/**
 * Pure layout for connector labels.
 *
 * Builds candidate label rects for every sub-segment of the (resolved)
 * polyline, ordered middle-segment-outward, then delegates to placeLabel.
 */
import type { NormalizedConnectorDef, NormalizedNodeDef } from '../types.js';
import type { GridLayout } from '../geometry/grid.js';
import type { LabelRect, LineSeg, CanvasBounds, Circle } from '../geometry/collision.js';
import { type AttemptRecord } from '../geometry/label-placer.js';
import { type Pixel } from '../geometry/connector-path.js';
export interface ConnectorLabelResult {
    rect: LabelRect;
    error: boolean;
    /** Every (segment, t-position) candidate tried, for diagnostic emission. */
    attempts: AttemptRecord[];
}
/** Labelled candidate: the pixel rect plus a short "seg 2 / t=0.5 above"
 *  description the pipeline can attach to diagnostics. */
interface AnnotatedRect {
    rect: LabelRect;
    description: string;
}
/**
 * Build hop order starting from the middle segment and alternating outward.
 * n=5 segments → [2, 1, 3, 0, 4]
 */
export declare function hopOrder(n: number): number[];
/**
 * Candidate rects for a single sub-segment at t-values 0.5, 0.25, 0.75.
 *
 * For every direction (horizontal, vertical, diagonal) each t-point
 * yields TWO candidates — one perpendicular-shifted to each side of the
 * line — so the placer can escape a busy axis by stepping off it. The
 * rect stays axis-aligned; only its center moves.
 *
 * Horizontal lines retain their familiar "above" / "below" labels in
 * the candidate descriptions; non-horizontal lines say "side-A" /
 * "side-B" where side-A sits on the perpendicular's +CCW side of the
 * line direction.
 *
 * Order: t=0.5 is tried first (both sides), then t=0.25 (both sides),
 * then t=0.75 (both sides). 6 candidates per segment.
 */
export declare function candidatesForSegment(p1: Pixel, p2: Pixel, labelWidth: number, labelH: number, fontSize: number, strokeWidth: number): AnnotatedRect[];
export declare function computeConnectorLabelRect(connector: NormalizedConnectorDef, nodeMap: Map<string, NormalizedNodeDef>, layout: GridLayout, placedLabels: LabelRect[], connLines: LineSeg[], pixelWaypoints?: Pixel[], bounds?: CanvasBounds, iconCircles?: Circle[], fromAngleOffset?: number, toAngleOffset?: number): ConnectorLabelResult | null;
export {};
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