ref: 2788a3510e621d1191849f5a03fd090de8bcba25
dir: /LEAF/Src/leaf-filter.c/
/*
==============================================================================
LEAFFilter.c
Created: 20 Jan 2017 12:01:10pm
Author: Michael R Mulshine
==============================================================================
*/
#if _WIN32 || _WIN64
#include "..\Inc\leaf-filter.h"
#include "..\Inc\leaf-wavetables.h"
#include "..\leaf.h"
#else
#include "../Inc/leaf-filter.h"
#include "../Inc/leaf-wavetables.h"
#include "../leaf.h"
#endif
void tButterworth_init(tButterworth* const f, int N, float f1, float f2)
{
f->f1 = f1;
f->f2 = f2;
f->gain = 1.0f;
f->N = N;
if (f->N > NUM_SVF_BW) f->N = NUM_SVF_BW;
for(int i = 0; i < N/2; ++i)
{
tSVF_init(&f->low[i], SVFTypeHighpass, f1, 0.5f/cosf((1.0f+2.0f*i)*PI/(2*N)));
tSVF_init(&f->high[i], SVFTypeLowpass, f2, 0.5f/cosf((1.0f+2.0f*i)*PI/(2*N)));
}
}
void tButterworth_free(tButterworth* const f)
{
for(int i = 0; i < f->N/2; ++i)
{
tSVF_free(&f->low[i]);
tSVF_free(&f->high[i]);
}
leaf_free(f);
}
float tButterworth_tick(tButterworth* const f, float samp)
{
for(int i = 0; i < ((f->N)/2); ++i)
{
samp = tSVF_tick(&f->low[i],samp);
samp = tSVF_tick(&f->high[i],samp);
}
return samp;
}
void tButterworth_setF1(tButterworth* const f, float f1)
{
f->f1 = f1;
for(int i = 0; i < ((f->N)/2); ++i) tSVF_setFreq(&f->low[i], f1);
}
void tButterworth_setF2(tButterworth* const f, float f2)
{
f->f2 = f2;
for(int i = 0; i < ((f->N)/2); ++i) tSVF_setFreq(&f->high[i], f2);
}
void tButterworth_setFreqs(tButterworth* const f, float f1, float f2)
{
f->f1 = f1;
f->f2 = f2;
for(int i = 0; i < ((f->N)/2); ++i)
{
tSVF_setFreq(&f->low[i], f1);
tSVF_setFreq(&f->high[i], f2);
}
}
// ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ OneZero Filter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ //
void tOneZero_init(tOneZero* const f, float theZero)
{
f->gain = 1.0f;
f->lastIn = 0.0f;
f->lastOut = 0.0f;
tOneZero_setZero(f, theZero);
}
void tOneZero_free(tOneZero* const f)
{
leaf_free(f);
}
float tOneZero_tick(tOneZero* const f, float input)
{
float in = input * f->gain;
float out = f->b1 * f->lastIn + f->b0 * in;
f->lastIn = in;
return out;
}
void tOneZero_setZero(tOneZero* const f, float theZero)
{
if (theZero > 0.0f) f->b0 = 1.0f / (1.0f + theZero);
else f->b0 = 1.0f / (1.0f - theZero);
f->b1 = -theZero * f->b0;
}
void tOneZero_setB0(tOneZero* const f, float b0)
{
f->b0 = b0;
}
void tOneZero_setB1(tOneZero* const f, float b1)
{
f->b1 = b1;
}
void tOneZero_setCoefficients(tOneZero* const f, float b0, float b1)
{
f->b0 = b0;
f->b1 = b1;
}
void tOneZero_setGain(tOneZero *f, float gain)
{
f->gain = gain;
}
float tOneZero_getPhaseDelay(tOneZero* const f, float frequency )
{
if ( frequency <= 0.0f) frequency = 0.05f;
f->frequency = frequency;
float omegaT = 2 * PI * frequency * leaf.invSampleRate;
float real = 0.0, imag = 0.0;
real += f->b0;
real += f->b1 * cosf(omegaT);
imag -= f->b1 * sinf(omegaT);
real *= f->gain;
imag *= f->gain;
float phase = atan2f( imag, real );
real = 0.0; imag = 0.0;
phase -= atan2f( imag, real );
phase = fmodf( -phase, 2 * PI );
return phase / omegaT;
}
// ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ TwoZero Filter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ //
void tTwoZero_init(tTwoZero* const f)
{
f->gain = 1.0f;
f->lastIn[0] = 0.0f;
f->lastIn[1] = 0.0f;
}
void tTwoZero_free(tTwoZero* const f)
{
leaf_free(f);
}
float tTwoZero_tick(tTwoZero* const f, float input)
{
float in = input * f->gain;
float out = f->b2 * f->lastIn[1] + f->b1 * f->lastIn[0] + f->b0 * in;
f->lastIn[1] = f->lastIn[0];
f->lastIn[0] = in;
return out;
}
void tTwoZero_setNotch(tTwoZero* const f, float freq, float radius)
{
// Should also deal with frequency being > half sample rate / nyquist. See STK
if (freq < 0.0f) freq = 0.0f;
if (radius < 0.0f) radius = 0.0f;
f->frequency = freq;
f->radius = radius;
f->b2 = radius * radius;
f->b1 = -2.0f * radius * cosf(TWO_PI * freq * leaf.invSampleRate); // OPTIMIZE with LOOKUP or APPROXIMATION
// Normalize the filter gain. From STK.
