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Version 4.4.3

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This commit is contained in:
Gary Scavone
2013-09-29 23:21:29 +02:00
committed by Stephen Sinclair
parent baca57040b
commit 0aec39260a
223 changed files with 26190 additions and 11130 deletions
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42
include/Filter.h
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@@ -3,6 +3,7 @@
#include "Stk.h"
#include <vector>
#include <cmath>
namespace stk {
@@ -14,7 +15,7 @@ namespace stk {
filter subclasses. It is general enough to support both
monophonic and polyphonic input/output classes.
by Perry R. Cook and Gary P. Scavone, 1995 - 2010.
by Perry R. Cook and Gary P. Scavone, 1995-2011.
*/
/***************************************************/
@@ -43,6 +44,14 @@ public:
//! Return the current filter gain.
StkFloat getGain( void ) const { return gain_; };
//! Return the filter phase delay at the specified frequency.
/*!
Note that the phase delay calculation accounts for the filter
gain. The frequency value should be greater than 0.0 and less
than or equal to one-half the sample rate.
*/
StkFloat phaseDelay( StkFloat frequency );
//! Return an StkFrames reference to the last output sample frame.
const StkFrames& lastFrame( void ) const { return lastFrame_; };
@@ -59,10 +68,10 @@ public:
protected:
StkFloat gain_;
unsigned int channelsIn_;
StkFrames lastFrame_;
StkFloat gain_;
std::vector<StkFloat> b_;
std::vector<StkFloat> a_;
StkFrames outputs_;
@@ -81,6 +90,35 @@ inline void Filter :: clear( void )
lastFrame_[i] = 0.0;
}
inline StkFloat Filter :: phaseDelay( StkFloat frequency )
{
if ( frequency <= 0.0 || frequency > 0.5 * Stk::sampleRate() ) {
oStream_ << "Filter::phaseDelay: argument (" << frequency << ") is out of range!";
handleError( StkError::WARNING ); return 0.0;
}
StkFloat omegaT = 2 * M_PI * frequency / Stk::sampleRate();
StkFloat real = 0.0, imag = 0.0;
for ( unsigned int i=0; i<b_.size(); i++ ) {
real += b_[i] * std::cos( i * omegaT );
imag -= b_[i] * std::sin( i * omegaT );
}
real *= gain_;
imag *= gain_;
StkFloat phase = atan2( imag, real );
real = 0.0, imag = 0.0;
for ( unsigned int i=0; i<a_.size(); i++ ) {
real += a_[i] * std::cos( i * omegaT );
imag -= a_[i] * std::sin( i * omegaT );
}
phase -= std::atan2( imag, real );
phase = std::fmod( -phase, 2 * M_PI );
return phase / omegaT;
}
} // stk namespace
#endif