Fix: SongPlayer working properly for the first time after the last bi…

…g refactor.

Examples/SynthTest/SynthGame.cs

@@ -20,8 +20,8 @@ protected override void Initialize() {
             base.Initialize();
 
             this._graphics.IsFullScreen = false;
-            this._graphics.PreferredBackBufferHeight = 768;
-            this._graphics.PreferredBackBufferWidth = 1024;
+            this._graphics.PreferredBackBufferHeight = 1080;
+            this._graphics.PreferredBackBufferWidth = 1920;
             this._graphics.ApplyChanges();
             this.IsMouseVisible = true;
         }
@@ -62,27 +62,33 @@ private Song CreateSong() {
 
             var firstTrack = song.Tracks.First();
             firstTrack.Instrument.Oscillator = new SawToothOscillator();
+            firstTrack.Instrument.NoteEnvelope.Attack = 50;
+            firstTrack.Instrument.NoteEnvelope.Release = 50;
             firstTrack.LeftChannelVolume = 0.25f;
             firstTrack.RightChannelVolume = 0.75f;
 
-            firstTrack.AddNote(0f, 1f, Note.C);
-            firstTrack.AddNote(1f, 1f, Note.F);
-            firstTrack.AddNote(2f, 1f, Note.G);
-            firstTrack.AddNote(3f, 1f, Note.C);
+            var secondTrack = song.AddTrack();
+            secondTrack.Instrument.Oscillator = new SineWaveOscillator();
+            secondTrack.Instrument.NoteEnvelope.Attack = 100;
+            secondTrack.Instrument.NoteEnvelope.Release = 500;
+            secondTrack.LeftChannelVolume = 0.75f;
+            secondTrack.RightChannelVolume = 0.25f;
 
-            //var secondTrack = song.AddTrack();
-            //secondTrack.Instrument.Oscillator = new SineWaveOscillator();
-            //secondTrack.LeftChannelVolume = 0.75f;
-            //secondTrack.RightChannelVolume = 0.25f;
+            for (var i = 0; i < 4; i++) {
+                firstTrack.AddNote((4f * i) + 0f, 1f, Note.C);
+                firstTrack.AddNote((4f * i) + 1f, 1f, Note.F);
+                firstTrack.AddNote((4f * i) + 2f, 1f, Note.G);
+                firstTrack.AddNote((4f * i) + 3f, 1f, Note.C);
 
-            //firstTrack.AddSlideNote(0f, 0.5f, new Frequency(Note.C, Pitch.Low), new Frequency(Note.C, Pitch.Normal), 1f);
-            //firstTrack.AddSlideNote(0.5f, 0.5f, new Frequency(Note.C, Pitch.Low), new Frequency(Note.C, Pitch.Normal), 1f);
-            //firstTrack.AddSlideNote(1f, 0.5f, new Frequency(Note.F, Pitch.Low), new Frequency(Note.F, Pitch.Normal), 1f);
-            //firstTrack.AddSlideNote(1.5f, 0.5f, new Frequency(Note.F, Pitch.Low), new Frequency(Note.F, Pitch.Normal), 1f);
-            //firstTrack.AddSlideNote(2f, 0.5f, new Frequency(Note.G, Pitch.Low), new Frequency(Note.G, Pitch.Normal), 1f);
-            //firstTrack.AddSlideNote(2.5f, 0.5f, new Frequency(Note.G, Pitch.Low), new Frequency(Note.G, Pitch.Normal), 1f);
-            //firstTrack.AddSlideNote(3f, 0.5f, new Frequency(Note.C, Pitch.Low), new Frequency(Note.C, Pitch.Normal), 1f);
-            //firstTrack.AddSlideNote(3.5f, 0.5f, new Frequency(Note.C, Pitch.Low), new Frequency(Note.C, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 0f, 0.4f, new Frequency(Note.C, Pitch.Low), new Frequency(Note.C, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 0.5f, 0.4f, new Frequency(Note.C, Pitch.Low), new Frequency(Note.C, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 1f, 0.4f, new Frequency(Note.F, Pitch.Low), new Frequency(Note.F, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 1.5f, 0.4f, new Frequency(Note.F, Pitch.Low), new Frequency(Note.F, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 2f, 0.4f, new Frequency(Note.G, Pitch.Low), new Frequency(Note.G, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 2.5f, 0.4f, new Frequency(Note.G, Pitch.Low), new Frequency(Note.G, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 3f, 0.4f, new Frequency(Note.C, Pitch.High), new Frequency(Note.C, Pitch.Normal), 1f);
+                secondTrack.AddSlideNote((4f * i) + 3.5f, 0.4f, new Frequency(Note.C, Pitch.High), new Frequency(Note.C, Pitch.Normal), 1f);
+            }
 
             return song;
         }

Framework/Audio/Synthesizer/LiveVoice.cs

@@ -1,22 +1,33 @@
 namespace Macabre2D.Framework {
 
+    /// <summary>
+    /// A live voice that isn't necesarrily tied to a real note instance.
+    /// </summary>
     public sealed class LiveVoice : Voice {
         private bool _isPlaying = false;
         private ulong _samplesBeforeRelease = 0;
 
+        /// <summary>
+        /// Gets the frequency.
+        /// </summary>
+        /// <value>The frequency.</value>
         public Frequency Frequency {
             get {
                 return this.Note.StartFrequency;
             }
         }
 
