// Gemeinsame Erzeugung temporärer Canvas-Flächen für Views und Meter.
export function createCanvasSurface(width, height) {
  const w = Math.max(1, Math.ceil(width));
  const h = Math.max(1, Math.ceil(height));
  if (typeof OffscreenCanvas === 'function') {
    const canvas = new OffscreenCanvas(w, h);
    const ctx = canvas.getContext('2d');
    if (ctx) return { canvas, ctx, width: w, height: h };
  }
  if (typeof document !== 'undefined') {
    const canvas = document.createElement('canvas');
    canvas.width = w;
    canvas.height = h;
    const ctx = canvas.getContext('2d');
    if (ctx) return { canvas, ctx, width: w, height: h };
  }
  return null;
}