1 files changed, 36 insertions, 0 deletions
diff --git a/src/wheel_tracker.rs b/src/wheel_tracker.rs
new file mode 100644
index 00000000..0163548a
--- /dev/null
+++ b/src/wheel_tracker.rs
@@ -0,0 +1,36 @@
+pub struct WheelTracker {
+    last: f64,
+    acc: f64,
+}
+
+impl WheelTracker {
+    #[allow(clippy::new_without_default)]
+    pub fn new() -> Self {
+        Self { last: 0., acc: 0. }
+    }
+
+    pub fn accumulate(&mut self, amount_v120: f64) -> i8 {
+        let changed_direction =
+            (self.last > 0. && amount_v120 < 0.) || (self.last < 0. && amount_v120 > 0.);
+        if changed_direction {
+            self.acc = 0.
+        }
+
+        self.last = amount_v120;
+        self.acc += amount_v120;
+
+        let mut ticks = 0;
+        if self.acc.abs() >= 120. {
+            let clamped = self.acc.clamp(-127. * 120., 127. * 120.);
+            ticks = (clamped as i16 / 120) as i8;
+            self.acc %= 120.;
+        }
+
+        ticks
+    }
+
+    pub fn reset(&mut self) {
+        self.last = 0.;
+        self.acc = 0.;
+    }
+}