Use SoundDirection rather than a boolean

examples/beep.rs

@@ -11,7 +11,7 @@ fn main(_argc: isize, _argv: *const *const u8) -> isize {
 
     gba.sound.enable();
 
-    let sweep_settings = gba::sound::SweepSettings::new(3, false, 7);
+    let sweep_settings = sound::SweepSettings::new(3, sound::SoundDirection::Decrease, 7);
     gba.sound.channel1().play_sound(&sweep_settings);
 
     loop {}

src/sound/mod.rs

@@ -31,37 +31,17 @@ impl Sound {
 #[non_exhaustive]
 pub struct Channel1 {}
 
-pub struct SweepSettings {
-    number_of_sweep_shifts: u8,
-    increase_sweep: bool,
-    sweep_time: u8,
+pub enum SoundDirection {
+    Increase,
+    Decrease,
 }
 
-impl SweepSettings {
-    pub fn new(number_of_sweep_shifts: u8, increase_sweep: bool, sweep_time: u8) -> Self {
-        assert!(
-            number_of_sweep_shifts < 8,
-            "Number of sweep shifts must be less than 8"
-        );
-        assert!(sweep_time < 8, "Sweep time must be less than 8");
-
-        SweepSettings {
-            number_of_sweep_shifts,
-            increase_sweep,
-            sweep_time,
-        }
-    }
-
+impl SoundDirection {
     fn as_bits(&self) -> u16 {
-        ((self.number_of_sweep_shifts as u16) & 0b111)
-            | ((self.increase_sweep as u16) << 3)
-            | ((self.sweep_time as u16) & 0b111) << 4
-    }
-}
-
-impl Default for SweepSettings {
-    fn default() -> Self {
-        SweepSettings::new(0, true, 0)
+        match &self {
+            SoundDirection::Increase => 1,
+            SoundDirection::Decrease => 0,
+        }
     }
 }
 
@@ -72,3 +52,41 @@ impl Channel1 {
         CHANNEL_1_FREQUENCY_CONTROL.set(0b1_0_000_01000000000);
     }
 }
+
+pub struct SweepSettings {
+    number_of_sweep_shifts: u8,
+    sound_direction: SoundDirection,
+    sweep_time: u8,
+}
+
+impl SweepSettings {
+    pub fn new(
+        number_of_sweep_shifts: u8,
+        sound_direction: SoundDirection,
+        sweep_time: u8,
+    ) -> Self {
+        assert!(
+            number_of_sweep_shifts < 8,
+            "Number of sweep shifts must be less than 8"
+        );
+        assert!(sweep_time < 8, "Sweep time must be less than 8");
+
+        SweepSettings {
+            number_of_sweep_shifts,
+            sound_direction,
+            sweep_time,
+        }
+    }
+
+    fn as_bits(&self) -> u16 {
+        ((self.number_of_sweep_shifts as u16) & 0b111)
+            | (self.sound_direction.as_bits() << 3)
+            | ((self.sweep_time as u16) & 0b111) << 4
+    }
+}
+
+impl Default for SweepSettings {
+    fn default() -> Self {
+        SweepSettings::new(0, SoundDirection::Increase, 0)
+    }
+}