piwalker/gbemu
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
435a4c5ebe
gbemu/lib/audio.c
Samuel Walker 89a1b4cec6
fixed fast forward
2025-02-18 19:45:13 -07:00

974 lines
28 KiB
C
Raw Blame History

#include <audio.h>
#include <emu.h>
#include <ppu.h>
#include <portaudio.h>
#include <pa_ringbuffer.h>
#include <math.h>
#include <string.h>
#define SAMPLE_RATE 192000.0
#define FRAMES_PER_BUFFER 64
#define SAMPLES_PER_AUDIO_TICK SAMPLE_RATE / 4194304.0
#define HISTORY_INTERVAL 5
const u8 square_sample_00[8] = {
0x0,
0xF,
0xF,
0xF,
0xF,
0xF,
0xF,
0xF
};
const u8 square_sample_01[8] = {
0x0,
0x0,
0xF,
0xF,
0xF,
0xF,
0xF,
0xF
};
const u8 square_sample_10[8] = {
0x0,
0x0,
0x0,
0x0,
0xF,
0xF,
0xF,
0xF
};
const u8 square_sample_11[8] = {
0x0,
0x0,
0x0,
0x0,
0x0,
0x0,
0xF,
0xF
};
const u8 *square_sample[4] = {
square_sample_00,
square_sample_01,
square_sample_10,
square_sample_11
};
static audio_context ctx;
static PaStream *stream;
audio_context *audio_get_context() {
return &ctx;
}
void audio_init(){
PaStreamParameters output_parameters;
PaError err;
ctx.left_audio_buffer = malloc(sizeof(float) * FRAMES_PER_BUFFER);
ctx.right_audio_buffer = malloc(sizeof(float) * FRAMES_PER_BUFFER);
memset(ctx.left_audio_buffer, 0, sizeof(float) * FRAMES_PER_BUFFER);
memset(ctx.right_audio_buffer, 0, sizeof(float) * FRAMES_PER_BUFFER);
ctx.audio_enabled = false;
ctx.ch1_left = false;
ctx.ch1_right = false;
ctx.ch2_left = false;
ctx.ch2_right = false;
ctx.ch3_left = false;
ctx.ch3_right = false;
ctx.ch4_left = false;
ctx.ch4_right = false;
ctx.volume_left = 0x1;
ctx.volume_right = 0x1;
ctx.sq1_duty = 0x0;
ctx.sq1_volume = 0x0;
ctx.sq1_sample = 0x0;
ctx.sq1_period_reset = 0x0;
ctx.sq1_period_timer = 0x0;
ctx.sq1_enable = false;
ctx.sq1_len_enable = false;
ctx.sq1_sweep_pace = 0x0;
ctx.sq1_sweep_direction = false;
ctx.sq1_initial_len = 0x0;
ctx.sq1_len = 0x0;
ctx.sq1_initial_volume = 0x0;
ctx.sq1_env_direction = false;
ctx.sq1_env_pace = 0x0;
ctx.sq1_env_timer = 0x0;
ctx.sq1_sweep_step = 0x0;
ctx.sq2_duty = 0x0;
ctx.sq2_volume = 0x0;
ctx.sq2_sample = 0x0;
ctx.sq2_period_reset = 0x0;
ctx.sq2_period_timer = 0x0;
ctx.sq2_enable = false;
ctx.sq2_len_enable = false;
ctx.sq2_initial_len = 0x0;
ctx.sq2_len = 0x0;
ctx.sq2_initial_volume = 0x0;
ctx.sq2_env_direction = false;
ctx.sq2_env_pace = 0x0;
ctx.sq2_env_timer = 0x0;
err = Pa_Initialize();
if (err != paNoError) goto error;
output_parameters.device = Pa_GetDefaultOutputDevice();
if(output_parameters.device == paNoDevice) {
fprintf(stderr, "No default audio device!\n");
goto error;
}
output_parameters.channelCount = 2;
output_parameters.sampleFormat = paFloat32 | paNonInterleaved;
