gml2ogrgeometry.cpp

用于读取TAB、MIF、SHP文件的类

/******************************************************************************
 * $Id: gml2ogrgeometry.cpp,v 1.10 2005/07/20 02:33:24 fwarmerdam Exp $
 *
 * Project:  GML Reader
 * Purpose:  Code to translate between GML and OGR geometry forms.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2002, Frank Warmerdam
 *
 * 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.
 *****************************************************************************
 *
 * Independent Security Audit 2003/04/17 Andrey Kiselev:
 *   Completed audit of this module. All functions may be used without buffer
 *   overflows and stack corruptions with any kind of input data.
 *
 * Security Audit 2003/03/28 warmerda:
 *   Completed security audit.  I believe that this module may be safely used 
 *   to parse, arbitrary GML potentially provided by a hostile source without
 *   compromising the system.
 *
 * $Log: gml2ogrgeometry.cpp,v $
 * Revision 1.10  2005/07/20 02:33:24  fwarmerdam
 * fix up dimension support
 *
 * Revision 1.9  2005/03/08 19:51:15  fwarmerdam
 * added gml:pos support
 *
 * Revision 1.8  2004/01/06 18:40:06  warmerda
 * do not crash if polygon fails to parse during multipolygon assembly
 *
 * Revision 1.7  2003/09/22 05:34:46  warmerda
 * implemented support for various kinds of geometry collections
 *
 * Revision 1.6  2003/04/17 08:23:07  dron
 * Completed security audit, few fixes in error format strings.
 *
 * Revision 1.5  2003/03/28 05:46:43  warmerda
 * completed security audit, fix error report risk
 *
 * Revision 1.4  2003/03/12 20:52:07  warmerda
 * implemented support for gml:Box
 *
 * Revision 1.3  2003/03/07 21:30:15  warmerda
 * expand tabs
 *
 * Revision 1.2  2003/03/07 14:52:40  warmerda
 * fixed type casting issing
 *
 * Revision 1.1  2003/03/06 20:28:38  warmerda
 * Migrated to here (gdal/ogr) from gdal/ogr/ogrsf_frmts/gml.
 * Changed to implement the C API entry points (OGR_G_*).
 * Added API to take/return CPLXMLNode's directly.
 *
 * Revision 1.4  2002/03/11 17:09:42  warmerda
 * added multipolygon support
 *
 * Revision 1.3  2002/03/07 22:37:10  warmerda
 * use ogr_gml_geom.h
 *
 * Revision 1.2  2002/03/06 20:07:12  warmerda
 * fixed point reading
 *
 * Revision 1.1  2002/01/24 17:39:22  warmerda
 * New
 *
 */

#include "cpl_minixml.h"
#include "ogr_geometry.h"
#include "ogr_api.h"
#include "cpl_error.h"
#include "cpl_string.h"
#include <ctype.h>

/************************************************************************/
/*                           BareGMLElement()                           */
/*                                                                      */
/*      Returns the passed string with any namespace prefix             */
/*      stripped off.                                                   */
/************************************************************************/

static const char *BareGMLElement( const char *pszInput )

{
    const char *pszReturn;

    pszReturn = strchr( pszInput, ':' );
    if( pszReturn == NULL )
        pszReturn = pszInput;
    else
        pszReturn++;

    return pszReturn;
}

/************************************************************************/
/*                          FindBareXMLChild()                          */
/*                                                                      */
/*      Find a child node with the indicated "bare" name, that is       */
/*      after any namespace qualifiers have been stripped off.          */
/************************************************************************/

static CPLXMLNode *FindBareXMLChild( CPLXMLNode *psParent, 
                                     const char *pszBareName )

{
    CPLXMLNode *psCandidate = psParent->psChild;

    while( psCandidate != NULL )
    {
        if( psCandidate->eType == CXT_Element
            && EQUAL(BareGMLElement(psCandidate->pszValue), pszBareName) )
            return psCandidate;

        psCandidate = psCandidate->psNext;
    }

    return NULL;
}

/************************************************************************/
/*                           GetElementText()                           */
/************************************************************************/

static const char *GetElementText( CPLXMLNode *psElement )

{
    if( psElement == NULL )
        return NULL;

    CPLXMLNode *psChild = psElement->psChild;

    while( psChild != NULL )
    {
        if( psChild->eType == CXT_Text )
            return psChild->pszValue;

        psChild = psChild->psNext;
    }
    
    return NULL;
}

/************************************************************************/
/*                              AddPoint()                              */
/*                                                                      */
/*      Add a point to the passed geometry.                             */
/************************************************************************/

static int AddPoint( OGRGeometry *poGeometry, 
                     double dfX, double dfY, double dfZ, int nDimension )

{
    if( poGeometry->getGeometryType() == wkbPoint 
        || poGeometry->getGeometryType() == wkbPoint25D )
    {
        OGRPoint *poPoint = (OGRPoint *) poGeometry;

        if( poPoint->getX() != 0.0 || poPoint->getY() != 0.0 )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "More than one coordinate for <Point> element.");
            return FALSE;
        }
            
        poPoint->setX( dfX );
        poPoint->setY( dfY );
        if( nDimension == 3 )
            poPoint->setZ( dfZ );

        return TRUE;
    }
                
    else if( poGeometry->getGeometryType() == wkbLineString
             || poGeometry->getGeometryType() == wkbLineString25D )
    {
        if( nDimension == 3 )
            ((OGRLineString *) poGeometry)->addPoint( dfX, dfY, dfZ );
        else
            ((OGRLineString *) poGeometry)->addPoint( dfX, dfY );

        return TRUE;
    }

    else
    {
        CPLAssert( FALSE );
        return FALSE;                                                   
    }
}

