Function prefetchUrlImages

src/utils/urlImageFiles.ts:236–249

(
  imageUrlBase: string | null,
  imageNames: string[],
  concurrency: number = 5,
  imageNameToUrl?: Record<string, string>
)

 * Useful for preloading visible frustum images.
 */
export async function prefetchUrlImages(
  imageUrlBase: string | null,
  imageNames: string[],
  concurrency: number = 5,
  imageNameToUrl?: Record<string, string>
): Promise<void> {
  const toFetch = imageNames.filter(name => !urlImageState.hasCached(name));
  if (toFetch.length === 0) return;

  for (let i = 0; i < toFetch.length; i += concurrency) {
    const batch = toFetch.slice(i, i + concurrency);
    await Promise.all(batch.map(name => fetchUrlImage(imageUrlBase, name, imageNameToUrl?.[name])));
  }
}

/**
 * Get URL image cache statistics.