import { World } from "koota";
//#region src/ecs/systems/batchSortSystem.d.ts
/**
 * Create a batch-sort system bound to its own scratch buffers.
 *
 * Each SpriteGroup constructs one; the returned function is called per
 * frame with the world to sort. Scratch state lives in this closure
 * so multiple SpriteGroups don't share buffers (each world gets clean
 * state and resizes its own arrays independently).
 *
 * Re-sorts batch instance rows by zIndex.
 *
 * Sort-dirty signal comes from each `SpriteBatch._sortDirty` boolean,
 * flipped by `Sprite2D.zIndex` setter (non-gated batches only) and by
 * `batchAssignSystem` on new sprite insertion. Replaces the prior
 * `Changed(SpriteZIndex)` channel — Koota's Changed tracker enumerated
 * every zIndex flip every frame even when the batch's material gate
 * trivially skipped the sort, costing ~7ms/frame at 12k sprites with
 * alphaTest. The per-batch boolean is the minimum information needed.
 *
 * Skips batches whose material opts into GPU depth ordering via
 * `alphaTest > 0 && depthWrite`. Those materials rely on the GPU depth
 * test (with the layer/zIndex-derived Z baked into the instance matrix
 * by transformSyncSystem) and don't need CPU-side sorting.
 *
 * Zero-alloc per frame: scratch arrays in closure are reused frame to
 * frame, growing to the high-water mark of the largest mesh seen.
 */
declare function createBatchSortSystem(): (world: World) => void;
//#endregion
export { createBatchSortSystem };
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