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- #ifndef STK_MESH2D_H
- #define STK_MESH2D_H
-
- #include "Instrmnt.h"
- #include "OnePole.h"
-
- namespace stk {
-
- /***************************************************/
- /*! \class Mesh2D
- \brief Two-dimensional rectilinear waveguide mesh class.
-
- This class implements a rectilinear,
- two-dimensional digital waveguide mesh
- structure. For details, see Van Duyne and
- Smith, "Physical Modeling with the 2-D Digital
- Waveguide Mesh", Proceedings of the 1993
- International Computer Music Conference.
-
- This is a digital waveguide model, making its
- use possibly subject to patents held by Stanford
- University, Yamaha, and others.
-
- Control Change Numbers:
- - X Dimension = 2
- - Y Dimension = 4
- - Mesh Decay = 11
- - X-Y Input Position = 1
-
- by Julius Smith, 2000 - 2002.
- Revised by Gary Scavone for STK, 2002.
- */
- /***************************************************/
-
- const unsigned short NXMAX = 12;
- const unsigned short NYMAX = 12;
-
- class Mesh2D : public Instrmnt
- {
- public:
- //! Class constructor, taking the x and y dimensions in samples.
- Mesh2D( unsigned short nX, unsigned short nY );
-
- //! Class destructor.
- ~Mesh2D( void );
-
- //! Reset and clear all internal state.
- void clear( void );
-
- //! Set the x dimension size in samples.
- void setNX( unsigned short lenX );
-
- //! Set the y dimension size in samples.
- void setNY( unsigned short lenY );
-
- //! Set the x, y input position on a 0.0 - 1.0 scale.
- void setInputPosition( StkFloat xFactor, StkFloat yFactor );
-
- //! Set the loss filters gains (0.0 - 1.0).
- void setDecay( StkFloat decayFactor );
-
- //! Impulse the mesh with the given amplitude (frequency ignored).
- void noteOn( StkFloat frequency, StkFloat amplitude );
-
- //! Stop a note with the given amplitude (speed of decay) ... currently ignored.
- void noteOff( StkFloat amplitude );
-
- //! Calculate and return the signal energy stored in the mesh.
- StkFloat energy( void );
-
- //! Input a sample to the mesh and compute one output sample.
- StkFloat inputTick( StkFloat input );
-
- //! Perform the control change specified by \e number and \e value (0.0 - 128.0).
- void controlChange( int number, StkFloat value );
-
- //! Compute and return one output sample.
- StkFloat tick( unsigned int channel = 0 );
-
- //! 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:
-
- StkFloat tick0();
- StkFloat tick1();
- void clearMesh();
-
- unsigned short NX_, NY_;
- unsigned short xInput_, yInput_;
- OnePole filterX_[NXMAX];
- OnePole filterY_[NYMAX];
- StkFloat v_[NXMAX-1][NYMAX-1]; // junction velocities
- StkFloat vxp_[NXMAX][NYMAX]; // positive-x velocity wave
- StkFloat vxm_[NXMAX][NYMAX]; // negative-x velocity wave
- StkFloat vyp_[NXMAX][NYMAX]; // positive-y velocity wave
- StkFloat vym_[NXMAX][NYMAX]; // negative-y velocity wave
-
- // Alternate buffers
- StkFloat vxp1_[NXMAX][NYMAX]; // positive-x velocity wave
- StkFloat vxm1_[NXMAX][NYMAX]; // negative-x velocity wave
- StkFloat vyp1_[NXMAX][NYMAX]; // positive-y velocity wave
- StkFloat vym1_[NXMAX][NYMAX]; // negative-y velocity wave
-
- int counter_; // time in samples
- };
-
- inline StkFrames& Mesh2D :: tick( StkFrames& frames, unsigned int channel )
- {
- unsigned int nChannels = lastFrame_.channels();
- #if defined(_STK_DEBUG_)
- if ( channel > frames.channels() - nChannels ) {
- oStream_ << "Mesh2D::tick(): channel and StkFrames arguments are incompatible!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
- #endif
-
- StkFloat *samples = &frames[channel];
- unsigned int j, hop = frames.channels() - nChannels;
- if ( nChannels == 1 ) {
- for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
- *samples++ = tick();
- }
- else {
- for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
- *samples++ = tick();
- for ( j=1; j<nChannels; j++ )
- *samples++ = lastFrame_[j];
- }
- }
-
- return frames;
- }
-
- } // stk namespace
-
- #endif
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