Add 3 additional audio channels for a total of 4

src/audio.rs

@@ -1,17 +1,70 @@
 // audio.rs
 
-pub struct Audio {
+use crate::Interrupt;
-    pub current_buffer_is_0: bool,
+use crate::memory::Memory;
+
+use std::sync::{Arc, Mutex};
+use std::sync::mpsc::Sender;
+use std::{thread, time};
+use rodio::{OutputStream, buffer::SamplesBuffer, Sink};
+
+const AUDIO_BUFFER_0_ADDRESS: usize = 0x0212C000;
+const AUDIO_BUFFER_1_ADDRESS: usize = 0x02134000;
+const AUDIO_BUFFER_2_ADDRESS: usize = 0x02290000;
+const AUDIO_BUFFER_3_ADDRESS: usize = 0x02298000;
+const AUDIO_BUFFER_SIZE: usize = 0x8000;
+
+const AUDIO_CHANNEL_0_INTERRUPT: u8 = 0xFE;
+const AUDIO_CHANNEL_1_INTERRUPT: u8 = 0xFD;
+const AUDIO_CHANNEL_2_INTERRUPT: u8 = 0xFC;
+const AUDIO_CHANNEL_3_INTERRUPT: u8 = 0xFB;
+
+pub struct AudioChannel {
+    pub id: u8,
     pub playing: bool,
     pub sample_rate: u32,
 }
 
-impl Audio {
+impl AudioChannel {
-    pub fn new() -> Self {
+    pub fn new(id: u8) -> Self {
-        Audio {
+        AudioChannel {
-            current_buffer_is_0: true,
+            id,
             playing: false,
             sample_rate: 0,
         }
     }
+
+    // this is terrible
+    pub fn spawn_thread(this: Arc<Mutex<Self>>, interrupt_sender: Sender<Interrupt>, memory: Memory) {
+        let (audio_buffer_address, audio_channel_interrupt) = match this.lock().unwrap().id {
+            0 => (AUDIO_BUFFER_0_ADDRESS, AUDIO_CHANNEL_0_INTERRUPT),
+            1 => (AUDIO_BUFFER_1_ADDRESS, AUDIO_CHANNEL_1_INTERRUPT),
+            2 => (AUDIO_BUFFER_2_ADDRESS, AUDIO_CHANNEL_2_INTERRUPT),
+            3 => (AUDIO_BUFFER_3_ADDRESS, AUDIO_CHANNEL_3_INTERRUPT),
+            _ => unreachable!(),
+        };
+        let builder = thread::Builder::new().name("audio".to_string());
+        builder.spawn({
+            move || {
+                let (_stream, stream_handle) = OutputStream::try_default().unwrap();
+                let channel = Sink::try_new(&stream_handle).unwrap();
+                loop {
+                    // every `sleep` number of ms, play what is in the audio buffer
+                    let self_lock = this.lock().unwrap();
+                    if self_lock.playing {
+                        let audio_buffer: Vec<i16> = memory.ram()[audio_buffer_address..audio_buffer_address+AUDIO_BUFFER_SIZE]
+                                                    .to_vec()
+                                                    .chunks_exact(2)
+                                                    .map(|x| ((x[1] as i16) << 8) | x[0] as i16)
+                                                    .collect();
+                        // 1 Hz = 1000 ms
+                        let sleep: f32 = (1000 as f32 / self_lock.sample_rate as f32) * (AUDIO_BUFFER_SIZE as f32 / 2.0);
+                        channel.append(SamplesBuffer::new(1, self_lock.sample_rate, audio_buffer));
+                        interrupt_sender.send(Interrupt::Request(audio_channel_interrupt)).unwrap();
+                        thread::sleep(time::Duration::from_millis(sleep as u64));
+                    }
+                }
+            }
+        }).unwrap();
+    }
 }

src/bus.rs

@@ -1,6 +1,6 @@
 // bus.rs
 
-use crate::{Memory, Audio, DiskController, Keyboard, Mouse, Overlay};
+use crate::{Memory, AudioChannel, DiskController, Keyboard, Mouse, Overlay};
 
 use std::sync::{Arc, Mutex};
 use std::io::{Write, stdout};
@@ -10,7 +10,10 @@ pub struct Bus {
 
