ogrlinestring.cpp

在linux环境下

/******************************************************************************
 * $Id: ogrlinestring.cpp,v 1.38 2003/06/09 13:48:54 warmerda Exp $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  The OGRLineString geometry class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 1999, 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.
 ******************************************************************************
 *
 * $Log: ogrlinestring.cpp,v $
 * Revision 1.38  2003/06/09 13:48:54  warmerda
 * added DB2 V7.2 byte order hack
 *
 * Revision 1.37  2003/05/28 19:16:43  warmerda
 * fixed up argument names and stuff for docs
 *
 * Revision 1.36  2003/03/07 21:28:56  warmerda
 * support 0x8000 style 3D WKB flags
 *
 * Revision 1.35  2003/01/06 17:43:13  warmerda
 * fixed buffer sizing problem for 3D geometries
 *
 * Revision 1.34  2003/01/06 16:18:40  warmerda
 * getEnvlope() crash fix if there are no points
 *
 * Revision 1.33  2002/09/11 13:47:17  warmerda
 * preliminary set of fixes for 3D WKB enum
 *
 * Revision 1.32  2002/08/19 14:11:35  warmerda
 * correct second setPoints() method properly.
 *
 * Revision 1.31  2002/08/19 03:24:51  warmerda
 * Fixed serious bug with 3D points in setPoints() methods.
 *
 * Revision 1.30  2002/07/15 13:31:07  warmerda
 * patch from Graeme for exportToWkb() with swapping code
 *
 * Revision 1.29  2002/05/02 19:45:36  warmerda
 * added flattenTo2D() method
 *
 * Revision 1.28  2002/04/17 21:43:09  warmerda
 * Free z array in descructor.
 *
 * Revision 1.27  2002/04/08 17:50:09  warmerda
 * Ensure Equal operator tests first vertex too.
 *
 * Revision 1.26  2002/03/05 14:25:14  warmerda
 * expand tabs
 *
 * Revision 1.25  2002/02/22 22:24:08  warmerda
 * clarify setPoints code
 *
 * Revision 1.24  2001/11/14 14:44:06  warmerda
 * fixed problem with WKT translation
 *
 * Revision 1.23  2001/11/01 17:20:33  warmerda
 * added DISABLE_OGRGEOM_TRANSFORM macro
 *
 * Revision 1.22  2001/11/01 17:01:28  warmerda
 * pass output buffer into OGRMakeWktCoordinate
 *
 * Revision 1.21  2001/09/21 16:24:20  warmerda
 * added transform() and transformTo() methods
 *
 * Revision 1.20  2001/07/19 18:25:07  warmerda
 * expanded tabs
 *
 * Revision 1.19  2001/07/18 05:03:05  warmerda
 * added CPL_CVSID
 *
 * Revision 1.18  2001/05/24 18:06:06  warmerda
 * fixed comment
 *
 * Revision 1.17  2001/01/19 21:10:47  warmerda
 * replaced tabs
 *
 * Revision 1.16  2000/01/26 21:20:47  warmerda
 * fixed crash assigning 2D points when already 3D
 *
 * Revision 1.15  1999/12/23 14:47:16  warmerda
 * improved 2D/3D handling to avoid 3D unless padfZ != 0.0
 *
 * Revision 1.14  1999/11/18 19:02:19  warmerda
 * expanded tabs
 *
 * Revision 1.13  1999/11/17 19:38:22  warmerda
 * Further performance tweaks to exportToWkt().
 *
 * Revision 1.12  1999/11/04 18:31:32  warmerda
 * Improved efficiency of exportToWkt() for large line strings.
 *
 * Revision 1.11  1999/09/13 14:34:07  warmerda
 * updated to use wkbZ of 0x8000 instead of 0x80000000
 *
 * Revision 1.10  1999/09/13 02:27:33  warmerda
 * incorporated limited 2.5d support
 *
 * Revision 1.9  1999/07/27 00:48:11  warmerda
 * Added Equal() support
 *
 * Revision 1.8  1999/07/06 21:36:47  warmerda
 * tenatively added getEnvelope() and Intersect()
 *
 * Revision 1.7  1999/06/25 20:44:43  warmerda
 * implemented assignSpatialReference, carry properly
 *
 * Revision 1.6  1999/05/31 20:43:34  warmerda
 * added empty(), and another setPoints()
 *
 * Revision 1.5  1999/05/31 15:01:59  warmerda
 * OGRCurve now an abstract base class with essentially no implementation.
 * Everything moved down to OGRLineString where it belongs.  Also documented
 * classes.
 *
 * Revision 1.4  1999/05/23 05:34:40  warmerda
 * added support for clone(), multipolygons and geometry collections
 *
 * Revision 1.3  1999/05/20 14:35:44  warmerda
 * added support for well known text format
 *
 * Revision 1.2  1999/03/30 21:21:43  warmerda
 * added linearring/polygon support
 *
 * Revision 1.1  1999/03/29 21:21:10  warmerda
 * New
 *
 */

