import { cubicAt, cubicRootAt } from '../core/curve';
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import { trim } from '../core/util';
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const regexp = /cubic-bezier\(([0-9,\.e ]+)\)/;
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export function createCubicEasingFunc(cubicEasingStr: string) {
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const cubic = cubicEasingStr && regexp.exec(cubicEasingStr);
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if (cubic) {
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const points = cubic[1].split(',');
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const a = +trim(points[0]);
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const b = +trim(points[1]);
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const c = +trim(points[2]);
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const d = +trim(points[3]);
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if (isNaN(a + b + c + d)) {
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return;
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}
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const roots: number[] = [];
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return (p: number) => {
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return p <= 0
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? 0 : p >= 1
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? 1
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: cubicRootAt(0, a, c, 1, p, roots) && cubicAt(0, b, d, 1, roots[0]);
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};
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}
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}
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