time Signature functionality wip

source/funkin/backend/system/Conductor.hx

@@ -10,6 +10,8 @@ typedef BPMChangeEvent =
 	var stepTime:Float;
 	var songTime:Float;
 	var bpm:Float;
+	var beatsPerMeasure:Float;
+	var stepsPerBeat:Float;
 }
 
 class Conductor
@@ -21,6 +23,8 @@ class Conductor
 	public static var onBeatHit:FlxTypedSignal<Int->Void> = new FlxTypedSignal();
 	public static var onStepHit:FlxTypedSignal<Int->Void> = new FlxTypedSignal();
 	public static var onBPMChange:FlxTypedSignal<Float->Void> = new FlxTypedSignal();
+	public static var onBeatsPerMeasureChange:FlxTypedSignal<Float->Void> = new FlxTypedSignal();
+	public static var onStepsPerBeatChange:FlxTypedSignal<Float->Void> = new FlxTypedSignal();
 
 	/**
 	 * Current BPM
@@ -108,45 +112,76 @@ class Conductor
 		songPosition = lastSongPos = curBeatFloat = curStepFloat = curBeat = curStep = 0;
 		bpmChangeMap = [];
 		changeBPM(0);
+		changeTimeSignature(4, 4);
 	}
 
 	public static function setupSong(SONG:ChartData) {
 		reset();
 		mapBPMChanges(SONG);
-		changeBPM(SONG.meta.bpm, cast SONG.meta.beatsPerMeasure.getDefault(4), cast SONG.meta.stepsPerBeat.getDefault(4));
+		changeBPM(SONG.meta.bpm);
+		changeTimeSignature(cast SONG.meta.beatsPerMeasure.getDefault(4), cast SONG.meta.stepsPerBeat.getDefault(4));
 	}
 	/**
 	 * Maps BPM changes from a song.
 	 * @param song Song to map BPM changes from.
 	 */
-	public static function mapBPMChanges(song:ChartData)
-	{
+	public static function mapBPMChanges(song:ChartData) {
 		bpmChangeMap = [
 			{
 				stepTime: 0,
 				songTime: 0,
-				bpm: song.meta.bpm
+				bpm: song.meta.bpm,
+				beatsPerMeasure: song.meta.beatsPerMeasure.getDefault(4),
+				stepsPerBeat: song.meta.stepsPerBeat.getDefault(4)
 			}
 		];
-
+		
 		if (song.events == null) return;
-
+		
 		var curBPM:Float = song.meta.bpm;
+		var curBeatsPerMeasure:Float = song.meta.beatsPerMeasure.getDefault(4);
+		var curStepsPerBeat:Float = song.meta.stepsPerBeat.getDefault(4);
 		var songTime:Float = 0;
 		var stepTime:Float = 0;
-
-		for(e in song.events) if (e.name == "BPM Change" && e.params != null && e.params[0] is Float) {
-			if (e.params[0] == curBPM) continue;
-			var steps = (e.time - songTime) / ((60 / curBPM) * 1000 / 4);
-			stepTime += steps;
-			songTime = e.time;
-			curBPM = e.params[0];
-
-			bpmChangeMap.push({
-				stepTime: stepTime,
-				songTime: songTime,
-				bpm: curBPM
-			});
+		
+		for(e in song.events) {
+			if (e.name == "BPM Change" && e.params != null && e.params[0] is Float) {
+				if (e.params[0] == curBPM) continue;
+				var steps = (e.time - songTime) / ((60 / curBPM) * 1000 / stepsPerBeat);
+				stepTime += steps;
+				songTime = e.time;
+				curBPM = e.params[0];
+		
+				bpmChangeMap.push({
+					stepTime: stepTime,
+					songTime: songTime,
+					bpm: curBPM,
+					beatsPerMeasure: curBeatsPerMeasure, // keep old beatsPerMeasure and stepsPerMeasure so shit doesnt break
+					stepsPerBeat: curStepsPerBeat
+				});
+			}
+		
+			if (e.name == "Time Signature Change" && e.params != null) {
+				var newBeatsPerMeasure = e.params[0];
+				var newStepsPerBeat = e.params[1];
+		
+				if (newBeatsPerMeasure == curBeatsPerMeasure && newStepsPerBeat == curStepsPerBeat) continue;
+		
+				var steps = (e.time - songTime) / ((60 / curBPM) * 1000 / stepsPerBeat);
+				stepTime += steps;
+				songTime = e.time;
+		
+				curBeatsPerMeasure = newBeatsPerMeasure;
+				curStepsPerBeat = newStepsPerBeat;
+		
+				bpmChangeMap.push({
+					stepTime: stepTime,
+					songTime: songTime,
+					bpm: curBPM, // keep old bpm so shit doesnt break
+					beatsPerMeasure: curBeatsPerMeasure,
+					stepsPerBeat: curStepsPerBeat
+				});
+			}
 		}
 	}
 
