ogrshapelayer.cpp

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

        && eRequestedGeomType == wkbUnknown 
        && poFeature->GetGeometryRef() != NULL )
    {
        OGRGeometry     *poGeom = poFeature->GetGeometryRef();
        int             nShapeType;
        
        switch( poGeom->getGeometryType() )
        {
          case wkbPoint:
            nShapeType = SHPT_POINT;
            eRequestedGeomType = wkbPoint;
            break;

          case wkbPoint25D:
            nShapeType = SHPT_POINTZ;
            eRequestedGeomType = wkbPoint25D;
            break;

          case wkbMultiPoint:
            nShapeType = SHPT_MULTIPOINT;
            eRequestedGeomType = wkbMultiPoint;
            break;

          case wkbMultiPoint25D:
            nShapeType = SHPT_MULTIPOINTZ;
            eRequestedGeomType = wkbMultiPoint25D;
            break;

          case wkbLineString:
            nShapeType = SHPT_ARC;
            eRequestedGeomType = wkbLineString;
            break;

          case wkbLineString25D:
            nShapeType = SHPT_ARCZ;
            eRequestedGeomType = wkbLineString25D;
            break;

          case wkbPolygon:
          case wkbMultiPolygon:
            nShapeType = SHPT_POLYGON;
            eRequestedGeomType = wkbPolygon;
            break;

          case wkbPolygon25D:
          case wkbMultiPolygon25D:
            nShapeType = SHPT_POLYGONZ;
            eRequestedGeomType = wkbPolygon25D;
            break;

          default:
            nShapeType = -1;
            break;
        }

        if( nShapeType != -1 )
        {
            ResetGeomType( nShapeType );
        }
    }
    
    eErr = SHPWriteOGRFeature( hSHP, hDBF, poFeatureDefn, poFeature );

    if( hSHP != NULL )
        nTotalShapeCount = hSHP->nRecords;
    else 
        nTotalShapeCount = hDBF->nRecords;
    
    return eErr;
}

/************************************************************************/
/*                          GetFeatureCount()                           */
/*                                                                      */
/*      If a spatial filter is in effect, we turn control over to       */
/*      the generic counter.  Otherwise we return the total count.      */
/*      Eventually we should consider implementing a more efficient     */
/*      way of counting features matching a spatial query.              */
/************************************************************************/

int OGRShapeLayer::GetFeatureCount( int bForce )

{
    if( m_poFilterGeom != NULL || m_poAttrQuery != NULL )
        return OGRLayer::GetFeatureCount( bForce );
    else
        return nTotalShapeCount;
}

/************************************************************************/
/*                             GetExtent()                              */
/*                                                                      */
/*      Fetch extent of the data currently stored in the dataset.       */
/*      The bForce flag has no effect on SHO files since that value     */
/*      is always in the header.                                        */
/*                                                                      */
/*      Returns OGRERR_NONE/OGRRERR_FAILURE.                            */
/************************************************************************/

OGRErr OGRShapeLayer::GetExtent (OGREnvelope *psExtent, int bForce)

{
    double adMin[4], adMax[4];

    if( hSHP == NULL )
        return OGRERR_FAILURE;

    SHPGetInfo(hSHP, NULL, NULL, adMin, adMax);

    psExtent->MinX = adMin[0];
    psExtent->MinY = adMin[1];
    psExtent->MaxX = adMax[0];
    psExtent->MaxY = adMax[1];

    return OGRERR_NONE;
}

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

int OGRShapeLayer::TestCapability( const char * pszCap )

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

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

    else if( EQUAL(pszCap,OLCFastFeatureCount) )
        return m_poFilterGeom == NULL;

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

    else if( EQUAL(pszCap,OLCFastGetExtent) )
        return TRUE;

    else if( EQUAL(pszCap,OLCFastSetNextByIndex) )
        return m_poFilterGeom == NULL && m_poAttrQuery == NULL;

    else if( EQUAL(pszCap,OLCCreateField) )
        return TRUE;

    else 
        return FALSE;
}

/************************************************************************/
/*                            CreateField()                             */
/************************************************************************/

OGRErr OGRShapeLayer::CreateField( OGRFieldDefn *poField, int bApproxOK )

{
    int         iNewField;
    if( GetFeatureCount(TRUE) != 0 )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Can't create fields on a Shapefile layer with features.\n");
        return OGRERR_FAILURE;
    }

    if( !bUpdateAccess )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Can't create fields on a read-only shapefile layer.\n");
        return OGRERR_FAILURE;
    }

    if( poField->GetType() == OFTInteger )
    {
        if( poField->GetWidth() == 0 )
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTInteger, 11, 0 );
        else
            iNewField = DBFAddField( hDBF, poField->GetNameRef(), FTInteger,
                                     poField->GetWidth(), 0 );

        if( iNewField != -1 )
            poFeatureDefn->AddFieldDefn( poField );
    }
    else if( poField->GetType() == OFTReal )
    {
        if( poField->GetWidth() == 0 )
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTDouble, 24, 15 );
        else
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTDouble,
                             poField->GetWidth(), poField->GetPrecision() );

        if( iNewField != -1 )
            poFeatureDefn->AddFieldDefn( poField );
    }
    else if( poField->GetType() == OFTString )
    {
        if( poField->GetWidth() < 1 )
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTString, 80, 0 );
        else
            iNewField = DBFAddField( hDBF, poField->GetNameRef(), FTString, 
                                     poField->GetWidth(), 0 );

        if( iNewField != -1 )
            poFeatureDefn->AddFieldDefn( poField );
    }
    else
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Can't create fields of type %s on shapefile layers.\n",
                  OGRFieldDefn::GetFieldTypeName(poField->GetType()) );

        return OGRERR_FAILURE;
    }

    if( iNewField != -1 )
        return OGRERR_NONE;
    else        
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Can't create field %s in Shape DBF file, reason unknown.\n",
                  poField->GetNameRef() );

        return OGRERR_FAILURE;
    }
}

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

OGRSpatialReference *OGRShapeLayer::GetSpatialRef()

