Merge pull request #114 from FunkinCrew/bugfix/conductor-monster

Fixes to Conductor for Monster

source/funkin/Conductor.hx

@@ -1,23 +1,18 @@
 package funkin;
 
-import funkin.play.song.SongData.SongTimeChange;
+import funkin.util.Constants;
 import flixel.util.FlxSignal;
+import flixel.math.FlxMath;
+import funkin.SongLoad.SwagSong;
 import funkin.play.song.Song.SongDifficulty;
-
+import funkin.play.song.SongData.SongTimeChange;
-typedef BPMChangeEvent =
-{
-  var stepTime:Int;
-  var songTime:Float;
-  var bpm:Float;
-}
 
 /**
- * A global source of truth for timing information.
+ * A core class which handles musical timing throughout the game,
+ * both in gameplay and in menus.
  */
 class Conductor
 {
-  static final STEPS_PER_BEAT:Int = 4;
-
   // onBeatHit is called every quarter note
   // onStepHit is called every sixteenth note
   // 4/4 = 4 beats per measure = 16 steps per measure
@@ -33,11 +28,22 @@ class Conductor
   //   60 BPM = 240 sixteenth notes per minute = 4 onStepHit per second
   // 7/8 = 3.5 beats per measure = 14 steps per measure
 
+  /**
+   * The list of time changes in the song.
+   * There should be at least one time change (at the beginning of the song) to define the BPM.
+   */
+  static var timeChanges:Array<SongTimeChange> = [];
+
+  /**
+   * The current time change.
+   */
+  static var currentTimeChange:SongTimeChange;
+
   /**
    * The current position in the song in milliseconds.
    * Updated every frame based on the audio position.
    */
-  public static var songPosition:Float;
+  public static var songPosition:Float = 0;
 
   /**
    * Beats per minute of the current song at the current time.
@@ -48,33 +54,17 @@ class Conductor
   {
     if (bpmOverride != null) return bpmOverride;
 
-    if (currentTimeChange == null) return 100;
+    if (currentTimeChange == null) return Constants.DEFAULT_BPM;
 
     return currentTimeChange.bpm;
   }
 
+  /**
+   * The current value set by `forceBPM`.
+   * If false, BPM is determined by time changes.
+   */
   static var bpmOverride:Null<Float> = null;
 
-  /**
-   * Current position in the song, in whole measures.
-   */
-  public static var currentMeasure(default, null):Int;
-
-  /**
-   * Current position in the song, in whole beats.
-  **/
-  public static var currentBeat(default, null):Int;
-
-  /**
-   * Current position in the song, in whole steps.
-   */
-  public static var currentStep(default, null):Int;
-
-  /**
-   * Current position in the song, in steps and fractions of a step.
-   */
-  public static var currentStepTime(default, null):Float;
-
   /**
    * Duration of a measure in milliseconds. Calculated based on bpm.
    */
@@ -86,119 +76,99 @@ class Conductor
   }
 
   /**
-   * Duration of a beat (quarter note) in milliseconds. Calculated based on bpm.
+   * Duration of a beat in milliseconds. Calculated based on bpm.
    */
   public static var beatLengthMs(get, null):Float;
 
   static function get_beatLengthMs():Float
   {
-    // Tied directly to BPM.
+    return ((Constants.SECS_PER_MIN / bpm) * Constants.MS_PER_SEC);
-    return ((60 / bpm) * 1000);
   }
 
   /**
-   * Duration of a step (sixteenth) in milliseconds. Calculated based on bpm.
+   * Duration of a step (quarter) in milliseconds. Calculated based on bpm.
    */
   public static var stepLengthMs(get, null):Float;
 
   static function get_stepLengthMs():Float
   {
-    return beatLengthMs / STEPS_PER_BEAT;
+    return beatLengthMs / timeSignatureNumerator;
   }
 
