mirror of
https://github.com/thestk/stk
synced 2026-01-16 06:21:51 +00:00
Version 4.1
This commit is contained in:
Gary Scavone
committed by
Stephen Sinclair
Stephen Sinclair
parent
81475b04c5
commit
2f09fcd019
488
src/Filter.cpp
488
src/Filter.cpp
@@ -1,244 +1,244 @@
|
||||
/***************************************************/
|
||||
/*! \class Filter
|
||||
\brief STK filter class.
|
||||
|
||||
This class implements a generic structure which
|
||||
can be used to create a wide range of filters.
|
||||
It can function independently or be subclassed
|
||||
to provide more specific controls based on a
|
||||
particular filter type.
|
||||
|
||||
In particular, this class implements the standard
|
||||
difference equation:
|
||||
|
||||
a[0]*y[n] = b[0]*x[n] + ... + b[nb]*x[n-nb] -
|
||||
a[1]*y[n-1] - ... - a[na]*y[n-na]
|
||||
|
||||
If a[0] is not equal to 1, the filter coeffcients
|
||||
are normalized by a[0].
|
||||
|
||||
The \e gain parameter is applied at the filter
|
||||
input and does not affect the coefficient values.
|
||||
The default gain value is 1.0. This structure
|
||||
results in one extra multiply per computed sample,
|
||||
but allows easy control of the overall filter gain.
|
||||
|
||||
by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
|
||||
*/
|
||||
/***************************************************/
|
||||
|
||||
#include "Filter.h"
|
||||
#include <stdio.h>
|
||||
|
||||
Filter :: Filter()
|
||||
{
|
||||
// The default constructor should setup for pass-through.
|
||||
gain = 1.0;
|
||||
nB = 1;
|
||||
nA = 1;
|
||||
b = new MY_FLOAT[nB];
|
||||
b[0] = 1.0;
|
||||
a = new MY_FLOAT[nA];
|
||||
a[0] = 1.0;
|
||||
|
||||
inputs = new MY_FLOAT[nB];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
this->clear();
|
||||
}
|
||||
|
||||
Filter :: Filter(int nb, MY_FLOAT *bCoefficients, int na, MY_FLOAT *aCoefficients)
|
||||
{
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( nb < 1 || na < 1 ) {
|
||||
sprintf(message, "Filter: nb (%d) and na (%d) must be >= 1!", nb, na);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if ( aCoefficients[0] == 0.0 ) {
|
||||
sprintf(message, "Filter: a[0] coefficient cannot == 0!");
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
gain = 1.0;
|
||||
nB = nb;
|
||||
nA = na;
|
||||
b = new MY_FLOAT[nB];
|
||||
a = new MY_FLOAT[nA];
|
||||
|
||||
inputs = new MY_FLOAT[nB];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
this->clear();
|
||||
|
||||
this->setCoefficients(nB, bCoefficients, nA, aCoefficients);
|
||||
}
|
||||
|
||||
Filter :: ~Filter()
|
||||
{
|
||||
delete [] b;
|
||||
delete [] a;
|
||||
delete [] inputs;
|
||||
delete [] outputs;
|
||||
}
|
||||
|
||||
void Filter :: clear(void)
|
||||
{
|
||||
int i;
|
||||
for (i=0; i<nB; i++)
|
||||
inputs[i] = 0.0;
|
||||
for (i=0; i<nA; i++)
|
||||
outputs[i] = 0.0;
|
||||
}
|
||||
|
||||
void Filter :: setCoefficients(int nb, MY_FLOAT *bCoefficients, int na, MY_FLOAT *aCoefficients)
|
||||
{
|
||||
int i;
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( nb < 1 || na < 1 ) {
|
||||
sprintf(message, "Filter: nb (%d) and na (%d) must be >= 1!", nb, na);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if ( aCoefficients[0] == 0.0 ) {
|
||||
sprintf(message, "Filter: a[0] coefficient cannot == 0!");
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if (nb != nB) {
