Struct Heap 

struct Heap {
    idx: Vec<usize>,
    len: usize,
}

mexUnwrap.c’s binary max-heap of voxel indices, keyed on the magnitude. Kept as the C writes it (module docs, Heap order and ties): its tie behaviour decides the growth order.

Fields

idx: Vec<usize>

heap: calloc(numel, sizeof(int)), so one slot per voxel, zero-initialised.

len: usize

heap_length

Implementations

impl Heap

fn add(&mut self, mag: &[f32], index: usize)

heap_add: append, then sift up while the parent’s magnitude is strictly less.

fn pop(&mut self, mag: &[f32]) -> usize

heap_pop: take the root, move the last element there (and zero its old slot), then sift down: the left child if its magnitude is strictly greater than the right’s, else the right, else the left when the right is past the end; swap while the parent’s magnitude is strictly less than that child’s.