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JetTable.h
1 #ifndef STK_JETTABL_H
2 #define STK_JETTABL_H
3
4 #include "Function.h"
5
6 namespace stk {
7
8 /***************************************************/
21 /***************************************************/
22
23 class JetTable : public Function
24 {
25 public:
26
28 StkFloat tick( StkFloat input );
29
31
39 StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
40
42
50 StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
51
52 };
53
54 inline StkFloat JetTable :: tick( StkFloat input )
55 {
56 // Perform "table lookup" using a polynomial
57 // calculation (x^3 - x), which approximates
58 // the jet sigmoid behavior.
59 lastFrame_[0] = input * (input * input - 1.0);
60
61 // Saturate at +/- 1.0.
62 if ( lastFrame_[0] > 1.0 ) lastFrame_[0] = 1.0;
63 if ( lastFrame_[0] < -1.0 ) lastFrame_[0] = -1.0;
64 return lastFrame_[0];
65 }
66
67 inline StkFrames& JetTable :: tick( StkFrames& frames, unsigned int channel )
68 {
69 #if defined(_STK_DEBUG_)
70 if ( channel >= frames.channels() ) {
71 oStream_ << "JetTable::tick(): channel and StkFrames arguments are incompatible!";
72 handleError( StkError::FUNCTION_ARGUMENT );
73 }
74 #endif
75
76 StkFloat *samples = &frames[channel];
77 unsigned int hop = frames.channels();
78 for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
79 *samples = *samples * (*samples * *samples - 1.0);
80 if ( *samples > 1.0) *samples = 1.0;
81 if ( *samples < -1.0) *samples = -1.0;
82 }
83
84 lastFrame_[0] = *(samples-hop);
85 return frames;
86 }
87
88 inline StkFrames& JetTable :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
89 {
90 #if defined(_STK_DEBUG_)
91 if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
92 oStream_ << "JetTable::tick(): channel and StkFrames arguments are incompatible!";
93 handleError( StkError::FUNCTION_ARGUMENT );
94 }
95 #endif
96
97 StkFloat *iSamples = &iFrames[iChannel];
98 StkFloat *oSamples = &oFrames[oChannel];
99 unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
100 for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
101 *oSamples = *oSamples * (*oSamples * *oSamples - 1.0);
102 if ( *oSamples > 1.0) *oSamples = 1.0;
103 if ( *oSamples < -1.0) *oSamples = -1.0;
104 }
105
106 lastFrame_[0] = *(oSamples-oHop);
107 return iFrames;
108 }
109
110 } // stk namespace
111
112 #endif

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