ogrspatialreference.cpp

mitab,读取MapInfo的地图文件

const OGR_SRSNode *
OGRSpatialReference::GetAttrNode( const char * pszNodePath ) const

{
    OGR_SRSNode *poNode;

    poNode = ((OGRSpatialReference *) this)->GetAttrNode(pszNodePath);

    return poNode;
}

/************************************************************************/
/*                            GetAttrValue()                            */
/************************************************************************/

/**
 * Fetch indicated attribute of named node.
 *
 * This method uses GetAttrNode() to find the named node, and then extracts
 * the value of the indicated child.  Thus a call to GetAttrValue("UNIT",1)
 * would return the second child of the UNIT node, which is normally the
 * length of the linear unit in meters.
 *
 * This method does the same thing as the C function OSRGetAttrValue().
 *
 * @param pszNodeName the tree node to look for (case insensitive).
 * @param iAttr the child of the node to fetch (zero based).
 *
 * @return the requested value, or NULL if it fails for any reason. 
 */

const char *OGRSpatialReference::GetAttrValue( const char * pszNodeName,
                                               int iAttr ) const

{
    const OGR_SRSNode *poNode;

    poNode = GetAttrNode( pszNodeName );
    if( poNode == NULL )
        return NULL;

    if( iAttr < 0 || iAttr >= poNode->GetChildCount() )
        return NULL;

    return poNode->GetChild(iAttr)->GetValue();
}

/************************************************************************/
/*                          OSRGetAttrValue()                           */
/************************************************************************/

const char * CPL_STDCALL OSRGetAttrValue( OGRSpatialReferenceH hSRS,
                             const char * pszKey, int iChild )

{
    return ((OGRSpatialReference *) hSRS)->GetAttrValue( pszKey, iChild );
}

/************************************************************************/
/*                               Clone()                                */
/************************************************************************/

/**
 * Make a duplicate of this OGRSpatialReference.
 *
 * This method is the same as the C function OSRClone().
 *
 * @return a new SRS, which becomes the responsibility of the caller.
 */

OGRSpatialReference *OGRSpatialReference::Clone() const

{
    OGRSpatialReference *poNewRef;

    poNewRef = new OGRSpatialReference();

    if( poRoot != NULL )
        poNewRef->poRoot = poRoot->Clone();

    return poNewRef;
}

/************************************************************************/
/*                              OSRClone()                              */
/************************************************************************/

OGRSpatialReferenceH CPL_STDCALL OSRClone( OGRSpatialReferenceH hSRS )

{
    return (OGRSpatialReferenceH) ((OGRSpatialReference *) hSRS)->Clone();
}

/************************************************************************/
/*                         exportToPrettyWkt()                          */
/*                                                                      */
/*      Translate into a nicely formatted string for display to a       */
/*      person.                                                         */
/************************************************************************/

OGRErr OGRSpatialReference::exportToPrettyWkt( char ** ppszResult, 
                                               int bSimplify ) const

{
    if( poRoot == NULL )
    {
        *ppszResult = CPLStrdup("");
        return OGRERR_NONE;
    }

    if( bSimplify )
    {
        OGRSpatialReference *poSimpleClone = Clone();
        OGRErr eErr;

        poSimpleClone->GetRoot()->StripNodes( "AXIS" );
        poSimpleClone->GetRoot()->StripNodes( "AUTHORITY" );
        poSimpleClone->GetRoot()->StripNodes( "EXTENSION" );
        eErr = poSimpleClone->GetRoot()->exportToPrettyWkt( ppszResult, 1 );
        delete poSimpleClone;
        return eErr;
    }
    else
        return poRoot->exportToPrettyWkt( ppszResult, 1 );
}

/************************************************************************/
/*                        OSRExportToPrettyWkt()                        */
/************************************************************************/

OGRErr CPL_STDCALL OSRExportToPrettyWkt( OGRSpatialReferenceH hSRS, char ** ppszReturn,
                             int bSimplify)

{
    *ppszReturn = NULL;

    return ((OGRSpatialReference *) hSRS)->exportToPrettyWkt( ppszReturn,
                                                              bSimplify );
}

/************************************************************************/
/*                            exportToWkt()                             */
/************************************************************************/

/**
 * Convert this SRS into WKT format.
 *
 * Note that the returned WKT string should be freed with OGRFree() or
 * CPLFree() when no longer needed.  It is the responsibility of the caller.
 *
 * This method is the same as the C function OSRExportToWkt().
 *
 * @param ppszResult the resulting string is returned in this pointer.
 *
 * @return currently OGRERR_NONE is always returned, but the future it
 * is possible error conditions will develop. 
 */
 
OGRErr  OGRSpatialReference::exportToWkt( char ** ppszResult ) const

{
    if( poRoot == NULL )
    {
        *ppszResult = CPLStrdup("");
        return OGRERR_NONE;
    }
    else
    {
        return poRoot->exportToWkt(ppszResult);
    }
}

/************************************************************************/
/*                           OSRExportToWkt()                           */
/************************************************************************/

OGRErr CPL_STDCALL OSRExportToWkt( OGRSpatialReferenceH hSRS, char ** ppszReturn )

{
    *ppszReturn = NULL;

    return ((OGRSpatialReference *) hSRS)->exportToWkt( ppszReturn );
}

/************************************************************************/
/*                           importFromWkt()                            */
/************************************************************************/

