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

static double _freqs[128];

void engine_init()
{
	uint32_t i;

	for (i = 0; i < 128; i++) {
		_freqs[i] = 440.0 * pow(2.0, (i - 69.0) / 12.0);
	}

	osc_init();
	env_init(&_env, 0.0125, 0.025, 5.0, 0.0, 0.25);
	env_init(&_env2, 0.0125, 0.025, 0.5, 0.0, 0.25);
}

void engine_run(struct engine_t *engine, uint32_t samples, float *left, float *right)
{
	struct voice_t *v;
	uint32_t pos;
	uint32_t i;

	for (pos = 0; pos < samples; pos++) {
		left[pos] = 0.0;
		right[pos] = 0.0;

		for (i = 0; i < NUM_LFO; i++) {
			osc_tick(&engine->osc[i]);
		}

		v = engine->voice;
		for (i = 0; i < NUM_POLYPHONY; i++, v++) {
			if (!v->playing) continue;

			voice_run(v, 1, left + pos, right + pos);
		}
	}
}

void engine_startvoice(struct engine_t *engine, uint8_t note, uint8_t velocity)
{
	struct voice_t *v = engine->voice;
	uint32_t i;

	for (i = 0; i < NUM_POLYPHONY; i++, v++) {
		if (v->playing) continue;

		/* Constant voice parameters */
		v->playing  = true;
		v->sample   = 0;
		v->released = 0;
		v->note     = note;
		v->velocity = velocity / 127.0;

		/* Voice parameters which determine sound */
		voice_init(v, _freqs[note]);

		return;
	}
}

void engine_endvoice(struct engine_t *engine, uint8_t note, uint8_t velocity)
{
	struct voice_t *v = engine->voice;
	uint32_t i;

	for (i = 0; i < NUM_POLYPHONY; i++, v++) {
		if (v->released > 0 || v->note != note) continue;

		v->released = v->sample;
	}
}