@@ -184,22 +219,32 @@ class Conductor
 		if (FlxG.state != null && FlxG.state is MusicBeatState && cast(FlxG.state, MusicBeatState).cancelConductorUpdate) return;
 
 		__updateSongPos(FlxG.elapsed);
-
+		
 		if (bpm > 0) {
-			// updates curbeat and stuff
+			// Check for BPM change
 			__lastChange = {
 				stepTime: 0,
 				songTime: 0,
-				bpm: 0
+				bpm: 0,
+				beatsPerMeasure: beatsPerMeasure,
+				stepsPerBeat: stepsPerBeat
 			};
-			for (change in Conductor.bpmChangeMap)
-			{
+		
+			for (change in Conductor.bpmChangeMap) {
 				if (Conductor.songPosition >= change.songTime)
 					__lastChange = change;
 			}
+		
+			// Change BPM if necessary
+			if (__lastChange.bpm > 0 && bpm != __lastChange.bpm) {
+				changeBPM(__lastChange.bpm);
+			}
 
-			if (__lastChange.bpm > 0 && bpm != __lastChange.bpm) changeBPM(__lastChange.bpm);
-
+			// Check for time signature change
+			if (__lastChange.beatsPerMeasure != beatsPerMeasure || __lastChange.stepsPerBeat != stepsPerBeat) {
+				changeTimeSignature(__lastChange.beatsPerMeasure, __lastChange.stepsPerBeat);
+			}
+		
 			curStepFloat = __lastChange.stepTime + ((Conductor.songPosition - __lastChange.songTime) / Conductor.stepCrochet);
 			curBeatFloat = curStepFloat / stepsPerBeat;
 			curMeasureFloat = curBeatFloat / beatsPerMeasure;
@@ -270,34 +315,50 @@ class Conductor
 
 		onBPMChange.dispatch(bpm);
 	}
+	
+	public static function changeTimeSignature(newBeatsPerMeasure:Float, newStepsPerBeat:Float) {
+		beatsPerMeasure = newBeatsPerMeasure;
+		stepsPerBeat = newStepsPerBeat;
+
+		crochet = ((60 / bpm) * 1000);
+		stepCrochet = crochet / stepsPerBeat;
+
+		onBeatsPerMeasureChange.dispatch(beatsPerMeasure);
+		onStepsPerBeatChange.dispatch(stepsPerBeat);
+	}
 
 	public static function getTimeForStep(step:Float) {
 		var bpmChange:BPMChangeEvent = {
 			stepTime: 0,
 			songTime: 0,
-			bpm: bpm
+			bpm: bpm,
+			beatsPerMeasure: beatsPerMeasure,
+			stepsPerBeat: stepsPerBeat
 		};
 
 		for(change in bpmChangeMap)
 			if (change.stepTime < step && change.stepTime >= bpmChange.stepTime)
 				bpmChange = change;
 
-		return bpmChange.songTime + ((step - bpmChange.stepTime) * ((60 / bpmChange.bpm) * (1000/stepsPerBeat)));
+		return bpmChange.songTime + ((step - bpmChange.stepTime) * ((60 / bpmChange.bpm) * (1000 / bpmChange.stepsPerBeat)));
 	}
 
 	public static function getStepForTime(time:Float) {
 		var bpmChange:BPMChangeEvent = {
 			stepTime: 0,
 			songTime: 0,
-			bpm: bpm
+			bpm: bpm,
+			beatsPerMeasure: beatsPerMeasure,
+			stepsPerBeat: stepsPerBeat
 		};
-
+		
 		for(change in bpmChangeMap)
 			if (change.songTime < time && change.songTime >= bpmChange.songTime)
 				bpmChange = change;
-
-		return bpmChange.stepTime + ((time - bpmChange.songTime) / ((60 / bpmChange.bpm) * (1000/stepsPerBeat)));
+		
+		return bpmChange.stepTime + ((time - bpmChange.songTime) / ((60 / bpmChange.bpm) * (1000 / bpmChange.stepsPerBeat)));
 	}
+	 
 
 	public static inline function getMeasureLength()
 		return stepsPerBeat * beatsPerMeasure;