interpreter/preprocessor/faust-0.9.47mr3/examples/faust-stk/bowed.dsp

   1 declare name "Bowed";
   2 declare description "Nonlinear WaveGuide Bowed Instrument";
   3 declare author "Romain Michon";
   4 declare copyright "Romain Michon (rmichon@ccrma.stanford.edu)";
   5 declare version "1.0";
   6 declare licence "STK-4.3"; // Synthesis Tool Kit 4.3 (MIT style license);
   7 declare description "A bowed string model, a la Smith (1986), after McIntyre, Schumacher, Woodhouse (1983).";
   8 declare reference "https://ccrma.stanford.edu/~jos/pasp/Bowed_Strings.html";
   9
  10 import("music.lib");
  11 import("instrument.lib");
  12
  13 //==================== GUI SPECIFICATION ================
  14
  15 freq = nentry("h:Basic_Parameters/freq [1][unit:Hz] [tooltip:Tone frequency]",440,20,20000,1);
  16 gain = nentry("h:Basic_Parameters/gain [1][tooltip:Gain (value between 0 and 1)]",1,0,1,0.01);
  17 gate = button("h:Basic_Parameters/gate [1][tooltip:noteOn = 1, noteOff = 0]");
  18
  19 bowPosition = hslider("h:Physical_and_Nonlinearity/v:Physical_Parameters/Bow_Position
  20 [2][tooltip:Bow position along the string (value between 0 and 1)]",0.7,0.01,1,0.01);
  21 bowPressure = hslider("h:Physical_and_Nonlinearity/v:Physical_Parameters/Bow_Pressure
  22 [2][tooltip:Bow pressure on the string (value between 0 and 1)]",0.75,0,1,0.01);
  23
  24 typeModulation = nentry("h:Physical_and_Nonlinearity/v:Nonlinear_Filter_Parameters/Modulation_Type
  25 [3][tooltip: 0=theta is modulated by the incoming signal; 1=theta is modulated by the averaged incoming signal;
  26 2=theta is modulated by the squared incoming signal; 3=theta is modulated by a sine wave of frequency freqMod;
  27 4=theta is modulated by a sine wave of frequency freq;]",0,0,4,1);
  28 nonLinearity = hslider("h:Physical_and_Nonlinearity/v:Nonlinear_Filter_Parameters/Nonlinearity
  29 [3][tooltip:Nonlinearity factor (value between 0 and 1)]",0,0,1,0.01);
  30 frequencyMod = hslider("h:Physical_and_Nonlinearity/v:Nonlinear_Filter_Parameters/Modulation_Frequency
  31 [3][unit:Hz][tooltip:Frequency of the sine wave for the modulation of theta (works if Modulation Type=3)]",220,20,1000,0.1);
  32 nonLinAttack = hslider("h:Physical_and_Nonlinearity/v:Nonlinear_Filter_Parameters/Nonlinearity_Attack
  33 [3][unit:s][Attack duration of the nonlinearity]",0.1,0,2,0.01);
  34
  35 vibratoFreq = hslider("h:Envelopes_and_Vibrato/v:Vibrato_Parameters/Vibrato_Freq
  36 [4][unit:Hz]",6,1,15,0.1);
  37 vibratoGain = hslider("h:Envelopes_and_Vibrato/v:Vibrato_Parameters/Vibrato_Gain
  38 [4][tooltip:A value between 0 and 1]",0.01,0,1,0.01);
  39 vibratoBegin = hslider("h:Envelopes_and_Vibrato/v:Vibrato_Parameters/Vibrato_Begin
  40 [4][unit:s][tooltip:Vibrato silence duration before attack]",0.05,0,2,0.01);
  41 vibratoAttack = hslider("h:Envelopes_and_Vibrato/v:Vibrato_Parameters/Vibrato_Attack
  42 [4][unit:s][tooltip:Vibrato attack duration]",0.5,0,2,0.01);
  43 vibratoRelease = hslider("h:Envelopes_and_Vibrato/v:Vibrato_Parameters/Vibrato_Release
  44 [4][unit:s][tooltip:Vibrato release duration]",0.01,0,2,0.01);
  45
  46 envelopeAttack = hslider("h:Envelopes_and_Vibrato/v:Envelope_Parameters/Envelope_Attack
