From 2e0f89978ab82b71682313699b319e4815a489dc Mon Sep 17 00:00:00 2001
From: Gwilym Inzani <email@gwilym.dev>
Date: Wed, 15 May 2024 22:30:13 +0100
Subject: [PATCH] Add note delay support (effect EDx)

---
 tracker/agb-tracker-interop/src/lib.rs | 2 ++
 tracker/agb-tracker/src/lib.rs         | 9 +++++++++
 tracker/agb-xm-core/src/lib.rs         | 1 +
 3 files changed, 12 insertions(+)

diff --git a/tracker/agb-tracker-interop/src/lib.rs b/tracker/agb-tracker-interop/src/lib.rs
index d0eb1aac..e9ccebc0 100644
--- a/tracker/agb-tracker-interop/src/lib.rs
+++ b/tracker/agb-tracker-interop/src/lib.rs
@@ -62,6 +62,7 @@ pub enum PatternEffect {
     VolumeSlide(Num<i16, 8>),
     FineVolumeSlide(Num<i16, 8>),
     NoteCut(u32),
+    NoteDelay(u32),
     Portamento(Num<u16, 12>),
     /// Slide each tick the first amount to at most the second amount
     TonePortamento(Num<u16, 12>, Num<u16, 12>),
@@ -289,6 +290,7 @@ impl quote::ToTokens for PatternEffect {
                 quote! { FineVolumeSlide(agb_tracker::__private::Num::from_raw(#amount))}
             }
             PatternEffect::NoteCut(wait) => quote! { NoteCut(#wait) },
+            PatternEffect::NoteDelay(wait) => quote! { NoteDelay(#wait) },
             PatternEffect::Portamento(amount) => {
                 let amount = amount.to_raw();
                 quote! { Portamento(agb_tracker::__private::Num::from_raw(#amount))}
diff --git a/tracker/agb-tracker/src/lib.rs b/tracker/agb-tracker/src/lib.rs
index 11212b20..9e1b55ab 100644
--- a/tracker/agb-tracker/src/lib.rs
+++ b/tracker/agb-tracker/src/lib.rs
@@ -405,6 +405,15 @@ impl TrackerChannel {
                         }
                     }
                 }
+                PatternEffect::NoteDelay(wait) => {
+                    if tick <= *wait {
+                        channel.volume(0);
+                    }
+
+                    if tick == *wait + 1 {
+                        channel.volume((self.volume * global_settings.volume).try_change_base().unwrap());
+                    }
+                }
                 PatternEffect::Portamento(amount) => {
                     if tick != 0 {
                         self.base_speed *= amount.change_base();
diff --git a/tracker/agb-xm-core/src/lib.rs b/tracker/agb-xm-core/src/lib.rs
index fcc20e0a..ee644b01 100644
--- a/tracker/agb-xm-core/src/lib.rs
+++ b/tracker/agb-xm-core/src/lib.rs
@@ -347,6 +347,7 @@ pub fn parse_module(module: &Module) -> TokenStream {
                             -Num::new((slot.effect_parameter & 0xf) as i16) / 128,
                         ),
                         0xC => PatternEffect::NoteCut((slot.effect_parameter & 0xf).into()),
+                        0xD => PatternEffect::NoteDelay((slot.effect_parameter & 0xf).into()),
                         _ => PatternEffect::None,
                     },
                     0xF => match slot.effect_parameter {