robert@464: /*
robert@464:  *
robert@464:  * Simple 1-Dimensional Waveguide
robert@464:  *
robert@464:  * Christian Heinrichs 04/2015
robert@464:  *
robert@464:  */
robert@464: 
robert@464: #ifndef WAVEGUIDE_H_
robert@464: #define WAVEGUIDE_H_
robert@464: 
robert@464: #include <cmath>
robert@464: 
robert@464: #ifndef WG_BUFFER_SIZE
robert@464: #define WG_BUFFER_SIZE 4096
robert@464: #endif
robert@464: 
robert@464: #ifndef FILTER_BUFFER_SIZE
robert@464: #define FILTER_BUFFER_SIZE 4
robert@464: #endif
robert@464: 
robert@464: #ifndef		M_PI
robert@464: #define		M_PI		3.14159265358979323846264338
robert@464: #endif
robert@464: 
robert@464: class Waveguide
robert@464: {
robert@464: 
robert@464: public:
robert@464: 
robert@464: 	Waveguide();
robert@464: 	void setup();
robert@464: 	float update(float in);
robert@464: 	void updateFilterCoeffs(float frequency);
robert@464: 	void setFrequency(float frequency);
robert@464: 
robert@464: private:
robert@464: 
robert@464: 	double _dt;
robert@464: 	float _periodInMilliseconds;
robert@464: 	int _periodInSamples;
robert@464: 
robert@464: 	float _buffer[WG_BUFFER_SIZE];
robert@464: 	int _readPtr;
robert@464: 
robert@464: 	float _filterBuffer_x[FILTER_BUFFER_SIZE];
robert@464: 	float _filterBuffer_y[FILTER_BUFFER_SIZE];
robert@464: 	float _hipBuffer_x[FILTER_BUFFER_SIZE];
robert@464: 	float _hipBuffer_y[FILTER_BUFFER_SIZE];
robert@464: 	int _filterReadPtr;
robert@464: 
robert@464: 	float b0_lp,b1_lp,b2_lp,a1_lp, a2_lp;
robert@464: 	float _lastY,_lastX;
robert@464: 
robert@464: };
robert@464: 
robert@464: #endif