Playtime: Fix audio interaction handler tests

base/src/approx_f64.rs

@@ -0,0 +1,43 @@
+use std::fmt::{Display, Formatter};
+
+/// An approximate floating-point type that uses the same epsilon for comparison as the == operator in
+/// [EEL2](https://www.cockos.com/EEL2/):
+/// Two values are considered equal if the difference is less than 0.00001 (1/100000), 0 if not.
+pub type AudioF64 = ApproxF64<100000>;
+
+/// Simple newtype that allows for approximate comparison of 64-bit floating-point numbers.
+///
+/// The const type parameter `E` ("epsilon") defines how tolerant floating-point comparison is. Two values are considered
+/// equal if the difference is less than 1/E.
+#[derive(Copy, Clone, PartialOrd, Debug, Default)]
+pub struct ApproxF64<const E: u32>(pub f64);
+
+impl<const E: u32> ApproxF64<E> {
+    pub fn new(raw: f64) -> Self {
+        Self(raw)
+    }
+}
+
+impl<const E: u32> PartialEq for ApproxF64<E> {
+    fn eq(&self, other: &Self) -> bool {
+        (self.0 - other.0).abs() < 1.0 / E as f64
+    }
+}
+
+impl<const E: u32> Display for ApproxF64<E> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn basics() {
+        assert_eq!(AudioF64::new(0.75), AudioF64::new(0.75));
+        assert_ne!(AudioF64::new(0.00001), AudioF64::new(0.00002));
+        assert_eq!(AudioF64::new(0.000001), AudioF64::new(0.000002));
+    }
+}

base/src/lib.rs

@@ -44,3 +44,6 @@ pub mod byte_pattern;
 pub mod serde_json_util;
 
 pub mod panic_util;
+
+mod approx_f64;
+pub use approx_f64::*;