Implement F command

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

@@ -54,6 +54,8 @@ pub enum PatternEffect {
     Portamento(Num<u16, 12>),
     /// Slide each tick the first amount to at most the second amount
     TonePortamento(Num<u16, 12>, Num<u16, 12>),
+    SetTicksPerStep(u32),
+    SetFramesPerTick(Num<u32, 8>),
 }
 
 #[cfg(feature = "quote")]
@@ -223,6 +225,13 @@ impl quote::ToTokens for PatternEffect {
                 let target = target.to_raw();
                 quote! { TonePortamento(agb_tracker::__private::Num::from_raw(#amount), agb_tracker::__private::Num::from_raw(#target))}
             }
+            PatternEffect::SetTicksPerStep(new_ticks) => {
+                quote! { SetTicksPerStep(#new_ticks) }
+            }
+            PatternEffect::SetFramesPerTick(new_frames_per_tick) => {
+                let amount = new_frames_per_tick.to_raw();
+                quote! { SetFramesPerTick(agb_tracker::__private::Num::from_raw(#amount)) }
+            }
         };
 
         tokens.append_all(quote! {

tracker/agb-tracker/src/lib.rs

@@ -95,6 +95,8 @@ pub struct Tracker {
     tick: u32,
     first: bool,
 
+    global_settings: GlobalSettings,
+
     current_row: usize,
     current_pattern: usize,
 }
@@ -105,6 +107,13 @@ struct TrackerChannel {
     volume: Num<i32, 8>,
 }
 
+#[derive(Clone)]
+struct GlobalSettings {
+    ticks_per_step: u32,
+
+    frames_per_tick: Num<u32, 8>,
+}
+
 impl Tracker {
     /// Create a new tracker playing a specified track. See the [example](crate#example) for how to use the tracker.
     pub fn new(track: &'static Track<'static>) -> Self {
@@ -115,6 +124,11 @@ impl Tracker {
             volume: 0.into(),
         });
 
+        let global_settings = GlobalSettings {
+            ticks_per_step: track.ticks_per_step,
+            frames_per_tick: track.frames_per_tick,
+        };
+
         Self {
             track,
             channels,
@@ -123,8 +137,10 @@ impl Tracker {
             first: true,
             tick: 0,
 
-            current_row: 0,
+            global_settings,
+
             current_pattern: 0,
+            current_row: 0,
         }
     }
 
@@ -153,8 +169,18 @@ impl Tracker {
                 channel.set_speed(mixer, pattern_slot.speed.change_base());
             }
 
-            channel.apply_effect(mixer, &pattern_slot.effect1, self.tick);
-            channel.apply_effect(mixer, &pattern_slot.effect2, self.tick);
+            channel.apply_effect(
+                mixer,
+                &pattern_slot.effect1,
+                self.tick,
+                &mut self.global_settings,
+            );
+            channel.apply_effect(
+                mixer,
+                &pattern_slot.effect2,
+                self.tick,
+                &mut self.global_settings,
+            );
         }
 
         self.increment_step();
@@ -168,11 +194,11 @@ impl Tracker {
 
         self.frame += 1;
 
-        if self.frame >= self.track.frames_per_tick {
+        if self.frame >= self.global_settings.frames_per_tick {
             self.tick += 1;
-            self.frame -= self.track.frames_per_tick;
+            self.frame -= self.global_settings.frames_per_tick;
 
-            if self.tick == self.track.ticks_per_step {
+            if self.tick >= self.global_settings.ticks_per_step {
                 self.current_row += 1;
 
                 if self.current_row
@@ -236,7 +262,13 @@ impl TrackerChannel {
         }
     }
 
-    fn apply_effect(&mut self, mixer: &mut Mixer<'_>, effect: &PatternEffect, tick: u32) {
+    fn apply_effect(
+        &mut self,
+        mixer: &mut Mixer<'_>,
+        effect: &PatternEffect,
+        tick: u32,
+        global_settings: &mut GlobalSettings,
+    ) {
         if let Some(channel) = self
             .channel_id
             .as_ref()
@@ -298,8 +330,25 @@ impl TrackerChannel {
 
                     channel.playback(self.base_speed.change_base());
                 }
+                // These are global effects handled below
+                PatternEffect::SetTicksPerStep(_) | PatternEffect::SetFramesPerTick(_) => {}
             }
         }
+
+        // Some effects have to happen regardless of if we're actually playing anything
+        match effect {
+            PatternEffect::SetTicksPerStep(amount) => {
+                if tick == 0 {
+                    global_settings.ticks_per_step = *amount;
+                }
+            }
+            PatternEffect::SetFramesPerTick(new_frames_per_tick) => {
+                if tick == 0 {
+                    global_settings.frames_per_tick = *new_frames_per_tick;
+                }
+            }
+            _ => {}
+        }
     }
 }
 

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

@@ -323,6 +323,13 @@ pub fn parse_module(module: &Module) -> TokenStream {
                         0xC => PatternEffect::NoteCut((slot.effect_parameter & 0xf).into()),
                         _ => PatternEffect::None,
                     },
+                    0xF => {
+                        if slot.effect_parameter < 0x20 {
+                            PatternEffect::SetTicksPerStep(slot.effect_parameter as u32)
+                        } else {
+                            PatternEffect::None
+                        }
+                    }
                     _ => PatternEffect::None,
                 };
 
@@ -379,7 +386,7 @@ pub fn parse_module(module: &Module) -> TokenStream {
         .collect::<Vec<_>>();
 
     // Number 150 here deduced experimentally
-    let frames_per_tick = Num::<u32, 8>::new(150) / module.default_bpm as u32;
+    let frames_per_tick = bpm_to_frames_per_tick(module.default_bpm as u32);
     let ticks_per_step = module.default_tempo;
 
     let interop = agb_tracker_interop::Track {
@@ -397,6 +404,10 @@ pub fn parse_module(module: &Module) -> TokenStream {
     quote!(#interop)
 }
 
+fn bpm_to_frames_per_tick(bpm: u32) -> Num<u32, 8> {
+    Num::<u32, 8>::new(150) / bpm
+}
+
 fn note_to_speed(
     note: Note,
     fine_tune: f64,