Merge pull request #73 from Nytra/audioWork

Add PhaseModulator, Add RingModulator, rename FrequencyModulator to SineShapedRingModulator

ProjectObsidian/Components/Audio/PhaseModulator.cs

@@ -0,0 +1,124 @@
+using System;
+using FrooxEngine;
+using Elements.Assets;
+using System.Threading;
+
+namespace Obsidian.Components.Audio
+{
+    [Category(new string[] { "Obsidian/Audio" })]
+    public class PhaseModulator : Component, IAudioSource, IWorldElement
+    {
+        [Range(0f, 5f, "0.00")]
+        public readonly Sync<float> ModulationIndex;
+
+        public readonly SyncRef<IAudioSource> CarrierSource;
+        public readonly SyncRef<IAudioSource> ModulatorSource;
+
+        public bool IsActive
+        {
+            get
+            {
+                return CarrierSource.Target != null &&
+                       ModulatorSource.Target != null &&
+                       CarrierSource.Target.IsActive &&
+                       ModulatorSource.Target.IsActive;
+            }
+        }
+
+        public int ChannelCount
+        {
+            get
+            {
+                return CarrierSource.Target?.ChannelCount ?? 0;
+            }
+        }
+
+        protected override void OnAwake()
+        {
+            base.OnAwake();
+            ModulationIndex.Value = 1f; // Default modulation index
+        }
+
+        /// <summary>
+        /// Calculates instantaneous phase of a signal using a simple Hilbert transform approximation
+        /// </summary>
+        private double[] CalculateInstantaneousPhase<S>(Span<S> buffer) where S : unmanaged, IAudioSample<S>
+        {
+            int length = buffer.Length;
+            double[] phase = new double[length];
+            double[] avgAmplitudes = new double[length];
+
+            for (int i = 1; i < length - 1; i++)
+            {
+                for (int j = 0; j < buffer[i].ChannelCount; j++)
+                {
+                    avgAmplitudes[i] += buffer[i][j];
+                }
+                avgAmplitudes[i] /= buffer[i].ChannelCount;
+            }
+
+            // Simple 3-point derivative for phase approximation
+            for (int i = 1; i < length - 1; i++)
+            {
+                double derivative = (avgAmplitudes[i + 1] - avgAmplitudes[i - 1]) / 2.0;
+                double hilbertApprox = avgAmplitudes[i] / Math.Sqrt(avgAmplitudes[i] * avgAmplitudes[i] + derivative * derivative);
+                phase[i] = Math.Acos(hilbertApprox);
+
+                // Correct phase quadrant based on derivative sign
+                if (derivative < 0)
+                    phase[i] = 2 * Math.PI - phase[i];
+            }
+
+            // Handle edge cases
+            phase[0] = phase[1];
+            phase[length - 1] = phase[length - 2];
+
+            return phase;
+        }
+
+        // TODO: Make this not click when the signal goes silent and then not silent?
+        public void Read<S>(Span<S> buffer) where S : unmanaged, IAudioSample<S>
+        {
+            if (!IsActive)
+            {
+                buffer.Fill(default(S));
+                return;
+            }
+
+            int channelCount = ChannelCount;
+            if (channelCount == 0)
+            {
+                buffer.Fill(default(S));
+                return;
+            }
+
+            Span<S> carrierBuffer = stackalloc S[buffer.Length];
+            Span<S> modulatorBuffer = stackalloc S[buffer.Length];
+
+            CarrierSource.Target.Read(carrierBuffer);
+            ModulatorSource.Target.Read(modulatorBuffer);
+
+            float modulationIndex = ModulationIndex.Value;
+
+            double[] carrierPhase = CalculateInstantaneousPhase(carrierBuffer);
+
+            // Apply phase modulation
+            for (int i = 0; i < buffer.Length; i++)
+            {
+                for (int j = 0; j < buffer[i].ChannelCount; j++)
+                {
+                    double modifiedPhase = carrierPhase[i] + (modulationIndex * modulatorBuffer[i][j]);
+
+                    // Calculate amplitude using original carrier amplitude
+                    float amplitude = carrierBuffer[i][j];
+
+                    // Generate output sample
+                    buffer[i] = buffer[i].SetChannel(j, amplitude * (float)Math.Sin(modifiedPhase));
+
+                    if (buffer[i][j] > 1f) buffer[i] = buffer[i].SetChannel(j, 1f);
+                    if (buffer[i][j] < -1f) buffer[i] = buffer[i].SetChannel(j, -1f);
+                }
+            }
+        }
+    }
+}

