shithub: leaf

ref: 8ab6a52fdfc58365c123dbab858f2d81f1b737c6
dir: /LEAF/Inc/leaf-filters.h/

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/*==============================================================================
 
 leaf-filters.h
 Created: 20 Jan 2017 12:01:10pm
 Author:  Michael R Mulshine
 
 ==============================================================================*/

#ifndef LEAF_FILTERS_H_INCLUDED
#define LEAF_FILTERS_H_INCLUDED

#ifdef __cplusplus
extern "C" {
#endif
    
    //==============================================================================
    
#include "leaf-math.h"
#include "leaf-delay.h"
#include "leaf-tables.h"
    
    //==============================================================================
    
    /* tAllpass: Schroeder allpass. Comb-filter with feedforward and feedback. */
    typedef struct _tAllpass
    {
        float gain;
        
        tLinearDelay delay;
        
        float lastOut;
        
    } _tAllpass;
    
    typedef _tAllpass* tAllpass;
    
    void        tAllpass_init           (tAllpass* const, float initDelay, uint32_t maxDelay);
    void        tAllpass_free           (tAllpass* const);
    
    float       tAllpass_tick           (tAllpass* const, float input);
    void        tAllpass_setGain        (tAllpass* const, float gain);
    void        tAllpass_setDelay       (tAllpass* const f, float delay);
    
    
    //==============================================================================
    
    /* tOnePole: OnePole filter, reimplemented from STK (Cook and Scavone). */
    typedef struct _tOnePole
    {
        float gain;
        float a0,a1;
        float b0,b1;
        
        float coef;
        
        float freq;
        
        float lastIn, lastOut;
        
    } _tOnePole;
    
    typedef _tOnePole* tOnePole;
    
    void        tOnePole_init           (tOnePole* const, float thePole);
    void        tOnePole_free           (tOnePole* const);
    
    float       tOnePole_tick           (tOnePole* const, float input);
    void        tOnePole_setB0          (tOnePole* const, float b0);
    void        tOnePole_setA1          (tOnePole* const, float a1);
    void        tOnePole_setPole        (tOnePole* const, float thePole);
    void        tOnePole_setFreq        (tOnePole* const, float freq);
    void        tOnePole_setCoefficients(tOnePole* const, float b0, float a1);
    void        tOnePole_setGain        (tOnePole* const, float gain);
    
    //==============================================================================
    
    /* TwoPole filter, reimplemented from STK (Cook and Scavone). */
    typedef struct _tTwoPole
    {
        float gain;
        float a0, a1, a2;
        float b0;
        
        float radius, frequency;
        oBool normalize;
        
        float lastOut[2];
        
    } _tTwoPole;
    
    typedef _tTwoPole* tTwoPole;
    
    void        tTwoPole_init           (tTwoPole*  const);
    void        tTwoPole_free           (tTwoPole*  const);
    
    float       tTwoPole_tick           (tTwoPole*  const, float input);
    void        tTwoPole_setB0          (tTwoPole*  const, float b0);
    void        tTwoPole_setA1          (tTwoPole*  const, float a1);
    void        tTwoPole_setA2          (tTwoPole*  const, float a2);
    void        tTwoPole_setResonance   (tTwoPole*  const, float freq, float radius, oBool normalize);
    void        tTwoPole_setCoefficients(tTwoPole*  const, float b0, float a1, float a2);
    void        tTwoPole_setGain        (tTwoPole*  const, float gain);
    
    //==============================================================================
    
    /* OneZero filter, reimplemented from STK (Cook and Scavone). */
    typedef struct _tOneZero
    {
        float gain;
        float b0,b1;
        float lastIn, lastOut, frequency;
        
