ogrspatialreference.cpp

用于读取TAB、MIF、SHP文件的类

/******************************************************************************
 * $Id: ogrspatialreference.cpp,v 1.104 2006/12/18 16:22:51 fwarmerdam Exp $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  The OGRSpatialReference class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 1999,  Les Technologies SoftMap Inc.
 *
 * 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: ogrspatialreference.cpp,v $
 * Revision 1.104  2006/12/18 16:22:51  fwarmerdam
 * added support for x-ogc as well as ogc namespace
 *
 * Revision 1.103  2006/11/30 17:48:32  fwarmerdam
 * Avoid uninitialized variable warning.
 *
 * Revision 1.102  2006/11/24 17:58:15  fwarmerdam
 * added extension management methods
 *
 * Revision 1.101  2006/11/21 21:25:27  fwarmerdam
 * Applied ESRI:: modifier to dictionary lookups if requested.
 *
 * Revision 1.100  2006/11/07 18:55:07  fwarmerdam
 * added OGC importFromURN()
 *
 * Revision 1.99  2006/10/14 01:31:14  fwarmerdam
 * NULL target for GetAuthorityName/Code now returns for the root node.
 *
 * Revision 1.98  2005/12/20 02:08:07  fwarmerdam
 * UTM should default to a linear units of meter.
 *
 * Revision 1.97  2005/12/01 04:59:46  fwarmerdam
 * added two point equidistant support
 *
 * Revision 1.96  2005/10/16 01:32:41  fwarmerdam
 * Apply epsilon testing to UTM zone false easting and northing.
 *
 * Revision 1.95  2005/09/21 03:00:42  fwarmerdam
 * fixed return for Release
 *
 * Revision 1.94  2005/09/21 00:51:27  fwarmerdam
 * added Release
 *
 * Revision 1.93  2005/04/06 00:02:05  fwarmerdam
 * various osr and oct functions now stdcall
 *
 * Revision 1.92  2005/03/03 04:55:42  fwarmerdam
 * make exportToWkt() const
 *
 * Revision 1.91  2005/02/11 14:21:28  fwarmerdam
 * added GEOS projection support
 *
 * Revision 1.90  2005/01/13 05:17:37  fwarmerdam
 * added SetLinearUnitsAndUpdateParameters
 *
 * Revision 1.89  2005/01/05 21:02:33  fwarmerdam
 * added Goode Homolosine
 *
 * Revision 1.88  2004/11/11 18:28:45  fwarmerdam
 * added Bonne projection support
 *
 * Revision 1.87  2004/09/23 16:20:13  fwarmerdam
 * added OSRCleanup
 *
 * Revision 1.86  2004/09/10 20:59:06  fwarmerdam
 * Added note on SetSOC() being deprecated.
 *
 * Revision 1.85  2004/05/06 19:26:04  dron
 * Added OSRSetProjection() function.
 *
 * Revision 1.84  2004/05/04 17:54:45  warmerda
 * internal longitude format is greenwich relative - no adjustments needed
 *
 * Revision 1.83  2004/03/04 18:04:45  warmerda
 * added importFromDict() support
 *
 * Revision 1.82  2004/02/05 17:07:59  dron
 * Support for HOM projection, specified by two points on centerline.
 *
 * Revision 1.81  2003/12/05 16:22:49  warmerda
 * optimized IsProjected
 *
 * Revision 1.80  2003/10/07 04:20:50  warmerda
 * added WMS AUTO: support
 *
 * Revision 1.79  2003/09/18 14:43:40  warmerda
 * Ensure that SetAuthority() clears old nodes.
 * Don't crash on NULL root in exportToPrettyWkt().
 *
 * Revision 1.78  2003/08/18 13:26:01  warmerda
 * added SetTMVariant() and related definitions
 *
 * Revision 1.77  2003/06/19 17:10:26  warmerda
 * a couple fixes in last commit
 *
 * Revision 1.76  2003/06/18 18:24:17  warmerda
 * added projection specific set methods to C API
 *
 * Revision 1.75  2003/05/30 18:34:41  warmerda
 * clear existing authority node in SetLinearUnits if one exists
 *
 * Revision 1.74  2003/05/28 19:16:43  warmerda
 * fixed up argument names and stuff for docs
 *
 * Revision 1.73  2003/04/01 14:34:45  warmerda
 * Clarify SetUTM() documentation.
 *
 * Revision 1.72  2003/03/28 17:42:05  warmerda
 * fixed reference/dereference problem
 *
 * Revision 1.71  2003/02/25 04:55:41  warmerda
 * Added SetGeogCSFrom() method. Modified SetWellKnownGeogCS() to use it.
 * Modfied SetGeogCS() to replace an existing GEOGCS node if there is one.
 *
 * Revision 1.70  2003/02/14 22:15:04  warmerda
 * expand tabs
 *
 * Revision 1.69  2003/02/08 00:37:15  warmerda
 * try to improve documentation
 *
 * Revision 1.68  2003/02/06 04:53:12  warmerda
 * added Fixup() method
 *
 * Revision 1.67  2003/01/31 02:27:08  warmerda
 * modified SetFromUserInput() to avoid large buffer on stack
 *
 * Revision 1.66  2003/01/08 18:14:28  warmerda
 * added FixupOrdering()
 */

#include "ogr_spatialref.h"
#include "ogr_p.h"
#include "cpl_csv.h"

