pub fn flat_material_colors(
element_material_colors: &FxHashMap<u32, Vec<[f32; 4]>>,
) -> (Vec<u32>, Vec<u32>, Vec<u8>)Expand description
Flat wire encoding of the element material colour lists (#407/#913 §2.3):
(element_ids, counts, rgba8) — counts[i] colours belong to
element_ids[i], in order, 4 bytes each.
Emitted sorted by element id (u32 ascending) - same explicit-order wire
contract as flat_voids; the per-element colour list order (file order)
is unchanged. The inverse material_colors_from_flat rebuilds a map, so
consumers are order-insensitive.