+declare name "Bass";
+declare description "Nonlinear WaveGuide Acoustic Bass";
+declare author "Romain Michon";
+declare copyright "Romain Michon (rmichon@ccrma.stanford.edu)";
+declare version "1.0";
+declare licence "STK-4.3"; // Synthesis Tool Kit 4.3 (MIT style license);
+
+import("instrument.lib");
+import("music.lib");
+
+//==================== GUI SPECIFICATION ================
+
+freq = nentry("h:Basic_Parameters/freq [1][unit:Hz] [tooltip:Tone frequency]",120,20,20000,1);
+gain = nentry("h:Basic_Parameters/gain [1][tooltip:Gain (value between 0 and 1)]",1,0,1,0.01);
+gate = button("h:Basic_Parameters/gate [1][tooltip:noteOn = 1, noteOff = 0]");
+
+touchLength = hslider("v:Physical_Parameters/Touch_Length
+[2][tooltip:A value between 0 and 1]",0.15,0,1,0.01)*2;
+
+typeModulation = nentry("v:Nonlinear_Filter_Parameters/Modulation_Type
+[3][tooltip: 0=theta is modulated by the incoming signal; 1=theta is modulated by the averaged incoming signal;
+2=theta is modulated by the squared incoming signal; 3=theta is modulated by a sine wave of frequency freqMod;
+4=theta is modulated by a sine wave of frequency freq;]",0,0,4,1);
+nonLinearity = hslider("v:Nonlinear_Filter_Parameters/Nonlinearity
+[3][tooltip:Nonlinearity factor (value between 0 and 1)]",0,0,1,0.01);
+frequencyMod = hslider("v:Nonlinear_Filter_Parameters/Modulation_Frequency
+[3][unit:Hz][tooltip:Frequency of the sine wave for the modulation of theta (works if Modulation Type=3)]",220,20,1000,0.1);
+
+//==================== SIGNAL PROCESSING ======================
+
+//----------------------- Nonlinear filter ----------------------------
+//nonlinearities are created by the nonlinear passive allpass ladder filter declared in filter.lib
+
+//nonlinear filter order
+nlfOrder = 6;
+
+//nonLinearModultor is declared in instrument.lib, it adapts allpassnn from filter.lib
+//for using it with waveguide instruments
+NLFM = nonLinearModulator((nonLinearity : smooth(0.999)),1,freq,
+ typeModulation,(frequencyMod : smooth(0.999)),nlfOrder);
+
+//----------------------- Synthesis parameters computing and functions declaration ----------------------------
+
+//delay length in number of samples
+delayLength = float(SR)/freq;
+
+//stereoizer is declared in instrument.lib and implement a stereo spacialisation in function of
+//the frequency period in number of samples
+stereo = stereoizer(delayLength);
+
+//string excitation
+excitation = asympT60(-0.5,-0.985,0.02,gate),noise*asympT60(gain,0,touchLength,gate) :
+ onePoleSwep : excitationFilter : excitationFilter
+ with{
+ //the exitation filter is a one pole filter (declared in instrument.lib)
+ excitationFilter = onePole(0.035,-0.965);
+ };
+
+//the bodyfilter is a bandpass filter (declared in instrument.lib)
+bodyFilter = bandPass(108,0.997);
+
+//the reflexion filter is pole zero filter (declared in instrument.lib) whose coefficients are
+//modulated in function of the tone being played
+reflexionFilter = poleZero(b0,b1,a1)
+ with{
+ //filter coefficients are stored in a C++ function
+ loopFilterb0 = ffunction(float getValueBassLoopFilterb0(float), <bass.h>,"");
+ loopFilterb1 = ffunction(float getValueBassLoopFilterb1(float), <bass.h>,"");
+ loopFiltera1 = ffunction(float getValueBassLoopFiltera1(float), <bass.h>,"");
+ freqToNoteNumber = (log - log(440))/log(2)*12 + 69 + 0.5 : int;
+ freqn = freq : freqToNoteNumber;
+ b0 = loopFilterb0(freqn);
+ b1 = loopFilterb1(freqn);
+ a1 = loopFiltera1(freqn);
+ };
+
+delayLine = asympT60(0,delayLength,0.01,gate),_ : fdelay(4096);
+
+//the resonance duration is different whether a note-on signal is sent or not
+resonanceGain = gate + (gate < 1 <: *(asympT60(1,0.9,0.05)));
+
+process = excitation :
+ (+)~(delayLine : NLFM : reflexionFilter*resonanceGain) <:
+ bodyFilter*1.5 + *(0.5) : *(4) : stereo : instrReverb;