feat: 渐变切歌

public/libs/control.js

@@ -3345,7 +3345,7 @@ control.prototype.screenFlash = function (
 control.prototype.playBgm = function (bgm, startTime) {
     bgm = core.getMappedName(bgm);
     if (main.mode !== 'play') return;
-    Mota.require('var', 'bgm').play(bgm, startTime);
+    Mota.require('var', 'bgm').changeTo(bgm, startTime);
 };
 
 ////// 暂停背景音乐的播放 //////

src/core/audio/audio.ts

@@ -13,10 +13,7 @@ interface AudioPlayerEvent extends EmitableEvent {
     end: (node: AudioBufferSourceNode) => void;
 }
 
-export type AudioParamOf<T extends AudioNode> = Record<
-    SelectKey<T, AudioParam>,
-    number
->;
+export type AudioParamOf<T> = Record<SelectKey<T, AudioParam>, number>;
 
 export class AudioPlayer extends EventEmitter<AudioPlayerEvent> {
     static ac: AudioContext = ac;

src/core/audio/bgm.ts

@@ -1,13 +1,39 @@
-import { has } from '@/plugin/utils';
+import { Animation, TimingFn, Transition, linear, sleep } from 'mutate-animate';
+import { Undoable } from '../interface';
 import { ResourceController } from '../loader/controller';
+import { has } from '@/plugin/utils';
 
-export class BgmController extends ResourceController<HTMLAudioElement> {
-    playing?: BgmIds;
-    lastBgm?: BgmIds;
+interface AnimatingBgm {
+    end: () => void;
+    ani: Transition;
+    timeout: number;
+    currentTime: number;
+}
+
+export class BgmController
+    extends ResourceController<HTMLAudioElement>
+    implements Undoable<BgmIds>
+{
+    /** Bgm播放栈，可以undo，最多存放10个 */
+    stack: BgmIds[] = [];
+    /** Bgm的redo栈，最多存放10个 */
+    redoStack: BgmIds[] = [];
+    /** 当前播放的bgm */
+    now?: BgmIds;
+
+    /** 渐变切歌时长 */
+    transitionTime: number = 2000;
+    /** 渐变切歌的音量曲线 */
+    transitionCurve: TimingFn = linear();
+
+    /** 音量 */
+    volume: number = 1;
+
+    private transitionData: Map<BgmIds, AnimatingBgm> = new Map();
 
     /**
      * 添加一个bgm
-     * @param uri bgm的uri
+     * @param uri bgm的`uri`，由于bgm是一类资源，因此`uri`为`bgms.xxx`的形式
      * @param data bgm音频元素
      */
     add(uri: string, data: HTMLAudioElement) {
@@ -18,25 +44,6 @@ export class BgmController extends ResourceController<HTMLAudioElement> {
         data.loop = true;
     }
 
-    /**
-     * 切换bgm
-     * @param id bgm的id
-     */
-    play(id: BgmIds, when: number = 0) {
-        if (this.playing === id) return;
-        this.pause();
-        if (core.musicStatus.bgmStatus) {
-            const bgm = this.get(id);
-            bgm.currentTime = when;
-            bgm.volume = core.musicStatus.userVolume;
-            bgm.play();
-            this.playing = id;
-        } else {
-            delete this.playing;
-        }
-        this.lastBgm = id;
-    }
-
     /**
      * 加载一个bgm
      * @param id 要加载的bgm
@@ -47,28 +54,191 @@ export class BgmController extends ResourceController<HTMLAudioElement> {
     }
 
     /**
-     * 停止当前的bgm播放
+     * 切换bgm，具有渐变效果，可以通过监听切换事件，同时调用preventDefault来阻止渐变，
+     * 并使用自己的切歌程序。阻止后，不会将切换的歌曲加入播放栈，也不会进行切歌，
+     * 所有的切歌操作均由你自己的程序执行
+     * @param id 要切换至的bgm
+     * @param when 切换至的歌从什么时候开始播放，默认-1，表示不改变，整数表示设置为目标值
      */
-    pause() {
-        if (!has(this.playing)) return;
-        const bgm = this.get(this.playing);
-        bgm.pause();
-        delete this.playing;
+    changeTo(id: BgmIds, when: number = -1, noStack: boolean = false) {
+        let prevent = false;
+        const preventDefault = () => {
+            prevent = true;
+        };
+        const ev = { preventDefault };
+
+        this.emit('changeBgm', ev, id, this.now);
+
+        if (prevent) return;
+
+        this.setTransitionAnimate(id, 1);
+        if (this.now) this.setTransitionAnimate(this.now, 0, when);
+
+        if (!noStack) {
+            if (this.now) this.stack.push(this.now);
+            this.redoStack = [];
+        }
+        this.now = id;
     }
 