-  /**
-   * The numerator of the current time signature (number of notes in a measure)
-   */
   public static var timeSignatureNumerator(get, null):Int;
 
   static function get_timeSignatureNumerator():Int
   {
-    if (currentTimeChange == null) return 4;
+    if (currentTimeChange == null) return Constants.DEFAULT_TIME_SIGNATURE_NUM;
 
     return currentTimeChange.timeSignatureNum;
   }
 
-  /**
-   * The numerator of the current time signature (length of notes in a measure)
-   */
   public static var timeSignatureDenominator(get, null):Int;
 
   static function get_timeSignatureDenominator():Int
   {
-    if (currentTimeChange == null) return 4;
+    if (currentTimeChange == null) return Constants.DEFAULT_TIME_SIGNATURE_DEN;
 
     return currentTimeChange.timeSignatureDen;
   }
 
-  public static var offset:Float = 0;
+  /**
-
+   * Current position in the song, in measures.
-  // TODO: What's the difference between visualOffset and audioOffset?
+   */
-  public static var visualOffset:Float = 0;
+  public static var currentMeasure(default, null):Int;
-  public static var audioOffset:Float = 0;
-
-  //
-  // Signals
-  //
 
   /**
-   * Signal that is dispatched every measure.
+   * Current position in the song, in beats.
-   * At 120 BPM 4/4, this is dispatched every 2 seconds.
-   * At 120 BPM 3/4, this is dispatched every 1.5 seconds.
    */
-  public static var measureHit(default, null):FlxSignal = new FlxSignal();
+  public static var currentBeat(default, null):Int;
 
   /**
-   * Signal that is dispatched every beat.
+   * Current position in the song, in steps.
-   * At 120 BPM 4/4, this is dispatched every 0.5 seconds.
-   * At 120 BPM 3/4, this is dispatched every 0.5 seconds.
    */
+  public static var currentStep(default, null):Int;
+
+  /**
+   * Current position in the song, in measures and fractions of a measure.
+   */
+  public static var currentMeasureTime(default, null):Float;
+
+  /**
+   * Current position in the song, in beats and fractions of a measure.
+   */
+  public static var currentBeatTime(default, null):Float;
+
+  /**
+   * Current position in the song, in steps and fractions of a step.
+   */
+  public static var currentStepTime(default, null):Float;
+
   public static var beatHit(default, null):FlxSignal = new FlxSignal();
-
-  /**
-   * Signal that is dispatched when a step is hit.
-   * At 120 BPM 4/4, this is dispatched every 0.125 seconds.
-   * At 120 BPM 3/4, this is dispatched every 0.125 seconds.
-   */
   public static var stepHit(default, null):FlxSignal = new FlxSignal();
 
-  //
-  // Internal Variables
-  //
-
-  /**
-   * The list of time changes in the song.
-   * There should be at least one time change (at the beginning of the song) to define the BPM.
-   */
-  static var timeChanges:Array<SongTimeChange> = [];
-
-  /**
-   * The current time change.
-   */
-  static var currentTimeChange:SongTimeChange;
-
   public static var lastSongPos:Float;
+  public static var visualOffset:Float = 0;
+  public static var audioOffset:Float = 0;
+  public static var offset:Float = 0;
 
-  /**
+  public static var beatsPerMeasure(get, null):Float;
-   * The number of beats (whole notes) in a measure.
-   */
-  public static var beatsPerMeasure(get, null):Int;
 
-  static function get_beatsPerMeasure():Int
+  static function get_beatsPerMeasure():Float
   {
-    return timeSignatureNumerator;
+    // NOTE: Not always an integer, for example 7/8 is 3.5 beats per measure
+    return stepsPerMeasure / Constants.STEPS_PER_BEAT;
   }
 
-  /**
-   * The number of steps (quarter-notes) in a measure.
-   */
   public static var stepsPerMeasure(get, null):Int;
 
   static function get_stepsPerMeasure():Int
   {
-    // This is always 4, b
+    // TODO: Is this always an integer?
-    return timeSignatureNumerator * 4;
+    return Std.int(timeSignatureNumerator / timeSignatureDenominator * Constants.STEPS_PER_BEAT * Constants.STEPS_PER_BEAT);
   }
 
+  function new() {}
+
   /**
    * Forcibly defines the current BPM of the song.
    * Useful for things like the chart editor that need to manipulate BPM in real time.
@@ -208,16 +178,11 @@ class Conductor
    * WARNING: Avoid this for things like setting the BPM of the title screen music,
    * you should have a metadata file for it instead.
    */
-  public static function forceBPM(?bpm:Float = null):Void
+  public static function forceBPM(?bpm:Float = null)
   {
-    if (bpm != null)
+    if (bpm != null) trace('[CONDUCTOR] Forcing BPM to ' + bpm);
-    {
-      trace('[CONDUCTOR] Forcing BPM to ' + bpm);
-    }
     else
-    {
       trace('[CONDUCTOR] Resetting BPM to default');
-    }
     Conductor.bpmOverride = bpm;
   }
 