if ( f->b1 > 0.0f ) // Maximum at z = 0.
f->b0 = 1.0f / ( 1.0f + f->b1 + f->b2 );
else // Maximum at z = -1.
f->b0 = 1.0f / ( 1.0f - f->b1 + f->b2 );
f->b1 *= f->b0;
f->b2 *= f->b0;
}
void tTwoZero_setB0(tTwoZero* const f, float b0)
{
f->b0 = b0;
}
void tTwoZero_setB1(tTwoZero* const f, float b1)
{
f->b1 = b1;
}
void tTwoZero_setCoefficients(tTwoZero* const f, float b0, float b1, float b2)
{
f->b0 = b0;
f->b1 = b1;
f->b2 = b2;
}
void tTwoZero_setGain(tTwoZero* const f, float gain)
{
f->gain = gain;
}
void tTwoZeroSampleRateChanged(tTwoZero* const f)
{
tTwoZero_setNotch(f, f->frequency, f->radius);
}
// ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ OnePole Filter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ //
void tOnePole_init(tOnePole* const f, float thePole)
{
f->gain = 1.0f;
f->a0 = 1.0;
tOnePole_setPole(f, thePole);
f->lastIn = 0.0f;
f->lastOut = 0.0f;
}
void tOnePole_free(tOnePole* const f)
{
leaf_free(f);
}
void tOnePole_setB0(tOnePole* const f, float b0)
{
f->b0 = b0;
}
void tOnePole_setA1(tOnePole* const f, float a1)
{
if (a1 >= 1.0f) a1 = 0.999999f;
f->a1 = a1;
}
void tOnePole_setPole(tOnePole* const f, float thePole)
{
if (thePole >= 1.0f) thePole = 0.999999f;
// Normalize coefficients for peak unity gain.
if (thePole > 0.0f) f->b0 = (1.0f - thePole);
else f->b0 = (1.0f + thePole);
f->a1 = -thePole;
}
void tOnePole_setCoefficients(tOnePole* const f, float b0, float a1)
{
if (a1 >= 1.0f) a1 = 0.999999f;
f->b0 = b0;
f->a1 = a1;
}
void tOnePole_setGain(tOnePole* const f, float gain)
{
f->gain = gain;
}
float tOnePole_tick(tOnePole* const f, float input)
{
float in = input * f->gain;
float out = (f->b0 * in) - (f->a1 * f->lastOut);
f->lastIn = in;
f->lastOut = out;
return out;
}
// ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ TwoPole Filter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ //
void tTwoPole_init(tTwoPole* const f)
{
f->gain = 1.0f;
f->a0 = 1.0;
f->b0 = 1.0;
f->lastOut[0] = 0.0f;
f->lastOut[1] = 0.0f;
}
void tTwoPole_free(tTwoPole* const f)
{
leaf_free(f);
}
float tTwoPole_tick(tTwoPole* const f, float input)
{
float in = input * f->gain;
float out = (f->b0 * in) - (f->a1 * f->lastOut[0]) - (f->a2 * f->lastOut[1]);
f->lastOut[1] = f->lastOut[0];
f->lastOut[0] = out;
return out;
}
void tTwoPole_setB0(tTwoPole* const f, float b0)
{
f->b0 = b0;
}
void tTwoPole_setA1(tTwoPole* const f, float a1)
{
f->a1 = a1;
}
void tTwoPole_setA2(tTwoPole* const f, float a2)
{
f->a2 = a2;
}
void tTwoPole_setResonance(tTwoPole* const f, float frequency, float radius, oBool normalize)
{
if (frequency < 0.0f) frequency = 0.0f; // need to also handle when frequency > nyquist
if (radius < 0.0f) radius = 0.0f;
if (radius >= 1.0f) radius = 0.999999f;
f->radius = radius;
f->frequency = frequency;
f->normalize = normalize;
f->a2 = radius * radius;
f->a1 = -2.0f * radius * cos(TWO_PI * frequency * leaf.invSampleRate);
if ( normalize )
{
// Normalize the filter gain ... not terribly efficient.
