--- /dev/null
+//instrument.lib - Faust function of various types usefull for building physical model instruments
+
+declare name "Faust-STK Tools Library";
+declare author "Romain Michon (rmichon@ccrma.stanford.edu)";
+declare copyright "Romain Michon";
+declare version "1.0";
+declare licence "STK-4.3"; // Synthesis Tool Kit 4.3 (MIT style license);
+
+import("math.lib");
+import("filter.lib");
+import("effect.lib");
+
+//========================= ENVELOPE GENERATORS ===============================
+
+//----------------------- VIBRATO ENVELOPE ----------------------------
+// 4 phases envelope to control vibrato gain
+//
+// USAGE:
+// _ : *(envVibrato(b,a,s,r,t)) : _
+// where
+// b = beginning duration (silence) in seconds
+// a = attack duration in seconds
+// s = sustain as a percentage of the amplitude to be modified
+// r = release duration in seconds
+// t = trigger signal
+
+envVibrato(b,a,s,r,t) = env ~ (_,_,_) : (!,!,_) // the 3 'state' signals are fed back
+with {
+ env (p2,cnt,y) =
+ (t>0) & (p2|(y>=1)),
+ (cnt + 1)*(t>0), // counter for the first step "b"
+ (y + p1*p3*u*(s/100) - p4*w*y)*((p4==0)|(y>=eps)) // y = envelop signal
+ //*(y>=eps) // cut off tails to prevent denormals
+ with {
+ p1 = (p2==0) & (t>0) & (y<1) & (cnt>(b*SR)); // p1 = attack phase
+ p3 = 1-(cnt<(nb)); // p3 = beginning phase
+ p4 = (t<=0) & (y>0); // p4 = release phase
+ // #samples in attack, release, must be >0
+ nb = SR*b+(b==0.0) ; na = SR*a+(a==0.0); nr = SR*r+(r==0.0);
+ // attack and (-60dB) release rates
+ z = s+(s==0.0)*db2linear(-60);
+ u = 1/na; w = 1-1/pow(z*db2linear(60), 1/nr);
+ // values below this threshold are considered zero in the release phase
+ eps = db2linear(-120);
+ };
+};
+
+//----------------------- ATTACK - SUSTAIN - RELEASE ----------------------------
+// Attack - Sustain - Release envelope
+//
+// USAGE:
+// _ : *(asr(a,s,r,t)) : _
+// where
+// a = attack duration in seconds
+// s = sustain as a percentage of the amplitude to be modified
+// r = release duration in seconds
+// t = trigger signal
+
+asr(a,s,r,t) = env ~ (_,_) : (!,_) // the 2 'state' signals are fed back
+with {
+ env (p2,y) =
+ (t>0) & (p2|(y>=1)),
+ (y + p1*u*(s/100) - p3*w*y) // y = envelop signal
+ *((p3==0)|(y>=eps)) // cut off tails to prevent denormals
+ with {
+ p1 = (p2==0) & (t>0) & (y<1); // p1 = attack phase
+ p3 = (t<=0) & (y>0); // p3 = release phase
+ // #samples in attack, release, must be >0
+ na = SR*a+(a==0.0); nr = SR*r+(r==0.0);
+ // correct zero sustain level
+ z = s+(s==0.0)*db2linear(-60);
+ // attack and (-60dB) release rates
+ u = 1/na; w = 1-1/pow(z*db2linear(60), 1/nr);
+ // values below this threshold are considered zero in the release phase
+ eps = db2linear(-120);
+ };
+};
+
+//----------------------- ASYMPT60 ----------------------------
+// Envelope generator which asymptotically approaches a target value.
+//
+// USAGE:
+// asympT60(value,trgt,T60,trig) : _
+// where
+// value = starting value
+// trgt = target value
+// T60 = ramping time
+// trig = trigger signal
+
+asympT60(value,trgt,T60,trig) = (_*factor + constant)~_
+ with{
+ cntSample = *(trig) + 1~_ : -(1);
+ attDur = float(2);
+ cndFirst = ((cntSample < attDur) & (trig > 0));
+ target = value*cndFirst + trgt*(cndFirst < 1);
+ factorAtt = exp(-7/attDur);
+ factorT60 = exp(-7/(T60*float(SR)));
+ factor = factorAtt*((cntSample < attDur) & (trig > 0)) +
+ ((cntSample >= attDur) | (trig < 1))*factorT60;
+ constant = (1 - factor)*target;
+ };
+
+//========================= TABLES ===============================
+
+//----------------------- CLIPPING FUNCTION ----------------------------
+// Positive and negative clipping functions.