output_parameters.suggestedLatency = Pa_GetDeviceInfo(output_parameters.device)->defaultLowOutputLatency;
output_parameters.hostApiSpecificStreamInfo = NULL;
err = Pa_OpenStream(&stream,
NULL,
&output_parameters,
SAMPLE_RATE,
FRAMES_PER_BUFFER,
paNoFlag,
NULL,
&ctx);
if(err != paNoError) goto error;
err = Pa_StartStream(stream);
if(err != paNoError) goto error;
return;
error:
Pa_Terminate();
fprintf(stderr, "portaudio stream error\n\tError Number: %d\n\tError Message: %s\n", err, Pa_GetErrorText(err));
}
void sq1_sweep() {
//frequency calculation
int step = (ctx.sq1_sweep_period >> ctx.sq1_sweep_step);
step = ctx.sq1_sweep_direction ? -step : step;
ctx.sq1_calc_period = ctx.sq1_sweep_period + step;
//overflow check
if(ctx.sq1_calc_period > 0x7FF) {
ctx.sq1_enable = false;
}
}
void lfsr_tick() {
ctx.lfsr_timer--;
if(ctx.lfsr_timer == 0) {
ctx.lfsr_timer = (ctx.ch4_clock_divider > 0 ? (ctx.ch4_clock_divider << 4) : 8) << ctx.ch4_clock_shift;
unsigned bit_mask = ctx.ch4_lfsr_width ? 0x4040 : 0x4000;
bool new_bit = (ctx.ch4_lfsr ^ (ctx.ch4_lfsr >> 1) ^ 1) & 1;
ctx.ch4_lfsr >>= 1;
if(new_bit) {
ctx.ch4_lfsr |= bit_mask;
} else {
ctx.ch4_lfsr &= ~bit_mask;
}
}
}
void audio_sample_tick() {
lfsr_tick();
float left = 0;
float right = 0;
float sq1_val = 0;
float sq2_val = 0;
float ch3_val = 0;
float ch4_val = 0;
if(ctx.audio_enabled){
if(ctx.ch1_dac){
sq1_val = -1;
if(ctx.sq1_enable && (ctx.ch1_left || ctx.ch1_right)) {
sq1_val = ((float)ctx.sq1_volume/15.0f) * (((float)(square_sample[ctx.sq1_duty][ctx.sq1_sample]) - 7.5f)/7.5f);
if(ctx.ch1_left) {
left += sq1_val;
}else {
left -= 1;
}
if(ctx.ch1_right) {
right += sq1_val;
}else {
right -= 1;
}
} else {
left -= 1;
right -= 1;
}
}
if(ctx.ch2_dac){
sq2_val = -1;
if(ctx.sq2_enable && (ctx.ch2_left || ctx.ch2_right)) {
sq2_val = ((float)ctx.sq2_volume/15.0f) * (((float)(square_sample[ctx.sq2_duty][ctx.sq2_sample]) - 7.5f)/7.5f);
if(ctx.ch2_left) {
left += sq2_val;
}else {
left -= 1;
}
if(ctx.ch2_right) {
right += sq2_val;
}else {
right -= 1;
}
} else {
left -= 1;
right -= 1;
}
}
if(ctx.ch3_dac){
u8 shift = 0;
if(ctx.ch3_volume == 0b10) {
shift = 1;
}
if(ctx.ch3_volume == 0b00) {
shift = 4;
}
if(ctx.ch3_volume == 0b11) {
shift = 2;
}
ch3_val = -1;
if(ctx.ch3_enable && (ctx.ch3_left || ctx.ch3_right)) {
ch3_val = (((float)(ctx.ch3_last_sample >> shift) - 7.5f)/7.5f);
if(ctx.ch3_left) {
left += ch3_val;
}else {
left -= 1;
}
if(ctx.ch3_right) {
right += ch3_val;
}else {
right -= 1;
}
} else {
left -= 1;
right -= 1;
}
}
if(ctx.ch4_dac){
ch4_val = -1;
if(ctx.ch4_enable && (ctx.ch4_left || ctx.ch4_right)) {
ch4_val = ((ctx.ch4_lfsr & 0b1) == 0b1) ? (((float)ctx.ch4_volume - 7.5f)/7.5f) : -1.0f;
if(ctx.ch4_left) {
left += ch4_val;
