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/*
ZynAddSubFX - a software synthesizer
EffectLFO.C - Stereo LFO used by some effects
Copyright (C) 2002-2005 Nasca Octavian Paul
Author: Nasca Octavian Paul
This program is free software; you can redistribute it and/or modify
it under the terms of version 2 of the GNU General Public License
as published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License (version 2) for more details.
You should have received a copy of the GNU General Public License (version 2)
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "EffectLFO.h"
EffectLFO::EffectLFO(){
xl=0.0;xr=0.0;
Pfreq=40;
Prandomness=0;
PLFOtype=0;
Pstereo=96;
updateparams();
ampl1=(1-lfornd)+lfornd*RND;
ampl2=(1-lfornd)+lfornd*RND;
ampr1=(1-lfornd)+lfornd*RND;
ampr2=(1-lfornd)+lfornd*RND;
};
EffectLFO::~EffectLFO(){
};
/*
* Update the changed parameters
*/
void EffectLFO::updateparams(){
REALTYPE lfofreq=(pow(2,Pfreq/127.0*10.0)-1.0)*0.03;
incx=fabs(lfofreq)*(REALTYPE)SOUND_BUFFER_SIZE/(REALTYPE)SAMPLE_RATE;
if (incx>0.49999999) incx=0.499999999; //Limit the Frequency
lfornd=Prandomness/127.0;
if (lfornd<0.0) lfornd=0.0; else if (lfornd>1.0) lfornd=1.0;
if (PLFOtype>1) PLFOtype=1;//this has to be updated if more lfo's are added
lfotype=PLFOtype;
xr=fmod(xl+(Pstereo-64.0)/127.0+1.0,1.0);
};
/*
* Compute the shape of the LFO
*/
REALTYPE EffectLFO::getlfoshape(REALTYPE x){
REALTYPE out;
switch (lfotype){
case 1: //EffectLFO_TRIANGLE
if ((x>0.0)&&(x<0.25)) out=4.0*x;
else if ((x>0.25)&&(x<0.75)) out=2-4*x;
else out=4.0*x-4.0;
break;
//more to be added here; also ::updateparams() need to be updated (to allow more lfotypes)
default:out=cos(x*2*PI);//EffectLFO_SINE
};
return(out);
};
/*
* LFO output
*/
void EffectLFO::effectlfoout(REALTYPE *outl,REALTYPE *outr){
REALTYPE out;
out=getlfoshape(xl);
if ((lfotype==0)||(lfotype==1)) out*=(ampl1+xl*(ampl2-ampl1));
xl+=incx;
if (xl>1.0) {
xl-=1.0;
ampl1=ampl2;
ampl2=(1.0-lfornd)+lfornd*RND;
};
*outl=(out+1.0)*0.5;
out=getlfoshape(xr);
if ((lfotype==0)||(lfotype==1)) out*=(ampr1+xr*(ampr2-ampr1));
xr+=incx;
if (xr>1.0) {
xr-=1.0;
ampr1=ampr2;
ampr2=(1.0-lfornd)+lfornd*RND;
};
*outr=(out+1.0)*0.5;
};
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