/**
 * Adapter that exposes a {@link PdfChartDrawingSurface} on top of a raw
 * {@link PdfContentStream}, letting the page-level exporter forward a chart's
 * vector drawing callback into the same stream that renders the spreadsheet
 * cells.
 *
 * Why this exists: the `chartToPdf` helper in `excel-bridge.ts` renders a
 * single chart onto a `PdfDocumentBuilder` page (which natively implements
 * the chart surface). For workbook-level `excelToPdf`, rendering happens via
 * `pdf-exporter.ts` + `PdfContentStream`, which predate the chart surface.
 * The adapter bridges the two worlds so a chart can be drawn at any
 * `(x, y, width, height)` rect on an already-populated page without
 * refactoring the exporter pipeline.
 *
 * All coordinates are PDF points with **bottom-left origin** — matching the
 * convention the chart renderer emits after its internal Y-flip (see
 * `translateScene` in `@excel/chart/chart-renderer.ts`).
 */
import type { PdfContentStream } from "../core/pdf-stream.js";
import type { FontManager } from "../font/font-manager.js";
import type { PdfChartDrawingSurface } from "../types.js";
/**
 * Build a {@link PdfChartDrawingSurface} that forwards to the given content
 * stream. The returned surface is stateful — callers should not mix it with
 * direct stream mutations for the duration of chart rendering.
 *
 * @param stream        Content stream receiving the drawing operators.
 * @param fontManager   Font manager used for text layout and Type3 fallback.
 * @param alphaValues   Shared set that accumulates transparency values for
 *                      later `ExtGState` registration. The surface adds any
 *                      `color.a` values it observes to this set.
 */
export declare function createChartSurface(stream: PdfContentStream, fontManager: FontManager, alphaValues: Set<number>): PdfChartDrawingSurface;