Struct LayerSlot 

pub struct LayerSlot {
    pub texture: CachedTexture,
    pub size: UVec2,
    pub format: TextureFormat,
    pub bind_group: Option<BindGroup>,
    pub mips: Option<MipChain>,
    pub mips_valid: bool,
    pub bind_group_mips: Option<BindGroup>,
    pub content_valid: bool,
    pub filter: Option<FilterSlot>,
    pub backdrop: Option<BackdropSlot>,
    pub last_seen: u64,
}

One layer’s persistent capture texture. Unlike Bevy’s TextureCache (descriptor-keyed pool — same-size layers can swap textures between frames, and nothing pins content), a slot is keyed by the layer root’s MainEntity, so a clean layer’s texture reliably still holds last frame’s capture.

Fields

texture: CachedTexture

The capture texture. For a mipped slot (Self::mips present) the default_view is a base-mip-only view, so every pre-mips consumer stays valid unchanged: the capture attachment (single-mip rule), the filter-pass sources (level-0, 1:1 contract), and the bilinear composite bind group (can never accidentally sample a stale mip).

size: UVec2

format: TextureFormat

bind_group: Option<BindGroup>

Composite bind group, built lazily and kept until realloc (per-frame bind-group creation is real cost at hundreds of layers).

mips: Option<MipChain>

Mip-chain views, present iff the layer wants mips (TRANSFORM3D promotion reason — see mips); presence joins the realloc key.

mips_valid: bool

Whether the mip chain matches the texture’s current level 0. Reset whenever a capture is staged; set by mips::prepare_layer_mips when the downsample run is certain to execute. While false the composite samples bilinear level 0 (correct, just unmipped).

bind_group_mips: Option<BindGroup>

Trilinear composite bind group (full-mip view + sampler_mips), for non-identity transformed quads; lazy like Self::bind_group.

content_valid: bool

Whether the texture holds a complete capture. A capture that runs while any of its items’ pipelines are still compiling renders those items as nothing (phase.render skips them silently) — serving that from cache would freeze a blank/partial layer on screen. Only a capture whose pipelines were all ready marks the content valid; until then extraction keeps re-capturing.

filter: Option<FilterSlot>

Filter-pass state, present iff the layer had a chain last frame. Cleared whenever the chain disappears (prepare_layer_textures): ResolvedFilterChain::version restarts at 1 per chain lifetime (demote/re-promote), so a stale params_version surviving the chain’s absence could collide with a restarted version and skip a needed re-run with old params.

backdrop: Option<BackdropSlot>

Backdrop state (snapshot + its ping-pong pair), present iff the layer had a backdropFilter chain last frame. Same clear-on-absence rule as Self::filter, for the same version-restart reason.

last_seen: u64