furnace/src/engine/platform/sound/vera_pcm.h

32 lines
890 B
C
Raw Normal View History

2022-03-10 15:51:27 -05:00
// Commander X16 Emulator
// Copyright (c) 2020 Frank van den Hoef
// All rights reserved. License: 2-clause BSD
#pragma once
#include <stdint.h>
#include <stdbool.h>
struct VERA_PCM {
uint8_t fifo[4096 - 1]; // Actual hardware FIFO is 4kB, but you can only use 4095 bytes.
unsigned fifo_wridx;
unsigned fifo_rdidx;
unsigned fifo_cnt;
uint8_t ctrl;
uint8_t rate;
int16_t cur_l, cur_r;
uint8_t phase;
};
void pcm_reset(struct VERA_PCM* pcm);
void pcm_write_ctrl(struct VERA_PCM* pcm, uint8_t val);
uint8_t pcm_read_ctrl(struct VERA_PCM* pcm);
void pcm_write_rate(struct VERA_PCM* pcm, uint8_t val);
uint8_t pcm_read_rate(struct VERA_PCM* pcm);
void pcm_write_fifo(struct VERA_PCM* pcm, uint8_t val);
void pcm_render(struct VERA_PCM* pcm, int16_t* buf_l, int16_t* buf_r, unsigned num_samples);
bool pcm_is_fifo_almost_empty(struct VERA_PCM* pcm);