1 /***************************************************/
2 /*! \class Flute
3 \brief STK flute physical model class.
4
5 This class implements a simple flute
6 physical model, as discussed by Karjalainen,
7 Smith, Waryznyk, etc. The jet model uses
8 a polynomial, a la Cook.
9
10 This is a digital waveguide model, making its
11 use possibly subject to patents held by Stanford
12 University, Yamaha, and others.
13
14 Control Change Numbers:
15 - Jet Delay = 2
16 - Noise Gain = 4
17 - Vibrato Frequency = 11
18 - Vibrato Gain = 1
19 - Breath Pressure = 128
20
21 by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
22 */
23 /***************************************************/
24
25 #include "Flute.h"
26 #include "SKINI.msg"
27
28 using namespace Nyq;
29
Flute(StkFloat lowestFrequency)30 Flute :: Flute(StkFloat lowestFrequency)
31 {
32 length_ = (unsigned long) (Stk::sampleRate() / lowestFrequency + 1);
33 boreDelay_.setMaximumDelay( length_ );
34 boreDelay_.setDelay( 100.0 );
35
36 length_ >>= 1;
37 jetDelay_.setMaximumDelay( length_ );
38 jetDelay_.setDelay( 49.0 );
39
40 vibrato_.setFrequency( 5.925 );
41
42 this->clear();
43
44 filter_.setPole( 0.7 - ((StkFloat) 0.1 * 22050.0 / Stk::sampleRate() ) );
45 filter_.setGain( -1.0 );
46
47 dcBlock_.setBlockZero();
48
49 adsr_.setAllTimes( 0.005, 0.01, 0.8, 0.010);
50 endReflection_ = 0.5;
51 jetReflection_ = 0.5;
52 noiseGain_ = 0.15; // Breath pressure random component.
53 vibratoGain_ = 0.05; // Breath periodic vibrato component.
54 jetRatio_ = 0.32;
55
56 maxPressure_ = 0.0;
57 lastFrequency_ = 220.0;
58 }
59
~Flute()60 Flute :: ~Flute()
61 {
62 }
63
clear()64 void Flute :: clear()
65 {
66 jetDelay_.clear();
67 boreDelay_.clear();
68 filter_.clear();
69 dcBlock_.clear();
70 }
71
setFrequency(StkFloat frequency)72 void Flute :: setFrequency(StkFloat frequency)
73 {
74 lastFrequency_ = frequency;
75 if ( frequency <= 0.0 ) {
76 errorString_ << "Flute::setFrequency: parameter is less than or equal to zero!";
77 handleError( StkError::WARNING );
78 lastFrequency_ = 220.0;
79 }
80
81 // We're overblowing here.
82 lastFrequency_ *= 0.66666;
83
84 // delay = length - approximate filter delay.
85 StkFloat delay = Stk::sampleRate() / lastFrequency_ - (StkFloat) 2.0;
86 if ( delay <= 0.0 ) delay = 0.3;
87 else if ( delay > length_ ) delay = length_;
88
89 boreDelay_.setDelay(delay);
90 jetDelay_.setDelay(delay * jetRatio_);
91 }
92
startBlowing(StkFloat amplitude,StkFloat rate)93 void Flute :: startBlowing(StkFloat amplitude, StkFloat rate)
94 {
95 adsr_.setAttackRate( rate );
96 maxPressure_ = amplitude / (StkFloat) 0.8;
97 adsr_.keyOn();
98 }
99
stopBlowing(StkFloat rate)100 void Flute :: stopBlowing(StkFloat rate)
101 {
102 adsr_.setReleaseRate( rate );
103 adsr_.keyOff();
104 }
105
noteOn(StkFloat frequency,StkFloat amplitude)106 void Flute :: noteOn(StkFloat frequency, StkFloat amplitude)
107 {
108 this->setFrequency( frequency );
109 this->startBlowing( 1.1 + (amplitude * 0.20), amplitude * 0.02 );
110 outputGain_ = amplitude + 0.001;
111
112 #if defined(_STK_DEBUG_)
113 errorString_ << "Flute::NoteOn: frequency = " << frequency << ", amplitude = " << amplitude << ".";
114 handleError( StkError::DEBUG_WARNING );
115 #endif
116 }
117
noteOff(StkFloat amplitude)118 void Flute :: noteOff(StkFloat amplitude)
119 {
120 this->stopBlowing( amplitude * 0.02 );
121
122 #if defined(_STK_DEBUG_)
123 errorString_ << "Flute::NoteOff: amplitude = " << amplitude << ".";
124 handleError( StkError::DEBUG_WARNING );
125 #endif
126 }
127
setJetReflection(StkFloat coefficient)128 void Flute :: setJetReflection(StkFloat coefficient)
129 {
130 jetReflection_ = coefficient;
131 }
132
setEndReflection(StkFloat coefficient)133 void Flute :: setEndReflection(StkFloat coefficient)
134 {
135 endReflection_ = coefficient;
136 }
137
setJetDelay(StkFloat aRatio)138 void Flute :: setJetDelay(StkFloat aRatio)
139 {
140 // Delay = length - approximate filter delay.
