WIP messier shit figuring out audio format changing that the sdl2 crate generics currently make impossible

ferretro_components/src/provided/sdl2/audio_ratecontrol.rs

@@ -6,22 +6,75 @@ use std::path::Path;
 use core::time::Duration;
 
 use sdl2::Sdl;
-use sdl2::audio::{AudioCallback, AudioDevice, AudioFormat, AudioSpec, AudioSpecDesired, AudioCVT, AudioFormatNum};
+use sdl2::audio::{AudioCallback, AudioDevice, AudioFormat, AudioSpec, AudioSpecDesired, AudioCVT, AudioFormatNum, AudioQueue};
+
+enum AudioQueueEnum {
+    U8(AudioQueue<u8>),
+    S8(AudioQueue<i8>),
+    U16(AudioQueue<u16>),
+    S16(AudioQueue<i16>),
+    S32(AudioQueue<i32>),
+    F32(AudioQueue<f32>),
+}
+
+impl AudioQueueEnum {
+    fn sample_size(&self) -> usize {
+        match self {
+            AudioQueueEnum::U8(_) => size_of::<u8>(),
+            AudioQueueEnum::S8(_) => size_of::<i8>(),
+            AudioQueueEnum::U16(_) => size_of::<u16>(),
+            AudioQueueEnum::S16(_) => size_of::<i16>(),
+            AudioQueueEnum::S32(_) => size_of::<i32>(),
+            AudioQueueEnum::F32(_) => size_of::<f32>(),
+        }
+    }
+
+    fn queue(&mut self, samples_i16: &[i16], cvt: &AudioCVT) -> bool {
+        let data = samples_i16.as_mut_ptr() as *mut u8;
+        let src_len = samples_i16.len() * size_of::<i16>();
+        let samples_u8 = unsafe { core::slice::from_raw_parts(data, src_len) };
+
+        let src = Vec::with_capacity(cvt.capacity(src_len));
+        src.copy_from_slice(samples_u8);
+        let resampled_u8 = cvt.convert(src);
+
+        fn reinterp<C: AudioFormatNum>(data_u8: Vec<u8>) -> Vec<C> {
+            const BYTE_SIZE: usize = size_of::<C>();
+            let ptr = data_u8.as_mut_ptr() as *mut Self::Channel;
+            let length = (data_u8.len() + (BYTE_SIZE - 1)) / BYTE_SIZE;
+            let capacity = (data_u8.capacity() + (BYTE_SIZE - 1)) / BYTE_SIZE;
+            std::mem::forget(data_u8);
+            unsafe { Vec::from_raw_parts(ptr, length, capacity) }
+        }
+
+        match self {
+            AudioQueueEnum::U8(q) => q.queue(reinterp(resampled_u8)),
+            AudioQueueEnum::S8(q) => q.queue(reinterp(resampled_u8)),
+            AudioQueueEnum::U16(q) => q.queue(reinterp(resampled_u8)),
+            AudioQueueEnum::S16(q) => q.queue(reinterp(resampled_u8)),
+            AudioQueueEnum::S32(q) => q.queue(reinterp(resampled_u8)),
+            AudioQueueEnum::F32(q) => q.queue(reinterp(resampled_u8)),
+        }
+    }
+}
 
 /// Trivially sends the core's audio data to the SDL audio subsystem for playback.
 pub struct Sdl2RateControlledAudioComponent {
     sample_rate: f64,
-    audio_buffer: Vec<i16>,
-    dest_spec: AudioSpec,
-    audio_device: AudioDevice<>,
-    cvt_send: crossbeam_channel::Sender<AudioCVT>,
-    send: crossbeam_channel::Sender<Vec<i16>>,
+    //audio_buffer: Vec<i16>,
+    queue: AudioQueueEnum,
+    spec: AudioSpec,
+    convert: AudioCVT,
+    //audio_device: AudioDevice<>,
+    //cvt_send: crossbeam_channel::Sender<AudioCVT>,
+    //send: crossbeam_channel::Sender<Vec<i16>>,
 }
 
 impl RetroCallbacks for Sdl2RateControlledAudioComponent {
     fn audio_samples(&mut self, stereo_pcm: &[i16]) -> usize {
+        let samples = stereo_pcm.len() / 2;
+
         self.audio_buffer.extend(stereo_pcm);
-        self.send_audio_samples();
         stereo_pcm.len() / 2
     }
 
@@ -64,7 +117,8 @@ impl Sdl2RateControlledAudioComponent {
             channels: Some(2),
             samples: None,
         };
-        let mut dest_spec_opt = None;
+        let queue = audio.open_queue::<i16>(None, &desired_spec)?;
+        /*let mut dest_spec_opt = None;
         let audio_device = audio
             .open_playback(None, &desired_spec, |dest_spec| {
                 dest_spec_opt = Some(dest_spec.clone());
@@ -90,16 +144,20 @@ impl Sdl2RateControlledAudioComponent {
                     ),
                 };
                 callback
-            })
-            .unwrap();
+            })?;
+         */
 
         Ok(Sdl2RateControlledAudioComponent {
             sample_rate: src_freq,
+            queue,
+            spec,
+            convert,
+            /*
             audio_buffer: Default::default(),
             dest_spec: dest_spec_opt.unwrap(),
             audio_device,
             cvt_send,
-            send,
+            send,*/
         })
     }