import { type PageMesh } from './mesh';
/**
 * Roll-and-flop. The leaf wraps a cylinder whose wrap angle grows 0→π over the first
 * half while its radius (= W/theta) shrinks, so the sheet rolls up off the surface in
 * place; over the second half it unwraps π→0 while rigidly rotating around the spine
 * 0→-π down onto the far side. Arc length across the width is exactly preserved.
 */
export declare function deformRoll(mesh: PageMesh, W: number, H: number, t: number): void;