}else {
left -= 1;
}
if(ctx.ch4_right) {
right += ch4_val;
} else {
right -= 1;
}
} else {
left -= 1;
right -= 1;
}
}
}
u8 left_vol = ctx.volume_left == 0 ? 1 : ctx.volume_left;
u8 right_vol = ctx.volume_right == 0 ? 1 : ctx.volume_right;
left *= (float)left_vol/7.0f;
right *= (float)right_vol/7.0f;
ctx.cycles_needed += emu_get_context()->fast_forward ? SAMPLES_PER_AUDIO_TICK/FAST_FORWARD_SPEED : SAMPLES_PER_AUDIO_TICK;
if(ctx.cycles_needed > 1){
ctx.cycles_needed -= 1;
bool dacs = ctx.ch1_dac || ctx.ch2_dac || ctx.ch3_dac || ctx.ch4_dac;
float left_out = 0;
float right_out = 0;
if(dacs) {
left_out = left - ctx.left_cap;
right_out = right - ctx.right_cap;
ctx.left_cap = left - left_out * 0.999958;
ctx.right_cap = right - right_out * 0.999958;
}
left_out /= 4;
right_out /= 4;
if(left_out < -1.0f) {
left_out = -1;
}
if(left_out > 1.0f) {
left_out = 1;
}
if(right_out < -1.0f) {
right_out = -1;
}
if(right_out > 1.0f) {
right_out = 1;
}
if(ctx.buffer_write_index < FRAMES_PER_BUFFER){
ctx.left_audio_buffer[(ctx.buffer_write_index)] = left_out;
ctx.right_audio_buffer[(ctx.buffer_write_index)] = right_out;
ctx.buffer_write_index++;
}
ctx.history_timer++;
if(ctx.history_timer >= HISTORY_INTERVAL){
ctx.history_timer = 0;
ctx.sq1_history[ctx.sq1_index++] = sq1_val;
if (ctx.sq1_index == 384) {
ctx.sq1_index = 0;
}
ctx.sq2_history[ctx.sq2_index++] = sq2_val;
if (ctx.sq2_index == 384) {
ctx.sq2_index = 0;
}
ctx.ch3_history[ctx.ch3_index++] = ch3_val;
if (ctx.ch3_index == 384) {
ctx.ch3_index = 0;
}
ctx.ch4_history[ctx.ch4_index++] = ch4_val;
if (ctx.ch4_index == 384) {
ctx.ch4_index = 0;
}
ctx.left_history[ctx.left_index++] = left_out;
if (ctx.left_index == 384) {
ctx.left_index = 0;
}
ctx.right_history[ctx.right_index++] = right_out;
if (ctx.right_index == 384) {
ctx.right_index = 0;
}
}
if(ctx.buffer_write_index == FRAMES_PER_BUFFER) {
ctx.buffer_write_index = 0;
float *data[2];
data[0] = ctx.left_audio_buffer;
data[1] = ctx.right_audio_buffer;
int err = Pa_WriteStream(stream, data, FRAMES_PER_BUFFER);
if(err != paNoError && err != paOutputUnderflowed) {
fprintf(stderr, "portaudio stream error\n\tError Number: %d\n\tError Message: %s\n", err, Pa_GetErrorText(err));
}
}
}
}
bool skipped = false;
void audio_period_tick() {
ctx.period_tick++;
if(ctx.period_tick % 2 == 0){
ctx.sq1_period_timer++;
ctx.sq2_period_timer++;
if(ctx.sq1_period_timer >= 0x800) {
ctx.sq1_period_timer = ctx.sq1_period_reset;
ctx.sq1_sample = (ctx.sq1_sample + 1) % 8;
}
if(ctx.sq2_period_timer >= 0x800) {
ctx.sq2_period_timer = ctx.sq2_period_reset;
ctx.sq2_sample = (ctx.sq2_sample + 1) % 8;
}
}
ctx.ch3_period_timer++;
if(ctx.ch3_period_timer >= 0x800) {
ctx.ch3_period_timer = ctx.ch3_period_reset;
