The Synthesis ToolKit in C++ (STK)

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OnePole.h
1 #ifndef STK_ONEPOLE_H
2 #define STK_ONEPOLE_H
3
4 #include "Filter.h"
5
6 namespace stk {
7
8 /***************************************************/
18 /***************************************************/
19
20 class OnePole : public Filter
21 {
22 public:
23
25 OnePole( StkFloat thePole = 0.9 );
26
28 ~OnePole();
29
31 void setB0( StkFloat b0 ) { b_[0] = b0; };
32
34 void setA1( StkFloat a1 ) { a_[1] = a1; };
35
37 void setCoefficients( StkFloat b0, StkFloat a1, bool clearState = false );
38
40
48 void setPole( StkFloat thePole );
49
51 StkFloat lastOut( void ) const { return lastFrame_[0]; };
52
54 StkFloat tick( StkFloat input );
55
57
65 StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
66
68
76 StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
77
78 };
79
80 inline StkFloat OnePole :: tick( StkFloat input )
81 {
82 inputs_[0] = gain_ * input;
83 lastFrame_[0] = b_[0] * inputs_[0] - a_[1] * outputs_[1];
84 outputs_[1] = lastFrame_[0];
85
86 return lastFrame_[0];
87 }
88
89 inline StkFrames& OnePole :: tick( StkFrames& frames, unsigned int channel )
90 {
91 #if defined(_STK_DEBUG_)
92 if ( channel >= frames.channels() ) {
93 oStream_ << "OnePole::tick(): channel and StkFrames arguments are incompatible!";
94 handleError( StkError::FUNCTION_ARGUMENT );
95 }
96 #endif
97
98 StkFloat *samples = &frames[channel];
99 unsigned int hop = frames.channels();
100 for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
101 inputs_[0] = gain_ * *samples;
102 *samples = b_[0] * inputs_[0] - a_[1] * outputs_[1];
103 outputs_[1] = *samples;
104 }
105
106 lastFrame_[0] = outputs_[1];
107 return frames;
108 }
109
110 inline StkFrames& OnePole :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
111 {
112 #if defined(_STK_DEBUG_)
113 if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
114 oStream_ << "OnePole::tick(): channel and StkFrames arguments are incompatible!";
115 handleError( StkError::FUNCTION_ARGUMENT );
116 }
117 #endif
118
119 StkFloat *iSamples = &iFrames[iChannel];
120 StkFloat *oSamples = &oFrames[oChannel];
121 unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
122 for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
123 inputs_[0] = gain_ * *iSamples;
124 *oSamples = b_[0] * inputs_[0] - a_[1] * outputs_[1];
125 outputs_[1] = *oSamples;
126 }
127
128 lastFrame_[0] = outputs_[1];
129 return iFrames;
130 }
131
132 } // stk namespace
133
134 #endif
stk::Stk::handleError
static void handleError(const char *message, StkError::Type type)
Static function for error reporting and handling using c-strings.
stk::StkFrames::frames
unsigned int frames(void) const
Return the number of sample frames represented by the data.
Definition: Stk.h:407
stk::OnePole::setB0
void setB0(StkFloat b0)
Set the b[0] coefficient value.
Definition: OnePole.h:31
stk::OnePole::setCoefficients
void setCoefficients(StkFloat b0, StkFloat a1, bool clearState=false)
Set all filter coefficients.
stk::Filter
STK abstract filter class.
Definition: Filter.h:22
stk
The STK namespace.
Definition: ADSR.h:6
stk::OnePole::setPole
void setPole(StkFloat thePole)
Set the pole position in the z-plane.
stk::OnePole::tick
StkFloat tick(StkFloat input)
Input one sample to the filter and return one output.
Definition: OnePole.h:80
stk::OnePole
STK one-pole filter class.
Definition: OnePole.h:20
stk::OnePole::lastOut
StkFloat lastOut(void) const
Return the last computed output value.
Definition: OnePole.h:51
stk::StkFrames::channels
unsigned int channels(void) const
Return the number of channels represented by the data.
Definition: Stk.h:404
stk::OnePole::~OnePole
~OnePole()
Class destructor.
stk::StkFrames
An STK class to handle vectorized audio data.
Definition: Stk.h:275
stk::OnePole::OnePole
OnePole(StkFloat thePole=0.9)
The default constructor creates a low-pass filter (pole at z = 0.9).
stk::OnePole::setA1
void setA1(StkFloat a1)
Set the a[1] coefficient value.
Definition: OnePole.h:34

The Synthesis ToolKit in C++ (STK)
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