backIn backInOut backOut bounceIn bounceInOut bounceOut byName circularIn circularInOut circularOut cubicIn cubicInOut cubicOut def elasticIn elasticInOut elasticOut exponentialIn exponentialInOut exponentialOut linear quadraticIn quadraticInOut quadraticOut quarticIn quarticInOut quarticOut quinticIn quinticInOut quinticOut sinusoidalIn sinusoidalInOut sinusoidalOut stepped

quarticOut detail::quarticOutEasing quarticOut {} inlineconstexpr Quartic polynomial easing (t⁴) with strong deceleration. The quarticOut easing function provides pronounced deceleration that's popular for animations needing clear emphasis without being as extreme as exponential. Characteristics: Strong deceleration curve Smooth, extended slowdown Emphasizes final position Balanced between cubic and exponential This easing excels at: Emphasized arrivals: Elements settling with impact Current design patterns: Strong deceleration suitable for emphasized arrivals Medium-length animations: 300-600ms sweet spot Purposeful motion: Clear acceleration and deceleration QuarticOut provides more "oomph" than cubic while remaining smooth and professional. It's a good choice when cubic feels too subtle. Mathematically: f(t) = 1 - (1-t)⁴ // Card sliding into place with emphasis auto y = tweeny::from(200.0f) .to(0.0f) .via(easing::quarticOut) .during(40U) .build(); See also quarticIn For strong acceleration quarticInOut For strong motion at both ends cubicOut For gentler deceleration quinticOut For even stronger deceleration Visualize at https://easings.net/#easeOutQuart