public GRIB2Record(int disciplineNo, IGRIB2GridDefinitionSection gds, IGRIB2ProductDefinitionSection pds, IGRIB2DataRepresentationSection drs, IGribBitMapSection bms, GRIB2DataSection ds, long gdsOffset, long pdsOffset, long dataOffset)
{
_gdsOffset = gdsOffset;
_pdsOffset = pdsOffset;
_dataOffset = dataOffset;
_gds = gds;
_pds = pds;
_drs = drs;
_bms = bms;
_ds = ds;
_parameter = ParametersFactory.GetParameter(disciplineNo, pds.ParameterCategory, pds.ParameterNumber);
}
private GRIB_Point[] Jpeg2000Unpacking(FileStream fs, IGRIB2GridDefinitionSection gds, IGRIB2DataRepresentationSection drs, IGribBitMapSection bms)
{
return(null);
}
private GRIB_Point[] SimpleUnpacking(FileStream fs, IGRIB2GridDefinitionSection gds, IGRIB2DataRepresentationSection drs, IGribBitMapSection bms)
{
// dataPoints are number of points encoded, it could be less than the
// numberPoints in the grid record if bitMap is used, otherwise equal
_bitPos = 0;
_bitBuf = 0;
int dataPoints = drs.DataPoints;
float pmv = drs.PrimaryMissingValue;
int nb = drs.NumberOfBits;
int D = drs.DecimalScaleFactor;
float DD = (float)System.Math.Pow((double)10, (double)D);
float R = drs.ReferenceValue;
int E = drs.BinaryScaleFactor;
float EE = (float)System.Math.Pow((double)2.0, (double)E);
int numberPoints = gds.PointsNumber;
GRIB_Point[] data = new GRIB_Point[numberPoints];
bool[] bitmap = bms.Bitmap;
// Y * 10**D = R + (X1 + X2) * 2**E
// E = binary scale factor
// D = decimal scale factor
// R = reference value
// X1 = 0
// X2 = scaled encoded value
// data[ i ] = (R + ( X1 + X2) * EE)/DD ;
if (bitmap == null)
{
for (int i = 0; i < numberPoints; i++)
{
data[i].Index = i;
data[i].Value = (R + Bits2UInt(nb, fs) * EE) / DD;
}
}
else
{
for (int i = 0; i < bitmap.Length; i++)
{
data[i].Index = i;
if (bitmap[i])
{
//data[ i ] = (R + ( X1 + X2) * EE)/DD ;
data[i].Value = (R + Bits2UInt(nb, fs) * EE) / DD;
}
else
{
data[i].Value = pmv;
}
}
}
return(data);
}
public GRIB_Point[] Read()
{
try
{
if (_fs != null)
{
IGribBitMapSection bms = null;
GRIB_Point[] points = null;
bool isConstant = false;
_fs.Seek(_dataOffset, SeekOrigin.Begin);
if (_isBmsExist)
{
bms = new Grib1BitMapSection(_fs);
}
// octets 1-3 (section _length)
int dataLength = GribNumberHelper.Uint3(_fs);
// octet 4, 1st half (packing flag)
int unusedbits = _fs.ReadByte();
if ((unusedbits & 192) != 0)
{
throw new NotSupportedException("BDS: (octet 4, 1st half) not grid point data and simple packing ");
}
// octet 4, 2nd half (number of unused bits at end of this section)
unusedbits = unusedbits & 15;
// octets 5-6 (binary scale factor)
int binscale = GribNumberHelper.Int2(_fs);
// octets 7-10 (reference point = minimum value)
float refvalue = GribNumberHelper.Float4(_fs);
// octet 11 (number of bits per value)
int numbits = _fs.ReadByte();
if (numbits == 0)
{
isConstant = true;
}
float refRenamed = (float)(Math.Pow(10.0, -_decscale) * refvalue);
float scale = (float)(System.Math.Pow(10.0, -_decscale) * System.Math.Pow(2.0, binscale));
if (_firstlat == 0 & _lastlat == 90)
{
if (bms != null)
{
bool[] bitmap = bms.Bitmap;
points = new GRIB_Point[bitmap.Length];
for (int i = 0; i < bitmap.Length; i++)
{
int m = (_height - (int)(i / _width) - 1) * _width + (i % _width);
if (bitmap[i])
{
if (!isConstant)
{
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
else
{
// rdg - added this to handle a constant valued parameter
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed;
}
}
else
{
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = -9999f;
}
}
}
else
{
if (!isConstant)
{
points = new GRIB_Point[((dataLength - 11) * 8 - unusedbits) / numbits];
for (int i = 0; i < points.Length; i++)
{
int m = (_height - (int)(i / _width) - 1) * _width + (i % _width);
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
}
else
{
// constant valued - same min and max
int x = 0, y = 0;
_fs.Seek(_fs.Position - 53, SeekOrigin.Begin); // return to start of GDS
dataLength = (int)GribNumberHelper.Uint3(_fs);
if (dataLength == 42)
{
// Lambert/Mercator offset
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
_fs.Seek(7, SeekOrigin.Current);
dataLength = GribNumberHelper.Uint3(_fs);
if (dataLength == 32)
{
// Polar sterographic
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
x = y = 1;
}
}
points = new GRIB_Point[x * y];
for (int i = 0; i < points.Length; i++)
{
int m = (_height - (int)(i / _width) - 1) * _width + (i % _width);
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed;
}
}
}
}
else
{
if (bms != null)
{
bool[] bitmap = bms.Bitmap;
points = new GRIB_Point[bitmap.Length];
for (int i = 0; i < bitmap.Length; i++)
{
if (bitmap[i])
{
if (!isConstant)
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
else
{
// rdg - added this to handle a constant valued parameter
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed;
}
}
else
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = -9999f;
}
}
}
else
{
if (!isConstant)
{
points = new GRIB_Point[((dataLength - 11) * 8 - unusedbits) / numbits];
for (int i = 0; i < points.Length; i++)
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
}
else
{
// constant valued - same min and max
int x = 0, y = 0;
_fs.Seek(_fs.Position - 53, SeekOrigin.Begin); // return to start of GDS
dataLength = (int)GribNumberHelper.Uint3(_fs);
if (dataLength == 42)
{
// Lambert/Mercator offset
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
_fs.Seek(7, SeekOrigin.Current);
dataLength = GribNumberHelper.Uint3(_fs);
if (dataLength == 32)
{
// Polar sterographic
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
x = y = 1;
}
}
points = new GRIB_Point[x * y];
for (int i = 0; i < points.Length; i++)
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed;
}
}
}
}
return(points);
}
return(null);
}
finally
{
_fs.Seek(0, SeekOrigin.Begin);
}
}
