robert@464: /*
robert@464:  * FeedbackOscillator.h
robert@464:  *
robert@464:  *  Created on: June 8, 2014
robert@464:  *      Author: Andrew McPherson
robert@464:  */
robert@464: 
robert@464: #ifndef FEEDBACKOSCILLATOR_H
robert@464: #define FEEDBACKOSCILLATOR_H
robert@464: 
robert@464: class FeedbackOscillator
robert@464: {
robert@464: public:
robert@464: 	FeedbackOscillator();
robert@464: 	~FeedbackOscillator();
robert@464: 
robert@464: 	// Initialise the settings for the feedback oscillator
robert@464: 	void initialise(int maxTableSize, float hpfCutoffFrequency, float matrixSampleRate);
robert@464: 
robert@464: 	// Process one sample and store the output value
robert@464: 	// Returns the length of table to interpolate; or 0 if nothing to process further
robert@464: 	int process(float input, float *output);
robert@464: 
robert@464: 	float *wavetable() { return wavetableRead; }
robert@464: 
robert@464: private:
robert@464: 	float coeffs[3];			// Coefficients of first-order high-pass filter
robert@464: 	float lastInput;			// last input sample for HPF
robert@464: 	float lastOutput;			// last output sample of HPF
robert@464: 	bool triggered;				// whether we are currently saving samples
robert@464: 	bool canTrigger;			// whether we are able to begin saving samples
robert@464: 	int wavetableMaxLength;		// how long the stored wavetable can be
robert@464: 	int sampleCount;			// how many samples have elapsed
robert@464: 	int lastTriggerCount;		// sample count when we last triggered
robert@464: 
robert@464: 	float *wavetable1, *wavetable2;			// Two wavetables where we record samples
robert@464: 	float *wavetableRead, *wavetableWrite;	// Pointers to the above wavetables
robert@464: 	int wavetableWritePointer;				// Where we are currently writing
robert@464: };
robert@464: 
robert@464: #endif