/************************************************************************/
/*                        ParseGMLCoordinates()                         */
/************************************************************************/

int ParseGMLCoordinates( CPLXMLNode *psGeomNode, OGRGeometry *poGeometry )

{
    CPLXMLNode *psCoordinates = FindBareXMLChild( psGeomNode, "coordinates" );
    int iCoord = 0;

/* -------------------------------------------------------------------- */
/*      Handle <coordinates> case.                                      */
/* -------------------------------------------------------------------- */
    if( psCoordinates != NULL )
    {
        const char *pszCoordString = GetElementText( psCoordinates );

        if( pszCoordString == NULL )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "<coordinates> element missing value." );
            return FALSE;
        }

        while( *pszCoordString != '\0' )
        {
            double dfX, dfY, dfZ = 0.0;
            int nDimension = 2;

            // parse out 2 or 3 tuple. 
            dfX = atof( pszCoordString );
            while( *pszCoordString != '\0'
                   && *pszCoordString != ','
                   && !isspace(*pszCoordString) )
                pszCoordString++;

            if( *pszCoordString == '\0' || isspace(*pszCoordString) )
            {
                CPLError( CE_Failure, CPLE_AppDefined, 
                          "Corrupt <coordinates> value." );
                return FALSE;
            }

            pszCoordString++;
            dfY = atof( pszCoordString );
            while( *pszCoordString != '\0' 
                   && *pszCoordString != ','
                   && !isspace(*pszCoordString) )
                pszCoordString++;

            if( *pszCoordString == ',' )
            {
                pszCoordString++;
                dfZ = atof( pszCoordString );
                nDimension = 3;
                while( *pszCoordString != '\0' 
                       && *pszCoordString != ','
                       && !isspace(*pszCoordString) )
                pszCoordString++;
            }

            while( isspace(*pszCoordString) )
                pszCoordString++;

            if( !AddPoint( poGeometry, dfX, dfY, dfZ, nDimension ) )
                return FALSE;

            iCoord++;
        }

        return iCoord > 0;
    }

/* -------------------------------------------------------------------- */
/*      Is this a "pos"?  I think this is a GML 3 construct.            */
/* -------------------------------------------------------------------- */
    CPLXMLNode *psPos = FindBareXMLChild( psGeomNode, "pos" );
    
    if( psPos != NULL )
    {
        char **papszTokens = CSLTokenizeStringComplex( 
            GetElementText( psPos ), " ,", FALSE, FALSE );
        int bSuccess = FALSE;

        if( CSLCount( papszTokens ) > 2 )
        {
            bSuccess = AddPoint( poGeometry, 
                                 atof(papszTokens[0]), 
                                 atof(papszTokens[1]),
                                 atof(papszTokens[2]), 3 );
        }
        else if( CSLCount( papszTokens ) > 1 )
        {
            bSuccess = AddPoint( poGeometry, 
                                 atof(papszTokens[0]), 
                                 atof(papszTokens[1]),
                                 0.0, 2 );
        }
        else
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "Did not get 2+ values in <gml:pos>%s</gml:pos> tuple.",
                      GetElementText( psPos ) );
        }

        CSLDestroy( papszTokens );

        return bSuccess;
    }
    

/* -------------------------------------------------------------------- */
/*      Handle form with a list of <coord> items each with an <X>,      */
/*      and <Y> element.                                                */
/* -------------------------------------------------------------------- */
    CPLXMLNode *psCoordNode;

    for( psCoordNode = psGeomNode->psChild; 
         psCoordNode != NULL;
         psCoordNode = psCoordNode->psNext )
    {
        if( psCoordNode->eType != CXT_Element 
            || !EQUAL(BareGMLElement(psCoordNode->pszValue),"coord") )
            continue;

        CPLXMLNode *psXNode, *psYNode, *psZNode;
        double dfX, dfY, dfZ = 0.0;
        int nDimension = 2;

        psXNode = FindBareXMLChild( psCoordNode, "X" );
        psYNode = FindBareXMLChild( psCoordNode, "Y" );
        psZNode = FindBareXMLChild( psCoordNode, "Z" );

        if( psXNode == NULL || psYNode == NULL 
            || GetElementText(psXNode) == NULL
            || GetElementText(psYNode) == NULL
            || (psZNode != NULL && GetElementText(psZNode) == NULL) )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Corrupt <coord> element, missing <X> or <Y> element?" );
            return FALSE;
        }

        dfX = atof( GetElementText(psXNode) );
        dfY = atof( GetElementText(psYNode) );

        if( psZNode != NULL && GetElementText(psZNode) != NULL )
        {
            dfZ = atof( GetElementText(psZNode) );
            nDimension = 3;
        }

        if( !AddPoint( poGeometry, dfX, dfY, dfZ, nDimension ) )
            return FALSE;

        iCoord++;
    }

    return iCoord > 0.0;
}