getLuminosityColor static method

Implementation

static Color getLuminosityColor(Color tintColor, double? luminosityOpacity) {
  // If luminosity opacity is specified, just use the values as is
  if (luminosityOpacity != null) {
    return Color.fromRGBO(
      tintColor.red,
      tintColor.green,
      tintColor.blue,
      luminosityOpacity.clamp(0.0, 1.0),
    );
  } else {
    // To create the Luminosity blend input color without luminosity opacity,
    // we're taking the TintColor input, converting to HSV, and clamping the V between these values
    const minHsvV = 0.125;
    const maxHsvV = 0.965;

    var hsvTintColor = HSVColor.fromColor(tintColor);

    var clampedHsvV = hsvTintColor.value.clamp(minHsvV, maxHsvV);

    var hsvLuminosityColor = hsvTintColor.withValue(clampedHsvV);
    var rgbLuminosityColor = hsvLuminosityColor.toColor();

    // Now figure out luminosity opacity
    // Map original *tint* opacity to this range
    const minLuminosityOpacity = 0.15;
    const maxLuminosityOpacity = 1.03;

    const luminosityOpacityRangeMax =
        maxLuminosityOpacity - minLuminosityOpacity;
    var mappedTintOpacity =
        ((tintColor.alpha / 255.0) * luminosityOpacityRangeMax) +
            minLuminosityOpacity;

    // Finally, combine the luminosity opacity and the HsvV-clamped tint color
    return Color.fromRGBO(
      rgbLuminosityColor.red,
      rgbLuminosityColor.green,
      rgbLuminosityColor.blue,
      math.min(mappedTintOpacity, 1.0),
    );
  }
}