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ADSR.h
1 #ifndef STK_ADSR_H
2 #define STK_ADSR_H
3
4 #include "Generator.h"
5
6 namespace stk {
7
8 /***************************************************/
22 /***************************************************/
23
24 class ADSR : public Generator
25 {
26 public:
27
29 enum {
30 ATTACK,
31 DECAY,
32 SUSTAIN,
33 RELEASE,
34 IDLE
35 };
36
38 ADSR( void );
39
41 ~ADSR( void );
42
44 void keyOn( void );
45
47 void keyOff( void );
48
50 void setAttackRate( StkFloat rate );
51
53 void setAttackTarget( StkFloat target );
54
56 void setDecayRate( StkFloat rate );
57
59 void setSustainLevel( StkFloat level );
60
62 void setReleaseRate( StkFloat rate );
63
65 void setAttackTime( StkFloat time );
66
68 void setDecayTime( StkFloat time );
69
71 void setReleaseTime( StkFloat time );
72
74 void setAllTimes( StkFloat aTime, StkFloat dTime, StkFloat sLevel, StkFloat rTime );
75
77 void setTarget( StkFloat target );
78
80 int getState( void ) const { return state_; };
81
83 void setValue( StkFloat value );
84
86 StkFloat lastOut( void ) const { return lastFrame_[0]; };
87
89 StkFloat tick( void );
90
92
99 StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
100
101 protected:
102
103 void sampleRateChanged( StkFloat newRate, StkFloat oldRate );
104
105 int state_;
106 StkFloat value_;
107 StkFloat target_;
108 StkFloat attackRate_;
109 StkFloat decayRate_;
110 StkFloat releaseRate_;
111 StkFloat releaseTime_;
112 StkFloat sustainLevel_;
113 };
114
115 inline StkFloat ADSR :: tick( void )
116 {
117 switch ( state_ ) {
118
119 case ATTACK:
120 value_ += attackRate_;
121 if ( value_ >= target_ ) {
122 value_ = target_;
123 target_ = sustainLevel_;
124 state_ = DECAY;
125 }
126 lastFrame_[0] = value_;
127 break;
128
129 case DECAY:
130 if ( value_ > sustainLevel_ ) {
131 value_ -= decayRate_;
132 if ( value_ <= sustainLevel_ ) {
133 value_ = sustainLevel_;
134 state_ = SUSTAIN;
135 }
136 }
137 else {
138 value_ += decayRate_; // attack target < sustain level
139 if ( value_ >= sustainLevel_ ) {
140 value_ = sustainLevel_;
141 state_ = SUSTAIN;
142 }
143 }
144 lastFrame_[0] = value_;
145 break;
146
147 case RELEASE:
148 value_ -= releaseRate_;
149 if ( value_ <= 0.0 ) {
150 value_ = 0.0;
151 state_ = IDLE;
152 }
153 lastFrame_[0] = value_;
154
155 }
156
157 return value_;
158 }
159
160 inline StkFrames& ADSR :: tick( StkFrames& frames, unsigned int channel )
161 {
162 #if defined(_STK_DEBUG_)
163 if ( channel >= frames.channels() ) {
164 oStream_ << "ADSR::tick(): channel and StkFrames arguments are incompatible!";
165 handleError( StkError::FUNCTION_ARGUMENT );
166 }
167 #endif
168
169 StkFloat *samples = &frames[channel];
170 unsigned int hop = frames.channels();
171 for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
172 *samples = ADSR::tick();
173
174 return frames;
175 }
176
177 } // stk namespace
178
179 #endif

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