Method Encode

IO/Core/vtkBase64Utilities.cxx:60–103

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
unsigned long vtkBase64Utilities::Encode(
  const unsigned char* input, unsigned long length, unsigned char* output, int mark_end)
{

  const unsigned char* ptr = input;
  const unsigned char* end = input + length;
  unsigned char* optr = output;

  // Encode complete triplet

  while ((end - ptr) >= 3)
  {
    vtkBase64Utilities::EncodeTriplet(
      ptr[0], ptr[1], ptr[2], &optr[0], &optr[1], &optr[2], &optr[3]);
    ptr += 3;
    optr += 4;
  }

  // Encodes a 2-byte ending into 3 bytes and 1 pad byte and writes.

  if (end - ptr == 2)
  {
    vtkBase64Utilities::EncodePair(ptr[0], ptr[1], &optr[0], &optr[1], &optr[2], &optr[3]);
    optr += 4;
  }

  // Encodes a 1-byte ending into 2 bytes and 2 pad bytes

  else if (end - ptr == 1)
  {
    vtkBase64Utilities::EncodeSingle(ptr[0], &optr[0], &optr[1], &optr[2], &optr[3]);
    optr += 4;
  }

  // Do we need to mark the end

  else if (mark_end)
  {
    optr[0] = optr[1] = optr[2] = optr[3] = '=';
    optr += 4;
  }

  return optr - output;
}

//------------------------------------------------------------------------------
static constexpr unsigned char vtkBase64UtilitiesDecodeTable[256] = {