ogrspatialreference.cpp

在linux环境下

/******************************************************************************
 * $Id: ogrspatialreference.cpp,v 1.77 2003/06/19 17:10:26 warmerda 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 1.77  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()
 *
 * Revision 1.65  2002/12/21 17:29:38  warmerda
 * fixed default degree/radian problem for GEOGCS
 *
 * Revision 1.64  2002/12/16 17:08:44  warmerda
 * added GetPrimeMeridian() method, and fiddled with OGRPrintDouble
 *
 * Revision 1.63  2002/12/16 14:41:19  warmerda
 * implement normalized Get/Set ProjParm
 *
 * Revision 1.62  2002/12/15 23:42:59  warmerda
 * added initial support for normalizing proj params
 *
 * Revision 1.61  2002/12/14 22:59:14  warmerda
 * added Krovak in ESRI compatible way
 *
 * Revision 1.60  2002/12/10 04:06:00  warmerda
 * updated well known GEOGCS descriptions
 *
 * Revision 1.59  2002/12/09 16:11:32  warmerda
 * fixed constness of get authority calls
 *
 * Revision 1.58  2002/12/01 21:16:10  warmerda
 * added Get/set angular units methods
 *
 * Revision 1.57  2002/12/01 20:22:39  warmerda
 * preserve a little more precision in projection parameters
 *
 * Revision 1.56  2002/11/30 16:44:08  warmerda
 * fixed some functions that claimed to use node paths, so they work
 *
 * Revision 1.55  2002/11/30 15:45:49  warmerda
 * be more careful about how AUTHORITY is fetched, to not get wrong one
 *
 * Revision 1.54  2002/11/25 16:12:54  warmerda
 * added GetAuthorityCode/Name
 *
 * Revision 1.53  2002/07/25 15:58:02  warmerda
 * Fixed docs for how to compute inverse flattening.
 *
 * Revision 1.52  2002/07/25 13:13:36  warmerda
 * fixed const correctness of some docs
 *
 * Revision 1.51  2002/04/25 20:56:28  warmerda
 * expanded tabs
 *
 * Revision 1.50  2002/04/18 14:22:45  warmerda
 * made OGRSpatialReference and co 'const correct'
 *
 * Revision 1.49  2002/03/12 18:06:09  warmerda
 * added ESRI:: style support to SetFromUserInput()
 *
 * Revision 1.48  2002/03/08 16:38:11  warmerda
 * ensure SetProjParm() will replace an existing node if available
 *
 * Revision 1.47  2002/03/05 14:25:14  warmerda
 * expand tabs
 *
 * Revision 1.46  2002/02/18 15:46:02  warmerda
 * Fixed serious problems in IsSame() method.  Still a work in progress.
 *
 * Revision 1.45  2002/01/24 16:22:18  warmerda
 * reworked StripCTParms and simplify support for prettywkt
 *
 * Revision 1.44  2002/01/18 15:30:41  warmerda
 * ensure all AXIS nodes wiped in StripCTParms
 *
 * Revision 1.43  2002/01/18 04:51:05  warmerda
 * added PROJ.4 support to SetFromUserInput()
 */

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

CPL_CVSID("$Id: ogrspatialreference.cpp,v 1.77 2003/06/19 17:10:26 warmerda Exp $");

/************************************************************************/
/*                           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 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 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 )

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

/************************************************************************/
/*                         GetReferenceCount()                          */
/************************************************************************/

/**
 * \fn int OGRSpatialReference::GetReferenceCount() const;
 *
 * Fetch current reference count.
 *
 * @return the current reference count.
 */

/************************************************************************/
/*                              SetRoot()                               */
/************************************************************************/

/**
 * Set the root SRS node.
 *
 * If the object has an existing tree of OGR_SRSNodes, they are destroyed
 * as part of assigning the new root.  Ownership of the passed OGR_SRSNode is
 * is assumed by the OGRSpatialReference.
 *
 * @param poNewRoot object to assign as root.