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

quarticIn detail::quarticInEasing quarticIn {} inlineconstexpr Quartic polynomial easing (t⁴) with strong acceleration. The quarticIn easing function uses a power-4 curve for acceleration, creating pronounced easing that's stronger than cubic but less extreme than exponential. Characteristics: Strong acceleration curve Polynomial with power of 4 Very slow start, rapid finish More dramatic than cubic This easing is ideal for: Dramatic entrances: Elements that burst into view Emphasis: Drawing attention to motion start Game animations: Action-oriented interfaces Long animations: Over 500ms where strong curves work Mathematically: f(t) = t⁴ // Panel sliding in with emphasis auto x = tweeny::from(-400.0f) .to(0.0f) .via(easing::quarticIn) .during(50U) .build(); See also quarticOut For strong deceleration quarticInOut For strong motion at both ends cubicIn For gentler acceleration quinticIn For even stronger acceleration Visualize at https://easings.net/#easeInQuart