/**
 * Pan/zoom geometry for the Stammbaum canvas (#692).
 *
 * The Stammbaum renders zoom by deriving the SVG `viewBox` rather than applying
 * a CSS transform (see `StammbaumTree.svelte`). This module is the single source
 * of truth for the zoom bounds, the view-state shape, and every pure geometry
 * helper used by the gesture action, the URL serialiser, and the page. Keeping
 * the math here (and free of DOM access) makes it unit-testable in the node
 * project. See ADR-026 for why this is custom rather than a third-party library.
 */

/** Resolved zoom bounds (OQ-001). */
export const MIN_ZOOM = 0.25;
export const MAX_ZOOM = 3.0;

/** Clamp a zoom factor into the supported range. */
export function clampZoom(z: number): number {
	return Math.min(MAX_ZOOM, Math.max(MIN_ZOOM, z));
}