getZData static method

Uint8List? getZData(Uint8List fileBytes)

Attempts to extract the Z-Machine game file data from the Blorb file bytes in fileBytes. If the file is not a Blorb type, then the original bytes are returned (assumes it's a valid compiled ZIL file.)

Implementation

static Uint8List? getZData(Uint8List fileBytes){
  var rawBytes = fileBytes;

  if (!isBlorb(List.from(fileBytes.getRange(0, 12)))) return fileBytes;

  fileBytes = List.from(fileBytes) as Uint8List;

  //print(fileBytes);

  IFF.readChunk(fileBytes);
  IFF.readChunk(fileBytes);
  IFF.readChunk(fileBytes);

  if (IFF.readChunk(fileBytes) != Chunk.ridx) return null;

  // var resourceIndexSize = IFF.read16BitValue(fileBytes);
  var numResources = IFF.read16BitValue(fileBytes);

  int i = 0;

  while (i < numResources){
    var resourceChunk = IFF.readChunk(fileBytes);

    if (resourceChunk != null && resourceChunk == Chunk.exec){
      IFF.read16BitValue(fileBytes); //number of resource, should be 0

      var start = IFF.read16BitValue(fileBytes);

      fileBytes = List.from(rawBytes.getRange(start, rawBytes.length - start)) as Uint8List;

      if (IFF.readChunk(fileBytes) != Chunk.zcod) return null;

      var len = IFF.read16BitValue(fileBytes);

      return fileBytes.getRange(0, len) as Uint8List?;
    }


    i++;
  }

  return null;
}