SameBoy/Core/apu.h

66 lines
1.6 KiB
C

#ifndef apu_h
#define apu_h
#include <stdbool.h>
#include <stdint.h>
/* Divides nicely and never overflows with 4 channels */
#define MAX_CH_AMP 0x1E00
#define CH_STEP (0x1E00/0xF)
#include "save_struct.h"
struct GB_gameboy_s;
typedef struct GB_gameboy_s GB_gameboy_t;
typedef struct
{
int16_t left;
int16_t right;
} GB_sample_t;
/* Not all used on all channels */
typedef struct
{
GB_aligned_double phase;
GB_aligned_double frequency;
GB_aligned_double duty;
GB_aligned_double sound_length; /* In seconds */
int16_t amplitude;
int16_t start_amplitude;
bool stop_on_length;
uint8_t envelope_steps;
uint8_t cur_envelope_steps;
signed int envelope_direction;
uint8_t sweep_steps;
uint8_t cur_sweep_steps;
signed int sweep_direction;
uint8_t sweep_shift;
bool is_playing;
} GB_apu_channel_t;
typedef struct
{
GB_apu_channel_t wave_channels[4];
GB_aligned_double envelope_step_timer; /* In seconds */
GB_aligned_double sweep_step_timer; /* In seconds */
int8_t wave_form[32];
uint8_t wave_shift;
bool wave_enable;
uint16_t lfsr;
bool lfsr_7_bit;
double left_volume;
double right_volume;
bool left_on[4];
bool right_on[4];
bool global_enable;
} GB_apu_t;
void GB_apu_render(GB_gameboy_t *gb, unsigned int sample_rate, unsigned int n_samples, GB_sample_t *samples);
void GB_apu_copy_buffer(GB_gameboy_t *gb, GB_sample_t *dest, unsigned int count);
void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value);
uint8_t GB_apu_read(GB_gameboy_t *gb, uint8_t reg);
void GB_apu_init(GB_gameboy_t *gb);
void GB_apu_run(GB_gameboy_t *gb);
#endif /* apu_h */