-        public override void Reinitialize(Song song, Track track, NoteInstance note, float offset = 0f) {
-            base.Reinitialize(song, track, note, offset);
+        /// <inheritdoc/>
+        public override void Reinitialize(Song song, Track track, NoteInstance note, float startingBeat = 0f) {
+            base.Reinitialize(song, track, note, startingBeat);
 
             this._isPlaying = true;
             this._samplesBeforeRelease = 0;
         }
 
+        /// <summary>
+        /// Stops this instance.
+        /// </summary>
         public void Stop() {
             this._isPlaying = false;
             this._samplesBeforeRelease = 0;

Framework/Audio/Synthesizer/Song.cs

@@ -41,9 +41,22 @@ public ushort BeatsPerMinute {
 
             set {
                 this._beatsPerMinute = value.Clamp(MinimumBeatsPerMinute, MaximummBeatsPerMinute);
+                this.BeatsPerSecond = this._beatsPerMinute / 60f;
             }
         }
 
+        /// <summary>
+        /// Gets the beats per second.
+        /// </summary>
+        /// <value>The beats per second.</value>
+        public float BeatsPerSecond { get; private set; } = 120f / 60f;
+
+        /// <summary>
+        /// Gets the inverse sample rate.
+        /// </summary>
+        /// <value>The inverse sample rate.</value>
+        public float InverseSampleRate { get; private set; } = 1f / MaximumSampleRate;
+
         /// <summary>
         /// Gets the length.
         /// </summary>
@@ -66,6 +79,7 @@ public ushort SampleRate {
 
             set {
                 this._sampleRate = value.Clamp(MinimumSampleRate, MaximumSampleRate);
+                this.InverseSampleRate = 1f / this._sampleRate;
             }
         }
 
@@ -95,7 +109,7 @@ public Track AddTrack() {
         /// <param name="beats">The beats.</param>
         /// <returns>The number of samples within the beat length.</returns>
         public ulong ConvertBeatsToSamples(float beats) {
-            return (ulong)Math.Floor((this.SampleRate * 60f * beats) / this.BeatsPerMinute);
+            return (ulong)Math.Floor((this.SampleRate * beats) / this.BeatsPerSecond);
         }
 
         /// <summary>
@@ -104,7 +118,7 @@ public ulong ConvertBeatsToSamples(float beats) {
         /// <param name="numberOfSamples">The number of samples.</param>
         /// <returns>The length of the beat that the number of samples encompass.</returns>
         public float ConvertSamplesToBeats(ushort numberOfSamples) {
-            return (this.BeatsPerMinute * numberOfSamples) / (this.SampleRate * 60f);
+            return this.BeatsPerSecond * numberOfSamples * this.InverseSampleRate;
         }
 
         /// <summary>

Framework/Audio/Synthesizer/SongPlayer.cs

@@ -73,15 +73,15 @@ public void Buffer(float volume, ushort numberOfSamples) {
                 if (endOfBuffer > this.Song.Length) {
                     endOfBuffer = this.Song.Length;
                     beatLengthOfBuffer = endOfBuffer - this._currentBeat;
+                    numberOfSamples = (ushort)this.Song.ConvertBeatsToSamples(beatLengthOfBuffer);
                 }
 
                 var range = new RangeVector(this._currentBeat, endOfBuffer);
                 foreach (var track in this.Song.Tracks) {
                     var notes = track.GetNotes(range);
 
                     foreach (var note in notes) {
-                        var offset = note.Beat - this._currentBeat;
-                        var voice = this._voicePool.GetNext(this.Song, track, note, offset);
+                        var voice = this._voicePool.GetNext(this.Song, track, note, this._currentBeat);
                         voice.OnFinished += this.Voice_OnFinished;
                         this._activeVoices.Add(voice);
                     }

Framework/Audio/Synthesizer/Voice.cs

@@ -6,7 +6,6 @@
     /// A synthesizer voice. These are pooled and used to play notes to completion.
     /// </summary>
     public class Voice : IDisposable, IVoice {
-        private float _inverseSampleRate;
         private bool _isActive;
         private bool _isDisposed = false;
         private ulong _noteLengthInSamples;
@@ -49,7 +48,7 @@ public AudioSample[] GetBuffer(ushort numberOfSamples) {
                 if (this._isActive && sampleNumber >= 0) {
                     var frequency = this.Note.GetFrequency((sampleNumber / (float)this._noteLengthInSamples).Clamp(0f, 1f));
                     var volume = this.GetSampleAmplitude((ulong)sampleNumber);
-                    var time = sampleNumber * this._inverseSampleRate;
+                    var time = sampleNumber * this._song.InverseSampleRate;
                     var leftSample = this.Instrument.Oscillator.GetSignal(time, frequency, volume * this._track.LeftChannelVolume);
                     var rightSample = this.Instrument.Oscillator.GetSignal(time, frequency, volume * this._track.RightChannelVolume);
 
@@ -86,10 +85,8 @@ public virtual void Reinitialize(Song song, Track track, NoteInstance note, floa
             this._noteLengthInSamples = this._song.ConvertBeatsToSamples(this.Note.Length);
             this._preReleaseVolume = 0f;
             this._peakAmplitude = this.Envelope.Decay > 0 ? this.Envelope.PeakAmplitude : this.Envelope.SustainAmplitude;
-            this._inverseSampleRate = 1f / this._song.SampleRate;
         }
 
-        // To detect redundant calls
         protected virtual void Dispose(bool disposing) {
             if (!this._isDisposed) {
                 this.OnFinished = null;