AnalogTapeModel

commit 7cc2afb5bc9e66326dc8d3b59445a1ec7ca8062d
parent 2baae13496804d66997e3de1911ddc9a858a0059
Author: jatinchowdhury18 <jatinchowdhury18@users.noreply.github.com>
Date:   Thu,  7 Feb 2019 17:31:18 -0800

Basic build

Diffstat:
M
Plugin/CHOWTapeModel.jucer
 | 
9
++++++++-
M
Plugin/JuceLibraryCode/AppConfig.h
 | 
2
+-
M
Plugin/Source/Processors/HysteresisProcessing.cpp
 | 
81
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
M
Plugin/Source/Processors/HysteresisProcessing.h
 | 
41
+++++++++++++++++++++++++++++++++--------

4 files changed, 115 insertions(+), 18 deletions(-)
diff --git a/Plugin/CHOWTapeModel.jucer b/Plugin/CHOWTapeModel.jucer
@@ -1,8 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<JUCERPROJECT id="uS0OjK" name="CHOWTapeModel" projectType="audioplug" jucerVersion="5.4.2">
+<JUCERPROJECT id="uS0OjK" name="CHOWTapeModel" projectType="audioplug" jucerVersion="5.4.2"
+              pluginFormats="buildAU,buildStandalone,buildVST,buildVST3">
   <MAINGROUP id="oKBSK1" name="CHOWTapeModel">
     <GROUP id="{7659EE80-6477-48A0-C7B6-CD8900735F10}" name="Source">
+      <GROUP id="{D2422983-A0E9-6A14-2092-2381CB1F3E7F}" name="Processors">
+        <FILE id="SSdMYR" name="HysteresisProcessing.cpp" compile="1" resource="0"
+              file="Source/Processors/HysteresisProcessing.cpp"/>
+        <FILE id="vvuNZS" name="HysteresisProcessing.h" compile="0" resource="0"
+              file="Source/Processors/HysteresisProcessing.h"/>
+      </GROUP>
       <FILE id="y330sp" name="PluginProcessor.cpp" compile="1" resource="0"
             file="Source/PluginProcessor.cpp"/>
       <FILE id="FvqAFZ" name="PluginProcessor.h" compile="0" resource="0"
diff --git a/Plugin/JuceLibraryCode/AppConfig.h b/Plugin/JuceLibraryCode/AppConfig.h
@@ -299,7 +299,7 @@
 // Audio plugin settings..
 
 #ifndef  JucePlugin_Build_VST
- #define JucePlugin_Build_VST              0
+ #define JucePlugin_Build_VST              1
 #endif
 #ifndef  JucePlugin_Build_VST3
  #define JucePlugin_Build_VST3             1
diff --git a/Plugin/Source/Processors/HysteresisProcessing.cpp b/Plugin/Source/Processors/HysteresisProcessing.cpp
@@ -1,11 +1,76 @@
-/*
-  ==============================================================================
+#include "HysteresisProcessing.h"
+#include <math.h>
 
-    HysteresisProcessing.cpp
-    Created: 7 Feb 2019 4:18:29pm
-    Author:  jatin
+HysteresisProcessor::HysteresisProcessor()
+{
 
-  ==============================================================================
-*/
+}
 
-#include "HysteresisProcessing.h"
+float HysteresisProcessor::langevin (float x)
+{
+    if (std::abs (x) > (float) (10e-4))
+        return (1.0f / (float) tanh (x)) - (1.0f / x);
+    else
+        return (x / 3.0f);
+}
+
+float HysteresisProcessor::langevinD (float x)
+{
+    if (std::abs (x) > (float) (10e-4))
+    {
+        float tanhRecip = 1.0f / tanh (x);
+        return (1.0f / (x * x)) - (tanhRecip * tanhRecip) + 1.0f;
+    }
+    else
+        return (1.0f / 3.0f);
+}
+
+float HysteresisProcessor::deriv (float x_n, float x_n1, float x_d_n1)
+{
+    return ((2.0f * fs) * (x_n - x_n1)) - x_d_n1;
+}
+
+float HysteresisProcessor::hysteresisFunc (float M, float H, float H_d)
+{
+    const float Q = (H + alpha * M) / a;
+    const float M_diff = M_s * langevin (Q) - M;
+
+    const float delta = H_d > 0 ? 1.0f : -1.0f;
+    const float delta_M = signbit (delta) == signbit (M_diff) ? 1.0f : 0.0f;
+
+    const float L_prime = langevinD (Q);
+
+    const float denominator = 1 - (c * alpha * (M_s / a) * L_prime);
+
+    const float t1_num = (1 - c) * delta_M * M_diff;
+    const float t1_den = ((1 - c) * delta * k) - (alpha * M_diff);
+    const float t1 = (t1_num / t1_den) * H_d;
+
+    const float t2 = c * (M_s / a) * H_d * L_prime;
+
+    return (t1 + t2) / denominator;
+}
+
+float HysteresisProcessor::M_n (float prevM, float k1, float k2, float k3, float k4)
+{
+    return prevM + (k1 / 6.0f) + (k2 / 3.0f) + (k3 / 3.0f) + (k4 / 6.0f);
+}
+
+float HysteresisProcessor::process (float H)
+{
+    const float H_d = deriv (H, H_n1, H_d_n1);
+
+    const float T = (1.0f / fs);
+    const float k1 = T * hysteresisFunc (M_n1, H_n1, H_d_n1);
+    const float k2 = T * hysteresisFunc (M_n1 + (k1 / 2.0f), (H + H_n1) / 2.0f, (H_d + H_d_n1) / 2.0f);
+    const float k3 = T * hysteresisFunc (M_n1 + (k2 / 2.0f), (H + H_n1) / 2.0f, (H_d + H_d_n1) / 2.0f);
+    const float k4 = T * hysteresisFunc (M_n1 + k3, H, H_d);
+
+    const float M = M_n (M_n1, k1, k2, k3, k4);
+
+    M_n1 = M;
+    H_n1 = H;
+    H_d_n1 = H_d;
+
+    return M;
+}
diff --git a/Plugin/Source/Processors/HysteresisProcessing.h b/Plugin/Source/Processors/HysteresisProcessing.h
@@ -1,11 +1,36 @@
-/*
-  ==============================================================================
+#ifndef HYSTERESISPROCESSOR_H_INCLUDED
+#define HYSTERESISPROCESSOR_H_INCLUDED
 
-    HysteresisProcessing.h
-    Created: 7 Feb 2019 4:18:29pm
-    Author:  jatin
+#include "JuceHeader.h"
 
-  ==============================================================================
-*/
+class HysteresisProcessor
+{
+public:
+    HysteresisProcessor();
 
-#pragma once
+    float process (float H);
+
+private:
+
+    float langevin (float x);
+    float langevinD (float x);
+    float deriv (float x_n, float x_n1, float x_d_n1);
+
+    float hysteresisFunc (float M, float H, float H_d);
+    float M_n (float M_n1, float k1, float k2, float k3, float k4);
+
+    float fs = 48000.0f;
+    const float M_s = 350000.0f;
+    const float a = (float) 2.2e4;
+    const float alpha = (float) 1.6e-3;
+    const float k = (float) 27.0e3;
+    const float c = (float) 1.7e-1;
+
+    float M_n1 = 0.0;
+    float H_n1 = 0.0f;
+    float H_d_n1 = 0.0f;
+
+    //JUCE_DECLARE_NONCOPYABLE_WITH_LEAK_DETECTOR (HysteresisProcessor)
+};
+
+#endif