interpretor/faust-0.9.47mr3/examples/faust-stk/instrument.lib

   1 //instrument.lib - Faust function of various types usefull for building physical model instruments
   2
   3 declare name "Faust-STK Tools Library";
   4 declare author "Romain Michon (rmichon@ccrma.stanford.edu)";
   5 declare copyright "Romain Michon";
   6 declare version "1.0";
   7 declare licence "STK-4.3"; // Synthesis Tool Kit 4.3 (MIT style license);
   8
   9 import("math.lib");
  10 import("filter.lib");
  11 import("effect.lib");
  12
  13 //========================= ENVELOPE GENERATORS ===============================
  14
  15 //----------------------- VIBRATO ENVELOPE ----------------------------
  16 // 4 phases envelope to control vibrato gain
  17 //
  18 // USAGE:
  19 //   _ : *(envVibrato(b,a,s,r,t)) : _
  20 // where
  21 //   b = beginning duration (silence) in seconds
  22 //   a = attack duration in seconds
  23 //   s = sustain as a percentage of the amplitude to be modified
  24 //   r = release duration in seconds
  25 //   t = trigger signal
  26
  27 envVibrato(b,a,s,r,t) = env ~ (_,_,_) : (!,!,_) // the 3 'state' signals are fed back
  28 with {
  29     env (p2,cnt,y) =
  30         (t>0) & (p2|(y>=1)),
  31                 (cnt + 1)*(t>0), // counter for the first step "b"
  32         (y + p1*p3*u*(s/100) - p4*w*y)*((p4==0)|(y>=eps))       // y  = envelop signal
  33                 //*(y>=eps) // cut off tails to prevent denormals
  34     with {
  35         p1 = (p2==0) & (t>0) & (y<1) & (cnt>(b*SR)); // p1 = attack phase
  36         p3 = 1-(cnt<(nb)); // p3 = beginning phase
  37         p4 = (t<=0) & (y>0);  // p4 = release phase
  38         // #samples in attack, release, must be >0
  39         nb = SR*b+(b==0.0) ; na = SR*a+(a==0.0); nr = SR*r+(r==0.0);
  40         // attack and (-60dB) release rates
  41         z = s+(s==0.0)*db2linear(-60);
  42         u = 1/na; w = 1-1/pow(z*db2linear(60), 1/nr);
  43         // values below this threshold are considered zero in the release phase
  44         eps = db2linear(-120);
  45     };
  46 };
  47
  48 //----------------------- ATTACK - SUSTAIN - RELEASE ----------------------------
  49 // Attack - Sustain - Release envelope
  50 //
  51 // USAGE:
  52 //   _ : *(asr(a,s,r,t)) : _
  53 // where
  54 //   a = attack duration in seconds
  55 //   s = sustain as a percentage of the amplitude to be modified
  56 //   r = release duration in seconds
  57 //   t = trigger signal
  58
  59 asr(a,s,r,t) = env ~ (_,_) : (!,_) // the 2 'state' signals are fed back
  60 with {
  61     env (p2,y) =
  62         (t>0) & (p2|(y>=1)),
  63         (y + p1*u*(s/100) - p3*w*y)     // y  = envelop signal
  64         *((p3==0)|(y>=eps)) // cut off tails to prevent denormals
  65     with {
  66         p1 = (p2==0) & (t>0) & (y<1); // p1 = attack phase
  67         p3 = (t<=0) & (y>0); // p3 = release phase
  68         // #samples in attack, release, must be >0
  69         na = SR*a+(a==0.0); nr = SR*r+(r==0.0);
  70         // correct zero sustain level
  71         z = s+(s==0.0)*db2linear(-60);
  72         // attack and (-60dB) release rates
  73         u = 1/na; w = 1-1/pow(z*db2linear(60), 1/nr);
  74         // values below this threshold are considered zero in the release phase
  75         eps = db2linear(-120);
  76     };
  77 };
  78
  79 //----------------------- ASYMPT60 ----------------------------
  80 // Envelope generator which asymptotically approaches a target value.
  81 //
  82 // USAGE:
  83 //   asympT60(value,trgt,T60,trig) : _
  84 // where
  85 //   value = starting value
  86 //   trgt = target value
  87 //   T60 = ramping time
  88 //   trig = trigger signal
  89
  90 asympT60(value,trgt,T60,trig) = (_*factor + constant)~_
  91         with{
  92                 cntSample = *(trig) + 1~_ : -(1);
  93                 attDur = float(2);
  94                 cndFirst = ((cntSample < attDur) & (trig > 0));
  95                 target = value*cndFirst + trgt*(cndFirst < 1);
  96                 factorAtt = exp(-7/attDur);
  97                 factorT60 = exp(-7/(T60*float(SR)));
  98                 factor = factorAtt*((cntSample < attDur) & (trig > 0)) +
  99                        ((cntSample >= attDur) | (trig < 1))*factorT60;
 100                 constant = (1 - factor)*target;
 101         };
 102
 103 //========================= TABLES ===============================
 104
 105 //----------------------- CLIPPING FUNCTION ----------------------------
 106 // Positive and negative clipping functions.
