ogrsdtslayer.cpp

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

/*      Process each subfield in the record.                            */
/* -------------------------------------------------------------------- */
    DDFFieldDefn        *poFDefn = poSR->GetFieldDefn();
        
    for( int iSF=0; iSF < poFDefn->GetSubfieldCount(); iSF++ )
    {
        DDFSubfieldDefn *poSFDefn = poFDefn->GetSubfield( iSF );
        int                     iField;
        int                     nMaxBytes;
        const char *    pachData = poSR->GetSubfieldData(poSFDefn,
                                                         &nMaxBytes);
/* -------------------------------------------------------------------- */
/*      Indentify this field on the feature.                            */
/* -------------------------------------------------------------------- */
        iField = poFeature->GetFieldIndex( poSFDefn->GetName() );

/* -------------------------------------------------------------------- */
/*      Handle each of the types.                                       */
/* -------------------------------------------------------------------- */
        switch( poSFDefn->GetType() )
        {
          case DDFString:
            const char  *pszValue;

            pszValue = poSFDefn->ExtractStringData(pachData, nMaxBytes,
                                                   NULL);

            if( iField != -1 )
                poFeature->SetField( iField, pszValue );
            break;

          case DDFFloat:
            double      dfValue;

            dfValue = poSFDefn->ExtractFloatData(pachData, nMaxBytes,
                                                 NULL);

            if( iField != -1 )
                poFeature->SetField( iField, dfValue );
            break;

          case DDFInt:
            int         nValue;

            nValue = poSFDefn->ExtractIntData(pachData, nMaxBytes, NULL);

            if( iField != -1 )
                poFeature->SetField( iField, nValue );
            break;

          default:
            break;
        }
    } /* next subfield */
}

/************************************************************************/
/*                      GetNextUnfilteredFeature()                      */
/************************************************************************/

OGRFeature * OGRSDTSLayer::GetNextUnfilteredFeature()

{
/* -------------------------------------------------------------------- */
/*      If not done before we need to assemble the geometry for a       */
/*      polygon layer.                                                  */
/* -------------------------------------------------------------------- */
    if( poTransfer->GetLayerType(iLayer) == SLTPoly )
    {
        ((SDTSPolygonReader *) poReader)->AssembleRings(poTransfer);
    }

/* -------------------------------------------------------------------- */
/*      Fetch the next sdts style feature object from the reader.       */
/* -------------------------------------------------------------------- */
    SDTSFeature *poSDTSFeature = poReader->GetNextFeature();
    OGRFeature  *poFeature;

    if( poSDTSFeature == NULL )
        return NULL;

/* -------------------------------------------------------------------- */
/*      Create the OGR feature.                                         */
/* -------------------------------------------------------------------- */
    poFeature = new OGRFeature( poFeatureDefn );

    m_nFeaturesRead++;

    switch( poTransfer->GetLayerType(iLayer) )
    {
/* -------------------------------------------------------------------- */
/*      Translate point feature specific information and geometry.      */
/* -------------------------------------------------------------------- */
      case SLTPoint:
      {
          SDTSRawPoint  *poPoint = (SDTSRawPoint *) poSDTSFeature;
          
          poFeature->SetGeometryDirectly( new OGRPoint( poPoint->dfX,
                                                        poPoint->dfY,
                                                        poPoint->dfZ ) );
      }
      break;

/* -------------------------------------------------------------------- */
/*      Translate line feature specific information and geometry.       */
/* -------------------------------------------------------------------- */
      case SLTLine:
      {
          SDTSRawLine   *poLine = (SDTSRawLine *) poSDTSFeature;
          OGRLineString *poOGRLine = new OGRLineString();

          poOGRLine->setPoints( poLine->nVertices,
                                poLine->padfX, poLine->padfY, poLine->padfZ );
          poFeature->SetGeometryDirectly( poOGRLine );
          poFeature->SetField( "SNID", (int) poLine->oStartNode.nRecord );
          poFeature->SetField( "ENID", (int) poLine->oEndNode.nRecord );
      }
      break;