+//
+// USAGE:
+// _ : saturationPos : _
+// _ : saturationNeg : _
+// _ : saturationPos : saturationNeg : _
+
+saturationPos(x) = x <: (_>1),(_<=1 : *(x)) :> +;
+saturationNeg(x) = x <: (_<-1),(_>=-1 : *(x)) :> *(-1) + _;
+
+//----------------------- BOW TABLE ----------------------------
+// Simple bow table.
+//
+// USAGE:
+// index : bow(offset,slope) : _
+// where
+// 0 <= index <= 1
+
+bow(offset,slope) = pow(abs(sample) + 0.75, -4) : saturationPos
+ with{
+ sample(y) = (y + offset)*slope;
+ };
+
+//----------------------- REED TABLE ----------------------------
+// Simple reed table to be used with waveguide models of clanrinet, saxophone, etc.
+//
+// USAGE:
+// _ : reed(offset,slope) : _
+// where
+// offset = offset between 0 and 1
+// slope = slope between 0 and 1
+// REFERENCE:
+// https://ccrma.stanford.edu/~jos/pasp/View_Single_Reed_Oscillation.html
+
+reed(offset,slope) = reedTable : saturationPos : saturationNeg
+ with{
+ reedTable = offset + (slope*_);
+ };
+
+//========================= FILTERS ===============================
+
+//----------------------- ONE POLE ----------------------------
+
+onePole(b0,a1,x) = (b0*x - a1*_)~_;
+
+//----------------------- ONE POLE SWEPT ----------------------------
+
+onePoleSwep(a1,x) = (1 + a1)*x - a1*x';
+
+//----------------------- POLE ZERO ----------------------------
+
+poleZero(b0,b1,a1,x) = (b0*x + b1*x' - a1*_)~_;
+
+//----------------------- ONE ZEROS ----------------------------
+// Simple One zero and One zero recursive filters
+//
+// USAGE:
+// _ : oneZero0(b0,b1) : _
+// _ : oneZero1(b0,b1) : _
+// REFERENCE:
+// https://ccrma.stanford.edu/~jos/fp2/One_Zero.html
+
+oneZero0(b0,b1,x) = (*(b1) + x*b0)~_;
+oneZero1(b0,b1,x) = (x'*b1 + x*b0);
+
+//----------------------- BANDPASS FILTER WITH CONSTANT UNITY PEAK GAIN BASED ON A BIQUAD ----------------------------
+
+bandPass(resonance,radius) = TF2(b0,b1,b2,a1,a2)
+ with{
+ a2 = radius*radius;
+ a1 = -2*radius*cos(PI*2*resonance/SR);
+ b0 = 0.5-0.5*a2;
+ b1 = 0;
+ b2 = -b0;
+ };
+
+//----------------------- BANDPASS FILTER BASED ON A BIQUAD ----------------------------
+// Band pass filter using a biquad (TF2 is declared in filter.lib)
+//
+// USAGE:
+// _ : bandPassH(resonance,radius) : _
+// where
+// resonance = center frequency
+// radius = radius
+
+bandPassH(resonance,radius) = TF2(b0,b1,b2,a1,a2)
+ with{
+ a2 = radius*radius;
+ a1 = -2*radius*cos(PI*2*resonance/SR);
+ b0 = 1;
+ b1 = 0;
+ b2 = 0;
+ };
+
+//----------------------- FLUE JET NON-LINEAR FUNCTION ----------------------------
+// Jet Table: flue jet non-linear function, computed by a polynomial calculation
+
+jetTable(x) = x <: _*(_*_-1) : saturationPos : saturationNeg;
+
+//----------------------- NON LINEAR MODULATOR ----------------------------
+// nonLinearModulator adapts the function allpassnn from filter.lib for using it with waveguide instruments
+//
+// USAGE:
+// _ : nonLinearModulator(nonlinearity,env,freq,typeMod,freqMod,order) : _
+// where
+// nonlinearity = nonlinearity coefficient between 0 and 1
+// env = input to connect any kind of envelope
+// freq = current tone frequency
+// typeMod = if 0: theta is modulated by the incoming signal;
+// if 1: theta is modulated by the averaged incoming signal;
+// if 2: theta is modulated by the squared incoming signal;
+// if 3: theta is modulated by a sine wave of frequency freqMod;
+// if 4: theta is modulated by a sine wave of frequency freq;
+// freqMod = frequency of the sine wave modulation
+// order = order of the filter
+
+nonLinearModulator(nonlinearity,env,freq,typeMod,freqMod,order) =
+ //theta is modulated by a sine wave
+ _ <: nonLinearFilterOsc*(typeMod >= 3),
+ //theta is modulated by the incoming signal
+ (_ <: nonLinearFilterSig*nonlinearity,_*(1 - nonlinearity) :> +)*(typeMod < 3)
+ :> +
+ with{
+ //which frequency to use for the sine wave oscillator?
