import type { Vec2 } from '../../math';
import type { DataSeries, ErrorBand, FillBoundary, FillCurveType, FillGradient, FillRegion } from './types';
export declare const LOG_EPSILON = 1e-10;
export interface Pt {
    x: number;
    y: number;
}
export interface ResolvedBoundary {
    points: Pt[];
    curve: FillCurveType;
}
export interface FillSegment {
    upper: Pt[];
    lower: Pt[];
    upper_curve: FillCurveType;
    lower_curve: FillCurveType;
}
export declare function resolve_series_ref(ref: {
    type: `series`;
    series_idx?: number;
    series_id?: string | number;
}, series: readonly DataSeries[]): DataSeries | null;
export declare function monotone_interpolate(xs: readonly number[], ys: readonly number[], x: number, tangents?: readonly number[]): number;
interface DomainContext {
    x_domain: Vec2;
    y_domain: Vec2;
    y2_domain?: Vec2;
}
export declare function resolve_boundary_points(boundary: FillBoundary, series: readonly DataSeries[], domains: DomainContext, companion?: Pt[] | null): ResolvedBoundary | null;
export declare function compute_fill_segments(region: FillRegion, series: readonly DataSeries[], domains: DomainContext): FillSegment[];
export declare function generate_fill_path(upper: readonly Pt[], lower: readonly Pt[], upper_curve?: FillCurveType, lower_curve?: FillCurveType): string;
export declare function convert_error_band_to_fill_region(error_band: ErrorBand, series: readonly DataSeries[], default_color?: string): FillRegion | null;
export declare const is_fill_gradient: (fill: string | FillGradient | undefined) => fill is FillGradient;
export {};