ProjectObsidian/Components/Audio/FrequencyModulator.cs → ProjectObsidian/Components/Audio/RingModulator.cs

@@ -1,11 +1,12 @@
 using System;
 using FrooxEngine;
 using Elements.Assets;
+using Elements.Core;
 
 namespace Obsidian.Components.Audio
 {
     [Category(new string[] { "Obsidian/Audio" })]
-    public class FrequencyModulator : Component, IAudioSource, IWorldElement
+    public class RingModulator : Component, IAudioSource, IWorldElement
     {
         [Range(0f, 5f, "0.00")]
         public readonly Sync<float> ModulationIndex;
@@ -63,15 +64,15 @@ public void Read<S>(Span<S> buffer) where S : unmanaged, IAudioSample<S>
 
             float modulationIndex = ModulationIndex.Value;
 
-            // Apply FM synthesis
+            // Apply ring modulation
             for (int i = 0; i < buffer.Length; i++)
             {
                 for (int j = 0; j < buffer[i].ChannelCount; j++)
                 {
                     float carrierValue = carrierBuffer[i][j];
                     float modulatorValue = modulatorBuffer[i][j];
 
-                    float modulatedValue = (float)(carrierValue * Math.Sin(2 * Math.PI * modulationIndex * modulatorValue));
+                    float modulatedValue = (float)(carrierValue * modulatorValue * modulationIndex);
 
                     buffer[i] = buffer[i].SetChannel(j, modulatedValue);
 

ProjectObsidian/Components/Audio/SineShapedRingModulator.cs

@@ -0,0 +1,86 @@
+using System;
+using FrooxEngine;
+using Elements.Assets;
+using Elements.Core;
+
+namespace Obsidian.Components.Audio
+{
+    [Category(new string[] { "Obsidian/Audio" })]
+    [OldTypeName("Obsidian.Components.Audio.FrequencyModulator")]
+    public class SineShapedRingModulator : Component, IAudioSource, IWorldElement
+    {
+        [Range(0f, 5f, "0.00")]
+        public readonly Sync<float> ModulationIndex;
+
+        public readonly SyncRef<IAudioSource> CarrierSource;
+        public readonly SyncRef<IAudioSource> ModulatorSource;
+
+        public bool IsActive
+        {
+            get
+            {
+                return CarrierSource.Target != null &&
+                       ModulatorSource.Target != null &&
+                       CarrierSource.Target.IsActive &&
+                       ModulatorSource.Target.IsActive;
+            }
+        }
+
+        public int ChannelCount
+        {
+            get
+            {
+                return CarrierSource.Target?.ChannelCount ?? 0;
+            }
+        }
+
+        protected override void OnAwake()
+        {
+            base.OnAwake();
+            ModulationIndex.Value = 1f; // Default modulation index
+        }
+
+        public void Read<S>(Span<S> buffer) where S : unmanaged, IAudioSample<S>
+        {
+            if (!IsActive)
+            {
+                buffer.Fill(default(S));
+                return;
+            }
+
+            int channelCount = ChannelCount;
+            if (channelCount == 0)
+            {
+                buffer.Fill(default(S));
+                return;
+            }
+
+            // Temporary buffers for carrier and modulator sources
+            Span<S> carrierBuffer = stackalloc S[buffer.Length];
+            Span<S> modulatorBuffer = stackalloc S[buffer.Length];
+
+            // Read data from sources
+            CarrierSource.Target.Read(carrierBuffer);
+            ModulatorSource.Target.Read(modulatorBuffer);
+
+            float modulationIndex = ModulationIndex.Value;
+
+            // Apply sine-shaped ring modulation
+            for (int i = 0; i < buffer.Length; i++)
+            {
+                for (int j = 0; j < buffer[i].ChannelCount; j++)
+                {
+                    float carrierValue = carrierBuffer[i][j];
+                    float modulatorValue = modulatorBuffer[i][j];
+
+                    float modulatedValue = (float)(carrierValue * Math.Sin(2 * Math.PI * modulationIndex * modulatorValue));
+
+                    buffer[i] = buffer[i].SetChannel(j, modulatedValue);
+
+                    if (buffer[i][j] > 1f) buffer[i] = buffer[i].SetChannel(j, 1f);
+                    if (buffer[i][j] < -1f) buffer[i] = buffer[i].SetChannel(j, -1f);
+                }
+            }
+        }
+    }
+}