--- /dev/null
+declare name "Commuted Piano";
+declare description "WaveGuide Commuted Piano";
+declare author "Romain Michon (rmichon@ccrma.stanford.edu)";
+declare copyright "Romain Michon";
+declare version "1.0";
+declare licence "STK-4.3"; // Synthesis Tool Kit 4.3 (MIT style license);
+declare description "A commuted WaveGuide piano.";
+
+import("music.lib");
+import("instrument.lib");
+
+//==================== GUI SPECIFICATION ================
+
+freq = nentry("h:Basic_Parameters/freq [1][unit:Hz] [tooltip:Tone frequency]",440,20,20000,1);
+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]");
+
+brightnessFactor = hslider("v:Physical_Parameters/Brightness_Factor
+[2][tooltip:A value between 0 and 1]",0,0,1,0.01);
+detuningFactor = hslider("v:Physical_Parameters/Detuning_Factor
+[2][tooltip:A value between 0 and 1]",0.1,0,1,0.01)*10;
+stiffnessFactor = hslider("v:Physical_Parameters/Stiffness_Factor
+[2][tooltip:A value between 0 and 1]",0.28,0,1,0.01)*3.7;
+hammerHardness = hslider("v:Physical_Parameters/Hammer_Hardness
+[2][tooltip:A value between 0 and 1]",0.1,0,1,0.01)*0.1;
+
+//==================== COMMUTED PIANO PARAMETERS ================
+
+//variables to set keybord splitting zone
+DCB2_TURNOFF_KEYNUM = 92;
+FIRST_HIGH_NOTE = 88;
+PEDAL_ENVELOPE_T60 = 7;
+
+//convert an amplitude in db
+dbinv(x) = pow(10,0.05*x);
+
+//convert a frequency in a midi note number
+freqToNoteNumber = (log-log(440))/log(2)*12+69+0.5 : int;
+freqn = freq : freqToNoteNumber;
+
+//a counter that restart a every note-on
+cntSample = *(gate)+1~_ : -(1);
+
+//==================== PIANO SOUND BOARD ================
+
+//exponential envelope with 3 phases for the pedal excitation
+asympT60pedal(value,T60) = (*(factor) + constant)~_
+ with{
+ attDur = hammerHardness*float(SR);
+ target = value*((cntSample < attDur) & (gate > 0));
+ factorAtt = exp (-1/(attDur));
+ factorG = exp(-1/(2*float(SR)));
+ factorT60 = exp(-7/(T60*float(SR)));
+ factor = factorAtt*gate*(cntSample < attDur) + (cntSample >= attDur)*gate*factorG + ((gate-1)*-1)*factorT60;
+ constant = (1 - factor)*target;
+ };
+
+//the sound of the piano sound board is generated by noise generator whose output gain is shaped by
+//an exponential envelope
+soundBoard = dryTapAmp*noise + pedalEnv*noise : *(0.5)
+ with{
+ //the values of the envelope cut-off time are stored in an external C++ function
+ dryTapAmpT60 = ffunction(float getValueDryTapAmpT60(float), <piano.h>,"");
+ sustainPedalLevel = ffunction(float getValueSustainPedalLevel(float), <piano.h>,"");
+
+ pedalEnvCutOffTime = 1.4;
+ noteCutOffTime = freqn : dryTapAmpT60*gain;
+ pedalEnvValue = freqn : sustainPedalLevel*0.2;
+ noteEnvValue = 0.15;
+ dryTapAmp = asympT60(noteEnvValue,0,noteCutOffTime,gate);
+ pedalEnv = asympT60pedal(pedalEnvValue,pedalEnvCutOffTime);
+ };
+
+//==================== HAMMER MODELING ================
+
+//To model the exitation hammer, we filter the sound from the soundboard with a serie of 4 one pole filters
+//connected in serie
+
+//onePole is declared in instrument.lib
+calcHammer = onePole((1-hammerPole)*hammerGain,-hammerPole)
+ with{
+ //filter gains and coefficients are stored in external C++ files
+ loudPole = ffunction(float getValueLoudPole(float), <piano.h>,"");
+ softPole = ffunction(float getValuePoleValue(float), <piano.h>,"");
