/**
 * Legend spec derivation (spec: "Built-in widgets / legend") — the legend
 * widget's default reflects each layer's ACTUAL color symbology, derived
 * statically from the authored `get-fill-color` expression:
 *
 *   scale($f, sequential|diverging, [...], domain=[a,b])  → gradient ramp
 *   scale($f, threshold, [...], domain=[b1..bN-1])        → class ranges
 *   $f == 'x' ? c1 : $f == 'y' ? c2 : cDefault            → categories
 *   '#hex' literal / `color` shorthand                    → single swatch
 *
 * Anything else (arithmetic, js blocks, function accessors on the
 * programmatic front-end) falls back to the single `color` swatch —
 * best-effort static analysis, never a guess. Pure string/AST work over the
 * SOURCE attribute, deliberately separate from the expression compiler: the
 * legend needs structure, the compiler needs functions, and coupling them
 * would make every legend tweak a compiler change.
 */
export type LegendSpec = {
    kind: "ramp";
    field: string;
    /** CSS color stops in order (hex/rgb strings as authored). */
    colors: string[];
    /** [min, max] displayed at the ramp ends. */
    domain: [number, number];
} | {
    kind: "classes";
    field: string;
    /** One entry per class: color + human-readable range label. */
    entries: {
        color: string;
        label: string;
    }[];
} | {
    kind: "categories";
    field: string;
    entries: {
        color: string;
        label: string;
    }[];
    /** The ternary chain's fallback color, when authored. */
    defaultColor?: string;
};
/**
 * Representative gradient stops per bundled raster colormap — used to PAINT
 * THE LEGEND, not the map (the map samples the GPU sprite; a 1-D CSS
 * gradient bar only needs a few stops and the eye fills in the rest).
 * Matplotlib reference colors at 0/.25/.5/.75/1. The sprite ships ~107
 * colormaps; this curated set covers the ones worth suggesting — an
 * authored name outside it still RENDERS (sprite lookup), it just gets the
 * single-swatch legend fallback.
 */
export declare const RASTER_COLORMAP_STOPS: Record<string, string[]>;
/**
 * Raster twin of deriveLegendSpec: a COGLayer with an authored rescale
 * window exposes its colormap as a ramp. Both `min` and `max` must be
 * authored — without a window the ramp ends would be a guess (the runtime
 * defaults to 0–255, but promising that in a legend for float data would
 * label it wrong).
 */
export declare function deriveRasterLegendSpec(colormap: string | null | undefined, min: number | null | undefined, max: number | null | undefined): LegendSpec | undefined;
export declare function deriveLegendSpec(source: string | null | undefined): LegendSpec | undefined;