{
    return poSRS;
}

/************************************************************************/
/*                           ResetGeomType()                            */
/*                                                                      */
/*      Modify the geometry type for this file.  Used to convert to     */
/*      a different geometry type when a layer was created with a       */
/*      type of unknown, and we get to the first feature to             */
/*      establish the type.                                             */
/************************************************************************/

int OGRShapeLayer::ResetGeomType( int nNewGeomType )

{
    char        abyHeader[100];
    int         nStartPos;

    if( nTotalShapeCount > 0 )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Update .shp header.                                             */
/* -------------------------------------------------------------------- */
    nStartPos = ftell( hSHP->fpSHP );

    if( fseek( hSHP->fpSHP, 0, SEEK_SET ) != 0
        || fread( abyHeader, 100, 1, hSHP->fpSHP ) != 1 )
        return FALSE;

    *((GInt32 *) (abyHeader + 32)) = CPL_LSBWORD32( nNewGeomType );

    if( fseek( hSHP->fpSHP, 0, SEEK_SET ) != 0
        || fwrite( abyHeader, 100, 1, hSHP->fpSHP ) != 1 )
        return FALSE;

    if( fseek( hSHP->fpSHP, nStartPos, SEEK_SET ) != 0 )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Update .shx header.                                             */
/* -------------------------------------------------------------------- */
    nStartPos = ftell( hSHP->fpSHX );

    if( fseek( hSHP->fpSHX, 0, SEEK_SET ) != 0
        || fread( abyHeader, 100, 1, hSHP->fpSHX ) != 1 )
        return FALSE;

    *((GInt32 *) (abyHeader + 32)) = CPL_LSBWORD32( nNewGeomType );

    if( fseek( hSHP->fpSHX, 0, SEEK_SET ) != 0
        || fwrite( abyHeader, 100, 1, hSHP->fpSHX ) != 1 )
        return FALSE;

    if( fseek( hSHP->fpSHX, nStartPos, SEEK_SET ) != 0 )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Update other information.                                       */
/* -------------------------------------------------------------------- */
    hSHP->nShapeType = nNewGeomType;

    return TRUE;
}

/************************************************************************/
/*                             SyncToDisk()                             */
/************************************************************************/

OGRErr OGRShapeLayer::SyncToDisk()

{
    if( bHeaderDirty )
    {
        if( hSHP != NULL )
            SHPWriteHeader( hSHP );

        if( hDBF != NULL )
            DBFUpdateHeader( hDBF );
        
        bHeaderDirty = FALSE;
    }

    if( hSHP != NULL )
    {
        fflush( hSHP->fpSHP );
        fflush( hSHP->fpSHX );
    }

    if( hDBF != NULL )
        fflush( hDBF->fp );

    return OGRERR_NONE;
}

/************************************************************************/
/*                          DropSpatialIndex()                          */
/************************************************************************/

OGRErr OGRShapeLayer::DropSpatialIndex()

{
    if( !CheckForQIX() )
    {
        CPLError( CE_Warning, CPLE_AppDefined, 
                  "Layer %s has no spatial index, DROP SPATIAL INDEX failed.",
                  poFeatureDefn->GetName() );
        return OGRERR_FAILURE;
    }

    VSIFClose( fpQIX );
    fpQIX = NULL;
    bCheckedForQIX = FALSE;
    
    const char *pszQIXFilename;

    pszQIXFilename = CPLResetExtension( pszFullName, "qix" );
    CPLDebug( "SHAPE", "Unlinking index file %s", pszQIXFilename );

    if( VSIUnlink( pszQIXFilename ) != 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Failed to delete file %s.\n%s", 
                  pszQIXFilename, VSIStrerror( errno ) );
        return OGRERR_FAILURE;
    }
    else
        return OGRERR_NONE;
}

/************************************************************************/
/*                         CreateSpatialIndex()                         */
/************************************************************************/

OGRErr OGRShapeLayer::CreateSpatialIndex( int nMaxDepth )

{
/* -------------------------------------------------------------------- */
/*      If we have an existing spatial index, blow it away first.       */
/* -------------------------------------------------------------------- */
    if( CheckForQIX() )
        DropSpatialIndex();

    bCheckedForQIX = FALSE;

/* -------------------------------------------------------------------- */
/*      Build a quadtree structure for this file.                       */
/* -------------------------------------------------------------------- */
    SHPTree	*psTree;

    SyncToDisk();
    psTree = SHPCreateTree( hSHP, 2, nMaxDepth, NULL, NULL );

/* -------------------------------------------------------------------- */
/*      Trim unused nodes from the tree.                                */
/* -------------------------------------------------------------------- */
    SHPTreeTrimExtraNodes( psTree );

/* -------------------------------------------------------------------- */
/*      Dump tree to .qix file.                                         */
/* -------------------------------------------------------------------- */
    char *pszQIXFilename;

    pszQIXFilename = CPLStrdup(CPLResetExtension( pszFullName, "qix" ));

    CPLDebug( "SHAPE", "Creating index file %s", pszQIXFilename );

    SHPWriteTree( psTree, pszQIXFilename );
    CPLFree( pszQIXFilename );


/* -------------------------------------------------------------------- */
/*      cleanup                                                         */
/* -------------------------------------------------------------------- */
    SHPDestroyTree( psTree );

    CheckForQIX();

    return OGRERR_NONE;
}