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

   1 declare name "Bass";
   2 declare description "Nonlinear WaveGuide Acoustic Bass";
   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
   8 import("instrument.lib");
   9 import("music.lib");
  10
  11 //==================== GUI SPECIFICATION ================
  12
  13 freq = nentry("h:Basic_Parameters/freq [1][unit:Hz] [tooltip:Tone frequency]",120,20,20000,1);
  14 gain = nentry("h:Basic_Parameters/gain [1][tooltip:Gain (value between 0 and 1)]",1,0,1,0.01);
  15 gate = button("h:Basic_Parameters/gate [1][tooltip:noteOn = 1, noteOff = 0]");
  16
  17 touchLength = hslider("v:Physical_Parameters/Touch_Length
  18 [2][tooltip:A value between 0 and 1]",0.15,0,1,0.01)*2;
  19
  20 typeModulation = nentry("v:Nonlinear_Filter_Parameters/Modulation_Type
  21 [3][tooltip: 0=theta is modulated by the incoming signal; 1=theta is modulated by the averaged incoming signal;
  22 2=theta is modulated by the squared incoming signal; 3=theta is modulated by a sine wave of frequency freqMod;
  23 4=theta is modulated by a sine wave of frequency freq;]",0,0,4,1);
  24 nonLinearity = hslider("v:Nonlinear_Filter_Parameters/Nonlinearity
  25 [3][tooltip:Nonlinearity factor (value between 0 and 1)]",0,0,1,0.01);
  26 frequencyMod = hslider("v:Nonlinear_Filter_Parameters/Modulation_Frequency
  27 [3][unit:Hz][tooltip:Frequency of the sine wave for the modulation of theta (works if Modulation Type=3)]",220,20,1000,0.1);
  28
  29 //==================== SIGNAL PROCESSING ======================
  30
  31 //----------------------- Nonlinear filter ----------------------------
  32 //nonlinearities are created by the nonlinear passive allpass ladder filter declared in filter.lib
  33
  34 //nonlinear filter order
  35 nlfOrder = 6;
  36
  37 //nonLinearModultor is declared in instrument.lib, it adapts allpassnn from filter.lib
  38 //for using it with waveguide instruments
  39 NLFM =  nonLinearModulator((nonLinearity : smooth(0.999)),1,freq,
  40      typeModulation,(frequencyMod : smooth(0.999)),nlfOrder);
  41
  42 //----------------------- Synthesis parameters computing and functions declaration ----------------------------
  43
  44 //delay length in number of samples
  45 delayLength = float(SR)/freq;
  46
  47 //stereoizer is declared in instrument.lib and implement a stereo spacialisation in function of
  48 //the frequency period in number of samples
  49 stereo = stereoizer(delayLength);
  50
  51 //string excitation
  52 excitation = asympT60(-0.5,-0.985,0.02,gate),noise*asympT60(gain,0,touchLength,gate) :
  53            onePoleSwep : excitationFilter : excitationFilter
  54            with{
  55                 //the exitation filter is a one pole filter (declared in instrument.lib)
  56                 excitationFilter = onePole(0.035,-0.965);
  57            };
  58
  59 //the bodyfilter is a bandpass filter (declared in instrument.lib)
  60 bodyFilter = bandPass(108,0.997);
  61
  62 //the reflexion filter is pole zero filter (declared in instrument.lib) whose coefficients are
  63 //modulated in function of the tone being played
  64 reflexionFilter = poleZero(b0,b1,a1)
  65            with{
  66                 //filter coefficients are stored in a C++ function
  67                 loopFilterb0 = ffunction(float getValueBassLoopFilterb0(float), <bass.h>,"");
  68                 loopFilterb1 = ffunction(float getValueBassLoopFilterb1(float), <bass.h>,"");
  69                 loopFiltera1 = ffunction(float getValueBassLoopFiltera1(float), <bass.h>,"");
  70                 freqToNoteNumber = (log - log(440))/log(2)*12 + 69 + 0.5 : int;
  71                 freqn = freq : freqToNoteNumber;
  72                 b0 = loopFilterb0(freqn);
  73                 b1 = loopFilterb1(freqn);
  74                 a1 = loopFiltera1(freqn);
  75            };
  76
  77 delayLine = asympT60(0,delayLength,0.01,gate),_ : fdelay(4096);
  78
  79 //the resonance duration is different whether a note-on signal is sent or not
  80 resonanceGain = gate + (gate < 1 <: *(asympT60(1,0.9,0.05)));
  81
  82 process = excitation :
  83         (+)~(delayLine : NLFM : reflexionFilter*resonanceGain) <:
  84         bodyFilter*1.5 + *(0.5) : *(4) : stereo : instrReverb;