     /**
-     * 继续上一个BGM的播放
+     * 暂停当前bgm的播放，继续播放时将会延续暂停的时刻，同样可以使用preventDefault使用自己的暂停程序
+     * @param transition 是否使用渐变效果，默认使用
      */
-    resume() {
-        if (has(this.playing) || !this.lastBgm) return;
-        const bgm = this.get(this.lastBgm);
-        bgm.play();
-        this.playing = this.lastBgm;
+    pause(transition: boolean = true) {
+        if (!this.now) return;
+        let prevent = false;
+        const preventDefault = () => {
+            prevent = true;
+        };
+        const ev = { preventDefault };
+
+        this.emit('pause', ev, this.now);
+
+        if (prevent) return;
+
+        if (transition) this.setTransitionAnimate(this.now, 0);
+        else this.get(this.now).pause();
     }
 
+    /**
+     * 继续当前bgm的播放，从上一次暂停的时刻开始播放，同样可以使用preventDefault使用自己的播放程序
+     * @param transition 是否使用渐变效果，默认使用
+     */
+    resume(transition: boolean = true) {
+        if (!this.now) return;
+        let prevent = false;
+        const preventDefault = () => {
+            prevent = true;
+        };
+        const ev = { preventDefault };
+
+        this.emit('pause', ev, this.now);
+
+        if (prevent) return;
+
+        if (transition) this.setTransitionAnimate(this.now, 1);
+        else this.get(this.now).play();
+    }
+
+    /**
+     * 播放bgm，不进行渐变操作，效果为没有渐变的切歌
+     * @param id 要播放的bgm
+     * @param when 从bgm的何时开始播放
+     */
+    play(id: BgmIds, when: number = 0, noStack: boolean = false) {
+        const before = this.now ? null : this.get(this.now!);
+        const to = this.get(id);
+        if (before) {
+            before.pause();
+        }
+        to.currentTime = when;
+        to.volume = this.volume;
+        to.play();
+        if (!noStack) {
+            if (this.now) this.stack.push(this.now);
+            this.redoStack = [];
+        }
+        this.now = id;
+    }
+
+    /**
+     * 撤销当前播放，改为播放前一个bgm
+     */
+    undo(transition: boolean = true, when: number = 0) {
+        if (this.stack.length === 0) return;
+        else {
+            const to = this.stack.pop()!;
+            if (this.now) this.redoStack.push(this.now);
+            else return;
+
+            if (transition) this.changeTo(to, when, true);
+            else this.play(to, when, true);
+            return this.now;
+        }
+    }
+
+    /**
+     * 取消上一次的撤销，改为播放上一次撤销的bgm
+     */
+    redo(transition: boolean = true, when: number = 0) {
+        if (this.redoStack.length === 0) return;
+        else {
+            const to = this.redoStack.pop()!;
+            if (this.now) this.stack.push(this.now);
+            else return;
+
+            if (transition) this.changeTo(to, when, true);
+            else this.play(to, when, true);
+            return this.now;
+        }
+    }
+
+    /**
+     * 设置渐变切歌信息
+     * @param time 渐变时长
+     * @param curve 渐变的音量曲线
+     */
+    setTransition(time?: number, curve?: TimingFn) {
+        has(time) && (this.transitionTime = time);
+        has(curve) && (this.transitionCurve = curve);
+    }
+
+    /**
+     * 根据id获取bgm
+     * @param id 要获取的bgm的id
+     */
     get(id: BgmIds) {
         return this.list[`bgms.${id}`];
     }
+
+    private setTransitionAnimate(id: BgmIds, to: number, when: number = -1) {
+        const bgm = this.get(id);
+
+        let tran = this.transitionData.get(id);
+        if (!tran) {
+            const ani = new Transition();
+            ani.value.volume = bgm.paused ? 0 : 1;
+            const end = () => {
+                ani.ticker.destroy();
+                if (ani.value.volume === 0) {
+                    bgm.pause();
+                } else {
+                    bgm.volume = ani.value.volume * this.volume;
+                }
+                this.transitionData.delete(id);
+            };
+            tran = {
+                end,
+                ani: ani,
+                timeout: -1,
+                currentTime: bgm.currentTime
+            };
+            this.transitionData.set(id, tran);
+            ani.ticker.add(() => {
+                bgm.volume = ani.value.volume * this.volume;
+            });
+        }
+
+        if (to !== 0) {
+            bgm.volume = tran.ani.value.volume * this.volume;
+            if (bgm.paused) bgm.play();
+        }
+        if (when !== -1) {
+            bgm.currentTime = when;
+        }
+
+        tran.ani
+            .time(this.transitionTime)
+            .mode(this.transitionCurve)
+            .absolute()
+            .transition('volume', to);
+
+        if (tran.timeout !== -1) {
+            clearTimeout(tran.timeout);
+        }
+        tran.timeout = window.setTimeout(tran.end, this.transitionTime);
+    }
 }
 
