColor.redF() * a + baseColor.redF() * inv_a;
     const qreal g = tintColor.greenF() * a + baseColor.greenF() * inv_a;
     const qreal b = tintColor.blueF() * a + baseColor.blueF() * inv_a;

     return QColor::fromRgbF(r, g, b, a + inv_a * baseColor.alphaF());
}

Cheers
Kai Uwe

Am 23.11.25 um 20:17 schrieb Christian Ehrlicher via Development:
> Hi,
> 
> for the window11 style plugin I like to merge two QColors to avoid a 
> double painting. The first color has no alpha but the second. Is there 
> anything ready to use in Qt (internals) or do I have to write something 
> by my own?
> 
> 
> Thx,
> Christian