ogrpolygon.cpp

用于读取TAB、MIF、SHP文件的类

/******************************************************************************
 * $Id: ogrpolygon.cpp,v 1.42 2006/07/07 15:09:12 fwarmerdam Exp $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  The OGRPolygon 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: ogrpolygon.cpp,v $
 * Revision 1.42  2006/07/07 15:09:12  fwarmerdam
 * improve handling of empty linearrings and polygons in aggregates
 *
 * Revision 1.41  2006/07/07 00:05:46  mloskot
 * Removed GEOS C++ API usage from OGR and autotools.
 *
 * Revision 1.40  2006/06/19 23:19:45  mloskot
 * Added new functions OGRLinearRing::isPointInRing and OGRPolygon::IsPointOnSurface.
 *
 * Revision 1.39  2006/03/31 17:57:32  fwarmerdam
 * header updates
 *
 * Revision 1.38  2005/10/21 15:58:34  fwarmerdam
 * use c++ casting for GEOSGeom
 *
 * Revision 1.37  2005/10/21 03:56:52  fwarmerdam
 * Fixed up for only capi.
 *
 * Revision 1.36  2005/10/20 19:55:29  fwarmerdam
 * added GEOS C API support
 *
 * Revision 1.35  2005/07/22 19:30:25  fwarmerdam
 * Document get_Area().
 *
 * Revision 1.34  2005/07/20 02:34:09  fwarmerdam
 * maintain dimension better
 *
 * Revision 1.33  2005/07/20 01:43:51  fwarmerdam
 * upgraded OGR geometry dimension handling
 *
 * Revision 1.32  2005/07/12 17:34:00  fwarmerdam
 * updated to produce proper empty syntax and consume either
 *
 * Revision 1.31  2005/04/06 20:43:00  fwarmerdam
 * fixed a variety of method signatures for documentation
 *
 * Revision 1.30  2005/02/22 12:38:01  fwarmerdam
 * rename Equal/Intersect to Equals/Intersects
 *
 * Revision 1.29  2004/10/04 21:06:46  fwarmerdam
 * added centroid support
 *
 * Revision 1.28  2004/09/17 15:05:36  fwarmerdam
 * added get_Area() support
 *
 * Revision 1.27  2004/07/10 04:51:42  warmerda
 * added closeRings
 *
 * Revision 1.26  2004/02/22 09:56:54  dron
 * Fix compirison casting problems in OGRPolygon::Equal().
 *
 * Revision 1.25  2004/02/21 15:36:14  warmerda
 * const correctness updates for geometry: bug 289
 *
 * Revision 1.24  2004/01/16 21:57:17  warmerda
 * fixed up EMPTY support
 *
 * Revision 1.23  2004/01/16 21:20:00  warmerda
 * Added EMPTY support
 *
 * Revision 1.22  2003/08/27 15:40:37  warmerda
 * added support for generating DB2 V7.2 compatible WKB
 *
 * Revision 1.21  2003/06/09 13:48:54  warmerda
 * added DB2 V7.2 byte order hack
 *
 * Revision 1.20  2003/05/28 19:16:43  warmerda
 * fixed up argument names and stuff for docs
 *
 * Revision 1.19  2003/03/07 21:28:56  warmerda
 * support 0x8000 style 3D WKB flags
 *
 * Revision 1.18  2002/09/11 13:47:17  warmerda
 * preliminary set of fixes for 3D WKB enum
 *
 * Revision 1.17  2002/05/02 19:44:53  warmerda
 * fixed 3D binary support for polygon/linearring
 *
 * Revision 1.16  2002/03/05 14:25:14  warmerda
 * expand tabs
 *
 * Revision 1.15  2001/11/01 17:20:33  warmerda
 * added DISABLE_OGRGEOM_TRANSFORM macro
 *
 * Revision 1.14  2001/09/21 16:24:20  warmerda
 * added transform() and transformTo() methods
 *
 * Revision 1.13  2001/07/18 05:03:05  warmerda
 * added CPL_CVSID
 *
 * Revision 1.12  1999/11/18 19:02:19  warmerda
 * expanded tabs
 *
 * Revision 1.11  1999/09/22 13:18:55  warmerda
 * Added the addRingDirectly() method.
 *
 * Revision 1.10  1999/09/13 02:27:33  warmerda
 * incorporated limited 2.5d support
 *
 * Revision 1.9  1999/07/27 00:48:12  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 20:43:55  warmerda
 * added empty() method
 *
 * Revision 1.5  1999/05/31 14:59:06  warmerda
 * added documentation
 *
 * Revision 1.4  1999/05/23 05:34:41  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  1999/05/17 14:38:11  warmerda
 * Added new IPolygon style methods.
 *
 * Revision 1.1  1999/03/30 21:21:05  warmerda
 * New
 *
 */

