Struct ShadowState 

pub struct ShadowState {
    pub positions: Vec<CoeffPos>,
    pub bits: Vec<u8>,
    pub n_total: usize,
    pub parity_len: usize,
    pub frame_data_len: usize,
    pub frame_bytes: Vec<u8>,
    pub perm_seed: [u8; 32],
    pub cost_fraction: usize,
}

State for a single shadow layer during encoding.

Fields

positions: Vec<CoeffPos>

Cost-filtered + hash-permuted embedding positions (Y channel nzAC).

bits: Vec<u8>

The desired LSB bits (RS-encoded frame, no header).

n_total: usize

Total bits = RS-encoded data.

parity_len: usize

Current RS parity length.

frame_data_len: usize

Unencoded frame byte count (before RS).

frame_bytes: Vec<u8>

Raw frame bytes (before RS), needed for parity bump rebuild.

perm_seed: [u8; 32]

Cached shadow structural key (ChaCha20 seed for position permutation).

cost_fraction: usize

Cost pool fraction denominator (20=5%, 10=10%, 5=20%, 2=50%, 1=100%).

Trait Implementations

impl Clone for ShadowState

fn clone(&self) -> ShadowState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.