ntffilereader.cpp

支持各种栅格图像和矢量图像读取的库

                             papszTypes, papszValues );
    }

/* -------------------------------------------------------------------- */
/*      Cleanup.                                                        */
/* -------------------------------------------------------------------- */
    CSLDestroy( papszTypes );
    CSLDestroy( papszValues );
}
                                          

/************************************************************************/
/*                        ApplyAttributeValue()                         */
/*                                                                      */
/*      Apply the indicated attribute value to an OGRFeature field      */
/*      if it exists in the attribute value list given.                 */
/************************************************************************/

int NTFFileReader::ApplyAttributeValue( OGRFeature * poFeature, int iField,
                                        const char * pszAttName,
                                        char ** papszTypes,
                                        char ** papszValues )

{
/* -------------------------------------------------------------------- */
/*      Find the requested attribute in the name/value pair             */
/*      provided.  If not found that's fine, just return with           */
/*      notification.                                                   */
/* -------------------------------------------------------------------- */
    int         iValue;
    
    iValue = CSLFindString( papszTypes, pszAttName );
    if( iValue < 0 )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Process the attribute value ... this really only has a          */
/*      useful effect for real numbers.                                 */
/* -------------------------------------------------------------------- */
    char        *pszAttLongName, *pszAttValue, *pszCodeDesc;

    ProcessAttValue( pszAttName, papszValues[iValue],
                     &pszAttLongName, &pszAttValue, &pszCodeDesc );

/* -------------------------------------------------------------------- */
/*      Apply the value to the field using the simple set string        */
/*      method.  Leave it to the OGRFeature::SetField() method to       */
/*      take care of translation to other types.                        */
/* -------------------------------------------------------------------- */
    poFeature->SetField( iField, pszAttValue );

/* -------------------------------------------------------------------- */
/*      Apply the code description if we found one.                     */
/* -------------------------------------------------------------------- */
    if( pszCodeDesc != NULL )
    {
        char    szDescFieldName[256];

        sprintf( szDescFieldName, "%s_DESC", 
                 poFeature->GetDefnRef()->GetFieldDefn(iField)->GetNameRef() );
        poFeature->SetField( szDescFieldName, pszCodeDesc );
    }

    return TRUE;
}

/************************************************************************/
/*                             SaveRecord()                             */
/************************************************************************/

void NTFFileReader::SaveRecord( NTFRecord * poRecord )

{
    CPLAssert( poSavedRecord == NULL );
    poSavedRecord = poRecord;
}

/************************************************************************/
/*                             ReadRecord()                             */
/************************************************************************/

NTFRecord *NTFFileReader::ReadRecord()

{
    if( poSavedRecord != NULL )
    {
        NTFRecord       *poReturn;

        poReturn = poSavedRecord;

        poSavedRecord = NULL;

        return poReturn;
    }
    else
    {
        NTFRecord       *poRecord;

        CPLErrorReset();
        if( fp != NULL )
            nPreSavedPos = VSIFTell( fp );
        poRecord = new NTFRecord( fp );
        if( fp != NULL )
            nPostSavedPos = VSIFTell( fp );

        /* ensure termination if we fail to read a record */
        if( CPLGetLastErrorType() == CE_Failure )
        {
            delete poRecord;
            poRecord = NULL;
        }

        return poRecord;
    }
}

/************************************************************************/
/*                              GetFPPos()                              */
/*                                                                      */
/*      Return the current file pointer position.                       */
/************************************************************************/

void NTFFileReader::GetFPPos( long *pnPos, long *pnFID )

{
    if( poSavedRecord != NULL )
        *pnPos = nPreSavedPos;
    else
        *pnPos = nPostSavedPos;

    if( pnFID != NULL )
        *pnFID = nSavedFeatureId;
}

/************************************************************************/
/*                              SetFPPos()                              */
/************************************************************************/

int NTFFileReader::SetFPPos( long nNewPos, long nNewFID )

{
    if( nNewFID == nSavedFeatureId )
        return TRUE;

    if( poSavedRecord != NULL )
    {
        delete poSavedRecord;
        poSavedRecord = NULL;
    }

    if( fp != NULL && VSIFSeek( fp, nNewPos, SEEK_SET ) == 0 )
    {
        nPreSavedPos = nPostSavedPos = nNewPos;
        nSavedFeatureId = nNewFID;
        return TRUE;
    }
    else
        return FALSE;
}

/************************************************************************/
/*                               Reset()                                */
/*                                                                      */
/*      Reset reading to the first feature record.                      */
/************************************************************************/

void NTFFileReader::Reset()

{
    SetFPPos( nStartPos, nBaseFeatureId );
    ClearCGroup();
}

/************************************************************************/
/*                            ClearCGroup()                             */
/*                                                                      */
/*      Clear the currently loaded record group.                        */
/************************************************************************/

void NTFFileReader::ClearCGroup()

{
    for( int i = 0; apoCGroup[i] != NULL; i++ )
        delete apoCGroup[i];

    apoCGroup[0] = NULL;
    apoCGroup[1] = NULL;
}

/************************************************************************/
/*                      DefaultNTFRecordGrouper()                       */
/*                                                                      */
/*      Default rules for figuring out if a new candidate record        */
/*      belongs to a group of records that together form a feature      */
/*      (a record group).                                               */
/************************************************************************/

int DefaultNTFRecordGrouper( NTFFileReader *, NTFRecord ** papoGroup,
                             NTFRecord * poCandidate )