141 StkFloat temp = Stk::sampleRate() / lastFrequency_ - (StkFloat) 2.0;
142 jetRatio_ = aRatio;
143 jetDelay_.setDelay(temp * aRatio); // Scaled by ratio.
144 }
145
computeSample()146 StkFloat Flute :: computeSample()
147 {
148 StkFloat pressureDiff;
149 StkFloat breathPressure;
150
151 // Calculate the breath pressure (envelope + noise + vibrato)
152 breathPressure = maxPressure_ * adsr_.tick();
153 breathPressure += breathPressure * ( noiseGain_ * noise_.tick() + vibratoGain_ * vibrato_.tick() );
154 //breathPressure += breathPressure * vibratoGain_ * vibrato_.tick();
155
156 StkFloat temp = filter_.tick( boreDelay_.lastOut() );
157 temp = dcBlock_.tick( temp ); // Block DC on reflection.
158
159 pressureDiff = breathPressure - (jetReflection_ * temp);
160 pressureDiff = jetDelay_.tick( pressureDiff );
161 pressureDiff = jetTable_.tick( pressureDiff ) + (endReflection_ * temp);
162 lastOutput_ = (StkFloat) 0.3 * boreDelay_.tick( pressureDiff );
163
164 lastOutput_ *= outputGain_;
165 return lastOutput_;
166 }
167
controlChange(int number,StkFloat value)168 void Flute :: controlChange(int number, StkFloat value)
169 {
170 StkFloat norm = value * ONE_OVER_128;
171 if ( norm < 0 ) {
172 norm = 0.0;
173 errorString_ << "Flute::controlChange: control value less than zero ... setting to zero!";
174 handleError( StkError::WARNING );
175 }
176 else if ( norm > 1.0 ) {
177 norm = 1.0;
178 errorString_ << "Flute::controlChange: control value greater than 128.0 ... setting to 128.0!";
179 handleError( StkError::WARNING );
180 }
181
182 if (number == __SK_JetDelay_) // 2
183 this->setJetDelay( (StkFloat) (0.08 + (0.48 * norm)) );
184 else if (number == __SK_NoiseLevel_) // 4
185 noiseGain_ = ( norm * 0.4);
186 else if (number == __SK_ModFrequency_) // 11
187 vibrato_.setFrequency( norm * 12.0);
188 else if (number == __SK_ModWheel_) // 1
189 vibratoGain_ = ( norm * 0.4 );
190 else if (number == __SK_AfterTouch_Cont_) // 128
191 adsr_.setTarget( norm );
192 else {
193 errorString_ << "Flute::controlChange: undefined control number (" << number << ")!";
194 handleError( StkError::WARNING );
195 }
196
197 #if defined(_STK_DEBUG_)
198 errorString_ << "Flute::controlChange: number = " << number << ", value = " << value << ".";
199 handleError( StkError::DEBUG_WARNING );
200 #endif
201 }
202