/** Pan/zoom transform: content is scaled by `scale` then translated by (x, y). */
export interface ViewportTransform {
    scale: number;
    x: number;
    y: number;
}
export interface Size {
    width: number;
    height: number;
}
export interface Point {
    x: number;
    y: number;
}
export declare function clampScale(scale: number, min: number, max: number): number;
/**
 * Zooms by `factor` about a fixed screen `pivot` so the content point under the
 * pivot stays put. Scale is clamped to [min, max]; the translation is adjusted
 * by the *effective* factor after clamping so panning can't drift at the limits.
 */
export declare function zoomAt(view: ViewportTransform, factor: number, pivot: Point, min: number, max: number): ViewportTransform;
/**
 * Centers `content` within `viewport` at the largest scale that fits inside the
 * given padding (clamped to [min, max]). Use this for a "fit / reset" control.
 */
export declare function fitToBounds(content: Size, viewport: Size, padding: number, min: number, max: number): ViewportTransform;
/** Converts a screen point inside the viewport to content coordinates. */
export declare function screenToContent(view: ViewportTransform, screen: Point): Point;