{
/* -------------------------------------------------------------------- */
/*      Is this group going to be a CPOLY set?  We can recognise        */
/*      this because we get repeating POLY/CHAIN sets without an        */
/*      intermediate attribute record.  This is a rather special case!  */
/* -------------------------------------------------------------------- */
    if( papoGroup[0] != NULL && papoGroup[1] != NULL
        && papoGroup[0]->GetType() == NRT_POLYGON
        && papoGroup[1]->GetType() == NRT_CHAIN )
    {
        // We keep going till we get the seed geometry.
        int     iRec, bGotCPOLY=FALSE;

        for( iRec = 0; papoGroup[iRec] != NULL; iRec++ ) 
        {
            if( papoGroup[iRec]->GetType() == NRT_CPOLY )
                bGotCPOLY = TRUE;
        }

        if( bGotCPOLY 
            && poCandidate->GetType() != NRT_GEOMETRY
            && poCandidate->GetType() != NRT_ATTREC )
            return FALSE;

        /*
         * this logic assumes we always get a point geometry with a CPOLY
         * but that isn't always true, for instance with BL2000 data.  The
         * preceed check will handle this case.
         */
        if( papoGroup[iRec-1]->GetType() != NRT_GEOMETRY )
            return TRUE;
        else
            return FALSE;
    }
    
/* -------------------------------------------------------------------- */
/*      Is this a "feature" defining record?  If so break out if it     */
/*      isn't the first record in the group.                            */
/* -------------------------------------------------------------------- */
    if( papoGroup[0] != NULL 
        && (poCandidate->GetType() == NRT_NAMEREC
            || poCandidate->GetType() == NRT_NODEREC
            || poCandidate->GetType() == NRT_LINEREC
            || poCandidate->GetType() == NRT_POINTREC
            || poCandidate->GetType() == NRT_POLYGON
            || poCandidate->GetType() == NRT_CPOLY
            || poCandidate->GetType() == NRT_COLLECT
            || poCandidate->GetType() == NRT_TEXTREC
            || poCandidate->GetType() == NRT_COMMENT) )
    {
        return FALSE;
    }

/* -------------------------------------------------------------------- */
/*      Do we already have a record of this type?  If so, it likely     */
/*      doesn't belong in the group.  Attribute records do repeat in    */
/*      some products.                                                  */
/* -------------------------------------------------------------------- */
    if (poCandidate->GetType() != NRT_ATTREC )
    {
        int     iRec;
        for( iRec = 0; papoGroup[iRec] != NULL; iRec++ )
        {
            if( poCandidate->GetType() == papoGroup[iRec]->GetType() )
                break;
        }
           
        if( papoGroup[iRec] != NULL )
            return FALSE;
    }

    return TRUE;
}

/************************************************************************/
/*                          ReadRecordGroup()                           */
/*                                                                      */
/*      Read a group of records that form a single feature.             */
/************************************************************************/

NTFRecord **NTFFileReader::ReadRecordGroup()

{
   NTFRecord     *poRecord;
   int            nRecordCount = 0;

   ClearCGroup();
   
/* -------------------------------------------------------------------- */
/*      Loop, reading records till we think we have a grouping.         */
/* -------------------------------------------------------------------- */
   while( (poRecord = ReadRecord()) != NULL && poRecord->GetType() != NRT_VTR )
   {
       CPLAssert( nRecordCount < MAX_REC_GROUP);
       if( nRecordCount >= MAX_REC_GROUP )
       {
           CPLError( CE_Failure, CPLE_AppDefined, 
                     "Maximum record group size (%d) exceeded.\n", 
                     MAX_REC_GROUP );
           break;
       }

       if( !pfnRecordGrouper( this, apoCGroup, poRecord ) )
           break;
       
       apoCGroup[nRecordCount++] = poRecord;
       apoCGroup[nRecordCount] = NULL;
   }
   
/* -------------------------------------------------------------------- */
/*      Push the last record back on the input queue.                   */
/* -------------------------------------------------------------------- */
   if( poRecord != NULL )
       SaveRecord( poRecord );

/* -------------------------------------------------------------------- */
/*      Return the list, or NULL if we didn't get any records.          */
/* -------------------------------------------------------------------- */
   if( nRecordCount == 0 )
       return NULL;
   else
       return apoCGroup;
}

/************************************************************************/
/*                          GetFeatureClass()                           */
/************************************************************************/

int NTFFileReader::GetFeatureClass( int iFCIndex,
                                    char ** ppszFCId,
                                    char ** ppszFCName )

{
    if( iFCIndex < 0 || iFCIndex >= nFCCount )
    {
        *ppszFCId = NULL;
        *ppszFCName = NULL;
        return FALSE;
    }
    else
    {
        *ppszFCId   = papszFCNum[iFCIndex];
        *ppszFCName = papszFCName[iFCIndex];
        return TRUE;
    }
}

/************************************************************************/
/*                           ReadOGRFeature()                           */
/************************************************************************/

OGRFeature * NTFFileReader::ReadOGRFeature( OGRNTFLayer * poTargetLayer )

{
    OGRNTFLayer *poLayer = NULL;
    NTFRecord   **papoGroup;
    OGRFeature  *poFeature = NULL;

/* -------------------------------------------------------------------- */
/*      If this is a raster file, use a custom method to read the       */
/*      feature.                                                        */
/* -------------------------------------------------------------------- */
    if( IsRasterProduct() )
        return poRasterLayer->GetNextFeature();