teensy-audio/mixer.h

#ifndef mixer_h_
#define mixer_h_

#include "AudioStream.h"

class AudioMixer4 : public AudioStream
{
public:
        AudioMixer4(void) : AudioStream(4, inputQueueArray) {
		for (int i=0; i<4; i++) multiplier[i] = 65536;
	}
        virtual void update(void);
	void gain(unsigned int channel, float gain) {
		if (channel >= 4) return;
		if (gain > 32767.0f) gain = 32767.0f;
		else if (gain < 0.0f) gain = 0.0f;
		multiplier[channel] = gain * 65536.0f; // TODO: proper roundoff?
	}
private:
	int32_t multiplier[4];
	audio_block_t *inputQueueArray[4];
};

#endif