[cln] Restructure code

src/sdl_adapters/sdl_audio_adapter.rs

@@ -0,0 +1,71 @@
+use std::sync::{Arc, Mutex};
+use sdl2::audio::AudioQueue;
+use crate::device::timer::DeviceTimerManager;
+use crate::util::EmulatorResult;
+
+/// An Audio adapter using `AudioQueue`. Generates a square wave of specified frequency
+pub struct SdlAudioAdapter {
+    sound_timer: Arc<Mutex<u8>>,
+    phase_inc: f32,
+    phase: f32,
+    volume: f32,
+    audio_queue: AudioQueue<f32>,
+    internal_buffer: Vec<f32>,
+}
+
+impl SdlAudioAdapter {
+    /// Number of samples per second
+    pub const SAMPLING_FREQ:i32 = 15360;
+    pub const SAMPLES_PER_FRAME: usize = (Self::SAMPLING_FREQ as usize / 60) * 2;
+    pub fn new_timers(freq: f32,
+                 volume: f32,
+                 audio_queue: AudioQueue<f32>) ->(DeviceTimerManager,SdlAudioAdapter){
+        let device_sound_timer = Arc::new(Mutex::default());
+        let device_timer_manager = DeviceTimerManager::new(device_sound_timer.clone());
+        let sdl_audio_adapter = SdlAudioAdapter::new(device_sound_timer,freq,volume,audio_queue);
+        (device_timer_manager, sdl_audio_adapter)
+    }
+    fn new(sound_timer: Arc<Mutex<u8>>,
+               freq: f32,
+               volume: f32,
+               audio_queue: AudioQueue<f32>) -> SdlAudioAdapter {
+        audio_queue.resume();
+        // ensure frequency isn't too low
+        assert!(((2.0*freq) as i32) < Self::SAMPLING_FREQ);
+        SdlAudioAdapter {
+            sound_timer,
+            internal_buffer: vec![0f32; Self::SAMPLES_PER_FRAME],
+            phase: 0f32,
+            phase_inc: freq/Self::SAMPLING_FREQ as f32,
+            volume,
+            audio_queue,
+        }
+    }
+    pub fn process_push_audio(&mut self) -> EmulatorResult<()> {
+        // fill the audio vector.
+        let sound_timer = {
+            let sound_timer = self.sound_timer.lock().expect("Could not lock to play audio");
+            sound_timer.clone()
+        };
+        if sound_timer>0 && self.audio_queue.size() < Self::SAMPLING_FREQ as u32 {
+            self.fill_audio();
+            self.audio_queue.queue_audio(&self.internal_buffer)?;
+        }
+        Ok(())
+    }
+
+    fn fill_audio(&mut self) {
+        let out = &mut self.internal_buffer;
+
+        // Generate a square wave
+        for x in out.iter_mut() {
+            *x = if self.phase <= 0.5 {
+                self.volume
+            } else {
+                -self.volume
+            };
+
+            self.phase = (self.phase + self.phase_inc) % 1.0;
+        }
+    }
+}