ctx.ch3_sample = (ctx.ch3_sample + 1) % 32;
if((ctx.ch3_sample & 0b1) == 0b1) {
ctx.ch3_last_sample = ctx.wave_ram[ctx.ch3_sample >> 1] & 0xF;
} else {
ctx.ch3_last_sample = ctx.wave_ram[ctx.ch3_sample >> 1] >> 4;
}
}
}
void audio_tick(){
u32 prev_ticks = ctx.ticks;
ctx.ticks++;
if((ctx.ticks % 2) == 0) {
if(ctx.sq1_len_enable) {
ctx.sq1_len++;
if(ctx.sq1_len >= 64) {
ctx.sq1_len = 0;
ctx.sq1_enable = false;
ctx.ch1_len_fz = true;
}
}
if(ctx.sq2_len_enable) {
ctx.sq2_len++;
if(ctx.sq2_len >= 64) {
ctx.sq2_len = 0;
ctx.sq2_enable = false;
ctx.ch2_len_fz = true;
}
}
if(ctx.ch3_len_enable) {
ctx.ch3_len++;
if(ctx.ch3_len == 0) {
ctx.ch3_enable = false;
ctx.ch3_len_fz = true;
}
}
if(ctx.ch4_len_enable && ctx.ch4_enable) {
ctx.ch4_len++;
if(ctx.ch4_len >= 64) {
ctx.ch4_len = 0;
ctx.ch4_enable = false;
ctx.ch4_len_fz = true;
}
}
}
if((prev_ticks & (1 << 2)) && !(ctx.ticks & (1 << 2))) {
if(ctx.sq1_env_pace != 0){
ctx.sq1_env_timer++;
if(ctx.sq1_env_timer >= ctx.sq1_env_pace) {
ctx.sq1_env_timer = 0;
if((ctx.sq1_env_direction && ctx.sq1_volume != 15) || (!ctx.sq1_env_direction && ctx.sq1_volume != 0)){
ctx.sq1_volume += ctx.sq1_env_direction ? 1 : -1;
if(ctx.sq1_volume < 0)
ctx.sq1_volume = 0;
if(ctx.sq1_volume > 15)
ctx.sq1_volume = 15;
}
}
}
if(ctx.sq2_env_pace != 0){
ctx.sq2_env_timer++;
if(ctx.sq2_env_timer >= ctx.sq2_env_pace) {
ctx.sq2_env_timer = 0;
if((ctx.sq2_env_direction && ctx.sq2_volume != 15) || (!ctx.sq2_env_direction && ctx.sq2_volume != 0)){
ctx.sq2_volume += ctx.sq2_env_direction ? 1 : -1;
if(ctx.sq2_volume < 0)
ctx.sq2_volume = 0;
if(ctx.sq2_volume > 15)
ctx.sq2_volume = 15;
}
}
}
ctx.ch4_env_timer--;
if(ctx.ch4_env_timer <= 0) {
ctx.ch4_env_timer = ctx.ch4_env_pace_buffer != 0 ? ctx.ch4_env_pace_buffer : 8;
if(ctx.ch4_env_pace != 0 && ((ctx.ch4_env_direction && ctx.ch4_volume != 15) || (!ctx.ch4_env_direction && ctx.ch4_volume != 0))){
ctx.ch4_volume += ctx.ch4_env_direction ? 1 : -1;
if(ctx.ch4_volume < 0)
ctx.ch4_volume = 0;
if(ctx.ch4_volume > 15)
ctx.ch4_volume = 15;
}
}
}
if((prev_ticks & (1 << 1)) && !(ctx.ticks & (1 << 1)) && ctx.sq1_sweep_enabled) {
ctx.sq1_sweep_timer--;
if(ctx.sq1_sweep_timer <= 0){
ctx.sq1_sweep_timer = ctx.sq1_sweep_pace != 0 ? ctx.sq1_sweep_pace : 8;
if(ctx.sq1_enable && ctx.sq1_sweep_pace > 0 && ctx.sq1_sweep_enabled){
sq1_sweep();
if(ctx.sq1_calc_period <= 0x7FF && ctx.sq1_sweep_step != 0) {
ctx.sq1_sweep_period = ctx.sq1_calc_period;
ctx.sq1_period_reset = ctx.sq1_calc_period;
sq1_sweep();
}
}
}
}
}
void enable_square1() {
if(ctx.ch1_dac){
ctx.sq1_enable = true;
}
ctx.sq1_volume = ctx.sq1_initial_volume;
ctx.sq1_env_timer = 0;
ctx.sq1_sweep_period = ctx.sq1_period_reset;