    } _tOneZero;
    
    typedef _tOneZero* tOneZero;
    
    void        tOneZero_init           (tOneZero*  const, float theZero);
    void        tOneZero_free           (tOneZero*  const);
    float       tOneZero_tick           (tOneZero*  const, float input);
    void        tOneZero_setB0          (tOneZero*  const, float b0);
    void        tOneZero_setB1          (tOneZero*  const, float b1);
    void        tOneZero_setZero        (tOneZero*  const, float theZero);
    void        tOneZero_setCoefficients(tOneZero*  const, float b0, float b1);
    void        tOneZero_setGain        (tOneZero*  const, float gain);
    float       tOneZero_getPhaseDelay(tOneZero *f, float frequency );
    
    //==============================================================================
    
    /* TwoZero filter, reimplemented from STK (Cook and Scavone). */
    typedef struct _tTwoZero
    {
        float gain;
        float b0, b1, b2;
        
        float frequency, radius;
        
        float lastIn[2];
        
    } _tTwoZero;
    
    typedef _tTwoZero* tTwoZero;
    
    void        tTwoZero_init           (tTwoZero*  const);
    void        tTwoZero_free           (tTwoZero*  const);
    
    float       tTwoZero_tick           (tTwoZero*  const, float input);
    void        tTwoZero_setB0          (tTwoZero*  const, float b0);
    void        tTwoZero_setB1          (tTwoZero*  const, float b1);
    void        tTwoZero_setB2          (tTwoZero*  const, float b2);
    void        tTwoZero_setNotch       (tTwoZero*  const, float frequency, float radius);
    void        tTwoZero_setCoefficients(tTwoZero*  const, float b0, float b1, float b2);
    void        tTwoZero_setGain        (tTwoZero*  const, float gain);
    
    //==============================================================================
    
    /* PoleZero filter, reimplemented from STK (Cook and Scavone). */
    typedef struct _tPoleZero
    {
        float gain;
        float a0,a1;
        float b0,b1;
        
        float lastIn, lastOut;
        
    } _tPoleZero;
    
    typedef _tPoleZero* tPoleZero;
    
    void        tPoleZero_init              (tPoleZero*  const);
    void        tPoleZero_free              (tPoleZero*  const);
    
    float       tPoleZero_tick              (tPoleZero*  const, float input);
    void        tPoleZero_setB0             (tPoleZero*  const, float b0);
    void        tPoleZero_setB1             (tPoleZero*  const, float b1);
    void        tPoleZero_setA1             (tPoleZero*  const, float a1);
    void        tPoleZero_setCoefficients   (tPoleZero*  const, float b0, float b1, float a1);
    void        tPoleZero_setAllpass        (tPoleZero*  const, float coeff);
    void        tPoleZero_setBlockZero      (tPoleZero*  const, float thePole);
    void        tPoleZero_setGain           (tPoleZero*  const, float gain);
    
    //==============================================================================
    
    /* BiQuad filter, reimplemented from STK (Cook and Scavone). */
    typedef struct _tBiQuad
    {
        float gain;
        float a0, a1, a2;
        float b0, b1, b2;
        
        float lastIn[2];
        float lastOut[2];
        
        float frequency, radius;
        oBool normalize;
    } _tBiQuad;
    
    typedef _tBiQuad* tBiQuad;
    
    void        tBiQuad_init           (tBiQuad*  const);
    void        tBiQuad_free           (tBiQuad*  const);
    
    float       tBiQuad_tick           (tBiQuad*  const, float input);
    void        tBiQuad_setB0          (tBiQuad*  const, float b0);
    void        tBiQuad_setB1          (tBiQuad*  const, float b1);
    void        tBiQuad_setB2          (tBiQuad*  const, float b2);
    void        tBiQuad_setA1          (tBiQuad*  const, float a1);
    void        tBiQuad_setA2          (tBiQuad*  const, float a2);
    void        tBiQuad_setNotch       (tBiQuad*  const, float freq, float radius);
    void        tBiQuad_setResonance   (tBiQuad*  const, float freq, float radius, oBool normalize);
    void        tBiQuad_setCoefficients(tBiQuad*  const, float b0, float b1, float b2, float a1, float a2);
    void        tBiQuad_setGain        (tBiQuad*  const, float gain);
    
