Freeverb.h

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//
// Reverb.h -- The CSL port of the public domain Freeverb reverberator
//  Freeverb was written by Jezar at Dreampoint, June 2000 -- http://www.dreampoint.co.uk
//  See the copyright notice and acknowledgment of authors in the file COPYRIGHT
// 

#ifndef CSL_Reverb_H
#define CSL_Reverb_H

#include "CSL_Core.h"

#define undenormalise(sample) if(((*(unsigned int*)&sample)&0x7f800000)==0) sample=0.0f


namespace csl {

class Comb;         // predeclaration of utility classes
class Allpass;

class Freeverb : public Effect, public Scalable {

public:
    Freeverb(UnitGenerator &input);
    ~Freeverb();

    float roomSize();
    void setRoomSize(float size);   
    float dampening();  
    void setDampening(float damp);  
    float wetLevel();               
    void setWetLevel(float level);  
    float dryLevel();
    void setDryLevel(float level);  
    float width();
    void setWidth(float width);     
    
    void nextBuffer(Buffer &outputBuffer, unsigned outBufNum) throw (CException);

protected:          // accessable parameters
    float mRoomSize;
    float mDampening;   
    float mWetLevel;
    float mDryLevel;
    float mWidth;
                    // internal parameters  
    float mGain;

    std::vector<Comb*> mCombFilters;
    std::vector<Allpass*> mAllpassFilters;

    SampleBufferVector mCombBuffers;
    SampleBufferVector mAllpassBuffers; 

    void constructReverbGraph();
    void updateParameters();
    
};

class Comb {

public:

    Comb() : mFilterStore(0), mBufIdx(0) { };

    void    mute();
    float   damp() { return mDamp1; }
    float   feedback() { return mFeedback; }
    void    setDamp(float val);
    void    setFeedback(float val) { mFeedback = val; }
    void    setBuffer(float *buf, int size);
    
    inline  float   process(float inp); 

private:

    float   mFeedback;
    float   mFilterStore;
    float   mDamp1;
    float   mDamp2;
    float   *mBufferPtr;
    int     mBufSize;
    int     mBufIdx;

};

class Allpass {

public:

    Allpass() : mBufIdx(0) { };

    void    mute();
    float   feedback() { return mFeedback; };
    void    setFeedback(float val) { mFeedback = val; };
    void    setBuffer(float *buf, int size);
    
    inline  float process(float inp);

private:

    float   mFeedback;
    float   *mBufferPtr;
    int     mBufSize;
    int     mBufIdx;

};

// Big to inline - but crucial for speed
inline float Comb::process(float input) {

    float output = mBufferPtr[mBufIdx];
    undenormalise(output);

    mFilterStore = (output * mDamp2) + (mFilterStore * mDamp1);
    undenormalise(mFilterStore);
    
    mBufferPtr[mBufIdx] = input + (mFilterStore * mFeedback);
    if(++mBufIdx >= mBufSize) 
        mBufIdx = 0;

    return output;

}

inline float Allpass::process(float input) {

    float bufout = mBufferPtr[mBufIdx];
    undenormalise(bufout);

    float output = -input + bufout;
    mBufferPtr[mBufIdx] = input + (bufout * mFeedback);

    if(++mBufIdx >= mBufSize)
        mBufIdx = 0;

    return output;

}

// Stereoverb is a simple wrapper around 2 freeverbs with splitter/joiners for handling stereo inputs

//class Stereoverb : public Effect {
//
//protected:
//  Freeverb * leftRev, * rightRev; // 2 mono reverberators
//  Splitter * split;               // stereo-to-mono splitter
//  Joiner * join;                  // mono-to-stereo joiner
//
//public:
//  Stereoverb(FrameStream & input);
//  ~Stereoverb();
//
//  void set_room_size(float size);
//  void set_dampening(float damp);
//  void set_wet_level(float level);
//  void set_dry_level(float level);
//  void set_width(float width);
//
//  status next_buffer(Buffer & inputBuffer, Buffer & outputBuffer);
//
//};

}

#endif

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