Diff: reverb_unit.hpp

Revision:

0:72e321f29769

Child:

1:51c85e0a6e1e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/reverb_unit.hpp	Thu Oct 23 03:53:29 2014 +0000
@@ -0,0 +1,74 @@
+//--------------------------------------------------------------
+// Comb filter
+// 2014/10/23, Copyright (c) 2014 MIKAMI, Naoki
+//--------------------------------------------------------------
+
+#ifndef REVERB_UNIT_HPP
+#define REVERB_UNIT_HPP
+
+#include "mbed.h"
+
+// Base class for reverb unit
+template<int delay> class Reverb
+{
+private:
+    int ptr_;
+    float un_[delay];    // for delay
+protected:
+    float Get() { return un_[ptr_]; }
+    void Set(float x)
+    {
+        un_[ptr_] = x;   
+        if (++ptr_ >=  delay) ptr_ = 0;
+    }
+public:
+    // Constructor
+    Reverb() : ptr_(0) { Clear(); }
+
+    // Execute of filter (pure virtual function)
+    virtual float Execute(float x) = 0;
+
+    // Clear internal delay elements
+    void Clear()
+    { for (int n=0; n<delay; n++) un_[n] = 0; }
+};    
+   
+// Comb filter
+template<int delay> class CombFilter : public Reverb<delay>
+{
+private:
+    const float G0_;
+public:
+    // Constructor
+    CombFilter(float g) : G0_(g) {}
+
+    // Execute comb filter 
+    virtual float Execute(float x)
+    {
+        float yn = Reverb<delay>::Get();
+        Reverb<delay>::Set(x + G0_*yn);
+        return yn;
+     }
+};
+
+// Allpass filter
+template<int delay> class AllpassFilter : public Reverb<delay>
+{
+private:
+    const float G0_;
+public:
+    // Constructor
+    AllpassFilter(float g) : G0_(g) {}
+
+    // Execute comb filter 
+    virtual float Execute(float x)
+    {
+        float un = x + G0_*Reverb<delay>::Get();
+        float yn = -G0_*un + Reverb<delay>::Get();
+        Reverb<delay>::Set(un);
+        return yn;
+     }
+};
+
+#endif  // REVERB_UNIT_HPP
+