  47 [5][unit:s][tooltip:Envelope attack duration]",0.01,0,2,0.01);
  48 envelopeDecay = hslider("h:Envelopes_and_Vibrato/v:Envelope_Parameters/Envelope_Decay
  49 [5][unit:s][tooltip:Envelope decay duration]",0.05,0,2,0.01);
  50 envelopeRelease = hslider("h:Envelopes_and_Vibrato/v:Envelope_Parameters/Envelope_Release
  51 [5][unit:s][tooltip:Envelope release duration]",0.1,0,2,0.01);
  52
  53 //==================== SIGNAL PROCESSING ================
  54
  55 //----------------------- Nonlinear filter ----------------------------
  56 //nonlinearities are created by the nonlinear passive allpass ladder filter declared in filter.lib
  57
  58 //nonlinear filter order
  59 nlfOrder = 6;
  60
  61 //attack - sustain - release envelope for nonlinearity (declared in instrument.lib)
  62 envelopeMod = asr(nonLinAttack,100,envelopeRelease,gate);
  63
  64 //nonLinearModultor is declared in instrument.lib, it adapts allpassnn from filter.lib
  65 //for using it with waveguide instruments
  66 NLFM =  nonLinearModulator((nonLinearity : smooth(0.999)),envelopeMod,freq,
  67      typeModulation,(frequencyMod : smooth(0.999)),nlfOrder);
  68
  69 //----------------------- Synthesis parameters computing and functions declaration ----------------------------
  70
  71 //Parameters for the bow table
  72 tableOffset =  0;
  73 tableSlope = 5 - (4*bowPressure);
  74
  75 //the bow table is declared in instrument.lib
  76 bowTable = bow(tableOffset,tableSlope);
  77
  78 //a attack - decay - sustain - release envelope is used
  79 envelope = adsr(gain*envelopeAttack,envelopeDecay,90, (1-gain)*envelopeRelease,gate);
  80 maxVelocity = 0.03 + (0.2 * gain);
  81
  82 //Delay lines declaration and vibrato, the length of the two delay lines are evolving propotionally
  83 betaRatio = 0.027236 + (0.2*bowPosition);
  84 fdelneck = (SR/freq-4)*(1 - betaRatio);
  85 vibratoEnvelope = envVibrato(vibratoBegin,vibratoAttack,100,vibratoRelease,gate);
  86 vibrato = fdelneck + ((SR/freq - 4)*vibratoGain*vibratoEnvelope*osc(vibratoFreq));
  87 neckDelay = fdelay(4096,vibrato);
  88 fdelbridge = (SR/freq - 4)*betaRatio;
  89 bridgeDelay = delay(4096,fdelbridge);
  90
  91 //Body Filter: a biquad filter with a normalized pick gain (declared in instrument.lib)
  92 bodyFilter = bandPass(500,0.85);
  93
  94 //String Filter: a lowpass filter (declared in instrument.lib)
  95 stringFilter = *(0.95) : -onePole(b0,a1)
  96         with{
  97                 pole = 0.6 - (0.1*22050/SR);
  98                 gain = 0.95;
  99                 b0 = 1-pole;
 100                 a1 = -pole;
 101         };
 102
 103 //stereoizer is declared in instrument.lib and implement a stereo spacialisation in function of
 104 //the frequency period in number of samples
 105 stereo = stereoizer(SR/freq);
 106
 107 //----------------------- Algorithm implementation ----------------------------
 108
 109 bowVelocity = envelope*maxVelocity;
 110 instrumentBody(feedBckBridge) = (*(-1) <: +(feedBckBridge),_ : (bowVelocity-_ <: *(bowTable) <: _,_),_ :
 111         _, + : +(feedBckBridge),_) ~ (neckDelay) : !,_;
 112
 113 process = (stringFilter : instrumentBody) ~ (bridgeDelay : NLFM) : bodyFilter(*(0.2)) :
 114         _*gain*8 : stereo : instrReverb;