 export const bgm = new BgmController();

src/core/audio/sound.ts

@@ -6,6 +6,7 @@ import { ResourceController } from '../loader/controller';
 // todo: 立体声，可设置音源位置
 
 type Panner = AudioParamOf<PannerNode>;
+type Listener = AudioParamOf<AudioListener>;
 
 export class SoundEffect extends AudioPlayer {
     static playIndex = 0;
@@ -35,7 +36,7 @@ export class SoundEffect extends AudioPlayer {
         return this._stereo;
     }
 
-    constructor(data: ArrayBuffer, stereo: boolean = false) {
+    constructor(data: ArrayBuffer, stereo: boolean = true) {
         super(data);
 
         this.on('end', node => {
@@ -62,7 +63,7 @@ export class SoundEffect extends AudioPlayer {
      * ```
      * @param stereo 是否启用立体声
      */
-    protected initAudio(stereo: boolean = false) {
+    protected initAudio(stereo: boolean = true) {
         const channel = this.buffer?.numberOfChannels;
         const ac = AudioPlayer.ac;
         if (!channel) return;
@@ -125,13 +126,18 @@ export class SoundEffect extends AudioPlayer {
 
     /**
      * 设置立体声信息
-     * @param panner 立体声信息
+     * @param source 立体声声源位置与朝向
+     * @param listener 听者的位置、头顶方向、面朝方向
      */
-    setPanner(panner: Partial<Panner>) {
+    setPanner(source: Partial<Panner>, listener: Partial<Listener>) {
         if (!this.panner) return;
-        for (const [key, value] of Object.entries(panner)) {
+        for (const [key, value] of Object.entries(source)) {
             this.panner[key as keyof Panner].value = value;
         }
+        const l = AudioPlayer.ac.listener;
+        for (const [key, value] of Object.entries(listener)) {
+            l[key as keyof Listener].value = value;
+        }
     }
 }
 

src/core/interface.ts

@@ -0,0 +1,14 @@
+export interface Undoable<T> {
+    stack: T[];
+    redoStack: T[];
+
+    /**
+     * 撤销
+     */
+    undo(): T | undefined;
+
+    /**
+     * 重做
+     */
+    redo(): T | undefined;
+}

src/core/loader/controller.ts

@@ -1,4 +1,14 @@
-export abstract class ResourceController<D, T = D> {
+import { EmitableEvent, EventEmitter } from '../common/eventEmitter';
+
+interface ResourceControllerEvent<D = any, T = D> extends EmitableEvent {
+    add: (uri: string, data: D) => void;
+    delete: (uri: string, content: T) => void;
+}
+
+export abstract class ResourceController<
+    D,
+    T = D
+> extends EventEmitter<ResourceControllerEvent> {
     list: Record<string, T> = {};
 
     /**
@@ -8,7 +18,13 @@ export abstract class ResourceController<D, T = D> {
      */
     abstract add(uri: string, data: D): void;
 
+    /**
+     * 删除一个资源
+     * @param uri 要删除的资源的uri
+     */
     remove(uri: string) {
+        const content = this.list[uri];
         delete this.list[uri];
+        this.emit(uri, content);
     }
 }

src/core/loader/resource.ts

@@ -4,6 +4,7 @@ import { ensureArray } from '@/plugin/utils';
 import { has } from '@/plugin/utils';
 import JSZip from 'jszip';
 import { EmitableEvent, EventEmitter } from '../common/eventEmitter';
+import { bgm } from '../audio/bgm';
 
 // todo: 应当用register去注册资源类型，然后进行分块处理
 
@@ -53,7 +54,7 @@ export class Resource<
     protected onLoadStart(v?: ResourceData[T]) {
         if (this.format === 'bgm') {
             // bgm 单独处理，因为它可以边播放边加载
-            Mota.require('var', 'bgm').add(this.uri, v!);
+            bgm.add(this.uri, v!);
         }
     }