/**
 * Canvas zoom is the *displayed* scale (canvasScale × 100), not the internal
 * occupancy percentage. Occupancy is derived so 200% means 200% of the slide
 * pixel size — independent of how large the editor pane is.
 */
export declare const MIN_CANVAS_ZOOM = 10;
export declare const MAX_CANVAS_ZOOM = 200;
export declare const CANVAS_ZOOM_STEP = 5;
/** Wheel pixels that correspond to one CANVAS_ZOOM_STEP. */
export declare const WHEEL_ZOOM_PX_PER_STEP = 40;
/**
 * Chrome PDF viewer / Chromium page-zoom ladder, clipped to 10–200%.
 * +/- jumps to the next (or previous) stop; values between stops snap directionally.
 */
export declare const CANVAS_ZOOM_PRESETS: readonly [10, 25, 33, 50, 67, 75, 80, 90, 100, 110, 125, 150, 175, 200];
export declare function displayedZoomPercent(canvasScale: number): number;
export declare function clampCanvasZoom(zoom: number): number;
/**
 * Step displayed zoom like Chrome PDF: walk `CANVAS_ZOOM_PRESETS`.
 * Off-ladder values (wheel) snap to the next stop in that direction.
 */
export declare function stepCanvasZoom(current: number, direction: 1 | -1): number;
export declare function addCanvasZoom(current: number, delta: number): number;
export declare function wheelDeltaToZoom(deltaPx: number): number;
/**
 * Occupancy % that realizes `targetZoom` displayed percent given the current
 * scale and occupancy. Fallback when the canvas element is not available.
 */
export declare function occupancyForDisplayedZoom(targetZoom: number, canvasScale: number, canvasPercentage: number): number;
/**
 * Occupancy % from pane + slide geometry so 200% is 200% of the slide pixel
 * size regardless of a stale canvasScale (rapid +/- and wheel).
 */
export declare function occupancyForTargetZoom(targetZoom: number, canvasWidth: number, canvasHeight: number, viewportSize: number, viewportRatio: number): number;
export declare function getPendingZoom(): number | null;
export declare function setPendingZoom(zoom: number | null): void;