ogrdodssequencelayer.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

              break;
              
              case dods_uint16_c:
              {
                  GUInt16 nIntVal;
                  void *pValPtr = &nIntVal;
                  
                  poFieldVar->buf2val( &pValPtr );
                  panIntList[iSubIndex] = nIntVal;
              }
              break;
              
              case dods_int32_c:
              {
                  GInt32 nIntVal;
                  void *pValPtr = &nIntVal;
                  
                  poFieldVar->buf2val( &pValPtr );
                  panIntList[iSubIndex] = nIntVal;
              }
              break;

              case dods_uint32_c:
              {
                  GUInt32 nIntVal;
                  void *pValPtr = &nIntVal;
              
                  poFieldVar->buf2val( &pValPtr );
                  panIntList[iSubIndex] = nIntVal;
              }
              break;

              case dods_float32_c:
                padfDblList[iSubIndex] = 
                    dynamic_cast<Float32 *>(poFieldVar)->value();
                break;

              case dods_float64_c:
                padfDblList[iSubIndex] = 
                    dynamic_cast<Float64 *>(poFieldVar)->value();
                break;

              case dods_str_c:
              case dods_url_c:
              {
                  string *poStrVal = NULL;
                  poFieldVar->buf2val( (void **) &poStrVal );
                  papszStrList[iSubIndex] = CPLStrdup( poStrVal->c_str() );
                  delete poStrVal;
              }
              break;

              default:
                break;
            }
        }

/* -------------------------------------------------------------------- */
/*      Apply back to feature.                                          */
/* -------------------------------------------------------------------- */
        if( poOFD->GetType() == OFTIntegerList )
        {
            poFeature->SetField( iField, nSubSeqCount, panIntList );
            CPLFree(panIntList);
        }
        else if( poOFD->GetType() == OFTRealList )
        {
            poFeature->SetField( iField, nSubSeqCount, padfDblList );
            CPLFree(padfDblList);
        }
        else if( poOFD->GetType() == OFTStringList )
        {
            poFeature->SetField( iField, papszStrList );
            CSLDestroy( papszStrList );
        }
    }
    
/* ==================================================================== */
/*      Fetch the geometry.                                             */
/* ==================================================================== */
    if( oXField.bValid && oYField.bValid )
    {
        int iXField = poFeature->GetFieldIndex( oXField.pszFieldName );
        int iYField = poFeature->GetFieldIndex( oYField.pszFieldName );
        int iZField = -1;

        if( oZField.bValid )
            iZField = poFeature->GetFieldIndex(oZField.pszFieldName);

/* -------------------------------------------------------------------- */
/*      If we can't find the values in attributes then use the more     */
/*      general mechanism to fetch the value.                           */
/* -------------------------------------------------------------------- */
        
        if( iXField == -1 || iYField == -1 
            || (oZField.bValid && iZField == -1) )
        {
            poFeature->SetGeometryDirectly( 
                new OGRPoint( GetFieldValueAsDouble( &oXField, iSubSeq ),
                              GetFieldValueAsDouble( &oYField, iSubSeq ),
                              GetFieldValueAsDouble( &oZField, iSubSeq ) ) );
        }
/* -------------------------------------------------------------------- */
/*      If the fields are list values, then build a linestring.         */
/* -------------------------------------------------------------------- */
        else if( poFeature->GetFieldDefnRef(iXField)->GetType() == OFTRealList
            && poFeature->GetFieldDefnRef(iYField)->GetType() == OFTRealList )
        {
            const double *padfX, *padfY, *padfZ = NULL;
            int nPointCount, i;
            OGRLineString *poLS = new OGRLineString();
            
            padfX = poFeature->GetFieldAsDoubleList( iXField, &nPointCount );
            padfY = poFeature->GetFieldAsDoubleList( iYField, &nPointCount );
            if( iZField != -1 )
                padfZ = poFeature->GetFieldAsDoubleList(iZField,&nPointCount);

            poLS->setPoints( nPointCount, (double *) padfX, (double *) padfY,
                             (double *) padfZ );

