Add bandpass filter, update butterworth and others

ProjectObsidian/Components/Audio/BandPassFilter.cs

@@ -0,0 +1,64 @@
+using System;
+using FrooxEngine;
+using Elements.Assets;
+using System.Net;
+using ProtoFlux.Runtimes.Execution;
+
+namespace Obsidian.Components.Audio
+{
+    [Category(new string[] { "Obsidian/Audio" })]
+    public class BandPassFilter : Component, IAudioSource, IWorldElement
+    {
+        [Range(0.1f, 1.41f, "0.00")]
+        public readonly Sync<float> Resonance;
+
+        [Range(20f, 20000f, "0.00")]
+        public readonly Sync<float> LowFrequency;
+
+        [Range(20f, 20000f, "0.00")]
+        public readonly Sync<float> HighFrequency;
+
+        public readonly SyncRef<IAudioSource> Source;
+
+        private double lastTime;
+
+        public bool IsActive
+        {
+            get => Source.Target != null && Source.Target.IsActive;
+        }
+
+        public int ChannelCount => Source.Target?.ChannelCount ?? 0;
+
+        public void Read<S>(Span<S> buffer) where S : unmanaged, IAudioSample<S>
+        {
+            if (!IsActive)
+            {
+                return;
+            }
+
+            Span<S> tempBuffer = stackalloc S[buffer.Length];
+            tempBuffer = buffer;
+            Source.Target.Read(tempBuffer);
+
+            var LowPass = new ButterworthFilter.FilterButterworth<S>(HighFrequency, (int)(tempBuffer.Length / (Engine.Current.AudioSystem.DSPTime - lastTime)), ButterworthFilter.FilterButterworth<S>.PassType.Lowpass, Resonance);
+            var HighPass = new ButterworthFilter.FilterButterworth<S>(LowFrequency, (int)(tempBuffer.Length / (Engine.Current.AudioSystem.DSPTime - lastTime)), ButterworthFilter.FilterButterworth<S>.PassType.Highpass, Resonance);
+
+            for (int i = 0; i < tempBuffer.Length; i++)
+            {
+                LowPass.Update(ref tempBuffer[i]);
+                HighPass.Update(ref tempBuffer[i]);
+            }
+
+            lastTime = Engine.Current.AudioSystem.DSPTime;
+        }
+
+        protected override void OnAwake()
+        {
+            base.OnAwake();
+            Resonance.Value = 1.41f;
+            LowFrequency.Value = 20f;
+            HighFrequency.Value = 20000f;
+            lastTime = Engine.Current.AudioSystem.DSPTime;
+        }
+    }
+}

ProjectObsidian/Components/Audio/ButterworthFilter.cs

@@ -7,7 +7,7 @@ namespace Obsidian.Components.Audio;
 [Category(new string[] { "Obsidian/Audio" })]
 public class ButterworthFilter : Component, IAudioSource, IWorldElement
 {
-    [Range(0f, 10000f, "0.00")]
+    [Range(20f, 20000f, "0.00")]
     public readonly Sync<float> Frequency;
 
     [Range(0.1f, 1.41f, "0.00")]
@@ -30,7 +30,9 @@ public bool IsActive
     protected override void OnAwake()
     {
         base.OnAwake();
-        lastTime = -1;
+        lastTime = Engine.Current.AudioSystem.DSPTime;
+        Frequency.Value = 20f;
+        Resonance.Value = 1.41f;
     }
 
     public int ChannelCount => Source.Target?.ChannelCount ?? 0;