ogravcbinlayer.cpp

用于读取TAB、MIF、SHP文件的类

/******************************************************************************
 * $Id: ogravcbinlayer.cpp,v 1.8 2005/02/22 12:55:03 fwarmerdam Exp $
 *
 * Project:  OGR
 * Purpose:  Implements OGRAVCBinLayer class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2002, Frank Warmerdam <[e-mail]>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ******************************************************************************
 *
 * $Log: ogravcbinlayer.cpp,v $
 * Revision 1.8  2005/02/22 12:55:03  fwarmerdam
 * use OGRLayer base spatial filter support
 *
 * Revision 1.7  2003/01/03 15:43:29  warmerda
 * completed OGRBuildPolygonFromEdges() changes
 *
 * Revision 1.6  2003/01/02 21:45:23  warmerda
 * move OGRBuildPolygonsFromEdges into C API
 *
 * Revision 1.5  2002/06/18 18:59:00  warmerda
 * fixed bug 163, problem with assembling polygons with *bridges*
 *
 * Revision 1.4  2002/02/22 22:23:38  warmerda
 * added tolerances when assembling polygons
 *
 * Revision 1.3  2002/02/18 20:38:18  warmerda
 * Added spatial filtering.
 * Added Attribute query.
 * Set LAB FID based on sequence number rather than nValue field.
 * Use either LAB FID or PolyID for table lookup.
 * Add attributes to arcs and LABs.
 *
 * Revision 1.2  2002/02/14 23:01:04  warmerda
 * added region and attribute support
 *
 * Revision 1.1  2002/02/13 20:48:18  warmerda
 * New
 *
 */

#include "ogr_avc.h"
#include "ogr_api.h"
#include "cpl_conv.h"
#include "cpl_string.h"

CPL_CVSID("$Id: ogravcbinlayer.cpp,v 1.8 2005/02/22 12:55:03 fwarmerdam Exp $");

/************************************************************************/
/*                           OGRAVCBinLayer()                           */
/************************************************************************/

OGRAVCBinLayer::OGRAVCBinLayer( OGRAVCBinDataSource *poDSIn,
                                AVCE00Section *psSectionIn )
        : OGRAVCLayer( psSectionIn->eType, poDSIn )

{
    psSection = psSectionIn;
    hFile = NULL;
    poArcLayer = NULL;
    bNeedReset = FALSE;
    nNextFID = 1;

    hTable = NULL;
    nTableBaseField = -1;
    nTableAttrIndex = -1;

    SetupFeatureDefinition( psSection->pszName );
    
    szTableName[0] = '\0';
    if( psSection->eType == AVCFilePAL )
        sprintf( szTableName, "%s.PAT", poDS->GetCoverageName() );
    else if( psSection->eType == AVCFileRPL )
        sprintf( szTableName, "%s.PAT%s", poDS->GetCoverageName(),
                 psSectionIn->pszName );
    else if( psSection->eType == AVCFileARC )
        sprintf( szTableName, "%s.AAT", poDS->GetCoverageName() );
    else if( psSection->eType == AVCFileLAB )
    {
        AVCE00ReadPtr psInfo = ((OGRAVCBinDataSource *) poDS)->GetInfo();

        sprintf( szTableName, "%s.PAT", poDS->GetCoverageName() );

        for( int iSection = 0; iSection < psInfo->numSections; iSection++ )
        {
            if( psInfo->pasSections[iSection].eType == AVCFilePAL )
                nTableAttrIndex = poFeatureDefn->GetFieldIndex( "PolyId" );
        }
    }

    CheckSetupTable();
}

/************************************************************************/
/*                          ~OGRAVCBinLayer()                           */
/************************************************************************/

OGRAVCBinLayer::~OGRAVCBinLayer()

{
    ResetReading();
}

/************************************************************************/
/*                            ResetReading()                            */
/************************************************************************/

void OGRAVCBinLayer::ResetReading()

{
    if( hFile != NULL )
    {
        AVCBinReadClose( hFile );
        hFile = NULL;
    }

    bNeedReset = FALSE;
    nNextFID = 1;

    if( hTable != NULL )
    {
        AVCBinReadClose( hTable );
        hTable = NULL;
    }
}

/************************************************************************/
/*                             GetFeature()                             */
/************************************************************************/

OGRFeature *OGRAVCBinLayer::GetFeature( long nFID )

{
/* -------------------------------------------------------------------- */
/*      If we haven't started yet, open the file now.                   */
/* -------------------------------------------------------------------- */
    if( hFile == NULL )
    {
        AVCE00ReadPtr psInfo = ((OGRAVCBinDataSource *) poDS)->GetInfo();

        hFile = AVCBinReadOpen(psInfo->pszCoverPath, 
                               psSection->pszFilename, 
                               psInfo->eCoverType, 
                               psSection->eType,
                               psInfo->psDBCSInfo);
    }

/* -------------------------------------------------------------------- */
/*      Read the raw feature - the -3 fid is a special flag             */
/*      indicating serial access.                                       */
/* -------------------------------------------------------------------- */
    void *pFeature;

    if( nFID == -3 )
    {
        while( (pFeature = AVCBinReadNextObject( hFile )) != NULL
               && !MatchesSpatialFilter( pFeature ) )
        {
            nNextFID++;
        }
    }
    else
    {
        bNeedReset = TRUE;
        pFeature = AVCBinReadObject( hFile, nFID );
    }
        
    if( pFeature == NULL )
        return NULL;

/* -------------------------------------------------------------------- */
/*      Translate the feature.                                          */
/* -------------------------------------------------------------------- */
    OGRFeature *poFeature;

    poFeature = TranslateFeature( pFeature );
    if( poFeature == NULL )
        return NULL;

/* -------------------------------------------------------------------- */
/*      LAB's we have to assign the FID to directly, since it           */
/*      doesn't seem to be stored in the file structure.                */
/* -------------------------------------------------------------------- */
    if( psSection->eType == AVCFileLAB )
    {
        if( nFID == -3 )
            poFeature->SetFID( nNextFID++ );
        else
            poFeature->SetFID( nFID );
    }

/* -------------------------------------------------------------------- */
/*      If this is a polygon layer, try to assemble the arcs to form    */
/*      the whole polygon geometry.                                     */
/* -------------------------------------------------------------------- */
    if( psSection->eType == AVCFilePAL 
        || psSection->eType == AVCFileRPL )
        FormPolygonGeometry( poFeature, (AVCPal *) pFeature );

/* -------------------------------------------------------------------- */
/*      If we have an attribute table, append the attributes now.       */
/* -------------------------------------------------------------------- */
    AppendTableFields( poFeature );

    return poFeature;
}

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

OGRFeature *OGRAVCBinLayer::GetNextFeature()

{
    if( bNeedReset )
        ResetReading();

    OGRFeature *poFeature = GetFeature( -3 );

    // Skip universe polygon.