add super basic music engine

Signed-off-by: Jessie Williams <quorawings@gmail.com>

src/lib.rs

@@ -8,8 +8,7 @@ use sh0rk::{
     palette,
     sys::*,
     Direction::{self, *},
-    Rect,
-    Point,
+    Song, Point, Rect,
 };
 
 static mut GAME: Game = Game::new();
@@ -26,6 +25,8 @@ struct Game {
     bonk_timer: Option<u8>,
     gate_count: u8,
     gate_pos: Point,
+
+    song: Song<48>,
 }
 
 impl Game {
@@ -42,6 +43,7 @@ impl Game {
             bonk_timer: None,
             gate_count: 4,
             gate_pos: Point { x: 40, y: 64 },
+            song: Song::new(sh0rk::CHOPSTICKS),
         }
     }
 
@@ -96,6 +98,8 @@ impl Game {
 
     fn update(&mut self) {
         self.frame_count += 1;
+        self.song.update();
+
         if let Some(rem) = self.bonk_timer {
             if rem == 0 {
                 self.bonk_timer = None;
@@ -110,6 +114,9 @@ impl Game {
         let just_pressed = gamepad & (gamepad ^ self.prev_gamepad);
 
         let speed = if just_pressed & BUTTON_2 != 0 { 4 } else { 2 };
+        if just_pressed & BUTTON_1 != 0 {
+            self.song.pause();
+        }
 
         if gamepad & BUTTON_UP != 0 {
             self.mara_dir = Up;
@@ -134,8 +141,16 @@ impl Game {
 
         self.mara_walk();
 
-        let player = Rect { base: self.mara_position.clone(), width: 16, height: 16 };
-        let gate = Rect { base: self.gate_pos.clone(), width: 12, height: 4 * self.gate_count as i32 };
+        let player = Rect {
+            base: self.mara_position.clone(),
+            width: 16,
+            height: 16,
+        };
+        let gate = Rect {
+            base: self.gate_pos.clone(),
+            width: 12,
+            height: 4 * self.gate_count as i32,
+        };
         if player.collides(&gate) {
             self.mara_speed = 0;
             match self.mara_dir {

src/sh0rk/mod.rs

@@ -1,5 +1,8 @@
 pub mod palette;
 pub mod sys;
+mod music;
+
+pub use music::*;
 
 #[derive(Clone, Copy, PartialEq, Eq, Default)]
 pub struct Point {

src/sh0rk/music.rs

@@ -0,0 +1,129 @@
+use super::sys::{tone, TONE_PULSE1, TONE_PULSE2};
+
+pub struct Note {
+    pub freq: u32,
+    pub dur: u32,
+    pub volume: u32,
+    pub flags: u32,
+}
+
+impl Note {
+    pub fn play(&self) {
+        tone(self.freq, self.dur, self.volume, self.flags);
+    }
+}
+
+impl From<(u32, u32, u32, u32)> for Note {
+    fn from((freq, dur, volume, flags): (u32, u32, u32, u32)) -> Self {
+        Note {freq, dur, volume, flags}
+    }
+}
+
+pub enum Quantum {
+    Rest(u8),
+    Notes([(u32, u32, u32, u32); 2]),
+}
+pub use Quantum::*;
+
+pub const CHOPSTICKS: [Quantum; 48] = [
+    // G7
+    Notes([(196, 14, 25, TONE_PULSE1), (175, 14, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(196, 14, 25, TONE_PULSE1), (175, 14, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(196, 14, 25, TONE_PULSE1), (175, 14, 25, TONE_PULSE2)]),
+    Rest(15),
+    // G7
+    Notes([(196, 15, 25, TONE_PULSE1), (175, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(196, 15, 25, TONE_PULSE1), (175, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(196, 15, 25, TONE_PULSE1), (175, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    // C
+    Notes([(196, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(196, 15, 25, TONE_PULSE1), (175, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(196, 15, 25, TONE_PULSE1), (175, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    // C
+    Notes([(196, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(246, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(246, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    // G7
+    Notes([(246, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(246, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(246, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    // G7
+    Notes([(246, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(261, 15, 25, TONE_PULSE1), (130, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(261, 15, 25, TONE_PULSE1), (130, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    // C
+    Notes([(261, 15, 25, TONE_PULSE1), (130, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(261, 15, 25, TONE_PULSE1), (130, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(261, 15, 25, TONE_PULSE1), (130, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    // C
+    Notes([(261, 15, 25, TONE_PULSE1), (130, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(246, 15, 25, TONE_PULSE1), (146, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+    Notes([(220, 15, 25, TONE_PULSE1), (164, 15, 25, TONE_PULSE2)]),
+    Rest(15),
+];
+
+pub struct Song<const N: usize> {
+    position: usize,
+    sleep_timer: u8,
+    song: [Quantum; N],
+    paused: bool,
+}
+
+impl<const N: usize> Song<N> {
+    pub const fn new(song: [Quantum;N]) -> Self {
+        Self{
+            position: 0,
+            sleep_timer: 0,
+            song,
+            paused: false,
+        }
+    }
+
+    pub fn pause(&mut self) {
+        self.paused = !self.paused;
+    }
+
+    pub fn update(&mut self) {
+        if self.paused {
+            return;
+        }
+
+        if self.sleep_timer != 0 {
+            self.sleep_timer -= 1;
+            return;
+        }
+
+        match self.song[self.position % self.song.len()] {
+            Rest(n) => self.sleep_timer = n,
+            Notes(notes) => {
+                for note in notes {
+                    Note::from(note).play();
+                }
+            },
+        }
+
+        self.position += 1;
+    }
+}