From 095723bbf898c05eedaee9c0c2bf58f3bf3887da Mon Sep 17 00:00:00 2001
From: Gwilym Inzani <email@gwilym.dev>
Date: Sun, 23 Jul 2023 22:03:32 +0100
Subject: [PATCH] FineVolumeSlide

---
 tracker/agb-tracker-interop/src/lib.rs |  5 +++++
 tracker/agb-tracker/src/lib.rs         | 17 ++++++++++-------
 tracker/agb-xm-core/src/lib.rs         | 12 ++++++++++++
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/tracker/agb-tracker-interop/src/lib.rs b/tracker/agb-tracker-interop/src/lib.rs
index 4e787bdc..61b4deb9 100644
--- a/tracker/agb-tracker-interop/src/lib.rs
+++ b/tracker/agb-tracker-interop/src/lib.rs
@@ -48,6 +48,7 @@ pub enum PatternEffect {
     Panning(Num<i16, 4>),
     Volume(Num<i16, 4>),
     VolumeSlide(Num<i16, 4>),
+    FineVolumeSlide(Num<i16, 4>),
     NoteCut(u32),
     Portamento(Num<u16, 8>),
     /// Slide each tick the first amount to at most the second amount
@@ -205,6 +206,10 @@ impl quote::ToTokens for PatternEffect {
                 let amount = amount.to_raw();
                 quote! { VolumeSlide(agb_tracker::__private::Num::from_raw(#amount))}
             }
+            PatternEffect::FineVolumeSlide(amount) => {
+                let amount = amount.to_raw();
+                quote! { FineVolumeSlide(agb_tracker::__private::Num::from_raw(#amount))}
+            }
             PatternEffect::NoteCut(wait) => quote! { NoteCut(#wait) },
             PatternEffect::Portamento(amount) => {
                 let amount = amount.to_raw();
diff --git a/tracker/agb-tracker/src/lib.rs b/tracker/agb-tracker/src/lib.rs
index 1f4faca4..22ffb5d0 100644
--- a/tracker/agb-tracker/src/lib.rs
+++ b/tracker/agb-tracker/src/lib.rs
@@ -124,7 +124,7 @@ impl Tracker {
             tick: 0,
 
             current_row: 0,
-            current_pattern: 6,
+            current_pattern: 0x10,
         }
     }
 
@@ -143,7 +143,7 @@ impl Tracker {
         let pattern_slots =
             &self.track.pattern_data[pattern_data_pos..pattern_data_pos + self.track.num_channels];
 
-        for (channel, pattern_slot) in self.channels.iter_mut().zip(pattern_slots) {
+        for (channel, pattern_slot) in self.channels.iter_mut().zip(pattern_slots).skip(3) {
             if pattern_slot.sample != 0 && self.tick == 0 {
                 let sample = &self.track.samples[pattern_slot.sample as usize - 1];
                 channel.play_sound(mixer, sample);
@@ -219,7 +219,7 @@ impl TrackerChannel {
         }
 
         self.channel_id = mixer.play_sound(new_channel);
-        self.volume = 1.into();
+        self.volume = sample.volume;
     }
 
     fn set_speed(&mut self, mixer: &mut Mixer<'_>, speed: Num<u32, 8>) {
@@ -264,10 +264,13 @@ impl TrackerChannel {
                 }
                 PatternEffect::VolumeSlide(amount) => {
                     if tick != 0 {
-                        self.volume += *amount;
-                        if self.volume < 0.into() {
-                            self.volume = 0.into();
-                        }
+                        self.volume = (self.volume + *amount).max(0.into());
+                        channel.volume(self.volume);
+                    }
+                }
+                PatternEffect::FineVolumeSlide(amount) => {
+                    if tick == 0 {
+                        self.volume = (self.volume + *amount).max(0.into());
                         channel.volume(self.volume);
                     }
                 }
diff --git a/tracker/agb-xm-core/src/lib.rs b/tracker/agb-xm-core/src/lib.rs
index 553179f7..34fd935c 100644
--- a/tracker/agb-xm-core/src/lib.rs
+++ b/tracker/agb-xm-core/src/lib.rs
@@ -162,6 +162,12 @@ pub fn parse_module(module: &Module) -> TokenStream {
                                     .map(|note_and_sample| note_and_sample.1.volume)
                                     .unwrap_or(1.into()),
                         ),
+                        0x80..=0x8F => PatternEffect::FineVolumeSlide(
+                            -Num::new((slot.volume - 0x80) as i16) / 16,
+                        ),
+                        0x90..=0x9F => PatternEffect::FineVolumeSlide(
+                            Num::new((slot.volume - 0x90) as i16) / 16,
+                        ),
                         0xC0..=0xCF => PatternEffect::Panning(
                             Num::new(slot.volume as i16 - (0xC0 + (0xCF - 0xC0) / 2)) / 64,
                         ),
@@ -292,6 +298,12 @@ pub fn parse_module(module: &Module) -> TokenStream {
                         }
                     }
                     0xE => match slot.effect_parameter >> 4 {
+                        0xA => PatternEffect::FineVolumeSlide(
+                            Num::new((slot.effect_parameter & 0xf) as i16) / 16,
+                        ),
+                        0xB => PatternEffect::FineVolumeSlide(
+                            -Num::new((slot.effect_parameter & 0xf) as i16) / 16,
+                        ),
                         0xC => PatternEffect::NoteCut((slot.effect_parameter & 0xf).into()),
                         _ => PatternEffect::None,
                     },