[aud] Add audio subsystem

.gitignore

@@ -1,2 +1,3 @@
 .idea
 /target
+/roms

README.md

@@ -14,10 +14,10 @@ Screenshot program author: [Javamannen](https://esolangs.org/wiki/User:Javamanne
   - [X] Outer loop - 60fps display loop
 - [X] Display adapter
   - [X] SDL2 adapter
-- [ ] Keyboard
+- [X] Keyboard
-- [ ] Audio
+- [X] Audio
 - [ ] Load/Save memory
-  - [ ] Load a ROM
+  - [X] Load a ROM
 
 ## Usage instructions
 

src/emu/audio.rs

@@ -0,0 +1,48 @@
+use sdl2::audio::AudioQueue;
+
+use crate::emu::memory::RamMemory;
+use crate::misc::endian::read_big_endian_u16;
+use crate::misc::error::DeviceType::AUDIO;
+use crate::misc::error::EmulatorError;
+use crate::misc::result::EmulatorResult;
+
+pub const AUDIO_BUFFER_SIZE: usize = 256;
+
+
+pub struct AudioProcessor<'a> {
+    ram: &'a RamMemory,
+    frame_buffer: Box<[u8; AUDIO_BUFFER_SIZE]>,
+    audio_queue: &'a AudioQueue<u8>,
+}
+
+impl<'a> AudioProcessor<'a> {
+    pub fn try_new(ram: &'a RamMemory, audio_queue: &'a AudioQueue<u8>) -> EmulatorResult<AudioProcessor<'a>> {
+        let frame_buffer = vec![0u8; AUDIO_BUFFER_SIZE].into_boxed_slice()
+            .try_into()
+            .map_err(|_| {
+                EmulatorError::AllocationFailure(AUDIO, "Failed to allocate graphics")
+            })?;
+        Ok(AudioProcessor {
+            ram,
+            audio_queue,
+            frame_buffer,
+        })
+    }
+}
+
+impl<'a> AudioProcessor<'a> {
+    pub fn queue(&mut self) -> EmulatorResult<()> {
+        let audio_base_reg = (self.get_audio_base_reg() as u32) << 8;
+        let fb = self.frame_buffer.as_mut();
+        if self.audio_queue.size() == 0 {
+            log::warn!("Detected Queue empty!");
+        }
+        self.ram.try_copy_block(audio_base_reg, fb)?;
+        self.audio_queue.queue_audio(fb).map_err(|s| { EmulatorError::OtherError(Some(AUDIO), s) })
+    }
+    fn get_audio_base_reg(&self) -> u16 {
+        let data = self.ram.get_data_ref();
+        let audio_base_reg = data.get(6..8).unwrap();
+        read_big_endian_u16(audio_base_reg.try_into().unwrap())
+    }
+}

src/main.rs

@@ -2,6 +2,7 @@ use std::fs::File;
 use std::io::Read;
 use std::time::Duration;
 use clap::Parser;
+use sdl2::audio::{AudioQueue, AudioSpecDesired};
 use sdl2::event::Event;
 use sdl2::EventPump;
 use sdl2::keyboard::Keycode;
@@ -9,6 +10,7 @@ use sdl2::pixels::Color;
 use sdl2::render::{BlendMode, WindowCanvas};
 use simple_logger::SimpleLogger;
 use crate::args::BytePusherArgs;
+use crate::emu::audio::AudioProcessor;
 use crate::emu::cpu::Cpu;
 use crate::emu::graphics::GraphicsProcessor;
 use crate::emu::keyboard::Keyboard;
@@ -30,11 +32,12 @@ fn main() -> EmulatorResult<()> {
     let (file_bytes, x) = try_load_rom(&file_name)?;
     assert!(x < MEM_LENGTH);
 
-    let (mut canvas, mut event_pump) = initiate_sdl();
+    let (mut canvas, mut event_pump, mut audio_queue) = initiate_sdl();
 
 
     let ram = RamMemory::try_from(file_bytes.as_slice())?;
     let graphics_processor = GraphicsProcessor::try_new(&ram)?;
+    let mut audio_processor = AudioProcessor::try_new(&ram,&audio_queue)?;
     let mut keyboard = Keyboard::new(&ram);
     let cpu = Cpu::new(&ram, &graphics_processor);
 
@@ -70,6 +73,7 @@ fn main() -> EmulatorResult<()> {
         // draw graphics
         sdl2_graphics_adapter.draw(&mut canvas)?;
         // TODO render audio
+        audio_processor.queue()?;
 
         canvas.present();
 
@@ -115,12 +119,22 @@ fn try_load_rom(file_name_option: &Option<String>) -> EmulatorResult<(Vec<u8>, u
     Ok((file_bytes, bytes_read))
 }
 
-fn initiate_sdl() -> (WindowCanvas, EventPump) {
+fn initiate_sdl() -> (WindowCanvas, EventPump, AudioQueue<u8>) {
     const BASE_RESOLUTION: u32 = 256;
     const DRAW_FACTOR: u32 = 4;
     const WINDOW_RESOLUTION: u32 = BASE_RESOLUTION * DRAW_FACTOR;
     let sdl_context = sdl2::init().unwrap();
     let video_subsystem = sdl_context.video().unwrap();
+    // TODO audio subsystem
+    let audio_subsystem = sdl_context.audio().unwrap();
+    let wanted_spec = AudioSpecDesired{
+        channels: Some(1),
+        samples: Some(256),
+        freq: Some(15360),
+    };
+    let audio_queue = audio_subsystem.open_queue::<u8,_>(None, &wanted_spec).unwrap();
+    audio_queue.resume();
+
 
     let window = video_subsystem.window("byte-pusher-emu", WINDOW_RESOLUTION, WINDOW_RESOLUTION)
         .position_centered()
@@ -136,5 +150,5 @@ fn initiate_sdl() -> (WindowCanvas, EventPump) {
     canvas.set_blend_mode(BlendMode::None);
     canvas.present();
     let event_pump = sdl_context.event_pump().unwrap();
-    (canvas, event_pump)
+    (canvas, event_pump, audio_queue)
 }

src/misc/error.rs

@@ -15,6 +15,7 @@ pub enum EmulatorError {
     AllocationFailure(DeviceType, &'static str),
     UnreachableMemory(DeviceType, u32),
     EmulatorIOError(Error),
+    OtherError(Option<DeviceType>,String)
 }
 
 impl From<TryFromSliceError> for EmulatorError {