import type { WebGLContextManager } from "../webgl/context-manager";
import type { PlotLayout } from "../layout/plot-layout";
import type { TileSource } from "./tile-source";
type GL = WebGL2RenderingContext | WebGLRenderingContext;
/**
 * Renders an XYZ raster tile basemap into the chart's webgl canvas
 * inside the plot rect's scissor. Used by `MapChart` from inside
 * `renderInPlotFrame`, before the glyph draw, so chart glyphs (point,
 * line, density) composite naturally on top of the basemap.
 *
 * The layer owns:
 *   - The tile shader program (compiled once per WebGL context).
 *   - A unit-quad corner buffer (one 2-byte attribute, reused per
 *     tile).
 *   - A `TileCache` (LRU of `WebGLTexture`).
 *   - A `TileLoader` (async fetch + dedup).
 *
 * On each render: pick the integer zoom that matches the requested
 * meters-per-pixel, enumerate visible tiles at that zoom, and draw
 * each one — either with the loaded texture or with a parent
 * texture's sub-rect while the target is in flight.
 */
export declare class TileLayer {
    private _program;
    private _cornerBuffer;
    private _cache;
    private _loader;
    private _source;
    private _alpha;
    private _onTileLoad;
    /**
     * Hook the "tile arrived" notification through to the chart's
     * render scheduler. Called once when the layer is constructed
     * by `MapChart`.
     */
    setOnTileLoad(cb: () => void): void;
    /**
     * Swap the tile source (e.g. light ↔ dark theme). Drops the cache
     * because the cached textures came from the prior source's URLs.
     */
    setSource(gl: GL, source: TileSource): void;
    setAlpha(alpha: number): void;
    get source(): TileSource | null;
    /**
     * Render the basemap for the current visible Mercator extent.
     * Caller is responsible for binding the chart's main framebuffer
     * (the plot-frame scissor is already in place by the time we get
     * here). The same `projection` matrix the glyph draw uses is
     * passed straight through.
     */
    render(glManager: WebGLContextManager, layout: PlotLayout, projection: Float32Array, domain: {
        xMin: number;
        xMax: number;
        yMin: number;
        yMax: number;
    }, xOrigin: number, yOrigin: number): void;
    /**
     * Free every GPU resource. Called from `MapChart.destroyInternal`.
     */
    destroy(gl: GL): void;
    private _drawTile;
    private _issueDraw;
    private _kickLoad;
    private _ensureProgram;
}
export {};