Struct TrackerContext 

pub struct TrackerContext { /* private fields */ }

Reusable owner of every buffer the tracking hot path touches: both frame pyramids, the Lucas-Kanade scratch, the result vector and the forward-backward intermediates.

Create one per tracking thread and call prepare then track / track_fb each frame. After the first (warm-up) frame, a steady-state step with a fixed image size, level count, window size and point count performs no heap allocation — all buffers are resized in place. This is the allocation-free path the VIO front-end runs every frame; the free functions (calc_optical_flow_ex, calc_optical_flow_fb) are thin convenience wrappers that allocate their own scratch.

Implementations

impl TrackerContext

pub fn new() -> Self

Creates an empty context. Buffers grow to fit on the first prepare / track call and are reused thereafter.

pub fn prepare(&mut self, prev: &GrayImage, next: &GrayImage, levels: usize)

Builds the previous- and next-frame pyramids into the context’s reusable buffers. Zero-alloc in steady state (same image size and levels).

pub fn prev_pyramid(&self) -> &[GrayImage]

The previous-frame pyramid built by the last prepare.

pub fn next_pyramid(&self) -> &[GrayImage]

The next-frame pyramid built by the last prepare.

pub fn track( &mut self, prev_points: &[(f32, f32)], predicted: Option<&[(f32, f32)]>, window_size: usize, max_iterations: usize, min_eigen_threshold: f32, ) -> &[TrackResult]

Tracks prev_points using the prepared pyramids, returning the results held inside the context. See calc_optical_flow_ex for the argument semantics. Allocation-free in steady state.

pub fn track_fb( &mut self, prev_points: &[(f32, f32)], predicted: Option<&[(f32, f32)]>, window_size: usize, max_iterations: usize, min_eigen_threshold: f32, fb_threshold: f32, ) -> &[TrackResult]

Forward-backward consistent tracking using the prepared pyramids. See calc_optical_flow_fb for semantics. Reuses the context’s scratch and intermediate point buffers, so it is allocation-free in steady state.

Trait Implementations

impl Default for TrackerContext

fn default() -> TrackerContext

Returns the “default value” for a type.