/**
 * Shared pointer-to-canvas coordinate mapping for the interactive overlay
 * tools (color picker, densitometer, measure).
 *
 * Each tool's click-capture surface is an absolutely-positioned `inset: 0`
 * div over the rendered page. It receives viewport-space pointer coordinates
 * (`clientX`/`clientY`) but needs them in the canvas's **internal** coordinate
 * space — the space `canvasWidth`/`canvasHeight` are expressed in, which both
 * the PDF-point mapping and the on-page readout/markers use.
 *
 * In the host's separation/layer views the overlay's parent is sized exactly
 * to `canvasWidth`/`canvasHeight` with no transform, so the element's on-screen
 * rect matches and the scale is 1 (a no-op). In the default page view the
 * overlay lives **inside** the substrate's CSS zoom/pan transform, so the
 * element's on-screen rect is `canvasWidth × scale`. Scaling the
 * rect-relative offset by `canvasWidth / rect.width` recovers the internal
 * coordinate, keeping sampling and marker placement exact at any zoom.
 */
/** Minimal shape of the parts of a `DOMRect` this mapping reads. */
export interface RectLike {
    left: number;
    top: number;
    width: number;
    height: number;
}
/**
 * Map a viewport-space pointer position to the canvas's internal coordinate
 * space, given the click-capture element's on-screen bounding rect.
 *
 * A degenerate rect (zero width/height — e.g. an unmeasured element) falls
 * back to scale 1 so the offset passes through unchanged rather than dividing
 * by zero.
 */
export declare function toCanvasXY(clientX: number, clientY: number, rect: RectLike, canvasWidth: number, canvasHeight: number): [number, number];
//# sourceMappingURL=toolCoords.d.ts.map