+ freqOscMod = (typeMod == 4)*freq + (typeMod != 4)*freqMod;
+
+ //the incoming signal is scaled and the envelope is applied
+ tsignorm(x) = nonlinearity*PI*x*env;
+ tsigsquared(x) = nonlinearity*PI*x*x*env; //incoming signal is squared
+ tsigav(x) = nonlinearity*PI*((x + x')/2)*env; //incoming signal is averaged with its previous sample
+
+ //select which version of the incoming signal of theta to use
+ tsig(x) = tsignorm(x)*(typeMod == 0) + tsigav(x)*(typeMod == 1)
+ + tsigsquared(x)*(typeMod == 2);
+
+ //theta is modulated by a sine wave generator
+ tosc = nonlinearity*PI*osc(freqOscMod)*env;
+
+ //incoming signal is sent to the nonlinear passive allpass ladder filter
+ nonLinearFilterSig(x) = x <: allpassnn(order,(par(i,order,tsig(x))));
+ nonLinearFilterOsc = _ <: allpassnn(order,(par(i,order,tosc)));
+ };
+
+//========================= WAVE TABLES ===============================
+
+//----------------------- STICK IMPACT ----------------------------
+// Stick impact table.
+//
+// USAGE:
+// index : readMarmstk1 : _
+
+readMarmstk1 = ffunction(float readMarmstk1 (int), <instrument.h>,"");
+marmstk1TableSize = 246;
+
+//========================= TOOLS ===============================
+
+//----------------------- STEREOIZER ----------------------------
+// This function takes a mono input signal and spacialize it in stereo
+// in function of the period duration of the tone being played.
+//
+// USAGE:
+// _ : stereo(periodDuration) : _,_
+// where
+// periodDuration = period duration of the tone being played in number of samples
+// ACKNOWLEDGMENT
+// Formulation initiated by Julius O. Smith in https://ccrma.stanford.edu/realsimple/faust_strings/
+
+stereoizer(periodDuration) = _ <: _,widthdelay : stereopanner
+ with{
+ W = hslider("v:Spat/spatial width", 0.5, 0, 1, 0.01);
+ A = hslider("v:Spat/pan angle", 0.6, 0, 1, 0.01);
+ widthdelay = delay(4096,W*periodDuration/2);
+ stereopanner = _,_ : *(1.0-A), *(A);
+ };
+
+//----------------------- INSTRREVERB ----------------------------
+// GUI for zita_rev1_stereo from effect.lib
+//
+// USAGE:
+// _,_ : instrRerveb
+
+instrReverb = _,_ <: *(reverbGain),*(reverbGain),*(1 - reverbGain),*(1 - reverbGain) :
+zita_rev1_stereo(rdel,f1,f2,t60dc,t60m,fsmax),_,_ <: _,!,_,!,!,_,!,_ : +,+
+ with{
+ reverbGain = hslider("v:Reverb/reverbGain",0.137,0,1,0.01) : smooth(0.999);
+ roomSize = hslider("v:Reverb/roomSize",0.72,0.01,2,0.01);
+ rdel = 20;
+ f1 = 200;
+ f2 = 6000;
+ t60dc = roomSize*3;
+ t60m = roomSize*2;
+ fsmax = 48000;
+ };