Files
stk/PRCRev.cpp
Gary Scavone ea749b71d2 Version 2.01
2013-09-29 22:39:45 +02:00

114 lines
2.7 KiB
C++

/*******************************************/
/* PRCRev, a simple reverb unit */
/* by Perry Cook, 1996. */
/* Incorporated into the Reverb superclass */
/* by Gary Scavone, 1998. */
/* */
/* This is based on some of the famous */
/* Stanford CCRMA reverbs (NRev, KipRev) */
/* all based on the the Chowning/Moorer/ */
/* Schroeder reverberators, which use */
/* networks of simple allpass and comb */
/* delay filters. This particular */
/* structure consists of 2 allpass units */
/* in series followed by 2 comb filters in */
/* parallel. */
/*******************************************/
#include "PRCRev.h"
PRCRev :: PRCRev(MY_FLOAT T60)
{
int lens[4]={353,1097,1777,2137};
double srscale = SRATE / 44100.0;
int val, i;
if (SRATE < 44100.0) {
for (i=0; i<4; i++) {
val = (int) floor(srscale * lens[i]);
if ((val & 1) == 0) val++;
while (!this->isprime(val)) val += 2;
lens[i] = val;
}
}
for (i=0; i<2; i++)
{
APdelayLine[i] = new DLineN(lens[i] + 2);
APdelayLine[i]->setDelay(lens[i]);
CdelayLine[i] = new DLineN(lens[i+2] + 2);
CdelayLine[i]->setDelay(lens[i+2]);
combCoeff[i] = pow(10,(-3 * lens[i+2] / (T60 * SRATE)));
}
allPassCoeff = (MY_FLOAT) 0.7;
effectMix = (MY_FLOAT) 0.5;
this->clear();
}
PRCRev :: ~PRCRev()
{
delete APdelayLine[0];
delete APdelayLine[1];
delete CdelayLine[0];
delete CdelayLine[1];
}
void PRCRev :: clear()
{
APdelayLine[0]->clear();
APdelayLine[1]->clear();
CdelayLine[0]->clear();
CdelayLine[1]->clear();
lastOutL = (MY_FLOAT) 0.0;
lastOutR = (MY_FLOAT) 0.0;
}
void PRCRev :: setEffectMix(MY_FLOAT mix)
{
effectMix = mix;
}
MY_FLOAT PRCRev :: lastOutput()
{
return (lastOutL + lastOutR) * (MY_FLOAT) 0.5;
}
MY_FLOAT PRCRev :: lastOutputL()
{
return lastOutL;
}
MY_FLOAT PRCRev :: lastOutputR()
{
return lastOutR;
}
MY_FLOAT PRCRev :: tick(MY_FLOAT input)
{
MY_FLOAT temp,temp0,temp1,temp2,temp3;
temp = APdelayLine[0]->lastOut();
temp0 = allPassCoeff * temp;
temp0 += input;
APdelayLine[0]->tick(temp0);
temp0 = -(allPassCoeff * temp0) + temp;
temp = APdelayLine[1]->lastOut();
temp1 = allPassCoeff * temp;
temp1 += temp0;
APdelayLine[1]->tick(temp1);
temp1 = -(allPassCoeff * temp1) + temp;
temp2 = temp1 + (combCoeff[0] * CdelayLine[0]->lastOut());
temp3 = temp1 + (combCoeff[1] * CdelayLine[1]->lastOut());
lastOutL = effectMix * (CdelayLine[0]->tick(temp2));
lastOutR = effectMix * (CdelayLine[1]->tick(temp3));
temp = (MY_FLOAT) (1.0 - effectMix) * input;
lastOutL += temp;
lastOutR += temp;
return (lastOutL + lastOutR) * (MY_FLOAT) 0.5;
}