            // Make a pass clearing out NaN or Inf values. 
            for( i = 0; i < nPointCount; i++ )
            {
                double dfX = poLS->getX(i);
                double dfY = poLS->getY(i);
                double dfZ = poLS->getZ(i);
                int bReset = FALSE;

                if( OGRDODSIsDoubleInvalid( &dfX ) )
                {
                    dfX = 0.0;
                    bReset = TRUE;
                }
                if( OGRDODSIsDoubleInvalid( &dfY ) )
                {
                    dfY = 0.0;
                    bReset = TRUE;
                }
                if( OGRDODSIsDoubleInvalid( &dfZ ) )
                {
                    dfZ = 0.0;
                    bReset = TRUE;
                }

                if( bReset )
                    poLS->setPoint( i, dfX, dfY, dfZ );
            }

            poFeature->SetGeometryDirectly( poLS );
        }

/* -------------------------------------------------------------------- */
/*      Otherwise build a point.                                        */
/* -------------------------------------------------------------------- */
        else
        {
            poFeature->SetGeometryDirectly( 
                new OGRPoint( 
                    poFeature->GetFieldAsDouble( iXField ),
                    poFeature->GetFieldAsDouble( iYField ),
                    poFeature->GetFieldAsDouble( iZField ) ) );
        }
    }

    return poFeature;
}

/************************************************************************/
/*                          GetFeatureCount()                           */
/************************************************************************/

int OGRDODSSequenceLayer::GetFeatureCount( int bForce )

{
    if( !bDataLoaded && !bForce )
        return -1;

    ProvideDataDDS();

    return nRecordCount;
}

/************************************************************************/
/*                           ProvideDataDDS()                           */
/************************************************************************/

int OGRDODSSequenceLayer::ProvideDataDDS()

{
    if( bDataLoaded )
        return poTargetVar != NULL;

    int bResult = OGRDODSLayer::ProvideDataDDS();

    if( !bResult )
        return bResult;

    // If we are in nested sequence mode, we now need to properly set
    // the poTargetVar based on the current step in the supersequence. 
    poSuperSeq = FindSuperSequence( poTargetVar );

/* ==================================================================== */
/*      Figure out the record count.                                    */
/* ==================================================================== */
/* -------------------------------------------------------------------- */
/*      For simple sequences without a supersequence just return the    */
/*      count of elements.                                              */
/* -------------------------------------------------------------------- */
    if( poSuperSeq == NULL )
        nRecordCount = dynamic_cast<Sequence *>(poTargetVar)->number_of_rows();

/* -------------------------------------------------------------------- */
/*      Otherwise we have to count up all the target sequence           */
/*      instances for each of the super sequence items.                 */
/* -------------------------------------------------------------------- */
    else
    {
        int iSuper;

        nSuperSeqCount = poSuperSeq->number_of_rows();
        panSubSeqSize = (int *) calloc(sizeof(int),nSuperSeqCount);
        nRecordCount = 0;
        for( iSuper = 0; iSuper < nSuperSeqCount; iSuper++ )
        {
            Sequence *poSubSeq = dynamic_cast<Sequence *>( 
                poSuperSeq->var_value( iSuper, pszSubSeqPath ) );

            panSubSeqSize[iSuper] = poSubSeq->number_of_rows();
            nRecordCount += poSubSeq->number_of_rows();
        }    
    }

    return poTargetVar != NULL;
}

/* IEEE Constants:

  http://www.psc.edu/general/software/packages/ieee/ieee.html

Single Precision:

  S EEEEEEEE FFFFFFFFFFFFFFFFFFFFFFF
  0 1      8 9                    31

The value V represented by the word may be determined as follows:

    * If E=255 and F is nonzero, then V=NaN ("Not a number")
    * If E=255 and F is zero and S is 1, then V=-Infinity
    * If E=255 and F is zero and S is 0, then V=Infinity
    * If 0<E<255 then V=(-1)**S * 2 ** (E-127) * (1.F) where "1.F" is intended to represent the binary number created by prefixing F with an implicit leading 1 and a binary point.
    * If E=0 and F is nonzero, then V=(-1)**S * 2 ** (-126) * (0.F) These are "unnormalized" values.
    * If E=0 and F is zero and S is 1, then V=-0
    * If E=0 and F is zero and S is 0, then V=0 