+ loudGain = ffunction(float getValueLoudGain(float), <piano.h>,"");
+ softGain = ffunction(float getValueSoftGain(float), <piano.h>,"");
+
+ loudPoleValue = loudPole(freqn) + (brightnessFactor*-0.25) + 0.02;
+ softPoleValue = softPole(freqn);
+ normalizedVelocityValue = 1;
+ loudGainValue = loudGain(freqn);
+ softGainValue = softGain(freqn);
+ overallGain = 1;
+ hammerPole = softPoleValue + (loudPoleValue - softPoleValue)*normalizedVelocityValue;
+ hammerGain = overallGain*(softGainValue + (loudGainValue - softGainValue)*normalizedVelocityValue);
+ };
+
+hammer = seq(i,4,calcHammer);
+
+//==================== DC BLOCKERS ================
+
+//the values for the dcblockers a1 are stored in an external C++ file
+DCBa1 = ffunction(float getValueDCBa1(float), <piano.h>,"");
+dCBa1Value = freqn : DCBa1;
+dCBb0Value = 1 - dCBa1Value;
+
+dcBlock1 = poleZero((dCBb0Value*0.5),(dCBb0Value*-0.5),dCBa1Value);
+
+dcBlock2a = oneZero1(0.5,-0.5);
+
+dcBlock2b = onePole(dCBb0Value,dCBa1Value);
+
+//==================== HIGH TUNING CALCULATION ================
+
+//high tones are not generated with the waveguide technique but with a serie of biquad filters
+
+r1_1 = ffunction(float getValuer1_1db(float), <piano.h>,"");
+r1_2 = ffunction(float getValuer1_2db(float), <piano.h>,"");
+r2 = ffunction(float getValuer2db(float), <piano.h>,"");
+r3 = ffunction(float getValuer3db(float), <piano.h>,"");
+e = ffunction(float getValueSecondStageAmpRatio(float), <piano.h>,"");
+second_partial_factor = ffunction(float getValueSecondPartialFactor(float), <piano.h>,"");
+third_partial_factor = ffunction(float getValueThirdPartialFactor(float), <piano.h>,"");
+bq4_gEarBalled = ffunction(float getValueBq4_gEarBalled(float), <piano.h>,"");
+
+r1_1Value = r1_1(freqn)/SR : dbinv;
+r1_2Value = r1_2(freqn)/SR : dbinv;
+r2Value = r2(freqn)/SR : dbinv;
+r3Value = r3(freqn)/SR : dbinv;
+eValue = e(freqn) : dbinv;
+second_partial_factorValue = second_partial_factor(freqn);
+third_partial_factorValue = third_partial_factor(freqn);
+
+//set biquad gains and coeffs
+gainHighBq(0) = bq4_gEarBalled(freqn)/0.5;
+gainHighBq(1) = bq4_gEarBalled(freqn)/0.5;
+gainHighBq(2) = 1;
+gainHighBq(3) = 1;
+
+b0HighBq(0) = 1;
+b0HighBq(1) = 1;
+b0HighBq(2) = 1;
+b0HighBq(3) = 1;
+
+b1HighBq(0) = 0;
+b1HighBq(1) = 0;
+b1HighBq(2) = -2*(eValue*r1_1Value+(1-eValue)*r1_2Value)*cos(2*PI*freq/SR);
+b1HighBq(3) = 0;
+
+b2HighBq(0) = 0;
+b2HighBq(1) = 0;
+b2HighBq(2) = eValue*r1_1Value*r1_1Value+(1-eValue)*r1_2Value*r1_2Value;
+b2HighBq(3) = 0;
+
+a1HighBq(0) = -2*r3Value*cos(2*PI*freq*third_partial_factorValue/SR);
+a1HighBq(1) = -2*r2Value*cos(2*PI*freq*second_partial_factorValue/SR);
+a1HighBq(2) = -2*r1_1Value*cos(2*PI*freq/SR);
+a1HighBq(3) = -2*r1_2Value*cos(2*PI*freq/SR);
+
+a2HighBq(0) = r3Value*r3Value;
+a2HighBq(1) = r2Value*r2Value;
+a2HighBq(2) = r1_1Value*r1_1Value;
+a2HighBq(3) = r1_2Value*r1_2Value;
+
+highBqs = seq(i,4,*(gainHighBq(i)) : TF2(b0HighBq(i),b1HighBq(i),b2HighBq(i),a1HighBq(i),a2HighBq(i)));
+
+hiPass = oneZero1(b0,b1)
+ with{
+ b0 = -0.5;
+ b1 = -0.5;
+ };
+
+//==================== STRIKE POSITION COMB FILTER EQ ================
+
+eq = _*filterGain : TF2(b0,b1,b2,a1,a2)
+ with{
+ strikePosition = ffunction(float getValueStrikePosition(float), <piano.h>,"");