    //==============================================================================
    
    /* State Variable Filter, algorithm from Andy Simper. */
    typedef enum SVFType
    {
        SVFTypeHighpass = 0,
        SVFTypeLowpass,
        SVFTypeBandpass,
        SVFTypeNotch,
        SVFTypePeak,
    } SVFType;
    
    typedef struct _tSVF
    {
        SVFType type;
        float cutoff, Q;
        float ic1eq,ic2eq;
        float g,k,a1,a2,a3;
        
    } _tSVF;
    
    typedef _tSVF* tSVF;
    
    void        tSVF_init       (tSVF*  const, SVFType type, float freq, float Q);
    void        tSVF_free       (tSVF*  const);
    
    float       tSVF_tick       (tSVF*  const, float v0);
    void         tSVF_setFreq    (tSVF*  const, float freq);
    void         tSVF_setQ       (tSVF*  const, float Q);
    
    //==============================================================================
    
    /* Efficient State Variable Filter for 14-bit control input, [0, 4096). */
    typedef struct _tEfficientSVF
    {
        SVFType type;
        float cutoff, Q;
        float ic1eq,ic2eq;
        float g,k,a1,a2,a3;
        
    } _tEfficientSVF;
    
    typedef _tEfficientSVF* tEfficientSVF;
    
    void        tEfficientSVF_init      (tEfficientSVF*  const, SVFType type, uint16_t controlFreq, float Q);
    void        tEfficientSVF_free      (tEfficientSVF*  const);
    
    float       tEfficientSVF_tick      (tEfficientSVF*  const, float v0);
    void         tEfficientSVF_setFreq   (tEfficientSVF*  const, uint16_t controlFreq);
    void         tEfficientSVF_setQ      (tEfficientSVF*  const, float Q);
    
    //==============================================================================
    
    /* Simple Highpass filter. */
    typedef struct _tHighpass
    {
        float xs, ys, R;
        float frequency;
        
    } _tHighpass;
    
    typedef _tHighpass* tHighpass;
    
    void        tHighpass_init      (tHighpass*  const, float freq);
    void        tHighpass_free      (tHighpass*  const);
    
    float       tHighpass_tick      (tHighpass*  const, float x);
    void        tHighpass_setFreq   (tHighpass*  const, float freq);
    float       tHighpass_getFreq   (tHighpass*  const);
    
    //==============================================================================
    
    // Butterworth Filter
#define NUM_SVF_BW 16
    typedef struct _tButterworth
    {
        float gain;
        
        float N;
        
        tSVF low[NUM_SVF_BW];
        tSVF high[NUM_SVF_BW];
        
        float f1,f2;
        
    } _tButterworth;
    
    typedef _tButterworth* tButterworth;
    
    void        tButterworth_init       (tButterworth* const, int N, float f1, float f2);
    void        tButterworth_free       (tButterworth* const);
    
    float       tButterworth_tick       (tButterworth* const, float input);
    void        tButterworth_setF1      (tButterworth* const, float in);
    void        tButterworth_setF2      (tButterworth* const, float in);
    void        tButterworth_setFreqs   (tButterworth* const, float f1, float f2);
    
    //==============================================================================
    
    typedef struct _tFIR
    {
        float* past;
        float* coeff;
        int numTaps;
        
    } _tFIR;
    
    typedef _tFIR* tFIR;
    
    void        tFIR_init       (tFIR* const, float* coeffs, int numTaps);
    void        tFIR_free       (tFIR* const);
    
    float       tFIR_tick       (tFIR* const, float input);
    void        tFIR_coeffs      (tFIR* const, float in);
    
    //==============================================================================
    
#ifdef __cplusplus
}
#endif

#endif  // LEAF_FILTERS_H_INCLUDED

//==============================================================================