     pub disk_controller: DiskController,
 
-    pub audio: Arc<Mutex<Audio>>,
+    pub audio_channel_0: Arc<Mutex<AudioChannel>>,
+    pub audio_channel_1: Arc<Mutex<AudioChannel>>,
+    pub audio_channel_2: Arc<Mutex<AudioChannel>>,
+    pub audio_channel_3: Arc<Mutex<AudioChannel>>,
 
     pub keyboard: Arc<Mutex<Keyboard>>,
     pub mouse: Arc<Mutex<Mouse>>,
@@ -84,9 +87,27 @@ impl Bus {
                 let mut keyboard_lock = self.keyboard.lock().expect("failed to lock the keyboard mutex");
                 keyboard_lock.pop() as u32
             }
-            0x80000600 => { // audio port
+            0x80000600..=0x80000603 => { // audio port
-                let audio_lock = self.audio.lock().unwrap();
+                let channel = (port & 0x000000FF) as u8;
-                audio_lock.playing as u32
+                match channel {
+                    0 => {
+                        let audio_lock = self.audio_channel_0.lock().unwrap();
+                        audio_lock.sample_rate
+                    },
+                    1 => {
+                        let audio_lock = self.audio_channel_1.lock().unwrap();
+                        audio_lock.sample_rate
+                    },
+                    2 => {
+                        let audio_lock = self.audio_channel_2.lock().unwrap();
+                        audio_lock.sample_rate
+                    },
+                    3 => {
+                        let audio_lock = self.audio_channel_3.lock().unwrap();
+                        audio_lock.sample_rate
+                    },
+                    _ => panic!("invalid audio channel"),
+                }
             }
             0x80001000..=0x80002003 => { // disk controller port
                 let id = port as u8;
@@ -171,11 +192,31 @@ impl Bus {
                     _ => panic!("invalid mouse control port"),
                 }
             }
-            0x80000600 => { // audio port
+            0x80000600..=0x80000603 => { // audio port
-                let mut audio_lock = self.audio.lock().unwrap();
+                let channel = (port & 0x000000FF) as u8;
+                match channel {
+                    0 => {
+                        let mut audio_lock = self.audio_channel_0.lock().unwrap();
                         audio_lock.playing = word != 0;
                         audio_lock.sample_rate = word;
-                audio_lock.current_buffer_is_0 = false; // the first buffer refill interrupt will invert this to true
+                    },
+                    1 => {
+                        let mut audio_lock = self.audio_channel_1.lock().unwrap();
+                        audio_lock.playing = word != 0;
+                        audio_lock.sample_rate = word;
+                    },
+                    2 => {
+                        let mut audio_lock = self.audio_channel_2.lock().unwrap();
+                        audio_lock.playing = word != 0;
+                        audio_lock.sample_rate = word;
+                    },
+                    3 => {
+                        let mut audio_lock = self.audio_channel_3.lock().unwrap();
+                        audio_lock.playing = word != 0;
+                        audio_lock.sample_rate = word;
+                    },
+                    _ => panic!("invalid audio channel"),
+                };
             }
             0x80001000..=0x80005003 => { // disk controller port
                 let id = port as u8;

src/main.rs

@@ -8,7 +8,7 @@ pub mod keyboard;
 pub mod mouse;
 pub mod disk;
 
-use audio::Audio;
+use audio::AudioChannel;
 use bus::Bus;
 use cpu::{Cpu, Interrupt};
 use keyboard::Keyboard;
@@ -18,7 +18,6 @@ use memory::{MEMORY_RAM_START, MEMORY_ROM_START, MemoryRam, Memory};
 
 use std::sync::{Arc, mpsc, Mutex};
 use std::thread;
-use std::time;
 use std::process::exit;
 use std::env;
 use std::fs::{File, read};
@@ -26,7 +25,6 @@ use std::fs::{File, read};
 use image;
 use log::error;
 use pixels::{Pixels, SurfaceTexture};
-use rodio::{OutputStream, buffer::SamplesBuffer, Sink};
 use winit::dpi::LogicalSize;
 use winit::event::{ElementState, Event, WindowEvent};
 use winit::event_loop::{ControlFlow, EventLoop};
@@ -37,9 +35,6 @@ const WIDTH: usize = 640;
 const HEIGHT: usize = 480;
 
 const FRAMEBUFFER_ADDRESS: usize = 0x02000000;
-const AUDIO_BUFFER_0_ADDRESS: usize = 0x0212C000;
-const AUDIO_BUFFER_1_ADDRESS: usize = 0x02134000;
-const AUDIO_BUFFER_SIZE: usize = 0x8000;
 
 pub struct Display {
     background: Vec<u8>,
@@ -84,12 +79,18 @@ fn main() {
     let keyboard = Arc::new(Mutex::new(Keyboard::new()));
     let mouse = Arc::new(Mutex::new(Mouse::new()));
 