+ bandwidthFactors = ffunction(float getValueEQBandWidthFactor(float), <piano.h>,"");
+ eq_gain = ffunction(float getValueEQGain(float), <piano.h>,"");
+ eq_tuning = freq/strikePosition(freqn);
+ eq_bandwidth = bandwidthFactors(freqn)*freq;
+ filterGain = eq_gain(freqn);
+ a2 = (eq_bandwidth / SR) * (eq_bandwidth / SR);
+ a1 = -2*(eq_bandwidth / SR)*cos(2*PI*eq_tuning/SR);
+ b0 = 0.5 - 0.5 * a2;
+ b1 = 0;
+ b2 = -b0;
+ };
+
+//==================== PIANO COUPLED STRINGS ================
+
+//values for the couple strings are stored in externals C++ functions
+singleStringDecRate = ffunction(float getValueSingleStringDecayRate(float), <piano.h>,"");
+singleStringZero = ffunction(float getValueSingleStringZero(float), <piano.h>,"");
+singleStringPole = ffunction(float getValueSingleStringPole(float), <piano.h>,"");
+stiffnessCoefficient = ffunction(float getValueStiffnessCoefficient(float), <piano.h>,"");
+
+//coupling filter parameters
+g = pow(10,((singleStringDecRate(freqn)/freq)/20)); //attenuation per period
+b = singleStringZero(freqn);
+a = singleStringPole(freqn);
+tempd = 3*(1-b)-g*(1-a);
+b0Coupling = 2*(g*(1-a)-(1-b))/tempd;
+b1Coupling = 2*(a*(1-b)-g*(1-a)*b)/tempd;
+a1Coupling = (g*(1-a)*b - 3*a*(1-b))/tempd;
+
+//string stiffness
+stiffness = stiffnessFactor*stiffnessCoefficient(freqn);
+
+stiffnessAP = poleZero(b0s,b1s,a1s)
+ with{
+ b0s = stiffness;
+ b1s = 1;
+ a1s = stiffness;
+ };
+
+delayG(frequency,stiffnessCoefficient) = fdelay(4096,delayLength)
+ with{
+ allPassPhase(a1,WT) = atan2((a1*a1-1.0)*sin(WT),(2.0*a1+(a1*a1+1.0)*cos(WT)));
+ poleZeroPhase(b0,b1,a1,WT) = atan2(-b1*sin(WT)*(1 + a1*cos(WT)) + a1*sin(WT)*(b0 + b1*cos(WT)),
+ (b0 + b1*cos(WT))*(1 + a1*cos(WT)) + b1*sin(WT)*a1*sin(WT));
+ wT = frequency*2*PI/SR;
+ delayLength = (2*PI + 3*allPassPhase(stiffnessCoefficient, wT) +
+ poleZeroPhase((1+2*b0Coupling),
+ a1Coupling + 2*b1Coupling, a1Coupling, wT)) / wT;
+ };
+
+coupledStrings = (parallelStrings <: (_,(_+_ <: _,_),_ : _,_,(_ : couplingFilter),_ : adder))~(_,_) : !,!,_
+ with{
+ releaseLoopGain = ffunction(float getValueReleaseLoopGain(float), <piano.h>,"");
+ hz = ffunction(float getValueDetuningHz(float), <piano.h>,"");
+ coupledStringLoopGain = gate*0.9996 + ((gate-1)*-1)*releaseLoopGain(freqn)*0.9 : smooth(0.999);
+ couplingFilter = poleZero(b0Coupling,b1Coupling,a1Coupling);
+ hzValue = hz(freqn);
+ freq1 = freq + 0.5*hzValue*detuningFactor;
+ freq2 = freq - 0.5*hzValue*detuningFactor;
+ delay1 = delayG(freq1,stiffness);
+ delay2 = delayG(freq2,stiffness);
+ parallelStrings(x,y) = _ <: (+(x)*coupledStringLoopGain : seq(i,3,stiffnessAP) : delay1),
+ (_+y*coupledStringLoopGain : seq(i,3,stiffnessAP) : delay2);
+ adder(w,x,y,z) = (y <: +(w),+(z)),x ;
+ };
+
+//stereoizer is declared in instrument.lib and implement a stereo spacialisation in function of
+//the frequency period in number of samples
+stereo = stereoizer(SR/freq);
+
+//==================== PROCESSING ================
+
+conditionLowNote = freqn < FIRST_HIGH_NOTE;
+conditionHighNote = freqn >= FIRST_HIGH_NOTE;
+
+process = soundBoard <: (*(conditionLowNote)*6 : hammer : dcBlock1 : coupledStrings <: +(eq)),
+(*(conditionHighNote) : hiPass : dcBlock1 : hammer : dcBlock2a : highBqs : dcBlock2b) :> + : *(12) :
+stereo : instrReverb;
projects / Faustine.git / blobdiff