libs/kaptan-sensor: add optical-flow observations

libs/kaptan-sensor/src/lib.rs

@@ -8,5 +8,7 @@
 
 /// Inertial measurement unit observations.
 pub mod imu;
+/// Optical-flow observations.
+pub mod optical_flow;
 /// Distance sensor observations.
 pub mod range;

libs/kaptan-sensor/src/optical_flow.rs

@@ -0,0 +1,37 @@
+//! Optical-flow observations.
+
+use kaptan_time::Timestamp;
+
+/// Coherent ground-referenced optical-flow observation in the sensor frame.
+///
+/// Linear velocity and ground distance use integer SI subunits so acquisition
+/// remains independent of the floating-point representation required by some
+/// outbound wire protocols.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub struct OpticalFlowSnapshot {
+    /// Flight-controller monotonic time at observation reception.
+    pub timestamp: Timestamp,
+    /// Ground-referenced velocity along sensor X/Y, in millimetres per second.
+    pub velocity_millimetres_per_second: [i32; 2],
+    /// Ground distance, in millimetres.
+    pub ground_distance_millimetres: u32,
+    /// Device-reported observation quality, from 0 through 255.
+    pub quality: u8,
+}
+
+impl OpticalFlowSnapshot {
+    /// Creates one valid optical-flow observation.
+    pub const fn new(
+        timestamp: Timestamp,
+        velocity_millimetres_per_second: [i32; 2],
+        ground_distance_millimetres: u32,
+        quality: u8,
+    ) -> Self {
+        Self {
+            timestamp,
+            velocity_millimetres_per_second,
+            ground_distance_millimetres,
+            quality,
+        }
+    }
+}