Implement vibrato correctly and add a small test case

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

@@ -62,7 +62,8 @@ pub enum PatternEffect {
     Arpeggio(Num<u16, 8>, Num<u16, 8>),
     Panning(Num<i16, 4>),
     Volume(Num<i16, 8>),
-    VolumeSlide(Num<i16, 8>),
+    // bool = maintain vibrato?
+    VolumeSlide(Num<i16, 8>, bool),
     FineVolumeSlide(Num<i16, 8>),
     NoteCut(u32),
     NoteDelay(u32),
@@ -298,9 +299,9 @@ impl quote::ToTokens for PatternEffect {
                 let volume = volume.to_raw();
                 quote! { Volume(agb_tracker::__private::Num::from_raw(#volume))}
             }
-            PatternEffect::VolumeSlide(amount) => {
+            PatternEffect::VolumeSlide(amount, vibrato) => {
                 let amount = amount.to_raw();
-                quote! { VolumeSlide(agb_tracker::__private::Num::from_raw(#amount))}
+                quote! { VolumeSlide(agb_tracker::__private::Num::from_raw(#amount), #vibrato)}
             }
             PatternEffect::FineVolumeSlide(amount) => {
                 let amount = amount.to_raw();

tracker/agb-tracker/src/lib.rs

@@ -133,6 +133,8 @@ struct Waves {
     frame: usize,
     speed: usize,
     amount: Num<i32, 12>,
+
+    enable: bool,
 }
 
 impl Waves {
@@ -254,6 +256,8 @@ impl<'track, TChannelId> TrackerInner<'track, TChannelId> {
                 channel.set_speed(pattern_slot.speed.change_base());
             }
 
+            channel.vibrato.enable = false;
+
             channel.apply_effect(
                 &pattern_slot.effect1,
                 self.tick,
@@ -282,7 +286,7 @@ impl<'track, TChannelId> TrackerInner<'track, TChannelId> {
             {
                 let mut current_speed = tracker_channel.current_speed;
 
-                if tracker_channel.vibrato.speed != 0 {
+                if tracker_channel.vibrato.speed != 0 && tracker_channel.vibrato.enable {
                     current_speed *= tracker_channel.vibrato.value().change_base();
                 }
 
@@ -419,13 +423,15 @@ impl TrackerChannel {
 
                 self.volume = volume.change_base();
             }
-            PatternEffect::VolumeSlide(amount) => {
+            PatternEffect::VolumeSlide(amount, keep_vibrato) => {
                 if tick != 0 {
                     self.volume = (self.volume + amount.change_base()).max(0.into());
                     self.current_volume = (self.volume * global_settings.volume)
                         .try_change_base()
                         .unwrap();
                 }
+
+                self.vibrato.enable = *keep_vibrato;
             }
             PatternEffect::FineVolumeSlide(amount) => {
                 if tick == 0 {
@@ -506,9 +512,16 @@ impl TrackerChannel {
                     (global_settings.volume + *volume_delta).clamp(0.into(), 1.into());
             }
             PatternEffect::Vibrato(waveform, amount, speed) => {
+                if *amount != 0.into() {
+                    self.vibrato.amount = amount.change_base();
+                }
+
+                if *speed != 0 {
+                    self.vibrato.speed = *speed as usize;
+                }
+
                 self.vibrato.waveform = *waveform;
-                self.vibrato.amount = amount.change_base();
-                self.vibrato.speed = *speed as usize;
+                self.vibrato.enable = true;
             }
         }
     }

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

@@ -147,12 +147,14 @@ pub fn parse_module(module: &Module) -> agb_tracker_interop::Track {
                                     .map(|note_and_sample| note_and_sample.1.volume)
                                     .unwrap_or(1.into()),
                         ),
-                        0x60..=0x6F => {
-                            PatternEffect::VolumeSlide(-Num::new((slot.volume - 0x60) as i16) / 64)
-                        }
-                        0x70..=0x7F => {
-                            PatternEffect::VolumeSlide(Num::new((slot.volume - 0x70) as i16) / 64)
-                        }
+                        0x60..=0x6F => PatternEffect::VolumeSlide(
+                            -Num::new((slot.volume - 0x60) as i16) / 64,
+                            false,
+                        ),
+                        0x70..=0x7F => PatternEffect::VolumeSlide(
+                            Num::new((slot.volume - 0x70) as i16) / 64,
+                            false,
+                        ),
                         0x80..=0x8F => PatternEffect::FineVolumeSlide(
                             -Num::new((slot.volume - 0x80) as i16) / 128,
                         ),
@@ -283,7 +285,7 @@ pub fn parse_module(module: &Module) -> agb_tracker_interop::Track {
 
                         let c4_speed = note_to_speed(Note::C4, 0.0, 0, module.frequency_type);
                         let speed =
-                            note_to_speed(Note::C4, depth as f64 * 8.0, 0, module.frequency_type);
+                            note_to_speed(Note::C4, depth as f64 * 16.0, 0, module.frequency_type);
 
                         let amount = speed / c4_speed - 1;
 
@@ -301,9 +303,15 @@ pub fn parse_module(module: &Module) -> agb_tracker_interop::Track {
                         let second = effect_parameter & 0xF;
 
                         if first == 0 {
-                            PatternEffect::VolumeSlide(-Num::new(second as i16) / 64)
+                            PatternEffect::VolumeSlide(
+                                -Num::new(second as i16) / 64,
+                                slot.effect_type == 0x6,
+                            )
                         } else {
-                            PatternEffect::VolumeSlide(Num::new(first as i16) / 64)
+                            PatternEffect::VolumeSlide(
+                                Num::new(first as i16) / 64,
+                                slot.effect_type == 0x6,
+                            )
                         }
                     }
                     0xC => {