float real = 1 - radius + (f->a2 - radius) * cos(TWO_PI * 2 * frequency * leaf.invSampleRate);
float imag = (f->a2 - radius) * sin(TWO_PI * 2 * frequency * leaf.invSampleRate);
f->b0 = sqrt( pow(real, 2) + pow(imag, 2) );
}
}
void tTwoPole_setCoefficients(tTwoPole* const f, float b0, float a1, float a2)
{
f->b0 = b0;
f->a1 = a1;
f->a2 = a2;
}
void tTwoPole_setGain(tTwoPole* const f, float gain)
{
f->gain = gain;
}
void tTwoPoleSampleRateChanged (tTwoPole* const f)
{
f->a2 = f->radius * f->radius;
f->a1 = -2.0f * f->radius * cos(TWO_PI * f->frequency * leaf.invSampleRate);
if ( f->normalize )
{
// Normalize the filter gain ... not terribly efficient.
float real = 1 - f->radius + (f->a2 - f->radius) * cos(TWO_PI * 2 * f->frequency * leaf.invSampleRate);
float imag = (f->a2 - f->radius) * sin(TWO_PI * 2 * f->frequency * leaf.invSampleRate);
f->b0 = sqrt( pow(real, 2) + pow(imag, 2) );
}
}
// ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ PoleZero Filter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ //
void tPoleZero_init(tPoleZero* const f)
{
f->gain = 1.0f;
f->b0 = 1.0;
f->a0 = 1.0;
f->lastIn = 0.0f;
f->lastOut = 0.0f;
}
void tPoleZero_free(tPoleZero* const f)
{
leaf_free(f);
}
void tPoleZero_setB0(tPoleZero* const pzf, float b0)
{
pzf->b0 = b0;
}
void tPoleZero_setB1(tPoleZero* const pzf, float b1)
{
pzf->b1 = b1;
}
void tPoleZero_setA1(tPoleZero* const pzf, float a1)
{
if (a1 >= 1.0f) // a1 should be less than 1.0
{
a1 = 0.999999f;
}
pzf->a1 = a1;
}
void tPoleZero_setCoefficients(tPoleZero* const pzf, float b0, float b1, float a1)
{
if (a1 >= 1.0f) // a1 should be less than 1.0
{
a1 = 0.999999f;
}
pzf->b0 = b0;
pzf->b1 = b1;
pzf->a1 = a1;
}
void tPoleZero_setAllpass(tPoleZero* const pzf, float coeff)
{
if (coeff >= 1.0f) // allpass coefficient >= 1.0 makes filter unstable
{
coeff = 0.999999f;
}
pzf->b0 = coeff;
pzf->b1 = 1.0f;
pzf->a0 = 1.0f;
pzf->a1 = coeff;
}
void tPoleZero_setBlockZero(tPoleZero* const pzf, float thePole)
{
if (thePole >= 1.0f) // allpass coefficient >= 1.0 makes filter unstable
{
thePole = 0.999999f;
}
pzf->b0 = 1.0f;
pzf->b1 = -1.0f;
pzf->a0 = 1.0f;
pzf->a1 = -thePole;
}
void tPoleZero_setGain(tPoleZero* const pzf, float gain)
{
pzf->gain = gain;
}
float tPoleZero_tick(tPoleZero* const pzf, float input)
{
float in = input * pzf->gain;
float out = (pzf->b0 * in) + (pzf->b1 * pzf->lastIn) - (pzf->a1 * pzf->lastOut);
pzf->lastIn = in;
pzf->lastOut = out;
return out;
}
// ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ BiQuad Filter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ //
void tBiQuad_init(tBiQuad* const f)
{
f->gain = 1.0f;
f->b0 = 0.0f;
f->a0 = 0.0f;
f->lastIn[0] = 0.0f;
f->lastIn[1] = 0.0f;
f->lastOut[0] = 0.0f;
f->lastOut[1] = 0.0f;
}
void tBiQuad_free(tBiQuad* const f)
{
leaf_free(f);
}
float tBiQuad_tick(tBiQuad* const f, float input)
{
float in = input * f->gain;
float out = f->b0 * in + f->b1 * f->lastIn[0] + f->b2 * f->lastIn[1];
out -= f->a2 * f->lastOut[1] + f->a1 * f->lastOut[0];
f->lastIn[1] = f->lastIn[0];
f->lastIn[0] = in;
f->lastOut[1] = f->lastOut[0];
f->lastOut[0] = out;
return out;
}
void tBiQuad_setResonance(tBiQuad* const f, float freq, float radius, oBool normalize)
