Function processZipArchive

src/utils/zipLoader.ts:124–197

* Process a ZIP archive: extract COLMAP files immediately, build index for images.

(
  archive: ArchiveReader,
  onProgress: (progress: ZipProgress) => void
)

 * Process a ZIP archive: extract COLMAP files immediately, build index for images.
 */
async function processZipArchive(
  archive: ArchiveReader,
  onProgress: (progress: ZipProgress) => void
): Promise<{ colmapFiles: Map<string, File>; imageIndex: Map<string, ArchiveEntry>; imageCount: number }> {
  onProgress({ percent: 50, message: 'Reading archive contents...' });

  // Get list of files in archive
  const filesArray = await archive.getFilesArray();

  onProgress({ percent: 55, message: 'Identifying COLMAP files...' });

  // Separate COLMAP files and image files
  const colmapEntries: Array<{ file: ArchiveEntry; path: string }> = [];
  const splatEntries: Array<{ file: ArchiveEntry; path: string; size: number }> = [];
  const imageIndex = new Map<string, ArchiveEntry>();
  let imageCount = 0; // Track actual unique images (imageIndex has duplicates for lookup)

  for (const entry of filesArray) {
    const fullPath = buildArchiveEntryPath(entry.path, entry.file.name);

    if (isArchiveColmapPath(fullPath)) {
      colmapEntries.push({ file: entry.file, path: fullPath });
    } else if (isArchiveSplatPath(fullPath)) {
      splatEntries.push({ file: entry.file, path: fullPath, size: entry.file.size });
    } else if (isArchiveImagePath(fullPath)) {
      // Store in index for lazy extraction
      for (const key of getArchiveImageLookupKeys(fullPath)) {
        if (!imageIndex.has(key)) {
          imageIndex.set(key, entry.file);
        }
      }
      imageCount++; // Count unique images (only the full path entry)
    }
  }

  onProgress({ percent: 60, message: `Extracting ${colmapEntries.length} COLMAP files...` });

  // Extract COLMAP files immediately
  const colmapFiles = new Map<string, File>();

  for (let i = 0; i < colmapEntries.length; i++) {
    const entry = colmapEntries[i];
    const extractedFile = await entry.file.extract();

    const filename = entry.path.split('/').pop() ?? entry.path;
    const key = getColmapArchiveKey(entry.path);

    colmapFiles.set(key, extractedFile);

    const percent = 60 + Math.round(((i + 1) / colmapEntries.length) * 10); // 60-70%
    onProgress({ percent, message: `Extracting ${filename}...` });
  }

  if (splatEntries.length > 0) {
    const sortedSplatEntries = sortArchiveSplatCandidatesByPreference(splatEntries);
    if (sortedSplatEntries.length === 0) {
      throw new Error('Internal error selecting archive splat file');
    }