add delayed audio tween support

src/Audio/AudioDevice.cs

@@ -32,6 +32,7 @@ namespace MoonWorks.Audio
 
 		private AudioTweenPool AudioTweenPool = new AudioTweenPool();
 		private readonly List<AudioTween> AudioTweens = new List<AudioTween>();
+		private readonly List<AudioTween> DelayedAudioTweens = new List<AudioTween>();
 
 		private const int Step = 200;
 		private TimeSpan UpdateInterval;
@@ -163,6 +164,52 @@ namespace MoonWorks.Audio
 				}
 			}
 
+			for (var i = DelayedAudioTweens.Count - 1; i >= 0; i--)
+			{
+				var audioTween = DelayedAudioTweens[i];
+
+				if (audioTween.SoundInstanceReference.TryGetTarget(out var soundInstance))
+				{
+					audioTween.Time += elapsedSeconds;
+
+					if (audioTween.Time >= audioTween.DelayTime)
+					{
+						switch (audioTween.Property)
+						{
+							case AudioTweenProperty.Pan:
+								audioTween.StartValue = soundInstance.Pan;
+								break;
+
+							case AudioTweenProperty.Pitch:
+								audioTween.StartValue = soundInstance.Pitch;
+								break;
+
+							case AudioTweenProperty.Volume:
+								audioTween.StartValue = soundInstance.Volume;
+								break;
+
+							case AudioTweenProperty.FilterFrequency:
+								audioTween.StartValue = soundInstance.FilterFrequency;
+								break;
+
+							case AudioTweenProperty.Reverb:
+								audioTween.StartValue = soundInstance.Reverb;
+								break;
+						}
+
+						audioTween.Time = 0;
+						AudioTweens.Add(audioTween);
+						DelayedAudioTweens.RemoveAt(i);
+					}
+				}
+				else
+				{
+					AudioTweenPool.Free(audioTween);
+					DelayedAudioTweens.RemoveAt(i);
+				}
+
+			}
+
 			for (var i = AudioTweens.Count - 1; i >= 0; i--)
 			{
 				bool finished = true;
@@ -192,7 +239,8 @@ namespace MoonWorks.Audio
 			EasingFunction easingFunction,
 			float start,
 			float end,
-			float duration
+			float duration,
+			float delayTime
 		) {
 			lock (StateLock)
 			{
@@ -200,13 +248,21 @@ namespace MoonWorks.Audio
 				tween.SoundInstanceReference = new WeakReference<SoundInstance>(soundInstance);
 				tween.Property = property;
 				tween.EasingFunction = easingFunction;
-				tween.Start = start;
+				tween.StartValue = start;
-				tween.End = end;
+				tween.EndValue = end;
 				tween.Duration = duration;
 				tween.Time = 0;
+				tween.DelayTime = delayTime;
 
+				if (delayTime == 0)
+				{
 					AudioTweens.Add(tween);
 				}
+				else
+				{
+					DelayedAudioTweens.Add(tween);
+				}
+			}
 		}
 
 		private bool UpdateAudioTween(AudioTween audioTween, SoundInstance soundInstance, float delta)
@@ -215,16 +271,15 @@ namespace MoonWorks.Audio
 			audioTween.Time += delta;
 
 			var finished = audioTween.Time >= audioTween.Duration;
-
 			if (finished)
 			{
-				value = audioTween.End;
+				value = audioTween.EndValue;
 			}
 			else
 			{
 				value = MoonWorks.Math.Easing.Interp(
-					audioTween.Start,
+					audioTween.StartValue,
-					audioTween.End,
+					audioTween.EndValue,
 					audioTween.Time,
 					audioTween.Duration,
 					audioTween.EasingFunction

src/Audio/AudioTween.cs

@@ -18,8 +18,9 @@ namespace MoonWorks.Audio
 		public AudioTweenProperty Property;
 		public EasingFunction EasingFunction;
 		public float Time;
-		public float Start;
+		public float StartValue;
-		public float End;
+		public float EndValue;
+		public float DelayTime;
 		public float Duration;
 	}
 