@@ -228,13 +193,12 @@ class Conductor
    * @param	songPosition The current position in the song in milliseconds.
    *        Leave blank to use the FlxG.sound.music position.
    */
-  public static function update(songPosition:Float = null):Void
+  public static function update(songPosition:Float = null)
   {
     if (songPosition == null) songPosition = (FlxG.sound.music != null) ? FlxG.sound.music.time + Conductor.offset : 0.0;
 
-    var oldMeasure:Int = currentMeasure;
+    var oldBeat = currentBeat;
-    var oldBeat:Int = currentBeat;
+    var oldStep = currentStep;
-    var oldStep:Int = currentStep;
 
     Conductor.songPosition = songPosition;
 
@@ -252,16 +216,23 @@ class Conductor
     }
     else if (currentTimeChange != null)
     {
-      currentStepTime = (currentTimeChange.beatTime * 4) + (songPosition - currentTimeChange.timeStamp) / stepLengthMs;
+      // roundDecimal prevents representing 8 as 7.9999999
+      currentStepTime = FlxMath.roundDecimal((currentTimeChange.beatTime * 4) + (songPosition - currentTimeChange.timeStamp) / stepLengthMs, 6);
+      currentBeatTime = currentStepTime / Constants.STEPS_PER_BEAT;
+      currentMeasureTime = currentStepTime / stepsPerMeasure;
       currentStep = Math.floor(currentStepTime);
-      currentBeat = Math.floor(currentStep / 4);
+      currentBeat = Math.floor(currentBeatTime);
+      currentMeasure = Math.floor(currentMeasureTime);
     }
     else
     {
       // Assume a constant BPM equal to the forced value.
-      currentStepTime = (songPosition / stepLengthMs);
+      currentStepTime = FlxMath.roundDecimal((songPosition / stepLengthMs), 4);
+      currentBeatTime = currentStepTime / Constants.STEPS_PER_BEAT;
+      currentMeasureTime = currentStepTime / stepsPerMeasure;
       currentStep = Math.floor(currentStepTime);
-      currentBeat = Math.floor(currentStep / 4);
+      currentBeat = Math.floor(currentBeatTime);
+      currentMeasure = Math.floor(currentMeasureTime);
     }
 
     // FlxSignals are really cool.
@@ -274,31 +245,52 @@ class Conductor
     {
       beatHit.dispatch();
     }
-
-    if (currentMeasure != oldMeasure)
-    {
-      measureHit.dispatch();
-    }
   }
 
-  public static function mapTimeChanges(songTimeChanges:Array<SongTimeChange>):Void
+  public static function mapTimeChanges(songTimeChanges:Array<SongTimeChange>)
   {
     timeChanges = [];
 
     for (currentTimeChange in songTimeChanges)
     {
+      // TODO: Maybe handle this different?
+      // Do we care about BPM at negative timestamps?
+      // Without any custom handling, `currentStepTime` becomes non-zero at `songPosition = 0`.
+      if (currentTimeChange.timeStamp < 0.0) currentTimeChange.timeStamp = 0.0;
+
+      if (currentTimeChange.beatTime == null)
+      {
+        if (currentTimeChange.timeStamp <= 0.0)
+        {
+          currentTimeChange.beatTime = 0.0;
+        }
+        else
+        {
+          // Calculate the beat time of this timestamp.
+          currentTimeChange.beatTime = 0.0;
+
+          if (currentTimeChange.timeStamp > 0.0 && timeChanges.length > 0)
+          {
+            var prevTimeChange:SongTimeChange = timeChanges[timeChanges.length - 1];
+            currentTimeChange.beatTime = prevTimeChange.beatTime
+              + ((currentTimeChange.timeStamp - prevTimeChange.timeStamp) * prevTimeChange.bpm / Constants.SECS_PER_MIN / Constants.MS_PER_SEC);
+          }
+        }
+      }
+
       timeChanges.push(currentTimeChange);
     }
 
     trace('Done mapping time changes: ' + timeChanges);
 
-    // Done.
+    // Update currentStepTime
+    Conductor.update(Conductor.songPosition);
   }
 