|
||||
delete [] b;
|
||||
delete [] inputs;
|
||||
nB = nb;
|
||||
b = new MY_FLOAT[nB];
|
||||
inputs = new MY_FLOAT[nB];
|
||||
for (i=0; i<nB; i++) inputs[i] = 0.0;
|
||||
}
|
||||
|
||||
if (na != nA) {
|
||||
delete [] a;
|
||||
delete [] outputs;
|
||||
nA = na;
|
||||
a = new MY_FLOAT[nA];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
for (i=0; i<nA; i++) outputs[i] = 0.0;
|
||||
}
|
||||
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] = bCoefficients[i];
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] = aCoefficients[i];
|
||||
|
||||
// scale coefficients by a[0] if necessary
|
||||
if (a[0] != 1.0) {
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] /= a[0];
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] /= a[0];
|
||||
}
|
||||
}
|
||||
|
||||
void Filter :: setNumerator(int nb, MY_FLOAT *bCoefficients)
|
||||
{
|
||||
int i;
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( nb < 1 ) {
|
||||
sprintf(message, "Filter: nb (%d) must be >= 1!", nb);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if (nb != nB) {
|
||||
delete [] b;
|
||||
delete [] inputs;
|
||||
nB = nb;
|
||||
b = new MY_FLOAT[nB];
|
||||
inputs = new MY_FLOAT[nB];
|
||||
for (i=0; i<nB; i++) inputs[i] = 0.0;
|
||||
}
|
||||
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] = bCoefficients[i];
|
||||
}
|
||||
|
||||
void Filter :: setDenominator(int na, MY_FLOAT *aCoefficients)
|
||||
{
|
||||
int i;
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( na < 1 ) {
|
||||
sprintf(message, "Filter: na (%d) must be >= 1!", na);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if ( aCoefficients[0] == 0.0 ) {
|
||||
sprintf(message, "Filter: a[0] coefficient cannot == 0!");
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if (na != nA) {
|
||||
delete [] a;
|
||||
delete [] outputs;
|
||||
nA = na;
|
||||
a = new MY_FLOAT[nA];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
for (i=0; i<nA; i++) outputs[i] = 0.0;
|
||||
}
|
||||
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] = aCoefficients[i];
|
||||
|
||||
// scale coefficients by a[0] if necessary
|
||||
if (a[0] != 1.0) {
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] /= a[0];
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] /= a[0];
|
||||
}
|
||||
}
|
||||
|
||||
void Filter :: setGain(MY_FLOAT theGain)
|
||||
{
|
||||
gain = theGain;
|
||||
}
|
||||
|
||||
MY_FLOAT Filter :: getGain(void) const
|
||||
{
|
||||
return gain;
|
||||
}
|
||||
|
||||
MY_FLOAT Filter :: lastOut(void) const
|
||||
{
|
||||
return outputs[0];
|
||||
}
|
||||
|
||||
MY_FLOAT Filter :: tick(MY_FLOAT sample)
|
||||
{
|
||||
int i;
|
||||
|
||||
outputs[0] = 0.0;
|
||||
inputs[0] = gain * sample;
|
||||
for (i=nB-1; i>0; i--) {
|
||||
outputs[0] += b[i] * inputs[i];
|
||||
inputs[i] = inputs[i-1];
|
||||
}
|
||||
outputs[0] += b[0] * inputs[0];
|
||||
|
||||
for (i=nA-1; i>0; i--) {
|
||||
outputs[0] += -a[i] * outputs[i];
|
||||
outputs[i] = outputs[i-1];
|
||||
}
|
||||
|
||||
return outputs[0];
|
||||
}
|
||||
|
||||
MY_FLOAT *Filter :: tick(MY_FLOAT *vector, unsigned int vectorSize)
|
||||
{
|
||||
for (unsigned int i=0; i<vectorSize; i++)
|
||||
vector[i] = tick(vector[i]);
|
||||
|
||||
return vector;
|
||||
}
|
||||
/***************************************************/
|
||||
/*! \class Filter
|
||||
\brief STK filter class.