/**
 * Import from WKT string.
 *
 * This method will wipe the existing SRS definition, and
 * reassign it based on the contents of the passed WKT string.  Only as
 * much of the input string as needed to construct this SRS is consumed from
 * the input string, and the input string pointer
 * is then updated to point to the remaining (unused) input.
 *
 * This method is the same as the C function OSRImportFromWkt().
 *
 * @param ppszInput Pointer to pointer to input.  The pointer is updated to
 * point to remaining unused input text.
 *
 * @return OGRERR_NONE if import succeeds, or OGRERR_CORRUPT_DATA if it
 * fails for any reason.
 */

OGRErr OGRSpatialReference::importFromWkt( char ** ppszInput )

{
    if( poRoot != NULL )
        delete poRoot;

    bNormInfoSet = FALSE;

    poRoot = new OGR_SRSNode();

    return poRoot->importFromWkt( ppszInput );
}

/************************************************************************/
/*                          OSRImportFromWkt()                          */
/************************************************************************/

OGRErr OSRImportFromWkt( OGRSpatialReferenceH hSRS, char **ppszInput )

{
    return ((OGRSpatialReference *) hSRS)->importFromWkt( ppszInput );
}

/************************************************************************/
/*                              SetNode()                               */
/************************************************************************/

/**
 * Set attribute value in spatial reference.
 *
 * Missing intermediate nodes in the path will be created if not already
 * in existance.  If the attribute has no children one will be created and
 * assigned the value otherwise the zeroth child will be assigned the value.
 *
 * This method does the same as the C function OSRSetAttrValue(). 
 *
 * @param pszNodePath full path to attribute to be set.  For instance
 * "PROJCS|GEOGCS|UNITS".
 * 
 * @param pszNewNodeValue value to be assigned to node, such as "meter". 
 * This may be NULL if you just want to force creation of the intermediate
 * path.
 *
 * @return OGRERR_NONE on success. 
 */

OGRErr OGRSpatialReference::SetNode( const char * pszNodePath,
                                     const char * pszNewNodeValue )

{
    char        **papszPathTokens;
    int         i;
    OGR_SRSNode *poNode;

    papszPathTokens = CSLTokenizeStringComplex(pszNodePath, "|", TRUE, FALSE);

    if( CSLCount( papszPathTokens ) < 1 )
        return OGRERR_FAILURE;

    if( GetRoot() == NULL || !EQUAL(papszPathTokens[0],GetRoot()->GetValue()) )
    {
        SetRoot( new OGR_SRSNode( papszPathTokens[0] ) );
    }

    poNode = GetRoot();
    for( i = 1; papszPathTokens[i] != NULL; i++ )
    {
        int     j;
        
        for( j = 0; j < poNode->GetChildCount(); j++ )
        {
            if( EQUAL(poNode->GetChild( j )->GetValue(),papszPathTokens[i]) )
            {
                poNode = poNode->GetChild(j);
                j = -1;
                break;
            }
        }

        if( j != -1 )
        {
            OGR_SRSNode *poNewNode = new OGR_SRSNode( papszPathTokens[i] );
            poNode->AddChild( poNewNode );
            poNode = poNewNode;
        }
    }

    CSLDestroy( papszPathTokens );

    if( pszNewNodeValue != NULL )
    {
        if( poNode->GetChildCount() > 0 )
            poNode->GetChild(0)->SetValue( pszNewNodeValue );
        else
            poNode->AddChild( new OGR_SRSNode( pszNewNodeValue ) );
    }

    return OGRERR_NONE;
}

/************************************************************************/
/*                          OSRSetAttrValue()                           */
/************************************************************************/

OGRErr CPL_STDCALL OSRSetAttrValue( OGRSpatialReferenceH hSRS, 
                        const char * pszPath, const char * pszValue )

{
    return ((OGRSpatialReference *) hSRS)->SetNode( pszPath, pszValue );
}

/************************************************************************/
/*                              SetNode()                               */
/************************************************************************/

OGRErr OGRSpatialReference::SetNode( const char *pszNodePath,
                                     double dfValue )

{
    char        szValue[64];

    if( ABS(dfValue - (int) dfValue) == 0.0 )
        sprintf( szValue, "%d", (int) dfValue );
    else
        // notdef: sprintf( szValue, "%.16g", dfValue );
        OGRPrintDouble( szValue, dfValue );

    return SetNode( pszNodePath, szValue );
}

/************************************************************************/
/*                          SetAngularUnits()                           */
/************************************************************************/

/**
 * Set the angular units for the geographic coordinate system.
 *
 * This method creates a UNITS subnode with the specified values as a
 * child of the GEOGCS node. 
 *
 * This method does the same as the C function OSRSetAngularUnits(). 
 *
 * @param pszUnitsName the units name to be used.  Some preferred units
 * names can be found in ogr_srs_api.h such as SRS_UA_DEGREE. 
 *
 * @param dfInRadians the value to multiple by an angle in the indicated
 * units to transform to radians.  Some standard conversion factors can
 * be found in ogr_srs_api.h. 
 *
 * @return OGRERR_NONE on success.
 */

OGRErr OGRSpatialReference::SetAngularUnits( const char * pszUnitsName,
                                             double dfInRadians )

{
    OGR_SRSNode *poCS;
    OGR_SRSNode *poUnits;
    char        szValue[128];