diff options
Diffstat (limited to 'muse_qt4_evolution/synti/zynaddsubfx/Synth/LFO.C')
| -rw-r--r-- | muse_qt4_evolution/synti/zynaddsubfx/Synth/LFO.C | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/muse_qt4_evolution/synti/zynaddsubfx/Synth/LFO.C b/muse_qt4_evolution/synti/zynaddsubfx/Synth/LFO.C new file mode 100644 index 00000000..4ae548c1 --- /dev/null +++ b/muse_qt4_evolution/synti/zynaddsubfx/Synth/LFO.C @@ -0,0 +1,145 @@ +/* + ZynAddSubFX - a software synthesizer + + LFO.C - LFO implementation + 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 "LFO.h" + + +LFO::LFO(LFOParams *lfopars,REALTYPE basefreq){ + if (lfopars->Pstretch==0) lfopars->Pstretch=1; + REALTYPE lfostretch=pow(basefreq/440.0,(lfopars->Pstretch-64.0)/63.0);//max 2x/octave + + REALTYPE lfofreq=(pow(2,lfopars->Pfreq*10.0)-1.0)/12.0*lfostretch; + incx=fabs(lfofreq)*(REALTYPE)SOUND_BUFFER_SIZE/(REALTYPE)SAMPLE_RATE; + + if (lfopars->Pcontinous==0){ + if (lfopars->Pstartphase==0) x=RND; + else x=fmod((lfopars->Pstartphase-64.0)/127.0+1.0,1.0); + } else { + REALTYPE tmp=fmod(lfopars->time*incx,1.0); + x=fmod((lfopars->Pstartphase-64.0)/127.0+1.0+tmp,1.0); + }; + + //Limit the Frequency(or else...) + if (incx>0.49999999) incx=0.499999999; + + + lfornd=lfopars->Prandomness/127.0; + if (lfornd<0.0) lfornd=0.0; else if (lfornd>1.0) lfornd=1.0; + +// lfofreqrnd=pow(lfopars->Pfreqrand/127.0,2.0)*2.0*4.0; + lfofreqrnd=pow(lfopars->Pfreqrand/127.0,2.0)*4.0; + + switch (lfopars->fel){ + case 1:lfointensity=lfopars->Pintensity/127.0;break; + case 2:lfointensity=lfopars->Pintensity/127.0*4.0;break;//in octave + default:lfointensity=pow(2,lfopars->Pintensity/127.0*11.0)-1.0;//in centi + x-=0.25;//chance the starting phase + break; + }; + + amp1=(1-lfornd)+lfornd*RND; + amp2=(1-lfornd)+lfornd*RND; + lfotype=lfopars->PLFOtype; + lfodelay=lfopars->Pdelay/127.0*4.0;//0..4 sec + incrnd=nextincrnd=1.0; + freqrndenabled=(lfopars->Pfreqrand!=0); + computenextincrnd(); + computenextincrnd();//twice because I want incrnd & nextincrnd to be random +}; + +LFO::~LFO(){ +}; + +/* + * LFO out + */ +REALTYPE LFO::lfoout(){ + REALTYPE out; + switch (lfotype){ + case 1: //LFO_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; + case 2: //LFO_SQUARE + if (x<0.5) out=-1; + else out=1; + break; + case 3: //LFO_RAMPUP + out=(x-0.5)*2.0; + break; + case 4: //LFO_RAMPDOWN + out=(0.5-x)*2.0; + break; + case 5: //LFO_EXP_DOWN 1 + out=pow(0.05,x)*2.0-1.0; + break; + case 6: //LFO_EXP_DOWN 2 + out=pow(0.001,x)*2.0-1.0; + break; + default:out=cos(x*2.0*PI);//LFO_SINE + }; + + + if ((lfotype==0)||(lfotype==1)) out*=lfointensity*(amp1+x*(amp2-amp1)); + else out*=lfointensity*amp2; + if (lfodelay<0.00001) { + if (freqrndenabled==0) x+=incx; + else { + float tmp=(incrnd*(1.0-x)+nextincrnd*x); + if (tmp>1.0) tmp=1.0; + else if (tmp<0.0) tmp=0.0; + x+=incx*tmp; + }; + if (x>=1) { + x=fmod(x,1.0); + amp1=amp2; + amp2=(1-lfornd)+lfornd*RND; + + computenextincrnd(); + }; + } else lfodelay-=(REALTYPE)SOUND_BUFFER_SIZE/(REALTYPE)SAMPLE_RATE; + return(out); +}; + +/* + * LFO out (for amplitude) + */ +REALTYPE LFO::amplfoout(){ + REALTYPE out; + out=1.0-lfointensity+lfoout(); + if (out<-1.0) out=-1.0; + else if (out>1.0) out=1.0; + return(out); +}; + + +void LFO::computenextincrnd(){ + if (freqrndenabled==0) return; + incrnd=nextincrnd; + nextincrnd=pow(0.5,lfofreqrnd)+RND*(pow(2.0,lfofreqrnd)-1.0); +}; + |