Restore variable input format system

examples/beep.rs

@@ -22,12 +22,11 @@ fn main() {
     loop {
         let mut buffer = channel.append_data();
 
-        for sample in buffer.chunks_mut(4) {
+        for sample in buffer.chunks_mut(2) {
             let value = data_source.next().unwrap();
 
-            let mut writer = std::io::BufWriter::new(sample);
-            writer.write_le_u16(value).unwrap();
-            writer.write_le_u16(value).unwrap();
+            sample[0] = value;
+            sample[1] = value;
         }
     }
 }

src/lib.rs

@@ -19,7 +19,7 @@ pub type ChannelsCount = u16;
 /// Represents a buffer that must be filled with audio data.
 ///
 /// A `Buffer` object borrows the channel.
-pub struct Buffer<'a>(cpal_impl::Buffer<'a>);
+pub struct Buffer<'a, T>(cpal_impl::Buffer<'a, T>);
 
 /// Format that each sample has.
 #[deriving(Clone, Copy, Show, PartialEq, Eq)]
@@ -62,19 +62,19 @@ impl Channel {
     /// This function returns a `Buffer` object that must be filled with the audio data.
     /// You can't know in advance the size of the buffer, as it depends on the current state
     /// of the backend.
-    pub fn append_data<'a>(&'a mut self) -> Buffer<'a> {
+    pub fn append_data<'a, T>(&'a mut self) -> Buffer<'a, T> {
         Buffer(self.0.append_data())
     }
 }
 
-impl<'a> Deref<[u8]> for Buffer<'a> {
-    fn deref(&self) -> &[u8] {
+impl<'a, T> Deref<[T]> for Buffer<'a, T> {
+    fn deref(&self) -> &[T] {
         panic!()
     }
 }
 
-impl<'a> DerefMut<[u8]> for Buffer<'a> {
-    fn deref_mut(&mut self) -> &mut [u8] {
+impl<'a, T> DerefMut<[T]> for Buffer<'a, T> {
+    fn deref_mut(&mut self) -> &mut [T] {
         self.0.get_buffer()
     }
 }

src/wasapi/mod.rs

@@ -15,10 +15,10 @@ pub struct Channel {
     started: bool,
 }
 
-pub struct Buffer<'a> {
+pub struct Buffer<'a, T> {
     audio_client: *mut winapi::IAudioClient,
     render_client: *mut winapi::IAudioRenderClient,
-    buffer: CVec<u8>,
+    buffer: CVec<T>,
     frames: winapi::UINT32,
     start_on_drop: bool,
 }
@@ -43,7 +43,7 @@ impl Channel {
         }
     }
 
-    pub fn append_data<'a>(&'a mut self) -> Buffer<'a> {
+    pub fn append_data<'a, T>(&'a mut self) -> Buffer<'a, T> {
         unsafe {
             loop {
                 // 
@@ -63,7 +63,7 @@ impl Channel {
                 }
 
                 // loading buffer
-                let buffer: CVec<u8> = {
+                let buffer: CVec<T> = {
                     let mut buffer: *mut winapi::BYTE = mem::uninitialized();
                     let f = self.render_client.as_mut().unwrap().lpVtbl.as_ref().unwrap().GetBuffer;
                     let hresult = f(self.render_client, frames_available,
@@ -71,8 +71,9 @@ impl Channel {
                     check_result(hresult).unwrap();
                     assert!(!buffer.is_null());
 
-                    CVec::new(buffer as *mut u8,
-                              frames_available as uint * self.bytes_per_frame as uint)
+                    CVec::new(buffer as *mut T,
+                              frames_available as uint * self.bytes_per_frame as uint
+                                  / mem::size_of::<T>())
                 };
 
                 let buffer = Buffer {
@@ -106,14 +107,14 @@ impl Drop for Channel {
     }
 }
 
-impl<'a> Buffer<'a> {
-    pub fn get_buffer(&mut self) -> &mut [u8] {
+impl<'a, T> Buffer<'a, T> {
+    pub fn get_buffer(&mut self) -> &mut [T] {
         self.buffer.as_mut_slice()
     }
 }
 
 #[unsafe_destructor]
-impl<'a> Drop for Buffer<'a> {
+impl<'a, T> Drop for Buffer<'a, T> {
     fn drop(&mut self) {
         // releasing buffer
         unsafe {