/** CSS `translate(x, y) scale(scale)` with `transform-origin: 0 0`. */
export interface PanZoomTransform {
    x: number;
    y: number;
    scale: number;
}
export interface Point {
    x: number;
    y: number;
}
export interface Size {
    width: number;
    height: number;
}
/** A box in the viewport's own coordinates, before any transform. */
export interface Box {
    left: number;
    top: number;
    width: number;
    height: number;
}
export declare const IDENTITY: PanZoomTransform;
/** Below this, a scale counts as the fitted one. */
export declare const EPSILON = 0.001;
/** Scales to `scale` while the content point under `focus` stays where it is on screen. */
export declare function zoomAt(transform: PanZoomTransform, scale: number, focus: Point): PanZoomTransform;
/** Larger than the viewport on an axis, its edges stay outside the viewport's; smaller, it is centred. */
export declare function clampTransform(transform: PanZoomTransform, viewport: Size, content: Box): PanZoomTransform;
/**
 * At the fitted size the layout has centred the content already. Centring it again from measured
 * rects only adds their rounding: Chromium left 1/128 px, which counted as zoomed.
 */
export declare function settleTransform(transform: PanZoomTransform, viewport: Size, content: Box): PanZoomTransform;
/** Whether the content is larger than the viewport on either axis, so a drag can move it. */
export declare function canPan(scale: number, viewport: Size, content: Box): boolean;