Add files

src/renderer/components/audio-player/utils/list-handlers.ts

@@ -0,0 +1,131 @@
+/* eslint-disable no-nested-ternary */
+import type { Dispatch } from 'react';
+import { CrossfadeStyle } from '/@/renderer/types';
+
+export const gaplessHandler = (args: {
+  currentTime: number;
+  duration: number;
+  isFlac: boolean;
+  isTransitioning: boolean;
+  nextPlayerRef: any;
+  setIsTransitioning: Dispatch<boolean>;
+}) => {
+  const { nextPlayerRef, currentTime, duration, isTransitioning, setIsTransitioning, isFlac } =
+    args;
+
+  if (!isTransitioning) {
+    if (currentTime > duration - 2) {
+      return setIsTransitioning(true);
+    }
+
+    return null;
+  }
+
+  const durationPadding = isFlac ? 0.065 : 0.116;
+  if (currentTime + durationPadding >= duration) {
+    return nextPlayerRef.current.getInternalPlayer().play();
+  }
+
+  return null;
+};
+
+export const crossfadeHandler = (args: {
+  currentPlayer: 1 | 2;
+  currentPlayerRef: any;
+  currentTime: number;
+  duration: number;
+  fadeDuration: number;
+  fadeType: CrossfadeStyle;
+  isTransitioning: boolean;
+  nextPlayerRef: any;
+  player: 1 | 2;
+  setIsTransitioning: Dispatch<boolean>;
+  volume: number;
+}) => {
+  const {
+    currentTime,
+    player,
+    currentPlayer,
+    currentPlayerRef,
+    nextPlayerRef,
+    fadeDuration,
+    fadeType,
+    duration,
+    volume,
+    isTransitioning,
+    setIsTransitioning,
+  } = args;
+
+  if (!isTransitioning || currentPlayer !== player) {
+    const shouldBeginTransition = currentTime >= duration - fadeDuration;
+
+    if (shouldBeginTransition) {
+      setIsTransitioning(true);
+      return nextPlayerRef.current.getInternalPlayer().play();
+    }
+    return null;
+  }
+
+  const timeLeft = duration - currentTime;
+  let currentPlayerVolumeCalculation;
+  let nextPlayerVolumeCalculation;
+  let percentageOfFadeLeft;
+  let n;
+  switch (fadeType) {
+    case 'equalPower':
+      // https://dsp.stackexchange.com/a/14755
+      percentageOfFadeLeft = (timeLeft / fadeDuration) * 2;
+      currentPlayerVolumeCalculation = Math.sqrt(0.5 * percentageOfFadeLeft) * volume;
+      nextPlayerVolumeCalculation = Math.sqrt(0.5 * (2 - percentageOfFadeLeft)) * volume;
+      break;
+    case 'linear':
+      currentPlayerVolumeCalculation = (timeLeft / fadeDuration) * volume;
+      nextPlayerVolumeCalculation = ((fadeDuration - timeLeft) / fadeDuration) * volume;
+      break;
+    case 'dipped':
+      // https://math.stackexchange.com/a/4622
+      percentageOfFadeLeft = timeLeft / fadeDuration;
+      currentPlayerVolumeCalculation = percentageOfFadeLeft ** 2 * volume;
+      nextPlayerVolumeCalculation = (percentageOfFadeLeft - 1) ** 2 * volume;
+      break;
+    case fadeType.match(/constantPower.*/)?.input:
+      // https://math.stackexchange.com/a/26159
+      n =
+        fadeType === 'constantPower'
+          ? 0
+          : fadeType === 'constantPowerSlowFade'
+          ? 1
+          : fadeType === 'constantPowerSlowCut'
+          ? 3
+          : 10;
+
+      percentageOfFadeLeft = timeLeft / fadeDuration;
+      currentPlayerVolumeCalculation =
+        Math.cos((Math.PI / 4) * ((2 * percentageOfFadeLeft - 1) ** (2 * n + 1) - 1)) * volume;
+      nextPlayerVolumeCalculation =
+        Math.cos((Math.PI / 4) * ((2 * percentageOfFadeLeft - 1) ** (2 * n + 1) + 1)) * volume;
+      break;
+
+    default:
+      currentPlayerVolumeCalculation = (timeLeft / fadeDuration) * volume;
+      nextPlayerVolumeCalculation = ((fadeDuration - timeLeft) / fadeDuration) * volume;
+      break;
+  }
+
+  const currentPlayerVolume =
+    currentPlayerVolumeCalculation >= 0 ? currentPlayerVolumeCalculation : 0;
+
+  const nextPlayerVolume =
+    nextPlayerVolumeCalculation <= volume ? nextPlayerVolumeCalculation : volume;
+
+  if (currentPlayer === 1) {
+    currentPlayerRef.current.getInternalPlayer().volume = currentPlayerVolume;
+    nextPlayerRef.current.getInternalPlayer().volume = nextPlayerVolume;
+  } else {
+    currentPlayerRef.current.getInternalPlayer().volume = currentPlayerVolume;
+    nextPlayerRef.current.getInternalPlayer().volume = nextPlayerVolume;
+  }
+  // }
+
+  return null;
+};