Function getDataNumber

src/ts-default/Components/DomeGallery/DomeGallery.tsx:80–84

(el: HTMLElement, name: string, fallback: number)

  return a - 180;
};
const getDataNumber = (el: HTMLElement, name: string, fallback: number) => {
  const attr = el.dataset[name] ?? el.getAttribute(`data-${name}`);
  const n = attr == null ? NaN : parseFloat(attr);
  return Number.isFinite(n) ? n : fallback;
};

function buildItems(pool: ImageItem[], seg: number): ItemDef[] {
  const xCols = Array.from({ length: seg }, (_, i) => -37 + i * 2);