#include "ogr_geometry.h"
#include "ogr_p.h"
#include <assert.h>

CPL_CVSID("$Id: ogrlinestring.cpp,v 1.38 2003/06/09 13:48:54 warmerda Exp $");

/************************************************************************/
/*                           OGRLineString()                            */
/************************************************************************/

/**
 * Create an empty line string.
 */

OGRLineString::OGRLineString()

{
    nPointCount = 0;
    paoPoints = NULL;
    padfZ = NULL;
}

/************************************************************************/
/*                           ~OGRLineString()                           */
/************************************************************************/

OGRLineString::~OGRLineString()

{
    if( paoPoints != NULL )
        OGRFree( paoPoints );
    if( padfZ != NULL )
        OGRFree( padfZ );
}

/************************************************************************/
/*                          getGeometryType()                           */
/************************************************************************/

OGRwkbGeometryType OGRLineString::getGeometryType()

{
    if( getCoordinateDimension() == 3 )
        return wkbLineString25D;
    else
        return wkbLineString;
}

/************************************************************************/
/*                            flattenTo2D()                             */
/************************************************************************/

void OGRLineString::flattenTo2D()

{
    Make2D();
}

/************************************************************************/
/*                          getGeometryName()                           */
/************************************************************************/

const char * OGRLineString::getGeometryName()

{
    return "LINESTRING";
}

/************************************************************************/
/*                               clone()                                */
/************************************************************************/

OGRGeometry *OGRLineString::clone()

{
    OGRLineString       *poNewLineString;

    poNewLineString = new OGRLineString();

    poNewLineString->assignSpatialReference( getSpatialReference() );
    poNewLineString->setPoints( nPointCount, paoPoints, padfZ );

    // notdef: not 3D

    return poNewLineString;
}

/************************************************************************/
/*                               empty()                                */
/************************************************************************/

void OGRLineString::empty()

{
    setNumPoints( 0 );
}


/************************************************************************/
/*                            getDimension()                            */
/************************************************************************/

int OGRLineString::getDimension()

{
    return 1;
}

/************************************************************************/
/*                       getCoordinateDimension()                       */
/************************************************************************/

int OGRLineString::getCoordinateDimension()

{
    if( padfZ != NULL )
        return 3;
    else
        return 2;
}

/************************************************************************/
/*                              WkbSize()                               */
/*                                                                      */
/*      Return the size of this object in well known binary             */
/*      representation including the byte order, and type information.  */
/************************************************************************/

int OGRLineString::WkbSize()

{
    return 5 + 4 + 8 * nPointCount * getCoordinateDimension();
}

/************************************************************************/
/*                               Make2D()                               */
/************************************************************************/

void OGRLineString::Make2D()

{
    if( padfZ != NULL )
    {
        OGRFree( padfZ );
        padfZ = NULL;
    }
}

/************************************************************************/
/*                               Make3D()                               */
/************************************************************************/

void OGRLineString::Make3D()

{
    if( padfZ == NULL )
    {
        if( nPointCount == 0 )
            padfZ = (double *) OGRCalloc(sizeof(double),1);
        else
            padfZ = (double *) OGRCalloc(sizeof(double),nPointCount);
    }
}

/************************************************************************/
/*                              getPoint()                              */
/************************************************************************/

/**
 * Fetch a point in line string.
 *
 * This method relates to the SFCOM ILineString::get_Point() method.
 *
 * @param i the vertex to fetch, from 0 to getNumPoints()-1.
 * @param poPoint a point to initialize with the fetched point.
 */

void    OGRLineString::getPoint( int i, OGRPoint * poPoint )

{
    assert( i >= 0 );
    assert( i < nPointCount );
    assert( poPoint != NULL );

    poPoint->setX( paoPoints[i].x );
    poPoint->setY( paoPoints[i].y );

    if( getCoordinateDimension() == 3 )
        poPoint->setZ( padfZ[i] );
}

/************************************************************************/
/*                                getZ()                                */
/************************************************************************/

double OGRLineString::getZ( int i )

{
    if( padfZ != NULL && i >= 0 && i < nPointCount )
        return( padfZ[i] );
    else
        return 0.0;
}

/************************************************************************/
/*                            setNumPoints()                            */
/************************************************************************/

/**
 * Set number of points in geometry.
 *
 * This method primary exists to preset the number of points in a linestring
 * geometry before setPoint() is used to assign them to avoid reallocating
 * the array larger with each call to addPoint(). 
 *
 * This method has no SFCOM analog.
 *
 * @param nNewPointCount the new number of points for geometry.
 */

void OGRLineString::setNumPoints( int nNewPointCount )