|
||||
|
||||
This class implements a generic structure which
|
||||
can be used to create a wide range of filters.
|
||||
It can function independently or be subclassed
|
||||
to provide more specific controls based on a
|
||||
particular filter type.
|
||||
|
||||
In particular, this class implements the standard
|
||||
difference equation:
|
||||
|
||||
a[0]*y[n] = b[0]*x[n] + ... + b[nb]*x[n-nb] -
|
||||
a[1]*y[n-1] - ... - a[na]*y[n-na]
|
||||
|
||||
If a[0] is not equal to 1, the filter coeffcients
|
||||
are normalized by a[0].
|
||||
|
||||
The \e gain parameter is applied at the filter
|
||||
input and does not affect the coefficient values.
|
||||
The default gain value is 1.0. This structure
|
||||
results in one extra multiply per computed sample,
|
||||
but allows easy control of the overall filter gain.
|
||||
|
||||
by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
|
||||
*/
|
||||
/***************************************************/
|
||||
|
||||
#include "Filter.h"
|
||||
#include <stdio.h>
|
||||
|
||||
Filter :: Filter()
|
||||
{
|
||||
// The default constructor should setup for pass-through.
|
||||
gain = 1.0;
|
||||
nB = 1;
|
||||
nA = 1;
|
||||
b = new MY_FLOAT[nB];
|
||||
b[0] = 1.0;
|
||||
a = new MY_FLOAT[nA];
|
||||
a[0] = 1.0;
|
||||
|
||||
inputs = new MY_FLOAT[nB];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
this->clear();
|
||||
}
|
||||
|
||||
Filter :: Filter(int nb, MY_FLOAT *bCoefficients, int na, MY_FLOAT *aCoefficients)
|
||||
{
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( nb < 1 || na < 1 ) {
|
||||
sprintf(message, "Filter: nb (%d) and na (%d) must be >= 1!", nb, na);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if ( aCoefficients[0] == 0.0 ) {
|
||||
sprintf(message, "Filter: a[0] coefficient cannot == 0!");
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
gain = 1.0;
|
||||
nB = nb;
|
||||
nA = na;
|
||||
b = new MY_FLOAT[nB];
|
||||
a = new MY_FLOAT[nA];
|
||||
|
||||
inputs = new MY_FLOAT[nB];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
this->clear();
|
||||
|
||||
this->setCoefficients(nB, bCoefficients, nA, aCoefficients);
|
||||
}
|
||||
|
||||
Filter :: ~Filter()
|
||||
{
|
||||
delete [] b;
|
||||
delete [] a;
|
||||
delete [] inputs;
|
||||
delete [] outputs;
|
||||
}
|
||||
|
||||
void Filter :: clear(void)
|
||||
{
|
||||
int i;
|
||||
for (i=0; i<nB; i++)
|
||||
inputs[i] = 0.0;
|
||||
for (i=0; i<nA; i++)
|
||||
outputs[i] = 0.0;
|
||||
}
|
||||
|
||||
void Filter :: setCoefficients(int nb, MY_FLOAT *bCoefficients, int na, MY_FLOAT *aCoefficients)
|
||||
{
|
||||
int i;
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( nb < 1 || na < 1 ) {
|
||||
sprintf(message, "Filter: nb (%d) and na (%d) must be >= 1!", nb, na);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if ( aCoefficients[0] == 0.0 ) {
|
||||
sprintf(message, "Filter: a[0] coefficient cannot == 0!");
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if (nb != nB) {
|
||||
delete [] b;
|
||||
delete [] inputs;
|
||||
nB = nb;
|
||||
b = new MY_FLOAT[nB];
|
||||
inputs = new MY_FLOAT[nB];
|
||||
for (i=0; i<nB; i++) inputs[i] = 0.0;