{
// Should also deal with frequency being > half sample rate / nyquist. See STK
if (freq < 0.0f) freq = 0.0f;
if (radius < 0.0f) radius = 0.0f;
if (radius >= 1.0f) radius = 1.0f;
f->frequency = freq;
f->radius = radius;
f->normalize = normalize;
f->a2 = radius * radius;
f->a1 = -2.0f * radius * cosf(TWO_PI * freq * leaf.invSampleRate);
if (normalize)
{
f->b0 = 0.5f - 0.5f * f->a2;
f->b1 = 0.0f;
f->b2 = -f->b0;
}
}
void tBiQuad_setNotch(tBiQuad* const f, float freq, float radius)
{
// Should also deal with frequency being > half sample rate / nyquist. See STK
if (freq < 0.0f) freq = 0.0f;
if (radius < 0.0f) radius = 0.0f;
f->b2 = radius * radius;
f->b1 = -2.0f * radius * cosf(TWO_PI * freq * leaf.invSampleRate); // OPTIMIZE with LOOKUP or APPROXIMATION
// Does not attempt to normalize filter gain.
}
void tBiQuad_setEqualGainZeros(tBiQuad* const f)
{
f->b0 = 1.0f;
f->b1 = 0.0f;
f->b2 = -1.0f;
}
void tBiQuad_setB0(tBiQuad* const f, float b0)
{
f->b0 = b0;
}
void tBiQuad_setB1(tBiQuad* const f, float b1)
{
f->b1 = b1;
}
void tBiQuad_setB2(tBiQuad* const f, float b2)
{
f->b2 = b2;
}
void tBiQuad_setA1(tBiQuad* const f, float a1)
{
f->a1 = a1;
}
void tBiQuad_setA2(tBiQuad* const f, float a2)
{
f->a2 = a2;
}
void tBiQuad_setCoefficients(tBiQuad* const f, float b0, float b1, float b2, float a1, float a2)
{
f->b0 = b0;
f->b1 = b1;
f->b2 = b2;
f->a1 = a1;
f->a2 = a2;
}
void tBiQuad_setGain(tBiQuad* const f, float gain)
{
f->gain = gain;
}
void tBiQuadSampleRateChanged(tBiQuad* const f)
{
f->a2 = f->radius * f->radius;
f->a1 = -2.0f * f->radius * cosf(TWO_PI * f->frequency * leaf.invSampleRate);
if (f->normalize)
{
f->b0 = 0.5f - 0.5f * f->a2;
f->b1 = 0.0f;
f->b2 = -f->b0;
}
}
/* Highpass */
void tHighpass_setFreq(tHighpass* const f, float freq)
{
f->frequency = freq;
f->R = (1.0f-((freq * 2.0f * 3.14f) * leaf.invSampleRate));
}
float tHighpass_getFreq(tHighpass* const f)
{
return f->frequency;
}
// From JOS DC Blocker
float tHighpass_tick(tHighpass* const f, float x)
{
f->ys = x - f->xs + f->R * f->ys;
f->xs = x;
return f->ys;
}
void tHighpass_init(tHighpass* const f, float freq)
{
f->R = (1.0f-((freq * 2.0f * 3.14f)* leaf.invSampleRate));
f->ys = 0.0f;
f->xs = 0.0f;
f->frequency = freq;
}
void tHighpass_free(tHighpass* const f)
{
leaf_free(f);
}
void tHighpassSampleRateChanged(tHighpass* const f)
{
f->R = (1.0f-((f->frequency * 2.0f * 3.14f) * leaf.invSampleRate));
}
float tSVF_tick(tSVF* const svf, float v0)
{
float v1,v2,v3;
v3 = v0 - svf->ic2eq;
v1 = (svf->a1 * svf->ic1eq) + (svf->a2 * v3);
v2 = svf->ic2eq + (svf->a2 * svf->ic1eq) + (svf->a3 * v3);
svf->ic1eq = (2.0f * v1) - svf->ic1eq;
svf->ic2eq = (2.0f * v2) - svf->ic2eq;
if (svf->type == SVFTypeLowpass) return v2;
else if (svf->type == SVFTypeBandpass) return v1;
else if (svf->type == SVFTypeHighpass) return v0 - (svf->k * v1) - v2;
else if (svf->type == SVFTypeNotch) return v0 - (svf->k * v1);
else if (svf->type == SVFTypePeak) return v0 - (svf->k * v1) - (2.0f * v2);
else return 0.0f;
}
// Less efficient, more accurate version of SVF, in which cutoff frequency is taken as floating point Hz value and tanh
// is calculated when frequency changes.