/* -------------------------------------------------------------------- */
/*      Translate polygon feature specific information and geometry.    */
/* -------------------------------------------------------------------- */
      case SLTPoly:
      {
          SDTSRawPolygon *poPoly = (SDTSRawPolygon *) poSDTSFeature;
          OGRPolygon *poOGRPoly = new OGRPolygon();

          for( int iRing = 0; iRing < poPoly->nRings; iRing++ )
          {
              OGRLinearRing *poRing = new OGRLinearRing();
              int           nVertices;

              if( iRing == poPoly->nRings - 1 )
                  nVertices = poPoly->nVertices - poPoly->panRingStart[iRing];
              else
                  nVertices = poPoly->panRingStart[iRing+1]
                            - poPoly->panRingStart[iRing];

              poRing->setPoints( nVertices,
                                 poPoly->padfX + poPoly->panRingStart[iRing],
                                 poPoly->padfY + poPoly->panRingStart[iRing],
                                 poPoly->padfZ + poPoly->panRingStart[iRing] );

              poOGRPoly->addRingDirectly( poRing );
          }

          poFeature->SetGeometryDirectly( poOGRPoly );
      }
      break;

      default:
        break;
    }

/* -------------------------------------------------------------------- */
/*      Set attributes for any indicated attribute records.             */
/* -------------------------------------------------------------------- */
    int         iAttrRecord;
    
    for( iAttrRecord = 0; 
         iAttrRecord < poSDTSFeature->nAttributes; 
         iAttrRecord++)
    {
        DDFField        *poSR;

        poSR = poTransfer->GetAttr( poSDTSFeature->paoATID+iAttrRecord );
          
        AssignAttrRecordToFeature( poFeature, poTransfer, poSR );
    }

/* -------------------------------------------------------------------- */
/*      If this record is an attribute record, attach the local         */
/*      attributes.                                                     */
/* -------------------------------------------------------------------- */
    if( poTransfer->GetLayerType(iLayer) == SLTAttr )
    {
        AssignAttrRecordToFeature( poFeature, poTransfer, 
                                   ((SDTSAttrRecord *) poSDTSFeature)->poATTR);
    }
    
/* -------------------------------------------------------------------- */
/*      Translate the record id.                                        */
/* -------------------------------------------------------------------- */
    poFeature->SetFID( poSDTSFeature->oModId.nRecord );
    poFeature->SetField( 0, (int) poSDTSFeature->oModId.nRecord );
    if( poFeature->GetGeometryRef() != NULL )
        poFeature->GetGeometryRef()->assignSpatialReference(
            poDS->GetSpatialRef() );

    if( !poReader->IsIndexed() )
        delete poSDTSFeature;

    return poFeature;
}


/************************************************************************/
/*                           GetNextFeature()                           */
/************************************************************************/

OGRFeature *OGRSDTSLayer::GetNextFeature()

{
    OGRFeature  *poFeature = NULL;
    
/* -------------------------------------------------------------------- */
/*      Read features till we find one that satisfies our current       */
/*      spatial criteria.                                               */
/* -------------------------------------------------------------------- */
    while( TRUE )
    {
        poFeature = GetNextUnfilteredFeature();
        if( poFeature == NULL )
            break;

        if( (m_poFilterGeom == NULL
             || FilterGeometry( poFeature->GetGeometryRef() ) )
            && (m_poAttrQuery == NULL
                || m_poAttrQuery->Evaluate( poFeature )) )
            break;

        delete poFeature;
    }

    return poFeature;
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRSDTSLayer::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,OLCRandomRead) )
        return FALSE;

    else if( EQUAL(pszCap,OLCSequentialWrite) 
             || EQUAL(pszCap,OLCRandomWrite) )
        return FALSE;

    else if( EQUAL(pszCap,OLCFastFeatureCount) )
        return FALSE;

    else if( EQUAL(pszCap,OLCFastSpatialFilter) )
        return FALSE;

    else 
        return FALSE;
}


/************************************************************************/
/*                           GetSpatialRef()                            */
/************************************************************************/

OGRSpatialReference * OGRSDTSLayer::GetSpatialRef()

{
    return poDS->GetSpatialRef();
}