Tempo changes restored (#92)

* Prepwork for seeking + tempo change fixes

TODO: make playing after seeking function (I'll need help with the offset stuff so if anyone can push to this branch please do)

* functions to get the beat from a song position

will need more testing but I think it works well enough to get into prod
thanks @wooningcharithri#7419 for the psuedo-code

Assets/Scripts/Conductor.cs

@@ -85,6 +85,8 @@ namespace HeavenStudio
             bool negativeOffset = firstBeatOffset < 0f;
             bool negativeStartTime = false;
 
+            // Debug.Log("starting playback @ beat " + beat + ", offset is " + firstBeatOffset);
+
             var startPos = GetSongPosFromBeat(beat);
             if (negativeOffset)
             {
@@ -99,8 +101,10 @@ namespace HeavenStudio
                 else
                     time = startPos;
             }
-
-            songPosBeat = time / secPerBeat; 
+            
+            //TODO: make this take into account past tempo changes
+            songPosBeat = GetBeatFromSongPos(time - firstBeatOffset);
+            // Debug.Log("corrected starting playback @ beat " + songPosBeat);
 
             isPlaying = true;
             isPaused = false;
@@ -232,11 +236,93 @@ namespace HeavenStudio
             return GetBeatFromPosition(position, targetBeat - margin, margin);
         }
 
+        private List<Beatmap.TempoChange> GetSortedTempoChanges(Beatmap chart)
+        {
+            //iterate over all tempo changes, adding to counter
+            List<Beatmap.TempoChange> tempoChanges = chart.tempoChanges;
+            tempoChanges.Sort((x, y) => x.beat.CompareTo(y.beat)); //sorts all tempo changes by ascending time (GameManager already does this but juste en cas...)
+            return tempoChanges;
+        }
+
         public float GetSongPosFromBeat(float beat)
         {
-            return secPerBeat * beat;
+            Beatmap chart = GameManager.instance.Beatmap;
+            SetBpm(chart.bpm);
+
+            //initial counter
+            float counter = 0f;
+
+            //time of last tempo change, to know how much to add to counter
+            float lastTempoChangeBeat = 0f;
+
+            //iterate over all tempo changes, adding to counter
+            List<Beatmap.TempoChange> tempoChanges = GetSortedTempoChanges(chart);
+            foreach (var t in tempoChanges)
+            {
+                if (t.beat > beat)
+                {
+                    // this tempo change is past our requested time, abort
+                    break;
+                }
+                // Debug.Log("tempo change at " + t.beat);
+
+                counter += (t.beat - lastTempoChangeBeat) * secPerBeat;
+                // Debug.Log("counter is now " + counter);
+
+                // now update to new bpm
+                SetBpm(t.tempo);
+                lastTempoChangeBeat = t.beat;
+            }
+
+            //passed all past tempo changes, now extrapolate from last tempo change until requested position
+            counter += (beat - lastTempoChangeBeat) * secPerBeat;
+
+            // Debug.Log("GetSongPosFromBeat returning " + counter);
+            return counter;
         }
 
+        //thank you @wooningcharithri#7419 for the psuedo-code
+            private float BeatsToSecs(float beats, float bpm)
+            {
+                // Debug.Log("BeatsToSecs returning " + beats / bpm * 60);
+                return beats / bpm * 60f;
+            }
+            private float SecsToBeats(float s, float bpm)
+            {
+                // Debug.Log("SecsToBeats returning " + s / 60f / bpm);
+                return s / 60f * bpm;
+            }
+
+            public float GetBeatFromSongPos(float seconds)
+            {
+                // Debug.Log("Getting beat of seconds " + seconds);
+                Beatmap chart = GameManager.instance.Beatmap;
+                float lastTempoChangeBeat = 0f;
+                float lastBpm = chart.bpm;
+                float counterSeconds = -firstBeatOffset;
+                
+                List<Beatmap.TempoChange> tempoChanges = GetSortedTempoChanges(chart);
+                foreach (var t in tempoChanges)
+                {
+                    float beatToNext = t.beat - lastTempoChangeBeat;
+                    float secToNext = BeatsToSecs(beatToNext, lastBpm);
+                    float nextSecs = counterSeconds + secToNext;
+
+                    // Debug.Log("nextSecs is " + nextSecs + ", seconds " + seconds);
+                    if (nextSecs >= seconds)
+                        break;
+                    
+                    lastTempoChangeBeat = t.beat;
+                    lastBpm = t.tempo;
+                    counterSeconds = nextSecs;
+                }
+
+                // Debug.Log("lastTempoChangeBeat is " + lastTempoChangeBeat + ", counterSeconds is " + counterSeconds);
+
+                return lastTempoChangeBeat + SecsToBeats(seconds - counterSeconds, lastBpm);
+            }
+        //
+
         // convert real seconds to beats
         public float GetRestFromRealTime(float seconds)
         {
@@ -257,7 +343,7 @@ namespace HeavenStudio
         public float SongLengthInBeats()
         {
             if (!musicSource.clip) return 0;
-            return musicSource.clip.length / secPerBeat;
+            return GetBeatFromSongPos(musicSource.clip.length);
         }
 
         public bool SongPosLessThanClipLength(float t)

