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fix(apu): increase accuracy of apu
continuous-integration/drone/push Build is passing Details 

Due to this, not all instruments work. This is a regression and will be
fixed in a later commit when presumably the implementation of the APU is
a bit more correct
This commit is contained in:
Rekai Nyangadzayi Musuka 2021-07-25 17:42:09 -05:00
parent 6f6c308d84
commit 9e36e86c14
2 changed files with 191 additions and 90 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

199
src/apu.rs
View File

@ -127,6 +127,49 @@ impl Apu {
}
}
/// 0xFF26 | NR52 - Sound On/Off
pub(crate) fn set_status(&mut self, byte: u8) {
self.ctrl.enabled = (byte >> 7) & 0x01 == 0x01;
if !self.ctrl.enabled {
self.reset();
}
self.ch1.enabled = self.ctrl.enabled;
self.ch2.enabled = self.ctrl.enabled;
self.ch3.enabled = self.ctrl.enabled;
self.ch4.enabled = self.ctrl.enabled;
}
fn reset(&mut self) {
// TODO: Clear readable sound registers
self.ch1.sweep = Default::default();
self.ch1.duty = Default::default();
self.ch1.envelope = Default::default();
self.ch1.freq_hi = Default::default(); // FIXME: What about frequency low?
self.ch2.duty = Default::default();
self.ch2.envelope = Default::default();
self.ch2.freq_hi = Default::default();
self.ch3.enabled = Default::default();
self.ch3.len = Default::default();
self.ch3.volume = Default::default();
self.ch3.freq_hi = Default::default();
self.ch4.len = Default::default();
self.ch4.envelope = Default::default();
self.ch4.poly = Default::default();
self.ch4.freq = Default::default();
self.ch2 = Default::default();
self.ch3 = Default::default();
self.ch4 = Default::default();
self.ctrl.channel = Default::default();
self.ctrl.output = Default::default();
}
fn clock_length(freq_hi: &FrequencyHigh, length_timer: &mut u16, enabled: &mut bool) {
if freq_hi.idk() && *length_timer > 0 {
*length_timer -= 1;
@ -248,27 +291,45 @@ impl Apu {
#[derive(Debug, Clone, Copy, Default)]
pub(crate) struct SoundControl {
/// 0xFF24 | NR50 - Channel Control
pub(crate) channel: ChannelControl,
channel: ChannelControl,
/// 0xFF25 | NR51 - Selection of Sound output terminal
pub(crate) output: SoundOutput,
output: SoundOutput,
enabled: bool,
}
impl SoundControl {
/// 0xFF26 | NR52 - Sound On/Off
pub(crate) fn status(&self, snd: &Apu) -> u8 {
(self.enabled as u8) << 7
| (snd.ch4.enabled as u8) << 3
| (snd.ch3.enabled as u8) << 2
| (snd.ch2.enabled as u8) << 1
| snd.ch1.enabled as u8
/// 0xFF24 | NR50 - Channel Control
pub(crate) fn channel(&self) -> u8 {
u8::from(self.channel)
}
/// 0xFF24 | NR50 - Channel Control
pub(crate) fn set_channel(&mut self, byte: u8) {
if self.enabled {
self.channel = byte.into();
}
}
/// 0xFF25 | NR51 - Selection of Sound output terminal
pub(crate) fn output(&self) -> u8 {
u8::from(self.output)
}
/// 0xFF25 | NR51 - Selection of Sound output terminal
pub(crate) fn set_output(&mut self, byte: u8) {
if self.enabled {
self.output = byte.into();
}
}
/// 0xFF26 | NR52 - Sound On/Off
pub(crate) fn set_status(&mut self, byte: u8) {
// TODO: Should all channel enabled fields be disabled when this is reset?
self.enabled = (byte >> 7) & 0x01 == 0x01;
pub(crate) fn status(&self, apu: &Apu) -> u8 {
(self.enabled as u8) << 7
| (apu.ch4.enabled as u8) << 3
| (apu.ch3.enabled as u8) << 2
| (apu.ch2.enabled as u8) << 1
| apu.ch1.enabled as u8
}
}
@ -324,7 +385,7 @@ impl Channel1 {
/// 0xFF10 | NR10 - Channel 1 Sweep Register
pub(crate) fn sweep(&self) -> u8 {
self.sweep.into()
u8::from(self.sweep) | 0x80
}
/// 0xFF10 | NR10 - Channel 1 Sweep Register
@ -336,7 +397,7 @@ impl Channel1 {
/// 0xFF11 | NR11 - Channel 1 Sound length / Wave pattern duty
pub(crate) fn duty(&self) -> u8 {
u8::from(self.duty) & 0xC0 // Only bits 7 and 6 can be read
u8::from(self.duty) | 0x3F
}
/// 0xFF11 | NR11 - Channel 1 Sound length / Wave pattern duty
@ -349,7 +410,7 @@ impl Channel1 {
/// 0xFF12 | NR12 - Channel 1 Volume Envelope
pub fn envelope(&self) -> u8 {
self.envelope.into()
u8::from(self.envelope)
}
/// 0xFF12 | NR12 - Channel 1 Volume Envelope
@ -368,7 +429,7 @@ impl Channel1 {
/// 0xFF14 | NR14 - Channel 1 Frequency high
pub(crate) fn freq_hi(&self) -> u8 {
u8::from(self.freq_hi) & 0x40 // Only bit 6 is readable
u8::from(self.freq_hi) | 0xBF
}
/// 0xFF14 | NR14 - Channel 1 Frequency high
@ -480,7 +541,7 @@ impl Channel2 {
/// 0xFF16 | NR21 - Channel 2 Sound length / Wave Pattern Duty
pub(crate) fn duty(&self) -> u8 {