   /**
    * Given a time in milliseconds, return a time in steps.
    */
-  public static function getTimeInSteps(ms:Float):Int
+  public static function getTimeInSteps(ms:Float):Float
   {
     if (timeChanges.length == 0)
     {
@@ -307,7 +299,7 @@ class Conductor
     }
     else
     {
-      var resultStep:Int = 0;
+      var resultStep:Float = 0;
 
       var lastTimeChange:SongTimeChange = timeChanges[0];
       for (timeChange in timeChanges)
@@ -329,4 +321,14 @@ class Conductor
       return resultStep;
     }
   }
+
+  public static function reset():Void
+  {
+    beatHit.removeAll();
+    stepHit.removeAll();
+
+    mapTimeChanges([]);
+    forceBPM(null);
+    update(0);
+  }
 }

source/funkin/MusicBeatState.hx

@@ -67,9 +67,11 @@ class MusicBeatState extends FlxUIState implements IEventHandler
     if (FlxG.keys.justPressed.F5) debug_refreshModules();
 
     // Display Conductor info in the watch window.
-    FlxG.watch.addQuick("songPos", Conductor.songPosition);
+    FlxG.watch.addQuick("songPosition", Conductor.songPosition);
-    FlxG.watch.addQuick("currentStepTime", Conductor.currentStepTime);
     FlxG.watch.addQuick("bpm", Conductor.bpm);
+    FlxG.watch.addQuick("currentMeasureTime", Conductor.currentBeatTime);
+    FlxG.watch.addQuick("currentBeatTime", Conductor.currentBeatTime);
+    FlxG.watch.addQuick("currentStepTime", Conductor.currentStepTime);
 
     dispatchEvent(new UpdateScriptEvent(elapsed));
   }

source/funkin/MusicBeatSubState.hx

@@ -3,7 +3,6 @@ package funkin;
 import flixel.FlxSubState;
 import funkin.modding.IScriptedClass.IEventHandler;
 import flixel.util.FlxColor;
-import funkin.Conductor.BPMChangeEvent;
 import funkin.modding.events.ScriptEvent;
 import funkin.modding.module.ModuleHandler;
 import flixel.text.FlxText;

source/funkin/Paths.hx

@@ -6,7 +6,8 @@ import openfl.utils.Assets as OpenFlAssets;
 
 class Paths
 {
-  inline public static var SOUND_EXT = #if web "mp3" #else "ogg" #end;
+  public static var SOUND_EXT = #if web "mp3" #else "ogg" #end;
+  public static var VIDEO_EXT = "mp4";
 
   static var currentLevel:String;
 
@@ -96,14 +97,19 @@ class Paths
     return getPath('music/$key.$SOUND_EXT', MUSIC, library);
   }
 
-  inline static public function voices(song:String, ?suffix:String)
+  inline static public function videos(key:String, ?library:String)
+  {
+    return getPath('videos/$key.$VIDEO_EXT', BINARY, library);
+  }
+
+  inline static public function voices(song:String, ?suffix:String = '')
   {
     if (suffix == null) suffix = ""; // no suffix, for a sorta backwards compatibility with older-ish voice files
 
     return 'songs:assets/songs/${song.toLowerCase()}/Voices$suffix.$SOUND_EXT';
   }
 
-  inline static public function inst(song:String, ?suffix:String)
+  inline static public function inst(song:String, ?suffix:String = '')
   {
     return 'songs:assets/songs/${song.toLowerCase()}/Inst$suffix.$SOUND_EXT';
   }

source/funkin/PauseSubState.hx

@@ -4,7 +4,7 @@ import funkin.play.PlayStatePlaylist;
 import flixel.FlxSprite;
 import flixel.addons.transition.FlxTransitionableState;
 import flixel.group.FlxGroup.FlxTypedGroup;
-import flixel.system.FlxSound;
+import flixel.sound.FlxSound;
 import flixel.text.FlxText;
 import flixel.tweens.FlxEase;
 import flixel.tweens.FlxTween;

source/funkin/TitleState.hx

@@ -12,6 +12,8 @@ import flixel.util.FlxTimer;
 import funkin.audiovis.SpectogramSprite;
 import funkin.shaderslmfao.ColorSwap;
 import funkin.shaderslmfao.LeftMaskShader;
+import funkin.play.song.SongData.SongDataParser;
+import funkin.play.song.SongData.SongMetadata;
 import funkin.shaderslmfao.TitleOutline;
 import funkin.ui.AtlasText;
 import funkin.util.Constants;
@@ -135,12 +137,7 @@ class TitleState extends MusicBeatState
 