ctx.sq1_sweep_timer = ctx.sq1_sweep_pace != 0 ? ctx.sq1_sweep_pace : 8;
ctx.sq1_env_direction = ctx.sq1_env_direction_buffer;
ctx.sq1_env_pace = ctx.sq1_env_pace_buffer;
if(ctx.sq1_sweep_step != 0) {
sq1_sweep();
}
}
void enable_square2() {
if(!ctx.ch2_dac){
return;
}
ctx.sq2_enable = true;
ctx.sq2_volume = ctx.sq2_initial_volume;
ctx.sq2_env_timer = 0;
ctx.sq2_sample = 0;
ctx.sq2_period_timer = ctx.sq2_period_reset;
ctx.sq2_env_direction = ctx.sq2_env_direction_buffer;
ctx.sq2_env_pace = ctx.sq2_env_pace_buffer;
}
void enable_wave() {
if(!ctx.ch3_dac){
return;
}
ctx.ch3_enable = true;
ctx.ch3_sample = 0;
ctx.ch3_period_timer = ctx.ch3_period_reset;
}
void enable_noise() {
ctx.ch4_enable = true;
ctx.ch4_env_timer = ctx.ch4_env_pace_buffer != 0 ? ctx.ch4_env_pace_buffer : 8;
ctx.ch4_env_direction = ctx.ch4_env_direction_buffer;
ctx.ch4_env_pace = ctx.ch4_env_pace_buffer;
ctx.ch4_volume = ctx.ch4_initial_volume;
ctx.ch4_lfsr = 0;
ctx.lfsr_timer = (ctx.ch4_clock_divider > 0 ? (ctx.ch4_clock_divider << 4) : 8) << ctx.ch4_clock_shift;
if(!ctx.ch4_dac){
ctx.ch4_enable = false;
}
}
u8 audio_read(u16 address) {
//printf("read at %02X\n", address);
if(address == 0xFF26) {
u8 value = (ctx.audio_enabled << 7) | (ctx.ch4_enable << 3) | (ctx.ch3_enable << 2) | (ctx.sq2_enable << 1) | (ctx.sq1_enable);
return value | 0b01110000;
}
if(address == 0xFF25) {
u8 value = 0x0;
value |= ctx.ch4_left << 7;
value |= ctx.ch3_left << 6;
value |= ctx.ch2_left << 5;
value |= ctx.ch1_left << 4;
value |= ctx.ch4_right << 3;
value |= ctx.ch3_right << 2;
value |= ctx.ch2_right << 1;
value |= ctx.ch1_right;
//printf("read at %02X; Value: %02X\n", address, value);
return value;
}
if(address == 0xFF24) {
u8 value = (ctx.volume_left & 0b111) << 4;
value |= (ctx.volume_right & 0b111);
value |= (ctx.vin_left << 7);
value |= (ctx.vin_right << 3);
return value;
}
if(address == 0xFF10) {
u8 value = (ctx.sq1_sweep_pace & 0b111) << 4;
value |= (ctx.sq1_sweep_direction) << 3;
value |= ctx.sq1_sweep_step & 0b111;
return value | 0x80;
}
if(address == 0xFF11) {
u8 value = (ctx.sq1_duty & 0b11) << 6;
return value | 0b00111111;
}
if(address == 0xFF12) {
u8 value = (ctx.sq1_initial_volume & 0b1111) << 4;
value |= ctx.sq1_env_direction_buffer << 3;
value |= (ctx.sq1_env_pace_buffer & 0b111);
return value;
}
if(address == 0xFF13) {
return 0xFF;
}
if(address == 0xFF14) {
return (ctx.sq1_len_enable << 6) | 0b10111111;
}
if(address == 0xFF16) {
u8 value = (ctx.sq2_duty & 0b11) << 6;
return value | 0b00111111;
}
if(address == 0xFF17) {
u8 value = (ctx.sq2_initial_volume & 0b1111) << 4;
value |= ctx.sq2_env_direction_buffer << 3;
value |= (ctx.sq2_env_pace_buffer & 0b111);
return value;