u8::from(self.duty) & 0xC0 // Only bits 7 & 6 are readable
u8::from(self.duty) | 0x3F
}
/// 0xFF16 | NR21 - Channel 2 Sound length / Wave Pattern Duty
@ -493,7 +554,7 @@ impl Channel2 {
/// 0xFF17 | NR22 - Channel 2 Volume ENvelope
pub(crate) fn envelope(&self) -> u8 {
self.envelope.into()
u8::from(self.envelope)
}
/// 0xFF17 | NR22 - Channel 2 Volume ENvelope
@ -512,7 +573,7 @@ impl Channel2 {
/// 0xFF19 | NR24 - Channel 2 Frequency high
pub(crate) fn freq_hi(&self) -> u8 {
u8::from(self.freq_hi) & 0x40 // only bit 6 is readable
u8::from(self.freq_hi) | 0xBF
}
/// 0xFF19 | NR24 - Channel 2 Frequency high
@ -560,29 +621,64 @@ pub(crate) struct Channel3 {
}
impl Channel3 {
/// 0xFF1A | NR30 - Channel 3 Sound on/off
pub(crate) fn enabled(&self) -> u8 {
((self.enabled as u8) << 7) | 0x7F
}
/// 0xFF1A | NR30 - Channel 3 Sound on/off
pub(crate) fn set_enabled(&mut self, byte: u8) {
self.enabled = (byte >> 7) & 0x01 == 0x01;
}
/// 0xFF1B | NR31 - Sound Length
pub(crate) fn len(&self) -> u8 {
self.len
self.len | 0xFF
}
/// 0xFF1B | NR31 - Sound Length
pub(crate) fn set_len(&mut self, byte: u8) {
if self.enabled {
self.len = byte;
self.length_timer = 256 - self.len as u16;
}
}
/// 0xFF1C | NR32 - Channel 3 Volume
pub(crate) fn volume(&self) -> u8 {
((self.volume as u8) << 5) | 0x9F
}
/// 0xFF1C | NR32 - Channel 3 Volume
pub(crate) fn set_volume(&mut self, byte: u8) {
use Ch3Volume::*;
if self.enabled {
self.volume = match (byte >> 5) & 0x03 {
0b00 => Mute,
0b01 => Full,
0b10 => Half,
0b11 => Quarter,
_ => unreachable!("{:#04X} is not a valid value for Channel3Volume", byte),
};
}
}
/// 0xFF1D | NR33 - Channel 3 Frequency low (lower 8 bits)
pub(crate) fn set_freq_lo(&mut self, byte: u8) {
if self.enabled {
self.freq_lo = byte;
}
}
/// 0xFF1E | NR34 - Channel 3 Frequency high
pub(crate) fn freq_hi(&self) -> u8 {
u8::from(self.freq_hi) & 0x40 // Only bit 6 readable
u8::from(self.freq_hi) | 0xBF
}
/// 0xFF1E | NR34 - Channel 3 Frequency high
pub(crate) fn set_freq_hi(&mut self, byte: u8) {
if self.enabled {
self.freq_hi = byte.into();
if self.freq_hi.initial() {
@ -592,29 +688,6 @@ impl Channel3 {
}
}
}
pub(crate) fn enabled(&self) -> u8 {
(self.enabled as u8) << 7
}
pub(crate) fn set_enabled(&mut self, byte: u8) {
self.enabled = (byte >> 7) & 0x01 == 0x01;
}
pub(crate) fn volume(&self) -> u8 {
(self.volume as u8) << 5
}
pub(crate) fn set_volume(&mut self, byte: u8) {
use Ch3Volume::*;
self.volume = match (byte >> 5) & 0x03 {
0b00 => Mute,
0b01 => Full,
0b10 => Half,
0b11 => Quarter,
_ => unreachable!("{:#04X} is not a valid value for Channel3Volume", byte),
};
}
fn amplitude(&self) -> f32 {
@ -656,9 +729,9 @@ pub(crate) struct Channel4 {
/// 0xFF20 | NR41 - Channel 4 Sound Length
len: u8,
/// 0xFF21 | NR42 - Channel 4 Volume Envelope
pub(crate) envelope: VolumeEnvelope,
envelope: VolumeEnvelope,
/// 0xFF22 | NR43 - Chanel 4 Polynomial Counter
pub(crate) poly: PolynomialCounter,
poly: PolynomialCounter,
/// 0xFF23 | NR44 - Channel 4 Counter / Consecutive Selector and Restart
freq: Ch4Frequency,
@ -680,22 +753,49 @@ pub(crate) struct Channel4 {
impl Channel4 {
/// 0xFF20 | NR41 - Channel 4 Sound Length
pub(crate) fn len(&self) -> u8 {
self.len & 0x3F
self.len | 0xFF
}
/// 0xFF20 | NR41 - Channel 4 Sound Length
pub(crate) fn set_len(&mut self, byte: u8) {
if self.enabled {
self.len = byte & 0x3F;
self.length_timer = 256 - self.len as u16;
}
}
/// 0xFF21 | NR42 - Channel 4 Volume Envelope
pub(crate) fn envelope(&self) -> u8 {
u8::from(self.envelope)
}
/// 0xFF21 | NR42 - Channel 4 Volume Envelope
pub(crate) fn set_envelope(&mut self, byte: u8) {
if self.enabled {
self.envelope = byte.into()
}
}
/// 0xFF22 | NR43 - Chanel 4 Polynomial Counter
pub(crate) fn poly(&self) -> u8 {
u8::from(self.poly)
}
/// 0xFF22 | NR43 - Chanel 4 Polynomial Counter
pub(crate) fn set_poly(&mut self, byte: u8) {
if self.enabled {
self.poly = byte.into();
}
}
/// 0xFF23 | NR44 - Channel 4 Counter / Consecutive Selector and Restart
pub(crate) fn freq_data(&self) -> u8 {
u8::from(self.freq) & 0x40 // only bit 6 readable
pub(crate) fn frequency(&self) -> u8 {
u8::from(self.freq) | 0xBF
}
/// 0xFF23 | NR44 - Channel 4 Counter / Consecutive Selector and Restart
pub(crate) fn set_freq_data(&mut self, byte: u8) {
if self.enabled {
self.freq = byte.into();
if self.freq.initial() {
@ -712,6 +812,7 @@ impl Channel4 {
self.lf_shift = 0x7FFF;
}
}
}
fn amplitude(&self) -> f32 {
let dac_input = (!self.lf_shift & 0x01) as u8 * self.current_volume;

