/**
 * Contour Plot Generation (Marching Squares)
 */
export interface ContourPoint {
    x: number;
    y: number;
}
export interface ContourLine {
    level: number;
    points: ContourPoint[];
    /** Joined polylines (populated when `joinPaths` is enabled). */
    polylines?: ContourPoint[][];
    /** Suggested isoline label placements (populated when `labels` is enabled). */
    labels?: ContourLabel[];
}
/** A placed label for an isoline, including rotation to follow the line. */
export interface ContourLabel {
    x: number;
    y: number;
    level: number;
    /** Text of the label (formatted level value). */
    text: string;
    /** Rotation angle in radians so the label follows the contour direction. */
    angle: number;
}
export interface ContourOptions {
    levels?: number[];
    numLevels?: number;
    /** Join marching-squares segments into continuous polylines. */
    joinPaths?: boolean;
    /** Compute isoline label placements (implies `joinPaths`). */
    labels?: boolean;
    /**
     * Minimum polyline length (in polyline vertices) required to receive a label.
     * Prevents cluttering short/noisy isolines. Default: 6.
     */
    minLabelLength?: number;
    /** Formatter for label text. Default: fixed to 2 significant decimals. */
    labelFormatter?: (level: number) => string;
}
/**
 * Generate contour lines from a 2D grid of values
 * Values are assumed to be in row-major order: z = values[y * width + x]
 */
export declare function generateContours(z: Float32Array | number[], xValues: Float32Array | number[], yValues: Float32Array | number[], options?: ContourOptions): ContourLine[];
/**
 * Join disjoint marching-squares segments into continuous polylines by
 * chaining segments whose endpoints coincide (within a tolerance). This yields
 * smooth isolines suitable for labeling (task 3.13).
 */
export declare function joinSegments(segments: Array<[number, number, number, number]>, tolerance?: number): ContourPoint[][];