}
if(address == 0xFF18) {
return 0xFF;
}
if(address == 0xFF19) {
return (ctx.sq2_len_enable << 6) | 0b10111111;
}
if(address == 0xFF1A) {
return (ctx.ch3_dac << 7) | 0b01111111;
}
if(address == 0xFF1B) {
return 0xFF;
}
if(address == 0xFF1C) {
return ((ctx.ch3_volume & 0b11) << 5) | 0b10011111;
}
if(address == 0xFF1D) {
return 0xFF;
}
if(address == 0xFF1E) {
return (ctx.ch3_len_enable << 6) | 0b10111111;
}
if(address == 0xFF20) {
return 0xFF;
}
if(address == 0xFF21) {
u8 value = (ctx.ch4_initial_volume & 0b1111) << 4;
value |= ctx.ch4_env_direction_buffer << 3;
value |= (ctx.ch4_env_pace_buffer & 0b111);
return value;
}
if(address == 0xFF22) {
u8 value = (ctx.ch4_clock_shift & 0xF) << 4;
value |= ctx.ch4_lfsr_width << 3;
value |= (ctx.ch4_clock_divider & 0b111);
return value;
}
if(address == 0xFF23) {
return (ctx.ch4_len_enable << 6) | 0b10111111;
}
if(BETWEEN(address, 0xFF30, 0xFF3F)) {
return ctx.wave_ram[address - 0xFF30];
}
return 0xFF;
}
void reset_buffers(){
ctx.ch1_dac = 0;
ctx.ch2_dac = 0;
ctx.ch3_dac = 0;
ctx.ch1_left = false;
ctx.ch1_right = false;
ctx.ch2_left = false;
ctx.ch2_right = false;
ctx.ch3_left = false;
ctx.ch3_right = false;
ctx.ch4_left = false;
ctx.ch4_right = false;
ctx.volume_left = 0;
ctx.volume_right = 0;
ctx.vin_left = 0;
ctx.vin_right = 0;
ctx.sq1_duty = 0;
ctx.sq1_volume = 0;
ctx.sq1_sample = 0;
ctx.sq1_period_reset = 0;
ctx.sq1_period_timer = 0;
ctx.sq1_enable = 0;
ctx.sq1_len_enable = 0;
ctx.sq1_sweep_pace = 0;
ctx.sq1_sweep_direction = 0;
ctx.sq1_initial_len = 0;
ctx.sq1_len = 0;
ctx.sq1_initial_volume = 0;
ctx.sq1_env_direction = 0;
ctx.sq1_env_direction_buffer = 0;
ctx.sq1_env_pace = 0;
ctx.sq1_env_pace_buffer = 0;
ctx.sq1_env_timer = 0;
ctx.sq1_sweep_step = 0;
ctx.sq1_sweep_timer = 0;
ctx.sq1_sweep_enabled = 0;
ctx.sq1_sweep_period = 0;
ctx.sq1_calc_period = 0;
ctx.sq2_duty = 0;
ctx.sq2_volume = 0;
ctx.sq2_sample = 0;
ctx.sq2_period_reset = 0;
ctx.sq2_period_timer = 0;
ctx.sq2_enable = 0;
ctx.sq2_len_enable = 0;
ctx.sq2_initial_len = 0;
ctx.sq2_len = 0;
ctx.sq2_initial_volume = 0;
ctx.sq2_env_direction = 0;
ctx.sq2_env_direction_buffer = 0;
ctx.sq2_env_pace = 0;
ctx.sq2_env_pace_buffer = 0;
ctx.sq2_env_timer = 0;
ctx.ch3_enable = 0;
ctx.ch3_dac = 0;
ctx.ch3_initial_len = 0;
ctx.ch3_len = 0;
ctx.ch3_volume = 0;
ctx.ch3_initial_volume = 0;
ctx.ch3_period_timer = 0;
ctx.ch3_period_reset = 0;
ctx.ch3_len_enable = 0;
ctx.ch3_last_sample = 0;
ctx.ch3_sample = 0;
ctx.ch4_enable = 0;
ctx.ch4_initial_len = 0;
ctx.ch4_len = 0;
ctx.ch4_initial_volume = 0;
ctx.ch4_volume = 0;
ctx.ch4_env_pace = 0;
ctx.ch4_env_pace_buffer = 0;
ctx.ch4_env_timer = 0;
ctx.ch4_env_direction = 0;
ctx.ch4_env_direction_buffer = 0;
