private static double lerp( double v1, double v2, double t ) {
		return (v1 * (1 - t)) + (v2 * t);
	}
Calculates linear interpolation between two values.

https://en.wikipedia.org/wiki/Linear_interpolation#Programming_language_support
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java