eccodes/definitions/grib2/section.6.def

# (C) Copyright 2005- ECMWF.

# SECTION 6, BIT-MAP SECTION
position offsetSection6;
position offsetBSection6;

section_length[4] section6Length ;
meta section6 section_pointer(offsetSection6,section6Length,6);

#  Number of section
unsigned[1] numberOfSection = 6:read_only;

#  Bit-map indicator
codetable[1] bitMapIndicator ('6.0.table',masterDir,localDir) = 255 : dump;

#transient bitmapPresent=1;
meta geography.bitmapPresent g2bitmap_present(bitMapIndicator): dump;
transient missingValuesPresent = bitmapPresent : hidden, read_only;

# Bitmap...
if (bitMapIndicator == 0) {
  if (dataRepresentationTemplateNumber == 1) {
    if (matrixBitmapsPresent == 1) {
      meta primaryBitmap g2bitmap( tableReference,
          missingValue,
          offsetBSection6,
          section6Length,
          numberOfDataMatrices) : read_only;
    }
    else {
      meta geography.bitmap g2bitmap( tableReference,
          missingValue,
          offsetBSection6,
          section6Length,
          numberOfDataPoints) : read_only;
    }
  }
  else {
    meta geography.bitmap g2bitmap( tableReference,
        missingValue,
        offsetBSection6,
        section6Length,
        numberOfDataPoints) : read_only;
  }
}

if (bitMapIndicator == 255)
{
  # No bitmap is used but some complex packing schemes embed the missing values in the data section
  if (dataRepresentationTemplateNumber == 2 || dataRepresentationTemplateNumber == 3) {
    transient missingValuesPresent = (missingValueManagementUsed != 0) : read_only;
  }
  if (dataRepresentationTemplateNumber == 200) {
    # This template can have undefined values within its Data Section
    transient missingValuesPresent = 1;
  }
}

meta md5Section6 md5(offsetSection6,section6Length);