ctx.ch4_clock_shift = 0;
ctx.ch4_lfsr_width = 0;
ctx.ch4_clock_divider = 0;
ctx.ch4_len_enable = 0;
ctx.ch4_lfsr = 0;
}
void audio_write(u16 address, u8 value){
if(BETWEEN(address, 0xFF30, 0xFF3F)) {
ctx.wave_ram[address - 0xFF30] = value;
}
if(address == 0xFF26) {
ctx.audio_enabled = (value & 0x80) == 0x80;
if(!ctx.audio_enabled) {
reset_buffers();
}
}
if(!ctx.audio_enabled){
return;
}
if(address == 0xFF25) {
ctx.ch4_left = value & 0b10000000;
ctx.ch3_left = value & 0b01000000;
ctx.ch2_left = value & 0b00100000;
ctx.ch1_left = value & 0b00010000;
ctx.ch4_right = value & 0b00001000;
ctx.ch3_right = value & 0b00000100;
ctx.ch2_right = value & 0b00000010;
ctx.ch1_right = value & 0b00000001;
}
if(address == 0xFF24) {
ctx.volume_left = (value >> 4) & 0b111;
ctx.volume_right = value & 0b111;
ctx.vin_left = value & 0x80;
ctx.vin_right = value & 0x8;
}
if(address == 0xFF10) {
ctx.sq1_sweep_pace = (value >> 4) & 0b111;
ctx.sq1_sweep_direction = value & 0x08;
ctx.sq1_sweep_step = value & 0b111;
ctx.sq1_sweep_enabled = ((ctx.sq1_sweep_pace != 0) || (ctx.sq1_sweep_step != 0));
}
if(address == 0xFF11) {
ctx.sq1_duty = value >> 6;
ctx.sq1_initial_len = value & 0x3F;
ctx.sq1_len = ctx.sq1_initial_len;
ctx.ch1_len_fz = false;
}
if(address == 0xFF12) {
ctx.sq1_initial_volume = (value >> 4) & 0x0F;
ctx.sq1_env_direction_buffer = (value & 0x8) == 0x8;
ctx.sq1_env_pace_buffer = value & 0b111;
if(ctx.sq1_env_direction_buffer == 0 && ctx.sq1_initial_volume == 0) {
ctx.sq1_enable = false;
ctx.ch1_dac = false;
} else {
ctx.ch1_dac = true;
}
}
if(address == 0xFF13) {
ctx.sq1_period_reset = (ctx.sq1_period_reset & 0xF00) | value;
}
if(address == 0xFF14) {
if(ctx.sq1_len == 64) {
ctx.sq1_len = 0;
}
ctx.sq1_period_reset = (ctx.sq1_period_reset & 0x0FF) | ((value & 0b111) << 8);
bool len_en = (value & 0x40) == 0x40;
if((ctx.ticks % 2) == 0 && !ctx.ch1_len_fz && !ctx.sq1_len_enable && len_en){
ctx.sq1_len++;
if(ctx.sq1_len >= 64) {
ctx.sq1_len = 0;
ctx.sq1_enable = false;
ctx.ch1_len_fz = true;
}
}
if((ctx.ticks % 2) == 0 && ctx.ch1_len_fz && (value & 0x80) == 0x80){
ctx.ch1_len_fz = false;
if(len_en){
ctx.sq1_len++;
}
}
ctx.sq1_len_enable = len_en;
if(value & 0x80) {
enable_square1();
}
}
if(address == 0xFF16) {
ctx.sq2_duty = value >> 6;
ctx.sq2_initial_len = value & 0x3F;
ctx.sq2_len = ctx.sq2_initial_len;
ctx.ch2_len_fz = false;
}
if(address == 0xFF17) {
ctx.sq2_initial_volume = (value >> 4) & 0x0F;
ctx.sq2_env_direction_buffer = (value & 0x8) == 0x8;
ctx.sq2_env_pace_buffer = value & 0b111;
if(ctx.sq2_env_direction_buffer == 0 && ctx.sq2_initial_volume == 0) {
ctx.sq2_enable = false;
ctx.ch2_dac = false;
} else {
ctx.ch2_dac = true;
}
}
if(address == 0xFF18) {