src/Audio/SoundInstance.cs

@@ -109,10 +109,12 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		private float FilterOneOverQ
+		public float FilterOneOverQ
 		{
 			get => filterParameters.OneOverQ;
-			set
+			internal set
+			{
+				if (filterParameters.OneOverQ != value)
 				{
 					value = System.Math.Clamp(value, 0.01f, MAX_FILTER_ONEOVERQ);
 					filterParameters.OneOverQ = value;
@@ -124,6 +126,7 @@ namespace MoonWorks.Audio
 					);
 				}
 			}
+		}
 
 		private FilterType filterType;
 		public FilterType FilterType
@@ -305,7 +308,12 @@ namespace MoonWorks.Audio
 
 		public void SetPan(float targetValue, float duration, EasingFunction easingFunction)
 		{
-			Device.CreateTween(this, AudioTweenProperty.Pan, easingFunction, Pan, targetValue, duration);
+			Device.CreateTween(this, AudioTweenProperty.Pan, easingFunction, Pan, targetValue, duration, 0);
+		}
+
+		public void SetPan(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Pan, easingFunction, Pan, targetValue, duration, delayTime);
 		}
 
 		public void SetPitch(float targetValue)
@@ -315,7 +323,12 @@ namespace MoonWorks.Audio
 
 		public void SetPitch(float targetValue, float duration, EasingFunction easingFunction)
 		{
-			Device.CreateTween(this, AudioTweenProperty.Pitch, easingFunction, Pan, targetValue, duration);
+			Device.CreateTween(this, AudioTweenProperty.Pitch, easingFunction, Pan, targetValue, duration, 0);
+		}
+
+		public void SetPitch(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Pitch, easingFunction, Pan, targetValue, duration, delayTime);
 		}
 
 		public void SetVolume(float targetValue)
@@ -325,7 +338,12 @@ namespace MoonWorks.Audio
 
 		public void SetVolume(float targetValue, float duration, EasingFunction easingFunction)
 		{
-			Device.CreateTween(this, AudioTweenProperty.Volume, easingFunction, Volume, targetValue, duration);
+			Device.CreateTween(this, AudioTweenProperty.Volume, easingFunction, Volume, targetValue, duration, 0);
+		}
+
+		public void SetVolume(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Volume, easingFunction, Volume, targetValue, duration, delayTime);
 		}
 
 		public void SetFilterFrequency(float targetValue)
@@ -335,7 +353,18 @@ namespace MoonWorks.Audio
 
 		public void SetFilterFrequency(float targetValue, float duration, EasingFunction easingFunction)
 		{
-			Device.CreateTween(this, AudioTweenProperty.FilterFrequency, easingFunction, FilterFrequency, targetValue, duration);
+			Device.CreateTween(this, AudioTweenProperty.FilterFrequency, easingFunction, FilterFrequency, targetValue, duration, 0);
+		}
+
+		public void SetFilterFrequency(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
+		{
+			Logger.LogInfo(duration.ToString());
+			Device.CreateTween(this, AudioTweenProperty.FilterFrequency, easingFunction, FilterFrequency, targetValue, duration, delayTime);
+		}
+
+		public void SetFilterOneOverQ(float targetValue)
+		{
+			FilterOneOverQ = targetValue;
 		}
 
 		public void SetReverb(float targetValue)
@@ -345,7 +374,12 @@ namespace MoonWorks.Audio
 
 		public void SetReverb(float targetValue, float duration, EasingFunction easingFunction)
 		{
-			Device.CreateTween(this, AudioTweenProperty.Reverb, easingFunction, Volume, targetValue, duration);
+			Device.CreateTween(this, AudioTweenProperty.Reverb, easingFunction, Volume, targetValue, duration, 0);
+		}
+
+		public void SetReverb(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Reverb, easingFunction, Volume, targetValue, duration, delayTime);
 		}
 
 		public abstract void Play();