Struct Backdrop 

pub struct Backdrop {
    pub sigma: f32,
    pub shared_key: Option<u64>,
}

Backdrop describes what a backdrop save layer samples from the scene beneath it.

Today that is a gaussian blur. Further seed-only stages (a color matrix for iOS glass saturation) join as fields here, never as effects on the layer paint — a paint effect would filter the children too.

Fields

sigma: f32

Gaussian σ in local units at record; replay scales it into device px. σ ≤ 0 records a plain save layer (nothing to blur — the scene already shows through).

shared_key: Option<u64>

Tiles sharing a key reuse the FIRST tile’s blur — and see the scene as of that tile. Use one key only for tiles over the same background.

Implementations

impl Backdrop

pub fn blur(sigma: f32) -> Self

blur is a gaussian backdrop blur of sigma local units.

pub fn shared(self, key: u64) -> Self

shared marks this backdrop as one tile of a keyed group.

Trait Implementations

impl Clone for Backdrop

fn clone(&self) -> Backdrop

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Backdrop

impl Debug for Backdrop

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.