apu.h

/**
 * Emulate the audio processing unit (APU) of the Game Boy.
 * Based on MiniGBS: https://github.com/baines/MiniGBS
 */

#pragma once

#include <stdint.h>

#define AUDIO_SAMPLE_RATE 48000.0

#define DMG_CLOCK_FREQ 4194304.0
#define SCREEN_REFRESH_CYCLES 70224.0
#define VERTICAL_SYNC (DMG_CLOCK_FREQ / SCREEN_REFRESH_CYCLES)

#define AUDIO_SAMPLES ((unsigned) (AUDIO_SAMPLE_RATE / VERTICAL_SYNC))

/**
 * Fill allocated buffer "data" with "len" number of 32-bit floating point
 * samples (native endian order) in stereo interleaved format.
 */
void audio_callback(void *ptr, uint8_t *data, int len);

/**
 * Read audio register at given address "addr".
 */
uint8_t audio_read(const uint16_t addr);

/**
 * Write "val" to audio register at given address "addr".
 */
void audio_write(const uint16_t addr, const uint8_t val);

/**
 * Initialize audio driver.
 */
void audio_init(void);