-    let audio = Arc::new(Mutex::new(Audio::new()));
+    let audio_channel_0 = Arc::new(Mutex::new(AudioChannel::new(0)));
+    let audio_channel_1 = Arc::new(Mutex::new(AudioChannel::new(1)));
+    let audio_channel_2 = Arc::new(Mutex::new(AudioChannel::new(2)));
+    let audio_channel_3 = Arc::new(Mutex::new(AudioChannel::new(3)));
 
     let memory = Memory::new(read_rom().as_slice());
     let mut bus = Bus {
         memory: memory.clone(),
-        audio: audio.clone(),
+        audio_channel_0: audio_channel_0.clone(),
+        audio_channel_1: audio_channel_1.clone(),
+        audio_channel_2: audio_channel_2.clone(),
+        audio_channel_3: audio_channel_3.clone(),
         disk_controller: DiskController::new(),
         keyboard: keyboard.clone(),
         mouse: mouse.clone(),
@@ -104,7 +105,6 @@ fn main() {
         }
     }
 
-    let memory_audio = memory.clone();
     let memory_cpu = memory.clone();
     let memory_eventloop = memory.clone();
 
@@ -145,6 +145,11 @@ fn main() {
     let (interrupt_sender, interrupt_receiver) = mpsc::channel::<Interrupt>();
     let (exit_sender, exit_receiver) = mpsc::channel::<bool>();
 
+    AudioChannel::spawn_thread(audio_channel_0, interrupt_sender.clone(), memory.clone());
+    AudioChannel::spawn_thread(audio_channel_1, interrupt_sender.clone(), memory.clone());
+    AudioChannel::spawn_thread(audio_channel_2, interrupt_sender.clone(), memory.clone());
+    AudioChannel::spawn_thread(audio_channel_3, interrupt_sender.clone(), memory.clone());
+
     let builder = thread::Builder::new().name("cpu".to_string());
     builder.spawn({
         move || {
@@ -180,35 +185,6 @@ fn main() {
         }
     }).unwrap();
 
-    let interrupt_sender_audio = interrupt_sender.clone();
-    let builder = thread::Builder::new().name("audio".to_string());
-    builder.spawn({
-        move || {
-            let (_stream, stream_handle) = OutputStream::try_default().unwrap();
-            let sink = Sink::try_new(&stream_handle).unwrap();
-            loop {
-                // every `sleep` number of ms, play what is in the audio buffer and tell fox32 to swap them
-                let mut audio_lock = audio.lock().unwrap();
-                if audio_lock.playing {
-                    let current_buffer: Vec<i16> = if audio_lock.current_buffer_is_0 {
-                        audio_lock.current_buffer_is_0 = false;
-                        memory_audio.ram()[AUDIO_BUFFER_0_ADDRESS..AUDIO_BUFFER_0_ADDRESS+AUDIO_BUFFER_SIZE].to_vec().chunks_exact(2).map(|x| ((x[1] as i16) << 8) | x[0] as i16).collect()
-                    } else {
-                        audio_lock.current_buffer_is_0 = true;
-                        memory_audio.ram()[AUDIO_BUFFER_1_ADDRESS..AUDIO_BUFFER_1_ADDRESS+AUDIO_BUFFER_SIZE].to_vec().chunks_exact(2).map(|x| ((x[1] as i16) << 8) | x[0] as i16).collect()
-                    };
-                    let buffer = SamplesBuffer::new(1, audio_lock.sample_rate, current_buffer);
-                    // 1 Hz = 1000 ms
-                    let sleep: f32 = (1000 as f32 / audio_lock.sample_rate as f32) * (AUDIO_BUFFER_SIZE as f32 / 2.0);
-                    sink.append(buffer);
-                    drop(audio_lock);
-                    interrupt_sender_audio.send(Interrupt::Request(0xFE)).unwrap(); // audio interrupt, swap audio buffers
-                    thread::sleep(time::Duration::from_millis(sleep as u64));
-                }
-            }
-        }
-    }).unwrap();
-
     event_loop.run(move |event, _, control_flow| {
         *control_flow = ControlFlow::Poll;