In particular,

  0 00000000 00000000000000000000000 = 0
  1 00000000 00000000000000000000000 = -0

  0 11111111 00000000000000000000000 = Infinity
  1 11111111 00000000000000000000000 = -Infinity

  0 11111111 00000100000000000000000 = NaN
  1 11111111 00100010001001010101010 = NaN

  0 10000000 00000000000000000000000 = +1 * 2**(128-127) * 1.0 = 2
  0 10000001 10100000000000000000000 = +1 * 2**(129-127) * 1.101 = 6.5
  1 10000001 10100000000000000000000 = -1 * 2**(129-127) * 1.101 = -6.5

  0 00000001 00000000000000000000000 = +1 * 2**(1-127) * 1.0 = 2**(-126)
  0 00000000 10000000000000000000000 = +1 * 2**(-126) * 0.1 = 2**(-127) 
  0 00000000 00000000000000000000001 = +1 * 2**(-126) * 
                                       0.00000000000000000000001 = 
                                       2**(-149)  (Smallest positive value)

Double Precision:

The IEEE double precision floating point standard representation requires a 64 bit word, which may be represented as numbered from 0 to 63, left to right. The first bit is the sign bit, S, the next eleven bits are the exponent bits, 'E', and the final 52 bits are the fraction 'F':

  S EEEEEEEEEEE FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
  0 1        11 12                                                63

The value V represented by the word may be determined as follows:

    * If E=2047 and F is nonzero, then V=NaN ("Not a number")
    * If E=2047 and F is zero and S is 1, then V=-Infinity
    * If E=2047 and F is zero and S is 0, then V=Infinity
    * If 0<E<2047 then V=(-1)**S * 2 ** (E-1023) * (1.F) where "1.F" is intended to represent the binary number created by prefixing F with an implicit leading 1 and a binary point.
    * If E=0 and F is nonzero, then V=(-1)**S * 2 ** (-1022) * (0.F) These are "unnormalized" values.
    * If E=0 and F is zero and S is 1, then V=-0
    * If E=0 and F is zero and S is 0, then V=0 

*/

/************************************************************************/
/*                       OGRDODSIsFloatInvalid()                        */
/*                                                                      */
/*      For now we are really just checking if the value is NaN, Inf    */
/*      or -Inf.                                                        */
/************************************************************************/


int OGRDODSIsFloatInvalid( const float * pfValToCheck )

{
    const unsigned char *pabyValToCheck = (unsigned char *) pfValToCheck;

#if CPL_IS_LSB == 0
    if( (pabyValToCheck[0] & 0x7f) == 0x7f 
        && (pabyValToCheck[1] & 0x80) == 0x80 )
        return TRUE;
    else 
        return FALSE;
#else
    if( pabyValToCheck[3] & 0x7f == 0x7f 
        && pabyValToCheck[2] & 0x80 == 0x80 )
        return TRUE;
    else 
        return FALSE;
#endif
}

/************************************************************************/
/*                       OGRDODSIsDoubleInvalid()                       */
/*                                                                      */
/*      For now we are really just checking if the value is NaN, Inf    */
/*      or -Inf.                                                        */
/************************************************************************/


int OGRDODSIsDoubleInvalid( const double * pdfValToCheck )

{
    const unsigned char *pabyValToCheck = (unsigned char *) pdfValToCheck;

#if CPL_IS_LSB == 0 
    if( pabyValToCheck[0] & 0x7f == 0x7f 
        && pabyValToCheck[1] & 0xf0 == 0xf0 )
        return TRUE;
    else 
        return FALSE;
#else
    if( (pabyValToCheck[7] & 0x7f) == 0x7f 
        && (pabyValToCheck[6] & 0xf0) == 0xf0 )
        return TRUE;
    else 
        return FALSE;
#endif
}