 107 //
 108 // USAGE:
 109 //   _ : saturationPos : _
 110 //   _ : saturationNeg : _
 111 //   _ : saturationPos : saturationNeg : _
 112
 113 saturationPos(x) = x <: (_>1),(_<=1 : *(x)) :> +;
 114 saturationNeg(x) = x <: (_<-1),(_>=-1 : *(x)) :> *(-1) + _;
 115
 116 //----------------------- BOW TABLE ----------------------------
 117 // Simple bow table.
 118 //
 119 // USAGE:
 120 //   index : bow(offset,slope) : _
 121 // where
 122 //   0 <= index <= 1
 123
 124 bow(offset,slope) = pow(abs(sample) + 0.75, -4) : saturationPos
 125         with{
 126         sample(y) = (y + offset)*slope;
 127         };
 128
 129 //----------------------- REED TABLE ----------------------------
 130 // Simple reed table to be used with waveguide models of clanrinet, saxophone, etc.
 131 //
 132 // USAGE:
 133 //   _ : reed(offset,slope) : _
 134 // where
 135 //   offset = offset between 0 and 1
 136 //   slope = slope between 0 and 1
 137 // REFERENCE:
 138 //   https://ccrma.stanford.edu/~jos/pasp/View_Single_Reed_Oscillation.html
 139
 140 reed(offset,slope) = reedTable : saturationPos : saturationNeg
 141         with{
 142         reedTable = offset + (slope*_);
 143         };
 144
 145 //========================= FILTERS ===============================
 146
 147 //----------------------- ONE POLE ----------------------------
 148
 149 onePole(b0,a1,x) = (b0*x - a1*_)~_;
 150
 151 //----------------------- ONE POLE SWEPT ----------------------------
 152
 153 onePoleSwep(a1,x) = (1 + a1)*x - a1*x';
 154
 155 //----------------------- POLE ZERO ----------------------------
 156
 157 poleZero(b0,b1,a1,x) = (b0*x + b1*x' - a1*_)~_;
 158
 159 //----------------------- ONE ZEROS ----------------------------
 160 // Simple One zero and One zero recursive filters
 161 //
 162 // USAGE:
 163 //   _ : oneZero0(b0,b1) : _
 164 //   _ : oneZero1(b0,b1) : _
 165 // REFERENCE:
 166 //   https://ccrma.stanford.edu/~jos/fp2/One_Zero.html
 167
 168 oneZero0(b0,b1,x) = (*(b1) + x*b0)~_;
 169 oneZero1(b0,b1,x) = (x'*b1 + x*b0);
 170
 171 //----------------------- BANDPASS FILTER WITH CONSTANT UNITY PEAK GAIN BASED ON A BIQUAD ----------------------------
 172
 173 bandPass(resonance,radius) = TF2(b0,b1,b2,a1,a2)
 174         with{
 175                 a2 = radius*radius;
 176                 a1 = -2*radius*cos(PI*2*resonance/SR);
 177                 b0 = 0.5-0.5*a2;
 178                 b1 = 0;
 179                 b2 = -b0;
 180         };
 181
 182 //----------------------- BANDPASS FILTER BASED ON A BIQUAD ----------------------------
 183 // Band pass filter using a biquad (TF2 is declared in filter.lib)
 184 //
 185 // USAGE:
 186 //   _ : bandPassH(resonance,radius) : _
 187 // where
 188 //   resonance = center frequency
 189 //   radius = radius
 190
 191 bandPassH(resonance,radius) = TF2(b0,b1,b2,a1,a2)
 192         with{
 193                 a2 = radius*radius;
 194                 a1 = -2*radius*cos(PI*2*resonance/SR);
 195                 b0 = 1;
 196                 b1 = 0;
 197                 b2 = 0;
 198         };
 199
 200 //----------------------- FLUE JET NON-LINEAR FUNCTION ----------------------------
 201 // Jet Table: flue jet non-linear function, computed by a polynomial calculation
 202
 203 jetTable(x) = x <: _*(_*_-1) : saturationPos : saturationNeg;
 204
 205 //----------------------- NON LINEAR MODULATOR ----------------------------
 206 // nonLinearModulator adapts the function allpassnn from filter.lib for using it with waveguide instruments
 207 //
 208 // USAGE:
 209 //   _ : nonLinearModulator(nonlinearity,env,freq,typeMod,freqMod,order) : _
 210 // where
 211 //   nonlinearity = nonlinearity coefficient between 0 and 1
 212 //   env = input to connect any kind of envelope
 213 //   freq = current tone frequency
 214 //   typeMod = if 0: theta is modulated by the incoming signal;
 215 //             if 1: theta is modulated by the averaged incoming signal;
 216 //             if 2: theta is modulated by the squared incoming signal;
 217 //             if 3: theta is modulated by a sine wave of frequency freqMod;
 218 //             if 4: theta is modulated by a sine wave of frequency freq;
 219 //   freqMod = frequency of the sine wave modulation
 220 //   order = order of the filter
 221
 222 nonLinearModulator(nonlinearity,env,freq,typeMod,freqMod,order) =
 223         //theta is modulated by a sine wave
 224         _ <: nonLinearFilterOsc*(typeMod >= 3),
 225         //theta is modulated by the incoming signal
 226              (_ <: nonLinearFilterSig*nonlinearity,_*(1 - nonlinearity) :> +)*(typeMod < 3)
 227         :> +
 228         with{
 229                 //which frequency to use for the sine wave oscillator?
