65 lines
1.2 KiB
JavaScript
65 lines
1.2 KiB
JavaScript
/**
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* @module ol/easing
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*/
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/**
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* Start slow and speed up.
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* @param {number} t Input between 0 and 1.
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* @return {number} Output between 0 and 1.
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* @api
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*/
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export function easeIn(t) {
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return Math.pow(t, 3);
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}
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/**
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* Start fast and slow down.
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* @param {number} t Input between 0 and 1.
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* @return {number} Output between 0 and 1.
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* @api
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*/
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export function easeOut(t) {
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return 1 - easeIn(1 - t);
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}
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/**
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* Start slow, speed up, and then slow down again.
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* @param {number} t Input between 0 and 1.
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* @return {number} Output between 0 and 1.
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* @api
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*/
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export function inAndOut(t) {
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return 3 * t * t - 2 * t * t * t;
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}
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/**
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* Maintain a constant speed over time.
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* @param {number} t Input between 0 and 1.
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* @return {number} Output between 0 and 1.
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* @api
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*/
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export function linear(t) {
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return t;
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}
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/**
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* Start slow, speed up, and at the very end slow down again. This has the
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* same general behavior as {@link module:ol/easing~inAndOut}, but the final
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* slowdown is delayed.
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* @param {number} t Input between 0 and 1.
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* @return {number} Output between 0 and 1.
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* @api
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*/
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export function upAndDown(t) {
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if (t < 0.5) {
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return inAndOut(2 * t);
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} else {
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return 1 - inAndOut(2 * (t - 0.5));
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}
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}
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