void tSVF_init(tSVF* const svf, SVFType type, float freq, float Q)
{
svf->type = type;
svf->ic1eq = 0;
svf->ic2eq = 0;
float a1,a2,a3,g,k;
g = tanf(PI * freq * leaf.invSampleRate);
k = 1.0f/LEAF_clip(0.01f,Q,10.0f);
a1 = 1.0f/(1.0f+g*(g+k));
a2 = g*a1;
a3 = g*a2;
svf->g = g;
svf->k = k;
svf->a1 = a1;
svf->a2 = a2;
svf->a3 = a3;
}
void tSVF_free(tSVF* const svf)
{
leaf_free(svf);
}
int tSVF_setFreq(tSVF* const svf, float freq)
{
svf->g = tanf(PI * freq * leaf.invSampleRate);
svf->a1 = 1.0f/(1.0f + svf->g * (svf->g + svf->k));
svf->a2 = svf->g * svf->a1;
svf->a3 = svf->g * svf->a2;
return 0;
}
int tSVF_setQ(tSVF* const svf, float Q)
{
svf->k = 1.0f/LEAF_clip(0.01f,Q,10.0f);
svf->a1 = 1.0f/(1.0f + svf->g * (svf->g + svf->k));
svf->a2 = svf->g * svf->a1;
svf->a3 = svf->g * svf->a2;
return 0;
}
// Efficient version of tSVF where frequency is set based on 12-bit integer input for lookup in tanh wavetable.
void tSVFE_init(tSVFE* const svf, SVFType type, uint16_t input, float Q)
{
svf->type = type;
svf->ic1eq = 0;
svf->ic2eq = 0;
float a1,a2,a3,g,k;
g = filtertan[input];
k = 1.0f/Q;
a1 = 1.0f/(1.0f+g*(g+k));
a2 = g*a1;
a3 = g*a2;
svf->g = g;
svf->k = k;
svf->a1 = a1;
svf->a2 = a2;
svf->a3 = a3;
}
float tSVFE_tick(tSVFE* const svf, float v0)
{
float v1,v2,v3;
v3 = v0 - svf->ic2eq;
v1 = (svf->a1 * svf->ic1eq) + (svf->a2 * v3);
v2 = svf->ic2eq + (svf->a2 * svf->ic1eq) + (svf->a3 * v3);
svf->ic1eq = (2.0f * v1) - svf->ic1eq;
svf->ic2eq = (2.0f * v2) - svf->ic2eq;
if (svf->type == SVFTypeLowpass) return v2;
else if (svf->type == SVFTypeBandpass) return v1;
else if (svf->type == SVFTypeHighpass) return v0 - (svf->k * v1) - v2;
else if (svf->type == SVFTypeNotch) return v0 - (svf->k * v1);
else if (svf->type == SVFTypePeak) return v0 - (svf->k * v1) - (2.0f * v2);
else return 0.0f;
}
int tSVFE_setFreq(tSVFE* const svf, uint16_t input)
{
svf->g = filtertan[input];
svf->a1 = 1.0f/(1.0f + svf->g * (svf->g + svf->k));
svf->a2 = svf->g * svf->a1;
svf->a3 = svf->g * svf->a2;
return 0;
}
int tSVFE_setQ(tSVFE* const svf, float Q)
{
svf->k = 1.0f/Q;
svf->a1 = 1.0f/(1.0f + svf->g * (svf->g + svf->k));
svf->a2 = svf->g * svf->a1;
svf->a3 = svf->g * svf->a2;
return 0;
}