Struct Palette 

pub struct Palette { /* private fields */ }

An A/B palette pair baked into two 256-entry RGB LUTs (Plan 0020 Phase 4). A preset declares palette A ([palette]) and, optionally, palette B ([palette_b]); a bindable palette_mix (0..1) crossfades between them per frame. With no [palette_b], lut_b == lut_a, so palette_mix is a no-op and a single-palette preset is unchanged. Sampled on the GPU (two 256×1 textures, lerped in-shader) and on the CPU (via sample) from the same tables.

Clone, deliberately not Copy (Plan 0031 Phase 6): the struct is 6144 bytes ([Rgb; 256] twice), so Copy made any accidental by-value use a silent 6 KB memcpy. A scene still holds its own baked copy for deferred upload — it just has to say .clone() to get one.

Implementations

impl Palette

pub fn bake(cfg: &PaletteConfig) -> Palette

Bake a single palette (A) into both LUTs, so palette_mix is a no-op. Pure; off the hot path (preset load only).

pub fn bake_pair(a: &PaletteConfig, b: &PaletteConfig) -> Palette

Bake an A/B pair for a palette_mix crossfade. Pure; off the hot path.

pub fn default_spectrum() -> Palette

The default palette (spectrum), used when a preset declares no [palette] table.

pub fn sample(&self, t: f32, mix: f32) -> Rgb

Sample the crossfaded palette at t with A/B mix (0 = A, 1 = B), linearly interpolated with the same texel-center convention (and wrap) the GPU texture sampler uses, so the CPU (swarm) and GPU scenes color consistently. Allocation-free — the swarm calls this per particle per frame. mix <= 0 returns palette A exactly (matching the GPU mix at 0), so palette_mix = 0 is identical to palette A alone.

pub fn lut_a_bytes(&self) -> [u8; 1024]

Palette A’s LUT as tight RGBA8 bytes for a 256×1 Rgba8Unorm texture upload. Alpha is opaque; the display surface is 8-bit, so 8-bit LUT storage adds no visible banding over the analytic cosine.

pub fn lut_b_bytes(&self) -> [u8; 1024]

Palette B’s LUT as tight RGBA8 bytes (the crossfade target texture).

Trait Implementations

impl Clone for Palette

fn clone(&self) -> Palette

Returns a duplicate of the value.

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

Performs copy-assignment from source.