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Version 4.4.0

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This commit is contained in:
Gary Scavone
2013-09-29 23:11:39 +02:00
committed by Stephen Sinclair
parent d199342e86
commit eccd8c9981
287 changed files with 11712 additions and 7676 deletions
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87
include/BlitSquare.h
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@@ -1,3 +1,12 @@
#ifndef STK_BLITSQUARE_H
#define STK_BLITSQUARE_H
#include "Generator.h"
#include <cmath>
#include <limits>
namespace stk {
/***************************************************/
/*! \class BlitSquare
\brief STK band-limited square wave class.
@@ -30,11 +39,6 @@
*/
/***************************************************/
#ifndef STK_BLITSQUARE_H
#define STK_BLITSQUARE_H
#include "Generator.h"
class BlitSquare: public Generator
{
public:
@@ -77,10 +81,25 @@ class BlitSquare: public Generator
*/
void setHarmonics( unsigned int nHarmonics = 0 );
//! Return the last computed output value.
StkFloat lastOut( void ) const { return lastFrame_[0]; };
//! Compute and return one output sample.
StkFloat tick( void );
//! Fill a channel of the StkFrames object with computed outputs.
/*!
The \c channel argument must be less than the number of
channels in the StkFrames argument (the first channel is specified
by 0). However, range checking is only performed if _STK_DEBUG_
is defined during compilation, in which case an out-of-range value
will trigger an StkError exception.
*/
StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
protected:
void updateHarmonics( void );
StkFloat computeSample( void );
unsigned int nHarmonics_;
unsigned int m_;
@@ -92,4 +111,60 @@ class BlitSquare: public Generator
StkFloat dcbState_;
};
inline StkFloat BlitSquare :: tick( void )
{
StkFloat temp = lastBlitOutput_;
// A fully optimized version of this would replace the two sin calls
// with a pair of fast sin oscillators, for which stable fast
// two-multiply algorithms are well known. In the spirit of STK,
// which favors clarity over performance, the optimization has
// not been made here.
// Avoid a divide by zero, or use of a denomralized divisor
// at the sinc peak, which has a limiting value of 1.0.
StkFloat denominator = sin( phase_ );
if ( fabs( denominator ) < std::numeric_limits<StkFloat>::epsilon() ) {
// Inexact comparison safely distinguishes betwen *close to zero*, and *close to PI*.
if ( phase_ < 0.1f || phase_ > TWO_PI - 0.1f )
lastBlitOutput_ = a_;
else
lastBlitOutput_ = -a_;
}
else {
lastBlitOutput_ = sin( m_ * phase_ );
lastBlitOutput_ /= p_ * denominator;
}
lastBlitOutput_ += temp;
// Now apply DC blocker.
lastFrame_[0] = lastBlitOutput_ - dcbState_ + 0.999 * lastFrame_[0];
dcbState_ = lastBlitOutput_;
phase_ += rate_;
if ( phase_ >= TWO_PI ) phase_ -= TWO_PI;
return lastFrame_[0];
}
inline StkFrames& BlitSquare :: tick( StkFrames& frames, unsigned int channel )
{
#if defined(_STK_DEBUG_)
if ( channel >= frames.channels() ) {
errorString_ << "BlitSquare::tick(): channel and StkFrames arguments are incompatible!";
handleError( StkError::FUNCTION_ARGUMENT );
}
#endif
StkFloat *samples = &frames[channel];
unsigned int hop = frames.channels();
for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
*samples = BlitSquare::tick();
return frames;
}
} // stk namespace
#endif