psyn/voice.c

#include <stdint.h>
#include <stdbool.h>
#include <math.h>
#include "osc.h"
#include "env.h"
#include "voice.h"
#include "psyn.h"

static inline void voice_tick(struct voice_t *voice)
{
	unsigned i;
	for (i = 0; i < VOICE_OSCILLATORS; i++) {
		osc_tick(voice->osc + i);
	}

	voice->sample++;
}

static double _R = 4700.0;
static double _C = 0.000000047;

static inline void voice_filter(struct voice_t *voice, float l, float r)
{
	double k = 1.0 / (_R * _C) / _sample_rate;

	voice->last_l += k * (l - voice->last_l);
	voice->last_r += k * (r - voice->last_r);
}

void voice_run(struct voice_t *voice, uint32_t samples, float *left, float *right)
{
//	uint32_t pos;
	double amplitude;
	double l;
	double r;

	//for (pos = 0; pos < samples; pos++) {
	voice_tick(voice);

	amplitude = env_getamplitude(&_env, voice->sample, voice->released);

	if (amplitude <= 0.0001) {
		voice->playing = false;
		return;
	}

	amplitude *= voice->velocity;

	l = amplitude * voice->osc[0].saw;
	r = amplitude * voice->osc[0].saw;

	amplitude = env_getamplitude(&_env2, voice->sample, voice->released) * voice->velocity * voice->velocity * 1.5;

	if (amplitude > 0.0) {
		l += amplitude * voice->osc[1].tri * (1.0 + voice->osc[2].sin * 0.25);
		r += amplitude * voice->osc[1].tri * (1.0 + voice->osc[2].sin * 0.25);
	}

	voice_filter(voice, l, r);

	*left += voice->last_l;
	*right += voice->last_r;
//	}
}