   function startIntro()
   {
-    if (FlxG.sound.music == null || !FlxG.sound.music.playing)
+    playMenuMusic();
-    {
-      FlxG.sound.playMusic(Paths.music('freakyMenu'), 0);
-      FlxG.sound.music.fadeIn(4, 0, 0.7);
-      Conductor.forceBPM(Constants.FREAKY_MENU_BPM);
-    }
 
     persistentUpdate = true;
 
@@ -234,6 +231,18 @@ class TitleState extends MusicBeatState
     if (FlxG.sound.music != null) FlxG.sound.music.onComplete = function() FlxG.switchState(new VideoState());
   }
 
+  function playMenuMusic():Void
+  {
+    if (FlxG.sound.music == null || !FlxG.sound.music.playing)
+    {
+      var freakyMenuMetadata:SongMetadata = SongDataParser.parseMusicMetadata('freakyMenu');
+      Conductor.mapTimeChanges(freakyMenuMetadata.timeChanges);
+
+      FlxG.sound.playMusic(Paths.music('freakyMenu/freakyMenu'), 0);
+      FlxG.sound.music.fadeIn(4, 0, 0.7);
+    }
+  }
+
   function getIntroTextShit():Array<Array<String>>
   {
     var fullText:String = Assets.getText(Paths.txt('introText'));

source/funkin/play/GameOverSubState.hx

@@ -3,7 +3,7 @@ package funkin.play;
 import flixel.FlxG;
 import flixel.FlxObject;
 import flixel.FlxSprite;
-import flixel.system.FlxSound;
+import flixel.sound.FlxSound;
 import funkin.ui.story.StoryMenuState;
 import flixel.util.FlxColor;
 import flixel.util.FlxTimer;

source/funkin/play/PlayState.hx

@@ -894,7 +894,7 @@ class PlayState extends MusicBeatState
       trace('Song difficulty could not be loaded.');
     }
 
-    Conductor.forceBPM(currentChart.getStartingBPM());
+    // Conductor.forceBPM(currentChart.getStartingBPM());
 
     vocals = currentChart.buildVocals(currentPlayerId);
     if (vocals.members.length == 0)
@@ -1208,13 +1208,10 @@ class PlayState extends MusicBeatState
       camHUD.zoom = FlxMath.lerp(defaultHUDCameraZoom, camHUD.zoom, 0.95);
     }
 
-    FlxG.watch.addQuick('beatShit', Conductor.currentBeat);
-    FlxG.watch.addQuick('stepShit', Conductor.currentStep);
     if (currentStage != null)
     {
       FlxG.watch.addQuick('bfAnim', currentStage.getBoyfriend().getCurrentAnimation());
     }
-    FlxG.watch.addQuick('songPos', Conductor.songPosition);
 
     // Handle GF dance speed.
     // TODO: Add a song event for this.

source/funkin/play/cutscene/VideoCutscene.hx

@@ -30,7 +30,8 @@ class VideoCutscene
 
     if (!openfl.Assets.exists(filePath))
     {
-      trace('ERROR: Video file does not exist: ${filePath}');
+      // Display a popup.
+      lime.app.Application.current.window.alert('Video file does not exist: ${filePath}', 'Error playing video');
       return;
     }
 

source/funkin/play/song/SongData.hx

@@ -3,6 +3,8 @@ package funkin.play.song;
 import funkin.modding.events.ScriptEvent;
 import funkin.modding.events.ScriptEventDispatcher;
 import flixel.util.typeLimit.OneOfTwo;
+import funkin.modding.events.ScriptEvent;
+import funkin.modding.events.ScriptEventDispatcher;
 import funkin.play.song.ScriptedSong;
 import funkin.util.assets.DataAssets;
 import haxe.DynamicAccess;
@@ -22,6 +24,7 @@ class SongDataParser
 
   static final DEFAULT_SONG_ID:String = 'UNKNOWN';
   static final SONG_DATA_PATH:String = 'songs/';
+  static final MUSIC_DATA_PATH:String = 'music/';
   static final SONG_DATA_SUFFIX:String = '-metadata.json';
 