CPL_CVSID("$Id: ogrspatialreference.cpp,v 1.104 2006/12/18 16:22:51 fwarmerdam Exp $");

// The current opinion is that WKT longitudes like central meridian
// should be relative to greenwich, not the prime meridian in use. 
// Define the following if they should be relative to the prime meridian
// of then geogcs.
#undef WKT_LONGITUDE_RELATIVE_TO_PM

/************************************************************************/
/*                           OGRPrintDouble()                           */
/************************************************************************/

static void OGRPrintDouble( char * pszStrBuf, double dfValue )

{
    sprintf( pszStrBuf, "%.16g", dfValue );

    int nLen = strlen(pszStrBuf);

    // The following hack is intended to truncate some "precision" in cases
    // that appear to be roundoff error. 
    if( nLen > 15 
        && (strcmp(pszStrBuf+nLen-6,"999999") == 0
            || strcmp(pszStrBuf+nLen-6,"000001") == 0) )
    {
        sprintf( pszStrBuf, "%.15g", dfValue );
    }
}

/************************************************************************/
/*                        OGRSpatialReference()                         */
/************************************************************************/

/**
 * Constructor.
 *
 * This constructor takes an optional string argument which if passed
 * should be a WKT representation of an SRS.  Passing this is equivelent
 * to not passing it, and then calling importFromWkt() with the WKT string.
 *
 * Note that newly created objects are given a reference count of one. 
 *
 * The C function OSRNewSpatialReference() does the same thing as this
 * constructor. 
 *
 * @param pszWKT well known text definition to which the object should
 * be initialized, or NULL (the default). 
 */

OGRSpatialReference::OGRSpatialReference( const char * pszWKT )

{
    bNormInfoSet = FALSE;
    nRefCount = 1;
    poRoot = NULL;

    if( pszWKT != NULL )
        importFromWkt( (char **) &pszWKT );
}

/************************************************************************/
/*                       OSRNewSpatialReference()                       */
/************************************************************************/

OGRSpatialReferenceH CPL_STDCALL OSRNewSpatialReference( const char *pszWKT )

{
    OGRSpatialReference * poSRS;

    poSRS = new OGRSpatialReference();

    if( pszWKT != NULL && strlen(pszWKT) > 0 )
    {
        if( poSRS->importFromWkt( (char **) (&pszWKT) ) != OGRERR_NONE )
        {
            delete poSRS;
            poSRS = NULL;
        }
    }

    return poSRS;
}

/************************************************************************/
/*                        OGRSpatialReference()                         */
/*                                                                      */
/*      Simple copy constructor.  See also Clone().                     */
/************************************************************************/

OGRSpatialReference::OGRSpatialReference(const OGRSpatialReference &oOther)

{
    bNormInfoSet = FALSE;
    nRefCount = 1;
    poRoot = NULL;

    if( oOther.poRoot != NULL )
        poRoot = oOther.poRoot->Clone();
}

/************************************************************************/
/*                        ~OGRSpatialReference()                        */
/************************************************************************/

/**
 * OGRSpatialReference destructor. 
 *
 * The C function OSRDestroySpatialReference() does the same thing as this
 * method. 
 */

OGRSpatialReference::~OGRSpatialReference()

{
    if( poRoot != NULL )
        delete poRoot;
}

/************************************************************************/
/*                     OSRDestroySpatialReference()                     */
/************************************************************************/

void CPL_STDCALL OSRDestroySpatialReference( OGRSpatialReferenceH hSRS )

{
    delete ((OGRSpatialReference *) hSRS);
}

/************************************************************************/
/*                               Clear()                                */
/************************************************************************/

/**
 * Wipe current definition.
 *
 * Returns OGRSpatialReference to a state with no definition, as it 
 * exists when first created.  It does not affect reference counts.
 */

void OGRSpatialReference::Clear()

{
    if( poRoot )
        delete poRoot;

    poRoot = NULL;
}

/************************************************************************/
/*                             operator=()                              */
/************************************************************************/

OGRSpatialReference &
OGRSpatialReference::operator=(const OGRSpatialReference &oSource)

{
    if( poRoot != NULL )
    {
        delete poRoot;
        poRoot = NULL;
    }
    
    if( oSource.poRoot != NULL )
        poRoot = oSource.poRoot->Clone();

    return *this;
}

/************************************************************************/
/*                             Reference()                              */
/************************************************************************/

/**
 * Increments the reference count by one.
 *
 * The reference count is used keep track of the number of OGRGeometry objects
 * referencing this SRS.
 *
 * The method does the same thing as the C function OSRReference(). 
 *
 * @return the updated reference count.
 */

int OGRSpatialReference::Reference()

{
    return ++nRefCount;
}

/************************************************************************/
/*                            OSRReference()                            */
/************************************************************************/

int OSRReference( OGRSpatialReferenceH hSRS )

{
    return ((OGRSpatialReference *) hSRS)->Reference();
}

/************************************************************************/
/*                            Dereference()                             */
/************************************************************************/

/**
 * Decrements the reference count by one.
 *
 * The method does the same thing as the C function OSRDereference(). 
 *
 * @return the updated reference count.
 */

int OGRSpatialReference::Dereference()

{
    return --nRefCount;
}

/************************************************************************/
/*                           OSRDereference()                           */
/************************************************************************/

int OSRDereference( OGRSpatialReferenceH hSRS )