//! 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,
        }
    }
}