   /**
@@ -181,6 +184,36 @@ class SongDataParser
     return rawJson;
   }
 
+  public static function parseMusicMetadata(musicId:String):SongMetadata
+  {
+    var rawJson:String = loadMusicMetadataFile(musicId);
+    var jsonData:Dynamic = null;
+    try
+    {
+      jsonData = Json.parse(rawJson);
+    }
+    catch (e) {}
+
+    var musicMetadata:SongMetadata = SongMigrator.migrateSongMetadata(jsonData, musicId);
+    musicMetadata = SongValidator.validateSongMetadata(musicMetadata, musicId);
+
+    return musicMetadata;
+  }
+
+  static function loadMusicMetadataFile(musicPath:String, variation:String = ''):String
+  {
+    var musicMetadataFilePath:String = (variation != '') ? Paths.file('$MUSIC_DATA_PATH$musicPath/$musicPath-metadata-$variation.json') : Paths.file('$MUSIC_DATA_PATH$musicPath/$musicPath-metadata.json');
+
+    var rawJson:String = Assets.getText(musicMetadataFilePath).trim();
+
+    while (!rawJson.endsWith("}"))
+    {
+      rawJson = rawJson.substr(0, rawJson.length - 1);
+    }
+
+    return rawJson;
+  }
+
   public static function parseSongChartData(songId:String, variation:String = ""):SongChartData
   {
     var rawJson:String = loadSongChartDataFile(songId, variation);
@@ -369,8 +402,7 @@ abstract SongNoteData(RawSongNoteData)
 
   public function get_stepTime():Float
   {
-    // TODO: Account for changes in BPM.
+    return Conductor.getTimeInSteps(this.t);
-    return this.t / Conductor.stepLengthMs;
   }
 
   /**
@@ -555,8 +587,7 @@ abstract SongEventData(RawSongEventData)
 
   public function get_stepTime():Float
   {
-    // TODO: Account for changes in BPM.
+    return Conductor.getTimeInSteps(this.t);
-    return this.t / Conductor.stepLengthMs;
   }
 
   public var event(get, set):String;
@@ -769,7 +800,7 @@ typedef RawSongTimeChange =
    * Time in beats (int). The game will calculate further beat values based on this one,
    * so it can do it in a simple linear fashion.
    */
-  var b:Int;
+  var b:Null<Float>;
 
   /**
    * Quarter notes per minute (float). Cannot be empty in the first element of the list,
@@ -799,9 +830,9 @@ typedef RawSongTimeChange =
  * Add aliases to the minimalized property names of the typedef,
  * to improve readability.
  */
-abstract SongTimeChange(RawSongTimeChange)
+abstract SongTimeChange(RawSongTimeChange) from RawSongTimeChange
 {
-  public function new(timeStamp:Float, beatTime:Int, bpm:Float, timeSignatureNum:Int = 4, timeSignatureDen:Int = 4, beatTuplets:Array<Int>)
+  public function new(timeStamp:Float, beatTime:Null<Float>, bpm:Float, timeSignatureNum:Int = 4, timeSignatureDen:Int = 4, beatTuplets:Array<Int>)
   {
     this =
       {
@@ -826,14 +857,14 @@ abstract SongTimeChange(RawSongTimeChange)
     return this.t = value;
   }
 
-  public var beatTime(get, set):Int;
+  public var beatTime(get, set):Null<Float>;
 
-  public function get_beatTime():Int
+  public function get_beatTime():Null<Float>
   {
     return this.b;
   }
 
-  public function set_beatTime(value:Int):Int
+  public function set_beatTime(value:Null<Float>):Null<Float>
   {
     return this.b = value;
   }

source/funkin/ui/debug/charting/ChartEditorState.hx

@@ -1877,7 +1877,7 @@ class ChartEditorState extends HaxeUIState
       {
         // Handle extending the note as you drag.
 