#include "ogr_geometry.h"
#include "ogr_p.h"
#include "ogr_geos.h"
#include "ogr_api.h"

CPL_CVSID("$Id: ogrpolygon.cpp,v 1.42 2006/07/07 15:09:12 fwarmerdam Exp $");

/************************************************************************/
/*                             OGRPolygon()                             */
/************************************************************************/

/**
 * Create an empty polygon.
 */

OGRPolygon::OGRPolygon()

{
    nRingCount = 0;
    papoRings = NULL;
}

/************************************************************************/
/*                            ~OGRPolygon()                             */
/************************************************************************/

OGRPolygon::~OGRPolygon()

{
    empty();
}

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

OGRGeometry *OGRPolygon::clone() const

{
    OGRPolygon  *poNewPolygon;

    poNewPolygon = new OGRPolygon;
    poNewPolygon->assignSpatialReference( getSpatialReference() );

    for( int i = 0; i < nRingCount; i++ )
    {
        poNewPolygon->addRing( papoRings[i] );
    }

    return poNewPolygon;
}

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

void OGRPolygon::empty()

{
    if( papoRings != NULL )
    {
        for( int i = 0; i < nRingCount; i++ )
        {
            delete papoRings[i];
        }
        OGRFree( papoRings );
    }

    papoRings = NULL;
    nRingCount = 0;
}

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

OGRwkbGeometryType OGRPolygon::getGeometryType() const

{
    if( getCoordinateDimension() == 3 )
        return wkbPolygon25D;
    else
        return wkbPolygon;
}

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

int OGRPolygon::getDimension() const

{
    return 2;
}

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

void OGRPolygon::flattenTo2D()

{
    for( int iRing = 0; iRing < nRingCount; iRing++ )
        papoRings[iRing]->flattenTo2D();
}

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

const char * OGRPolygon::getGeometryName() const

{
    return "POLYGON";
}

/************************************************************************/
/*                          getExteriorRing()                           */
/************************************************************************/

/**
 * Fetch reference to external polygon ring.
 *
 * Note that the returned ring pointer is to an internal data object of
 * the OGRPolygon.  It should not be modified or deleted by the application,
 * and the pointer is only valid till the polygon is next modified.  Use
 * the OGRGeometry::clone() method to make a separate copy within the
 * application.
 *
 * Relates to the SFCOM IPolygon::get_ExteriorRing() method.
 *
 * @return pointer to external ring.  May be NULL if the OGRPolygon is empty.
 */

OGRLinearRing *OGRPolygon::getExteriorRing()

{
    if( nRingCount > 0 )
        return papoRings[0];
    else
        return NULL;
}

const OGRLinearRing *OGRPolygon::getExteriorRing() const

{
    if( nRingCount > 0 )
        return papoRings[0];
    else
        return NULL;
}

/************************************************************************/
/*                        getNumInteriorRings()                         */
/************************************************************************/

/**
 * Fetch the number of internal rings.
 *
 * Relates to the SFCOM IPolygon::get_NumInteriorRings() method.
 *
 * @return count of internal rings, zero or more.
 */


int OGRPolygon::getNumInteriorRings() const

{
    if( nRingCount > 0 )
        return nRingCount-1;
    else
        return 0;
}

/************************************************************************/
/*                          getInteriorRing()                           */
/************************************************************************/

/**
 * Fetch reference to indicated internal ring.
 *
 * Note that the returned ring pointer is to an internal data object of
 * the OGRPolygon.  It should not be modified or deleted by the application,
 * and the pointer is only valid till the polygon is next modified.  Use
 * the OGRGeometry::clone() method to make a separate copy within the
 * application.
 *
 * Relates to the SFCOM IPolygon::get_InternalRing() method.
 *
 * @param iRing internal ring index from 0 to getNumInternalRings() - 1.
 *
 * @return pointer to external ring.  May be NULL if the OGRPolygon is empty.
 */

OGRLinearRing *OGRPolygon::getInteriorRing( int iRing )

{
    if( iRing < 0 || iRing >= nRingCount-1 )
        return NULL;
    else
        return papoRings[iRing+1];
}

const OGRLinearRing *OGRPolygon::getInteriorRing( int iRing ) const

{
    if( iRing < 0 || iRing >= nRingCount-1 )
        return NULL;
    else
        return papoRings[iRing+1];
}