Use 32768Hz for the tracker (#479)

Sounds way better and we can get away with it in DPL

- [x]  no changelog update needed

examples/the-dungeon-puzzlers-lament/src/lib.rs

@@ -109,7 +109,7 @@ pub fn entry(mut gba: agb::Gba) -> ! {
         let _ = save::save_max_level(&mut gba.save, 0);
     }
 
-    let mut mixer = gba.mixer.mixer(Frequency::Hz18157);
+    let mut mixer = gba.mixer.mixer(Frequency::Hz32768);
     let sfx = Sfx::new(&mut mixer);
 
     let mut g = Agb {

examples/the-dungeon-puzzlers-lament/src/sfx.rs

@@ -1,4 +1,5 @@
 use agb::{
+    fixnum::num,
     include_wav,
     sound::mixer::{Mixer, SoundChannel},
 };
@@ -37,38 +38,38 @@ impl<'a> Sfx<'a> {
     }
 
     pub fn bad_selection(&mut self) {
-        self.mixer.play_sound(SoundChannel::new(BAD_SELECTION));
+        self.play_effect(BAD_SELECTION);
     }
 
     pub fn select(&mut self) {
-        self.mixer.play_sound(SoundChannel::new(SELECT));
+        self.play_effect(SELECT);
     }
 
     pub fn place(&mut self) {
-        self.mixer.play_sound(SoundChannel::new(PLACE));
+        self.play_effect(PLACE);
     }
 
     pub fn play_sound_effect(&mut self, effect: Option<SoundEffect>) {
         if let Some(effect) = effect {
             match effect {
                 SoundEffect::WallHit => {
-                    self.mixer.play_sound(SoundChannel::new(WALL_HIT));
+                    self.play_effect(WALL_HIT);
                 }
                 SoundEffect::SlimeDie => {
-                    self.mixer.play_sound(SoundChannel::new(SLIME_DEATH));
+                    self.play_effect(SLIME_DEATH);
                 }
                 SoundEffect::HeroDie => {}
                 SoundEffect::SquidDie => {}
                 SoundEffect::SwordPickup => {
-                    self.mixer.play_sound(SoundChannel::new(SWORD_PICKUP));
+                    self.play_effect(SWORD_PICKUP);
                 }
                 SoundEffect::SwordKill => {}
                 SoundEffect::KeyPickup => {}
                 SoundEffect::DoorOpen => {
-                    self.mixer.play_sound(SoundChannel::new(DOOR_OPEN));
+                    self.play_effect(DOOR_OPEN);
                 }
                 SoundEffect::SwitchToggle => {
-                    self.mixer.play_sound(SoundChannel::new(SWICTH_TOGGLES[0]));
+                    self.play_effect(SWICTH_TOGGLES[0]);
                 }
                 SoundEffect::KeyDrop => {}
                 SoundEffect::SwordDrop => {}
@@ -77,6 +78,12 @@ impl<'a> Sfx<'a> {
             }
         }
     }
+
+    fn play_effect(&mut self, effect: &'static [u8]) {
+        let mut channel = SoundChannel::new(effect);
+        channel.playback(num!(0.5));
+        self.mixer.play_sound(channel);
+    }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]

tracker/agb-tracker/examples/basic.rs

@@ -12,7 +12,7 @@ const DB_TOFFE: Track = include_xm!("examples/db_toffe.xm");
 fn main(mut gba: Gba) -> ! {
     let vblank_provider = agb::interrupt::VBlank::get();
 
-    let mut mixer = gba.mixer.mixer(Frequency::Hz18157);
+    let mut mixer = gba.mixer.mixer(Frequency::Hz32768);
     mixer.enable();
 
     let mut tracker = Tracker::new(&DB_TOFFE);

tracker/agb-tracker/examples/timing.rs

@@ -18,7 +18,7 @@ fn main(mut gba: Gba) -> ! {
     timer.set_enabled(true);
     timer2.set_cascade(true).set_enabled(true);
 
-    let mut mixer = gba.mixer.mixer(Frequency::Hz18157);
+    let mut mixer = gba.mixer.mixer(Frequency::Hz32768);
     mixer.enable();
 
     let mut tracker = Tracker::new(&DB_TOFFE);

tracker/agb-tracker/src/lib.rs

@@ -35,7 +35,7 @@
 //! fn main(mut gba: Gba) -> ! {
 //!     let vblank_provider = agb::interrupt::VBlank::get();
 //!
-//!     let mut mixer = gba.mixer.mixer(Frequency::Hz18157);
+//!     let mut mixer = gba.mixer.mixer(Frequency::Hz32768);
 //!     mixer.enable();
 //!
 //!     let mut tracker = Tracker::new(&DB_TOFFE);
@@ -49,7 +49,7 @@
 //! }
 //! ```
 //!
-//! Note that currently you have to select 18157Hz as the frequency for the mixer.
+//! Note that currently you have to select 32768Hz as the frequency for the mixer.
 //! This restriction will be lifted in a future version.
 //!
 //! # Concepts

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

@@ -475,7 +475,7 @@ fn note_to_speed(
         FrequencyType::AmigaFrequencies => note_to_frequency_amega(note, fine_tune, relative_note),
     };
 
-    let gba_audio_frequency = 18157f64;
+    let gba_audio_frequency = 32768f64;
 
     let speed = frequency / gba_audio_frequency;
     Num::from_f64(speed)