20
src/bus.rs
View File

@ -236,11 +236,11 @@ impl BusIo for Bus {
0x1C => self.apu.ch3.volume(),
0x1E => self.apu.ch3.freq_hi(),
0x20 => self.apu.ch4.len(),
0x21 => self.apu.ch4.envelope.into(),
0x22 => self.apu.ch4.poly.into(),
0x23 => self.apu.ch4.freq_data(),
0x24 => self.apu.ctrl.channel.into(),
0x25 => self.apu.ctrl.output.into(),
0x21 => self.apu.ch4.envelope(),
0x22 => self.apu.ch4.poly(),
0x23 => self.apu.ch4.frequency(),
0x24 => self.apu.ctrl.channel(),
0x25 => self.apu.ctrl.output(),
0x26 => self.apu.ctrl.status(&self.apu),
0x30..=0x3F => self.apu.ch3.wave_ram[addr as usize - 0xFF30],
0x40 => self.ppu.ctrl.into(),
@ -357,12 +357,12 @@ impl BusIo for Bus {
0x1D => self.apu.ch3.set_freq_lo(byte),
0x1E => self.apu.ch3.set_freq_hi(byte),
0x20 => self.apu.ch4.set_len(byte),
0x21 => self.apu.ch4.envelope = byte.into(),
0x22 => self.apu.ch4.poly = byte.into(),
0x21 => self.apu.ch4.set_envelope(byte),
0x22 => self.apu.ch4.set_poly(byte),
0x23 => self.apu.ch4.set_freq_data(byte),
0x24 => self.apu.ctrl.channel = byte.into(),
0x25 => self.apu.ctrl.output = byte.into(),
0x26 => self.apu.ctrl.set_status(byte), // FIXME: Should we control which bytes are written to here?
0x24 => self.apu.ctrl.set_channel(byte),
0x25 => self.apu.ctrl.set_output(byte),
0x26 => self.apu.set_status(byte),
0x30..=0x3F => self.apu.ch3.wave_ram[addr as usize - 0xFF30] = byte,
0x40 => self.ppu.ctrl = byte.into(),
0x41 => self.ppu.stat.update(byte),