Interface Easing

fr/lavache/anime/Easing.java:3–445

package fr.lavache.anime;

public interface Easing {

    /**
     * Simple linear tweening - no easing.
     */
    Easing LINEAR = (t, b, c, d) -> c * t / d + b;
    /**
     * Quadratic easing in - accelerating from zero velocity.
     */
    Easing QUAD_IN = (t, b, c, d) -> c * (t /= d) * t + b;

    ///////////// QUADRATIC EASING: t^2 ///////////////////
    /**
     * Quadratic easing out - decelerating to zero velocity.
     */
    Easing QUAD_OUT = (t, b, c, d) -> -c * (t /= d) * (t - 2) + b;
    /**
     * Quadratic easing in/out - acceleration until halfway, then deceleration
     */
    Easing QUAD_IN_OUT = (t, b, c, d) -> {
        if ((t /= d / 2) < 1) return c / 2 * t * t + b;
        return -c / 2 * ((--t) * (t - 2) - 1) + b;
    };
    /**
     * Cubic easing in - accelerating from zero velocity.
     */
    Easing CUBIC_IN = (t, b, c, d) -> c * (t /= d) * t * t + b;


    ///////////// CUBIC EASING: t^3 ///////////////////////
    /**
     * Cubic easing out - decelerating to zero velocity.
     */
    Easing CUBIC_OUT = (t, b, c, d) -> c * ((t = t / d - 1) * t * t + 1) + b;
    /**
     * Cubic easing in/out - acceleration until halfway, then deceleration.
     */
    Easing CUBIC_IN_OUT = (t, b, c, d) -> {
        if ((t /= d / 2) < 1) return c / 2 * t * t * t + b;
        return c / 2 * ((t -= 2) * t * t + 2) + b;
    };
    /**
     * Quartic easing in - accelerating from zero velocity.
     */
    Easing QUARTIC_IN = (t, b, c, d) -> c * (t /= d) * t * t * t + b;

    ///////////// QUARTIC EASING: t^4 /////////////////////
    /**
     * Quartic easing out - decelerating to zero velocity.
     */
    Easing QUARTIC_OUT = (t, b, c, d) -> -c * ((t = t / d - 1) * t * t * t - 1) + b;
    /**
     * Quartic easing in/out - acceleration until halfway, then deceleration.
     */
    Easing QUARTIC_IN_OUT = (t, b, c, d) -> {
        if ((t /= d / 2) < 1) return c / 2 * t * t * t * t + b;
        return -c / 2 * ((t -= 2) * t * t * t - 2) + b;
    };