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

   1 declare name "Harpsichord";
   2 declare description "Nonlinear WaveGuide Commuted Harpsichord";
   3 declare author "Romain Michon (rmichon@ccrma.stanford.edu)";
   4 declare copyright "Romain Michon";
   5 declare version "1.0";
   6 declare licence "STK-4.3"; // Synthesis Tool Kit 4.3 (MIT style license);
   7 declare description "A commuted WaveGuide Harpsichord.";
   8
   9 import("music.lib");
  10 import("instrument.lib");
  11
  12 //==================== GUI SPECIFICATION ================
  13
  14 freq = nentry("h:Basic_Parameters/freq [1][unit:Hz] [tooltip:Tone frequency]",440,20,20000,1);
  15 gain = nentry("h:Basic_Parameters/gain [1][tooltip:Gain (value between 0 and 1)]",0.8,0,1,0.01);
  16 gate = button("h:Basic_Parameters/gate [1][tooltip:noteOn = 1, noteOff = 0]");
  17
  18 typeModulation = nentry("h:Physical_and_Nonlinearity/v:Nonlinear_Filter_Parameters/Modulation_Type
  19 [2][tooltip: 0=theta is modulated by the incoming signal; 1=theta is modulated by the averaged incoming signal;
  20 2=theta is modulated by the squared incoming signal; 3=theta is modulated by a sine wave of frequency freqMod;
  21 4=theta is modulated by a sine wave of frequency freq;]",0,0,4,1);
  22 nonLinearity = hslider("h:Physical_and_Nonlinearity/v:Nonlinear_Filter_Parameters/Nonlinearity
  23 [2][tooltip:Nonlinearity factor (value between 0 and 1)]",0,0,1,0.01);
  24 frequencyMod = hslider("h:Physical_and_Nonlinearity/v:Nonlinear_Filter_Parameters/Modulation_Frequency
  25 [2][unit:Hz][tooltip:Frequency of the sine wave for the modulation of theta (works if Modulation Type=3)]",220,20,1000,0.1);
  26
  27 //==================== PROCESSING ================
  28
  29 //----------------------- Nonlinear filter ----------------------------
  30 //nonlinearities are created by the nonlinear passive allpass ladder filter declared in filter.lib
  31
  32 //nonlinear filter order
  33 nlfOrder = 6;
  34
  35 //nonLinearModultor is declared in instrument.lib, it adapts allpassnn from filter.lib
  36 //for using it with waveguide instruments
  37 NLFM =  nonLinearModulator((nonLinearity : smooth(0.999)),1,freq,
  38      typeModulation,(frequencyMod : smooth(0.999)),nlfOrder);
  39
  40 //----------------------- Synthesis parameters computing and functions declaration ----------------------------
  41
  42 //convert a frequency in a midi note number
  43 freqToNoteNumber = (log-log(440))/log(2)*12+69+0.5 : int;
  44 freqn = freq : freqToNoteNumber;
  45
  46 //string excitation
  47 soundBoard = dryTapAmp*noise
  48         with{
  49                 dryTapAmpT60 = ffunction(float getValueDryTapAmpT60(float), <harpsichord.h>,"");
  50                 noteCutOffTime = freqn : dryTapAmpT60*gain;
  51                 dryTapAmp = asympT60(0.15,0,noteCutOffTime,gate);
  52         };
  53
  54 //loopfilter is a biquad filter whose coefficients are extracted from a C++ file using the foreign function mechanism
  55 loopFilter = TF2(b0,b1,b2,a1,a2)
  56            with{
  57                 //functions are imported from the C++ file
  58                 loopFilterb0 = ffunction(float getValueLoopFilterb0(float), <harpsichord.h>,"");
  59                 loopFilterb1 = ffunction(float getValueLoopFilterb1(float), <harpsichord.h>,"");
  60                 loopFilterb2 = ffunction(float getValueLoopFilterb2(float), <harpsichord.h>,"");
  61                 loopFiltera1 = ffunction(float getValueLoopFiltera1(float), <harpsichord.h>,"");
  62                 loopFiltera2 = ffunction(float getValueLoopFiltera2(float), <harpsichord.h>,"");
  63                 //coefficients are extracted from the functions
  64                 b0 = loopFilterb0(freqn);
  65                 b1 = loopFilterb1(freqn);
  66                 b2 = loopFilterb2(freqn);
  67                 a1 = loopFiltera1(freqn);
  68                 a2 = loopFiltera2(freqn);
  69            };
  70
  71 //delay length as a number of samples
  72 delayLength = SR/freq;
  73
  74 //stereoizer is declared in instrument.lib and implement a stereo spacialisation in function of
  75 //the frequency period in number of samples
  76 stereo = stereoizer(delayLength);
  77
  78 //----------------------- Algorithm implementation ----------------------------
  79
  80 //envelope for string loop resonance time
  81 stringLoopGainT = gate*0.9996 + (gate<1)*releaseLoopGain(freqn)*0.9 : smooth(0.999)
  82                 with{
  83                         releaseLoopGain = ffunction(float getValueReleaseLoopGain(float), <harpsichord.h>,"");
  84                 };
  85
  86 //one string
  87 string = (*(stringLoopGainT)+_ : delay(4096,delayLength) : loopFilter)~NLFM;
  88
  89 process = soundBoard : string : stereo : instrReverb;
  90