|
||||
}
|
||||
|
||||
if (na != nA) {
|
||||
delete [] a;
|
||||
delete [] outputs;
|
||||
nA = na;
|
||||
a = new MY_FLOAT[nA];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
for (i=0; i<nA; i++) outputs[i] = 0.0;
|
||||
}
|
||||
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] = bCoefficients[i];
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] = aCoefficients[i];
|
||||
|
||||
// scale coefficients by a[0] if necessary
|
||||
if (a[0] != 1.0) {
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] /= a[0];
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] /= a[0];
|
||||
}
|
||||
}
|
||||
|
||||
void Filter :: setNumerator(int nb, MY_FLOAT *bCoefficients)
|
||||
{
|
||||
int i;
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( nb < 1 ) {
|
||||
sprintf(message, "Filter: nb (%d) must be >= 1!", nb);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if (nb != nB) {
|
||||
delete [] b;
|
||||
delete [] inputs;
|
||||
nB = nb;
|
||||
b = new MY_FLOAT[nB];
|
||||
inputs = new MY_FLOAT[nB];
|
||||
for (i=0; i<nB; i++) inputs[i] = 0.0;
|
||||
}
|
||||
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] = bCoefficients[i];
|
||||
}
|
||||
|
||||
void Filter :: setDenominator(int na, MY_FLOAT *aCoefficients)
|
||||
{
|
||||
int i;
|
||||
char message[256];
|
||||
|
||||
// Check the arguments.
|
||||
if ( na < 1 ) {
|
||||
sprintf(message, "Filter: na (%d) must be >= 1!", na);
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if ( aCoefficients[0] == 0.0 ) {
|
||||
sprintf(message, "Filter: a[0] coefficient cannot == 0!");
|
||||
handleError( message, StkError::FUNCTION_ARGUMENT );
|
||||
}
|
||||
|
||||
if (na != nA) {
|
||||
delete [] a;
|
||||
delete [] outputs;
|
||||
nA = na;
|
||||
a = new MY_FLOAT[nA];
|
||||
outputs = new MY_FLOAT[nA];
|
||||
for (i=0; i<nA; i++) outputs[i] = 0.0;
|
||||
}
|
||||
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] = aCoefficients[i];
|
||||
|
||||
// scale coefficients by a[0] if necessary
|
||||
if (a[0] != 1.0) {
|
||||
for (i=0; i<nB; i++)
|
||||
b[i] /= a[0];
|
||||
for (i=0; i<nA; i++)
|
||||
a[i] /= a[0];
|
||||
}
|
||||
}
|
||||
|
||||
void Filter :: setGain(MY_FLOAT theGain)
|
||||
{
|
||||
gain = theGain;
|
||||
}
|
||||
|
||||
MY_FLOAT Filter :: getGain(void) const
|
||||
{
|
||||
return gain;
|
||||
}
|
||||
|
||||
MY_FLOAT Filter :: lastOut(void) const
|
||||
{
|
||||
return outputs[0];
|
||||
}
|
||||
|
||||
MY_FLOAT Filter :: tick(MY_FLOAT sample)
|
||||
{
|
||||
int i;
|
||||
|
||||
outputs[0] = 0.0;
|
||||
inputs[0] = gain * sample;
|
||||
for (i=nB-1; i>0; i--) {
|
||||
outputs[0] += b[i] * inputs[i];
|
||||
inputs[i] = inputs[i-1];
|
||||
}
|
||||
outputs[0] += b[0] * inputs[0];
|
||||
|
||||
for (i=nA-1; i>0; i--) {
|
||||
outputs[0] += -a[i] * outputs[i];
|
||||
outputs[i] = outputs[i-1];
|
||||
}
|
||||
|
||||
return outputs[0];
|
||||
}
|
||||
|
||||
MY_FLOAT *Filter :: tick(MY_FLOAT *vector, unsigned int vectorSize)
|
||||
{
|
||||
for (unsigned int i=0; i<vectorSize; i++)
|
||||
vector[i] = tick(vector[i]);
|
||||
|
||||
return vector;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user