 230                 freqOscMod = (typeMod == 4)*freq + (typeMod != 4)*freqMod;
 231
 232                 //the incoming signal is scaled and the envelope is applied
 233                 tsignorm(x) = nonlinearity*PI*x*env;
 234                 tsigsquared(x) = nonlinearity*PI*x*x*env; //incoming signal is squared
 235                 tsigav(x) = nonlinearity*PI*((x + x')/2)*env; //incoming signal is averaged with its previous sample
 236
 237                 //select which version of the incoming signal of theta to use
 238                 tsig(x) = tsignorm(x)*(typeMod == 0) + tsigav(x)*(typeMod == 1)
 239                           + tsigsquared(x)*(typeMod == 2);
 240
 241                 //theta is modulated by a sine wave generator
 242                 tosc = nonlinearity*PI*osc(freqOscMod)*env;
 243
 244                 //incoming signal is sent to the nonlinear passive allpass ladder filter
 245                 nonLinearFilterSig(x) = x <: allpassnn(order,(par(i,order,tsig(x))));
 246                 nonLinearFilterOsc = _ <: allpassnn(order,(par(i,order,tosc)));
 247         };
 248
 249 //========================= WAVE TABLES ===============================
 250
 251 //----------------------- STICK IMPACT ----------------------------
 252 // Stick impact table.
 253 //
 254 // USAGE:
 255 //   index : readMarmstk1 : _
 256
 257 readMarmstk1 = ffunction(float readMarmstk1 (int), <instrument.h>,"");
 258 marmstk1TableSize = 246;
 259
 260 //========================= TOOLS ===============================
 261
 262 //----------------------- STEREOIZER ----------------------------
 263 // This function takes a mono input signal and spacialize it in stereo
 264 // in function of the period duration of the tone being played.
 265 //
 266 // USAGE:
 267 //   _ : stereo(periodDuration) : _,_
 268 // where
 269 //   periodDuration = period duration of the tone being played in number of samples
 270 // ACKNOWLEDGMENT
 271 //   Formulation initiated by Julius O. Smith in https://ccrma.stanford.edu/realsimple/faust_strings/
 272
 273 stereoizer(periodDuration) = _ <: _,widthdelay : stereopanner
 274            with{
 275                 W = hslider("v:Spat/spatial width", 0.5, 0, 1, 0.01);
 276                 A = hslider("v:Spat/pan angle", 0.6, 0, 1, 0.01);
 277                 widthdelay = delay(4096,W*periodDuration/2);
 278                 stereopanner = _,_ : *(1.0-A), *(A);
 279            };
 280
 281 //----------------------- INSTRREVERB ----------------------------
 282 // GUI for zita_rev1_stereo from effect.lib
 283 //
 284 // USAGE:
 285 //  _,_ : instrRerveb
 286
 287 instrReverb = _,_ <: *(reverbGain),*(reverbGain),*(1 - reverbGain),*(1 - reverbGain) :
 288 zita_rev1_stereo(rdel,f1,f2,t60dc,t60m,fsmax),_,_ <: _,!,_,!,!,_,!,_ : +,+
 289        with{
 290        reverbGain = hslider("v:Reverb/reverbGain",0.137,0,1,0.01) : smooth(0.999);
 291        roomSize = hslider("v:Reverb/roomSize",0.72,0.01,2,0.01);
 292        rdel = 20;
 293        f1 = 200;
 294        f2 = 6000;
 295        t60dc = roomSize*3;
 296        t60m = roomSize*2;
 297        fsmax = 48000;
 298        };