u16 prev_period = ctx.sq2_period_reset;
ctx.sq2_period_reset = (ctx.sq2_period_reset & 0xF00) | value;
}
if(address == 0xFF19) {
if(ctx.sq2_len == 64) {
ctx.sq2_len = 0;
}
ctx.sq2_period_reset = (ctx.sq2_period_reset & 0x0FF) | ((value & 0b111) << 8);
bool len_en = (value & 0x40) == 0x40;
if((ctx.ticks % 2) == 0 && !ctx.ch2_len_fz && !ctx.sq2_len_enable && len_en){
ctx.sq2_len++;
if(ctx.sq2_len >= 64) {
ctx.sq2_len = 0;
ctx.sq2_enable = false;
ctx.ch2_len_fz = true;
}
}
if((ctx.ticks % 2) == 0 && ctx.ch2_len_fz && (value & 0x80) == 0x80){
ctx.ch2_len_fz = false;
if(len_en){
ctx.sq2_len++;
}
}
ctx.sq2_len_enable = len_en;
if(value & 0x80) {
enable_square2();
}
}
if(address == 0xFF1A) {
ctx.ch3_dac = value >> 7;
if(!ctx.ch3_dac){
ctx.ch3_enable = false;
}
}
if(address == 0xFF1B) {
ctx.ch3_initial_len = value;
ctx.ch3_len = ctx.ch3_initial_len;
ctx.ch3_len_fz = false;
}
if(address == 0xFF1C) {
ctx.ch3_volume = (value >> 5) & 0b11;
}
if(address == 0xFF1D) {
ctx.ch3_period_reset = (ctx.ch3_period_reset & 0xF00) | value;
}
if(address == 0xFF1E) {
ctx.ch3_period_reset = (ctx.ch3_period_reset & 0x0FF) | ((value & 0b111) << 8);
bool len_en = (value & 0x40) == 0x40;
if((ctx.ticks % 2) == 0 && !ctx.ch3_len_fz && !ctx.ch3_len_enable && len_en){
if(ctx.ch3_len >= 255) {
ctx.ch3_len = 0;
ctx.ch3_enable = false;
ctx.ch3_len_fz = true;
} else {
ctx.ch3_len++;
}
}
if((ctx.ticks % 2) == 0 && ctx.ch3_len_fz && (value & 0x80) == 0x80){
ctx.ch3_len_fz = false;
if(len_en){
ctx.ch3_len++;
}
}
ctx.ch3_len_enable = len_en;
if(value & 0x80) {
enable_wave();
}
}
if(address == 0xFF20) {
ctx.ch4_initial_len = value & 0b111111;
ctx.ch4_len = ctx.ch4_initial_len;
ctx.ch4_len_fz = false;
}
if(address == 0xFF21) {
ctx.ch4_initial_volume = (value >> 4) & 0x0F;
ctx.ch4_env_direction_buffer = (value & 0x8) == 0x8;
ctx.ch4_env_pace_buffer = value & 0b111;
if(ctx.ch4_env_direction_buffer == 0 && ctx.ch4_initial_volume == 0) {
ctx.ch4_enable = false;
ctx.ch4_dac = false;
} else {
ctx.ch4_dac = true;
}
}
if(address == 0xFF22) {
ctx.ch4_clock_shift = (value >> 4) & 0xF;
ctx.ch4_lfsr_width = (value & 0x08);
ctx.ch4_clock_divider = value & 0b111;
}
if(address == 0xFF23) {
if(ctx.ch4_len == 64) {
ctx.ch4_len = 0;
}
bool len_en = (value & 0x40) == 0x40;
if((ctx.ticks % 2) == 0 && !ctx.ch4_len_fz && !ctx.ch4_len_enable && len_en){
ctx.ch4_len++;
if(ctx.ch4_len >= 64) {
ctx.ch4_len = 0;
ctx.ch4_enable = false;
ctx.ch4_len_fz = true;
}
}
if((ctx.ticks % 2) == 0 && ctx.ch4_len_fz && (value & 0x80) == 0x80){
ctx.ch4_len_fz = false;
if(len_en){
ctx.ch4_len++;
}
}
ctx.ch4_len_enable = len_en;
if(value & 0x80) {
enable_noise();
}
}
}
Reference in New Issue View Git Blame Copy Permalink