mirror of
https://github.com/photonstorm/phaser
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49 lines
1.3 KiB
TypeScript
49 lines
1.3 KiB
TypeScript
/// <reference path="../../Game.ts" />
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/**
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* Phaser - Easing - Elastic
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*
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* For use with Phaser.Tween
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*/
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module Phaser.Easing {
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export class Elastic {
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public static In(k) {
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var s, a = 0.1, p = 0.4;
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if (k === 0) return 0;
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if (k === 1) return 1;
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if (!a || a < 1) { a = 1; s = p / 4; }
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else s = p * Math.asin(1 / a) / (2 * Math.PI);
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return -(a * Math.pow(2, 10 * (k -= 1)) * Math.sin((k - s) * (2 * Math.PI) / p));
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}
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public static Out(k) {
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var s, a = 0.1, p = 0.4;
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if (k === 0) return 0;
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if (k === 1) return 1;
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if (!a || a < 1) { a = 1; s = p / 4; }
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else s = p * Math.asin(1 / a) / (2 * Math.PI);
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return (a * Math.pow(2, -10 * k) * Math.sin((k - s) * (2 * Math.PI) / p) + 1);
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}
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public static InOut(k) {
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var s, a = 0.1, p = 0.4;
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if (k === 0) return 0;
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if (k === 1) return 1;
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if (!a || a < 1) { a = 1; s = p / 4; }
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else s = p * Math.asin(1 / a) / (2 * Math.PI);
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if ((k *= 2) < 1) return -0.5 * (a * Math.pow(2, 10 * (k -= 1)) * Math.sin((k - s) * (2 * Math.PI) / p));
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return a * Math.pow(2, -10 * (k -= 1)) * Math.sin((k - s) * (2 * Math.PI) / p) * 0.5 + 1;
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}
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}
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}
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