33 lines
1.2 KiB
TypeScript
33 lines
1.2 KiB
TypeScript
import type { LrcJsonData } from "lrc-parser-ts";
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export default function createLyricsSearcher(lrc: LrcJsonData): (progress: number) => number {
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if (!lrc || !lrc.scripts) return () => 0;
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const startTimes: number[] = lrc.scripts.map(script => script.start);
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const endTimes: number[] = lrc.scripts.map(script => script.end);
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return function(progress: number): number {
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// 使用二分查找定位 progress 对应的歌词索引
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let left = 0;
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let right = startTimes.length - 1;
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while (left <= right) {
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const mid = Math.floor((left + right) / 2);
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if (startTimes[mid] === progress) {
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return mid;
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} else if (startTimes[mid] < progress) {
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left = mid + 1;
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} else {
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right = mid - 1;
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}
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}
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// 循环结束后，检查 left 索引
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if (left < startTimes.length && startTimes[left] > progress && (left === 0 || endTimes[left - 1] <= progress)) {
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return left;
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}
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// 如果没有找到确切的 progress，返回小于等于 progress 的最大索引
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return Math.max(0, right);
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};
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} |