aproc: send data through channels

1 files changed, 73 insertions, 13 deletions

diff --git a/src/main.rs b/src/main.rs
index 799496b..b01dc9f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,58 @@ use cpal::traits::HostTrait;
 use cpal::traits::DeviceTrait;
 use cpal::traits::StreamTrait;
 
+use std::time;
+use std::thread;
+use std::sync::mpsc;
+
+struct AudioSink {
+    recv: mpsc::Receiver<Box<[f32]>>,
+    buffer: Option<Box<[f32]>>,
+    idx: usize
+}
+
+impl AudioSink {
+    fn new(recv: mpsc::Receiver<Box<[f32]>>) -> Self {
+        Self {
+            recv: recv,
+            buffer: None,
+            idx: 0
+        }
+    }
+    
+    fn pour(&mut self, mut dst: &mut [f32], i: usize) {
+        loop {
+            match self.buffer.as_ref() {
+                Some(src) => {
+                    let src_new = &src[self.idx..];
+                    let count = std::cmp::min(src_new.len(), dst.len());
+                    let src_new = &src_new[..count];
+                    let dst_new = &mut dst[..count];
+                    
+                    dst_new.copy_from_slice(&src_new);
+                    
+                    self.idx += count;
+                    
+                    if self.idx >= src.len() {
+                        self.buffer = None;
+                        self.idx = 0;
+                    }
+                    
+                    if dst.len() > count {
+                        dst = &mut dst[count..];
+                        continue;
+                    }
+                    
+                    return;
+                },
+                None => {
+                    self.buffer = Some(self.recv.recv().unwrap());
+                }
+            };
+        }
+    }
+}
+
 fn main() {
     let host = cpal::default_host();
     let dev = host.default_output_device().expect("no audio device found");
@@ -11,27 +63,35 @@ fn main() {
         .next()
         .expect("bogus device")
         .with_max_sample_rate().into();
-    
-    println!("sample rate {:?}", &cfg.sample_rate);
-    
-    let mut i: f32 = 0.0;
-    
+    let denom = cfg.sample_rate.0 as f32 * cfg.channels as f32;
+
+
+    let (send, recv) = mpsc::sync_channel(1);
+    let mut snk = AudioSink::new(recv);
+
+    let mut snum: f32 = 0.0;
     let stream = dev.build_output_stream(
         &cfg,
         move |data: &mut [f32], _: &cpal::OutputCallbackInfo| {
-            println!("{}", &data.len());
-            for sample in data.iter_mut() {
-                *sample = cpal::Sample::from(&(i/384000.0*2.0*3.141592 * 340.0).sin());
-                i += 1.0;
-            }
+            snk.pour(data, 0);
         },
         move |err| {
             println!("err: {}", err);
         }
     ).expect("could not build stream");
-    
+
     stream.play().unwrap();
 
-    loop {}
-    println!("Hello, world!");
+    let mut snum: usize = 0;
+    
+    loop {
+        let mut samples = vec![0.0f32;1024].into_boxed_slice();
+        
+        for s in samples.iter_mut() {
+            *s += (snum as f32 / denom * 2.0 * 3.141592 * 200.0 as f32).sin();
+            snum = snum.wrapping_add(1);
+        }
+        
+        send.send(samples).unwrap();
+    }
 }