Correctly track restart point

agb/src/sound/mixer/sw_mixer.rs

@@ -484,7 +484,7 @@ impl MixerBuffer {
         for i in 0..self.frequency.buffer_size() {
             if channel.pos >= channel_len {
                 if channel.should_loop {
-                    channel.pos -= channel_len + channel.restart_point;
+                    channel.pos -= channel_len - channel.restart_point;
                 } else {
                     channel.is_done = true;
                     break;

tracker/agb-tracker-interop/src/lib.rs

@@ -18,6 +18,7 @@ pub struct Track<'a> {
 pub struct Sample<'a> {
     pub data: &'a [u8],
     pub should_loop: bool,
+    pub restart_point: u32,
 }
 
 #[derive(Debug)]
@@ -95,6 +96,7 @@ impl<'a> quote::ToTokens for Sample<'a> {
         let self_as_u8s: Vec<_> = self.data.iter().map(|i| *i as u8).collect();
         let samples = ByteString(&self_as_u8s);
         let should_loop = self.should_loop;
+        let restart_point = self.restart_point;
 
         tokens.append_all(quote! {
             {
@@ -102,7 +104,7 @@ impl<'a> quote::ToTokens for Sample<'a> {
                 struct AlignmentWrapper<const N: usize>([u8; N]);
 
                 const SAMPLE_DATA: &[u8] = &AlignmentWrapper(*#samples).0;
-                agb_tracker::__private::agb_tracker_interop::Sample { data: SAMPLE_DATA, should_loop: #should_loop }
+                agb_tracker::__private::agb_tracker_interop::Sample { data: SAMPLE_DATA, should_loop: #should_loop, restart_point: #restart_point }
             }
         });
     }

tracker/agb-tracker/src/lib.rs

@@ -106,7 +106,8 @@ impl Tracker {
                 new_channel
                     .panning(pattern_slot.panning)
                     .volume(pattern_slot.volume)
-                    .playback(pattern_slot.speed);
+                    .playback(pattern_slot.speed)
+                    .restart_point(sample.restart_point);
 
                 if sample.should_loop {
                     new_channel.should_loop();

tracker/agb-xm-core/src/lib.rs

@@ -54,6 +54,7 @@ pub fn parse_module(module: &Module) -> TokenStream {
         fine_tune: f64,
         relative_note: i8,
         volume: f64,
+        restart_point: u32,
     }
 
     let mut samples = vec![];
@@ -66,14 +67,23 @@ pub fn parse_module(module: &Module) -> TokenStream {
             let fine_tune = sample.finetune as f64;
             let relative_note = sample.relative_note;
             let volume = sample.volume as f64;
+            let restart_point = sample.loop_start;
+            let sample_len = if sample.loop_length > 0 {
+                (sample.loop_length + sample.loop_start) as usize
+            } else {
+                usize::MAX
+            };
 
             let sample = match &sample.data {
-                SampleDataType::Depth8(depth8) => {
-                    depth8.iter().map(|value| *value as u8).collect::<Vec<_>>()
-                }
+                SampleDataType::Depth8(depth8) => depth8
+                    .iter()
+                    .map(|value| *value as u8)
+                    .take(sample_len)
+                    .collect::<Vec<_>>(),
                 SampleDataType::Depth16(depth16) => depth16
                     .iter()
                     .map(|sample| (sample >> 8) as i8 as u8)
+                    .take(sample_len)
                     .collect::<Vec<_>>(),
             };
 
@@ -84,6 +94,7 @@ pub fn parse_module(module: &Module) -> TokenStream {
                 fine_tune,
                 relative_note,
                 volume,
+                restart_point,
             });
         }
     }
@@ -193,6 +204,7 @@ pub fn parse_module(module: &Module) -> TokenStream {
         .map(|sample| agb_tracker_interop::Sample {
             data: &sample.data,
             should_loop: sample.should_loop,
+            restart_point: sample.restart_point,
         })
         .collect();