import type { MatchOptions, RawImage } from './types.js';
import { AsciiFrame } from './frame.js';
import { blankGlyphId } from './blankGlyph.js';
export declare const ALGORITHM_VERSION = "structural-v1";
export { blankGlyphId };
/** The per-cell outputs of a structural match, without the profile a frame carries. */
export interface StructuralCells {
    glyphIds: Uint16Array;
    foreground?: Uint32Array;
    background?: Uint32Array;
    flags: Uint16Array;
}
/**
 * The previous match of the same band, for exact temporal reuse (spec §21).
 *
 * A cell's result is a pure function of its 64 source samples and the options,
 * so a cell whose samples are byte-identical to last time already has its answer
 * — comparing 256 bytes is far cheaper than a prefilter over the charset plus a
 * rerank. The caller owns the "identical options" half of that precondition:
 * pass `reuse` only when `options`, `columns`, and `bandRows` all match the
 * match these cells came from. Nothing here can detect an option change, and
 * reusing across one silently serves stale cells.
 */
export interface BandReuse {
    /** The reduced samples those cells were matched from; same layout as `reduced`. */
    reduced: Uint8Array;
    /** That match's band-local outputs. */
    cells: StructuralCells;
}
/**
 * structural-v1 reference matcher (ALGORITHM.md §§3–11). Deterministic and
 * all-integer; this implementation defines correctness for every backend.
 *
 * Structural only. The approximate matchers (§18–19) and chromatic-v1 are their
 * own functions — `matchFrameShape6`, `matchFrameRamp`, `matchFrameChromatic` —
 * so a bundle that never calls them never contains them, and opting into one is
 * an import rather than a flag.
 */
export declare function matchFrame(source: RawImage, options: MatchOptions): AsciiFrame;
/**
 * structural-v1 over a band of `bandRows` cell rows, given that band's reduced
 * samples. Both the input and the outputs are band-local, and no step reads
 * outside the band — every cell in ALGORITHM.md §§5–10 is independent — so
 * concatenating bands reproduces `matchFrame` byte for byte. This is the one
 * implementation of the exact matcher; `matchFrame` is a whole-frame band.
 */
export declare function matchBand(reduced: Uint8Array, columns: number, bandRows: number, options: MatchOptions, reuse?: BandReuse): StructuralCells;