/**
 * Blob region geometry.
 *
 * A "blob" is the union of one or more axis-aligned grid spans, rendered as
 * a single closed SVG path with rounded convex AND concave corners.
 *
 * Workflow:
 *   buildBlob(spans, cols, rows, layout)
 *     1. paint spans into a boolean cell grid
 *     2. validate 4-connectivity (throws on disjoint)
 *     3. trace boundary edges and chain into CW polygons (pixel coords)
 *     4. simplify collinear vertices
 *
 *   blobPathD(blob, radius)
 *     emits an SVG path `d` attribute with rounded corners.
 */
import type { GridSpan } from '../types.js';
import type { GridLayout } from './grid.js';
export interface BlobBBox {
    minCol: number;
    maxCol: number;
    minRow: number;
    maxRow: number;
}
export interface Blob {
    cols: number;
    rows: number;
    /** cellGrid[row][col] = true if covered by at least one span */
    cellGrid: boolean[][];
    /** Grid-coord bbox of the union */
    bbox: BlobBBox;
    /** Closed polygons in pixel coordinates, traced clockwise */
    contours: {
        x: number;
        y: number;
    }[][];
}
export declare class DisjointRegionError extends Error {
    constructor(message?: string);
}
/**
 * Build a blob from spans. Throws DisjointRegionError if the union is not
 * 4-connected (diagonal-only contact counts as disjoint).
 *
 * `inset` (px) pulls every boundary vertex inward along the axis-aligned
 * inward normals of its adjacent edges, creating a visible gap between
 * neighboring regions. Radius clamping still applies on the offset polygon.
 */
export declare function buildBlob(spans: GridSpan[], layout: GridLayout, inset?: number): Blob;
/** Is the cell at (col, row) part of the blob? */
export declare function isCellFilled(blob: Blob, col: number, row: number): boolean;
/**
 * Emit the `d` attribute for an SVG path that draws the blob with rounded
 * convex and concave corners. Radius is clamped per-corner to half the
 * adjacent edge length so arcs never overlap.
 *
 * When `inset > 0`, concave corners use radius + 2*inset so that the arc
 * is concentric with the convex arc of an adjacent region — producing a
 * uniform 2*inset gap along the entire shared boundary (including corners).
 */
export declare function blobPathD(blob: Blob, radius: number, inset?: number): string;
//# sourceMappingURL=blob.d.ts.map