27 lines
842 B
Plaintext
27 lines
842 B
Plaintext
import { easingDefinitionToFunction } from 'motion-utils';
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function getOriginIndex(from, total) {
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if (from === "first") {
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return 0;
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}
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else {
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const lastIndex = total - 1;
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return from === "last" ? lastIndex : lastIndex / 2;
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}
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}
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function stagger(duration = 0.1, { startDelay = 0, from = 0, ease } = {}) {
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return (i, total) => {
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const fromIndex = typeof from === "number" ? from : getOriginIndex(from, total);
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const distance = Math.abs(fromIndex - i);
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let delay = duration * distance;
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if (ease) {
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const maxDelay = total * duration;
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const easingFunction = easingDefinitionToFunction(ease);
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delay = easingFunction(delay / maxDelay) * maxDelay;
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}
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return startDelay + delay;
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};
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}
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export { getOriginIndex, stagger };
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