Assets/Scripts/GameManager.cs

@@ -151,7 +151,7 @@ namespace HeavenStudio
         // LateUpdate works a bit better(?) but causes some bugs (like issues with bop animations).
         private void Update()
         {
-            if (Beatmap.entities.Count < 1)
+            if (BeatmapEntities() < 1) //bruh really you forgot to ckeck tempo changes
                 return;
             if (!Conductor.instance.isPlaying)
                 return;
@@ -197,9 +197,11 @@ namespace HeavenStudio
 
             if (currentTempoEvent < Beatmap.tempoChanges.Count && currentTempoEvent >= 0)
             {
+                // Debug.Log("Checking Tempo Change at " + tempoChanges[currentTempoEvent] + ", current beat " + Conductor.instance.songPositionInBeats);
                 if (Conductor.instance.songPositionInBeats >= tempoChanges[currentTempoEvent])
                 {
-                    Conductor.instance.songBpm = Beatmap.tempoChanges[currentTempoEvent].tempo;
+                    // Debug.Log("Tempo Change at " + Conductor.instance.songPositionInBeats + " of bpm " + Beatmap.tempoChanges[currentTempoEvent].tempo);
+                    Conductor.instance.SetBpm(Beatmap.tempoChanges[currentTempoEvent].tempo);
                     Conductor.instance.timeSinceLastTempoChange = Time.time;
                     currentTempoEvent++;
                 }
@@ -325,9 +327,20 @@ namespace HeavenStudio
 
             if (Beatmap.tempoChanges.Count > 0)
             {
+                currentTempoEvent = 0;
                 List<float> tempoChanges = Beatmap.tempoChanges.Select(c => c.beat).ToList();
 
-                currentTempoEvent = tempoChanges.IndexOf(Mathp.GetClosestInList(tempoChanges, beat));
+                //for tempo changes, just go over all of em until the last one we pass
+                for (int t = 0; t < tempoChanges.Count; t++)
+                {
+                    // Debug.Log("checking tempo event " + t + " against beat " + beat + "( tc beat " + tempoChanges[t] + ")");
+                    if (tempoChanges[t] > beat)
+                    {
+                        break;
+                    }
+                    currentTempoEvent = t;
+                }
+                // Debug.Log("currentTempoEvent is now " + currentTempoEvent);
             }
         }
 

Assets/Scripts/LevelEditor/Timeline/TempoTimeline.cs

@@ -129,11 +129,7 @@ namespace HeavenStudio.Editor.Track
         }
 
         private void AddTempoChange(bool create, Beatmap.TempoChange tempoChange_ = null)
-        {
-            // TEMP: DISABLED UNTIL CRITICAL FIXES
-            if (create)
-                return;
-               
+        {      
             GameObject tempoChange = Instantiate(RefTempoChange.gameObject, this.transform);
 
             tempoChange.transform.GetChild(0).GetComponent<Image>().color = EditorTheme.theme.properties.TempoLayerCol.Hex2RGB();

Assets/Scripts/LevelEditor/Timeline/Timeline.cs

@@ -296,7 +296,7 @@ namespace HeavenStudio.Editor.Track
             if (movingPlayback)
             {
                 RectTransformUtility.ScreenPointToLocalPointInRectangle(TimelineContent, Input.mousePosition, Editor.instance.EditorCamera, out lastMousePos);
-                TimelineSlider.localPosition = new Vector3(Mathf.Clamp(Mathp.Round2Nearest(lastMousePos.x + 0.12f, Timeline.SnapInterval()), 0, Mathf.Infinity), TimelineSlider.transform.localPosition.y);
+                TimelineSlider.localPosition = new Vector3(Mathf.Max(Mathp.Round2Nearest(lastMousePos.x + 0.12f, Timeline.SnapInterval()), 0), TimelineSlider.transform.localPosition.y);
 
                 if (TimelineSlider.localPosition.x != lastBeatPos)
                     Conductor.instance.SetBeat(TimelineSlider.transform.localPosition.x);