* to retreive the next OGRFeature. **********************************************************************/OGRFeature *IMapInfoFile::GetNextFeature(){    OGRFeature *poFeatureRef;    OGRGeometry *poGeom;    int nFeatureId;    while( (nFeatureId = GetNextFeatureId(m_nCurFeatureId)) != -1 )    {        poFeatureRef = GetFeatureRef(nFeatureId);        if (poFeatureRef == NULL)            return NULL;        else if( (m_poFilterGeom == NULL ||                  ((poGeom = poFeatureRef->GetGeometryRef()) != NULL &&                   FilterGeometry( poGeom )))                 && (m_poAttrQuery == NULL                     || m_poAttrQuery->Evaluate( poFeatureRef )) )        {            // Avoid cloning feature... return the copy owned by the class            CPLAssert(poFeatureRef == m_poCurFeature);            m_poCurFeature = NULL;              return poFeatureRef;        }    }    return NULL;}/********************************************************************** *                   IMapInfoFile::CreateFeature() * * Standard OGR CreateFeature implementation.  This methode is used * to create a new feature in current dataset  **********************************************************************/OGRErr     IMapInfoFile::CreateFeature(OGRFeature *poFeature){    TABFeature *poTABFeature;    OGRGeometry   *poGeom;    OGRwkbGeometryType eGType;    OGRErr  eErr;    TABPoint *poTABPointFeature = NULL;    TABRegion *poTABRegionFeature = NULL;    TABPolyline *poTABPolylineFeature = NULL;    /*-----------------------------------------------------------------     * MITAB won't accept new features unless they are in a type derived     * from TABFeature... so we have to do our best to map to the right     * feature type based on the geometry type.     *----------------------------------------------------------------*/    poGeom = poFeature->GetGeometryRef();    if( poGeom != NULL )        eGType = poGeom->getGeometryType();    else        eGType = wkbNone;    switch( wkbFlatten(eGType) )    {      /*-------------------------------------------------------------       * POINT       *------------------------------------------------------------*/      case wkbPoint:        poTABFeature = new TABPoint(poFeature->GetDefnRef());        if(poFeature->GetStyleString())        {            poTABPointFeature = (TABPoint*)poTABFeature;            poTABPointFeature->SetSymbolFromStyleString(                poFeature->GetStyleString());        }        break;      /*-------------------------------------------------------------       * REGION       *------------------------------------------------------------*/      case wkbPolygon:      case wkbMultiPolygon:        poTABFeature = new TABRegion(poFeature->GetDefnRef());        if(poFeature->GetStyleString())        {            poTABRegionFeature = (TABRegion*)poTABFeature;            poTABRegionFeature->SetPenFromStyleString(                poFeature->GetStyleString());            poTABRegionFeature->SetBrushFromStyleString(                poFeature->GetStyleString());        }        break;      /*-------------------------------------------------------------       * LINE/PLINE/MULTIPLINE       *------------------------------------------------------------*/      case wkbLineString:      case wkbMultiLineString:        poTABFeature = new TABPolyline(poFeature->GetDefnRef());        if(poFeature->GetStyleString())        {            poTABPolylineFeature = (TABPolyline*)poTABFeature;            poTABPolylineFeature->SetPenFromStyleString(                poFeature->GetStyleString());        }        break;      /*-------------------------------------------------------------       * Collection types that are not directly supported... convert       * to multiple features in output file through recursive calls.       *------------------------------------------------------------*/      case wkbGeometryCollection:      case wkbMultiPoint:      {          OGRErr eStatus = OGRERR_NONE;          int i;          OGRGeometryCollection *poColl = (OGRGeometryCollection*)poGeom;          OGRFeature *poTmpFeature = poFeature->Clone();          for (i=0; eStatus==OGRERR_NONE && i<poColl->getNumGeometries(); i++)          {              poTmpFeature->SetGeometry(poColl->getGeometryRef(i));              eStatus = CreateFeature(poTmpFeature);          }          delete poTmpFeature;          return eStatus;        }        break;      /*-------------------------------------------------------------       * Unsupported type.... convert to MapInfo geometry NONE       *------------------------------------------------------------*/      case wkbUnknown:      default:         poTABFeature = new TABFeature(poFeature->GetDefnRef());         break;    }    if( poGeom != NULL )        poTABFeature->SetGeometryDirectly(poGeom->clone());        for (int i=0; i< poFeature->GetDefnRef()->GetFieldCount();i++)    {        poTABFeature->SetField(i,poFeature->GetRawFieldRef( i ));    }        if (SetFeature(poTABFeature) > -1)        eErr = OGRERR_NONE;    else        eErr = OGRERR_FAILURE;    delete poTABFeature;        return eErr;}/********************************************************************** *                   IMapInfoFile::GetFeature() * * Standard OGR GetFeature implementation.  This methode is used * to get the wanted (nFeatureId) feature, a NULL value will be  * returned on error. **********************************************************************/OGRFeature *IMapInfoFile::GetFeature(long nFeatureId){    OGRFeature *poFeatureRef;    poFeatureRef = GetFeatureRef(nFeatureId);    if (poFeatureRef)    {        // Avoid cloning feature... return the copy owned by the class        CPLAssert(poFeatureRef == m_poCurFeature);        m_poCurFeature = NULL;          return poFeatureRef;    }    else      return NULL;}/************************************************************************//*                            CreateField()                             *//*                                                                      *//*      Create a native field based on a generic OGR definition.        *//************************************************************************/OGRErr IMapInfoFile::CreateField( OGRFieldDefn *poField, int bApproxOK ){    TABFieldType        eTABType;    int                 nWidth = poField->GetWidth();    if( poField->GetType() == OFTInteger )    {        eTABType = TABFInteger;        if( nWidth == 0 )            nWidth = 12;    }    else if( poField->GetType() == OFTReal )    {        eTABType = TABFFloat;        if( nWidth == 0 )            nWidth = 32;    }    else if( poField->GetType() == OFTString )    {        eTABType = TABFChar;        if( nWidth == 0 )            nWidth = 254;        else            nWidth = MIN(254,nWidth);    }    else    {        CPLError( CE_Failure, CPLE_AppDefined,                  "IMapInfoFile::CreateField() called with unsupported field"                  " type %d.\n"                  "Note that Mapinfo files don't support list field types.\n",                  poField->GetType() );        return OGRERR_FAILURE;    }    if( AddFieldNative( poField->GetNameRef(), eTABType,                        nWidth, poField->GetPrecision() ) > -1 )        return OGRERR_NONE;    else        return OGRERR_FAILURE;}