-        // Since use Math.floor and stepCrochet here, the hold notes will be beat snapped.
+        // Since use Math.floor and stepLengthMs here, the hold notes will be beat snapped.
         var dragLengthSteps:Float = Math.floor((cursorMs - currentPlaceNoteData.time) / Conductor.stepLengthMs);
 
         // Without this, the newly placed note feels too short compared to the user's input.

source/funkin/ui/story/StoryMenuState.hx

@@ -15,6 +15,7 @@ import funkin.modding.events.ScriptEventDispatcher;
 import funkin.play.PlayState;
 import funkin.play.PlayStatePlaylist;
 import funkin.play.song.Song;
+import funkin.play.song.SongData.SongMetadata;
 import funkin.play.song.SongData.SongDataParser;
 import funkin.util.Constants;
 
@@ -115,12 +116,7 @@ class StoryMenuState extends MusicBeatState
     transIn = FlxTransitionableState.defaultTransIn;
     transOut = FlxTransitionableState.defaultTransOut;
 
-    if (!FlxG.sound.music.playing)
+    playMenuMusic();
-    {
-      FlxG.sound.playMusic(Paths.music('freakyMenu'));
-      FlxG.sound.music.fadeIn(4, 0, 0.7);
-    }
-    Conductor.forceBPM(Constants.FREAKY_MENU_BPM);
 
     if (stickerSubState != null)
     {
@@ -129,8 +125,6 @@ class StoryMenuState extends MusicBeatState
 
       openSubState(stickerSubState);
       stickerSubState.degenStickers();
-
-      // resetSubState();
     }
 
     persistentUpdate = persistentDraw = true;
@@ -203,6 +197,18 @@ class StoryMenuState extends MusicBeatState
     #end
   }
 
+  function playMenuMusic():Void
+  {
+    if (FlxG.sound.music == null || !FlxG.sound.music.playing)
+    {
+      var freakyMenuMetadata:SongMetadata = SongDataParser.parseMusicMetadata('freakyMenu');
+      Conductor.mapTimeChanges(freakyMenuMetadata.timeChanges);
+
+      FlxG.sound.playMusic(Paths.music('freakyMenu/freakyMenu'), 0);
+      FlxG.sound.music.fadeIn(4, 0, 0.7);
+    }
+  }
+
   function updateData():Void
   {
     currentLevel = LevelRegistry.instance.fetchEntry(currentLevelId);

source/funkin/util/Constants.hx

@@ -118,27 +118,72 @@ class Constants
   public static final DEFAULT_SONG:String = 'tutorial';
 
   /**
-   * OTHER
+   * TIMING
    */
   // ==============================
 
+  /**
+   * The number of seconds in a minute.
+   */
+  public static final SECS_PER_MIN:Int = 60;
+
+  /**
+   * The number of milliseconds in a second.
+   */
+  public static final MS_PER_SEC:Int = 1000;
+
+  /**
+   * The number of microseconds in a millisecond.
+   */
+  public static final US_PER_MS:Int = 1000;
+
+  /**
+   * The number of microseconds in a second.
+   */
+  public static final US_PER_SEC:Int = US_PER_MS * MS_PER_SEC;
+
+  /**
+   * The number of nanoseconds in a microsecond.
+   */
+  public static final NS_PER_US:Int = 1000;
+
+  /**
+   * The number of nanoseconds in a millisecond.
+   */
+  public static final NS_PER_MS:Int = NS_PER_US * US_PER_MS;
+
+  /**
+   * The number of nanoseconds in a second.
+   */
+  public static final NS_PER_SEC:Int = NS_PER_US * US_PER_MS * MS_PER_SEC;
+
   /**
    * All MP3 decoders introduce a playback delay of `528` samples,
    * which at 44,100 Hz (samples per second) is ~12 ms.
    */
-  public static final MP3_DELAY_MS:Float = 528 / 44100 * 1000;
+  public static final MP3_DELAY_MS:Float = 528 / 44100 * MS_PER_SEC;
+
+  /**
+   * The default BPM of the conductor.
+   */
+  public static final DEFAULT_BPM:Float = 100.0;
+
+  public static final DEFAULT_TIME_SIGNATURE_NUM:Int = 4;
+
+  public static final DEFAULT_TIME_SIGNATURE_DEN:Int = 4;
+
+  public static final STEPS_PER_BEAT:Int = 4;
+
+  /**
+   * OTHER
+   */
+  // ==============================
 
   /**
    * The scale factor to use when increasing the size of pixel art graphics.
    */
   public static final PIXEL_ART_SCALE:Float = 6;
 
-  /**
-   * The BPM of the title screen and menu music.
-   * TODO: Move to metadata file.
-   */
-  public static final FREAKY_MENU_BPM:Float = 102;
-
   /**
    * The volume at which to play the countdown before the song starts.
    */