ogr_srs_proj4.cpp

用于读取TAB、MIF、SHP文件的类

          case '\t':
          case '\n':
            pszFullWrk[i] = '\0';
            break;

          default:
            break;
        }
    }

    if( pszStart != NULL && strlen(pszStart) > 0 )
        papszTokens = CSLAddString( papszTokens, pszStart );

    CPLFree( pszFullWrk );

    return papszTokens;
}


/************************************************************************/
/*                         OSRImportFromProj4()                         */
/************************************************************************/

OGRErr OSRImportFromProj4( OGRSpatialReferenceH hSRS, const char *pszProj4 )

{
    return ((OGRSpatialReference *) hSRS)->importFromProj4( pszProj4 );
}

/************************************************************************/
/*                              OSR_GDV()                               */
/*                                                                      */
/*      Fetch a particular parameter out of the parameter list, or      */
/*      the indicated default if it isn't available.  This is a         */
/*      helper function for importFromProj4().                          */
/************************************************************************/

static double OSR_GDV( char **papszNV, const char * pszField, 
                       double dfDefaultValue )

{
    const char * pszValue;

    pszValue = CSLFetchNameValue( papszNV, pszField );

    // special hack to use k_0 if available.
    if( pszValue == NULL && EQUAL(pszField,"k") )
        pszValue = CSLFetchNameValue( papszNV, "k_0" );

    if( pszValue == NULL )
        return dfDefaultValue;
    else
        return CPLDMSToDec(pszValue);
}

/************************************************************************/
/*                          importFromProj4()                           */
/************************************************************************/

/**
 * Import PROJ.4 coordinate string.
 *
 * The OGRSpatialReference is initialized from the passed PROJ.4 style
 * coordinate system string.  In addition to many +proj formulations which
 * have OGC equivelents, it is also possible to import "+init=epsg:n" style
 * definitions.  These are passed to importFromEPSG().  Other init strings
 * (such as the state plane zones) are not currently supported.   
 *
 * Example:
 *   pszProj4 = "+proj=utm +zone=11 +datum=WGS84" 
 *
 * This method is the equivelent of the C function OSRImportFromProj4().
 *
 * @param pszProj4 the PROJ.4 style string. 
 *
 * @return OGRERR_NONE on success or OGRERR_CORRUPT_DATA on failure.
 */

OGRErr OGRSpatialReference::importFromProj4( const char * pszProj4 )

{
    char **papszNV = NULL;
    char **papszTokens;
    int  i;
    char *pszCleanCopy;

/* -------------------------------------------------------------------- */
/*      Strip any newlines or other "funny" stuff that might occur      */
/*      if this string just came from reading a file.                   */
/* -------------------------------------------------------------------- */
    pszCleanCopy = CPLStrdup( pszProj4 );
    for( i = 0; pszCleanCopy[i] != '\0'; i++ )
    {
        if( pszCleanCopy[i] == 10 
            || pszCleanCopy[i] == 13 
            || pszCleanCopy[i] == 9 )
            pszCleanCopy[i] = ' ';
    }

/* -------------------------------------------------------------------- */
/*      Try to normalize the definition.  This should expand +init=     */
/*      clauses and so forth.                                           */
/* -------------------------------------------------------------------- */
    char *pszNormalized;

    pszNormalized = OCTProj4Normalize( pszCleanCopy );
    CPLFree( pszCleanCopy );
    
/* -------------------------------------------------------------------- */
/*      If we have an EPSG based init string, try to process it         */
/*      directly to get the fullest possible EPSG definition.           */
/* -------------------------------------------------------------------- */
    if( strstr(pszNormalized,"init=epsg:") != NULL )
    {
        OGRErr eErr;
        const char *pszNumber = strstr(pszNormalized,"init=epsg:") + 10;

        eErr = importFromEPSG( atoi(pszNumber) );
        if( eErr == OGRERR_NONE )
        {
            CPLFree( pszNormalized );
            return eErr;
        }
    }

/* -------------------------------------------------------------------- */
/*      Parse the PROJ.4 string into a cpl_string.h style name/value    */
/*      list.                                                           */
/* -------------------------------------------------------------------- */
    papszTokens = OSRProj4Tokenize( pszNormalized );
    CPLFree( pszNormalized );
    
    for( i = 0; papszTokens != NULL && papszTokens[i] != NULL; i++ )
    {
        char *pszEqual = strstr(papszTokens[i],"=");

        if( pszEqual == NULL )
            papszNV = CSLAddNameValue(papszNV, papszTokens[i], "" );
        else
        {
            pszEqual[0] = '\0';
            papszNV = CSLAddNameValue( papszNV, papszTokens[i], pszEqual+1 );
        }
    }

    CSLDestroy( papszTokens );

/* -------------------------------------------------------------------- */
/*      Extract the prime meridian, if there is one set.                */
/* -------------------------------------------------------------------- */
    const char *pszPM = CSLFetchNameValue( papszNV, "pm" );
    double dfFromGreenwich = 0.0;
    int    nPMCode = -1;

    if( pszPM != NULL )
    {
        if( EQUAL(pszPM,"lisbon") )
        {
            dfFromGreenwich = CPLDMSToDec( "9d07'54.862\"W" );
            nPMCode = 8902;
        }
        else if( EQUAL(pszPM,"paris") )
        {
            dfFromGreenwich = CPLDMSToDec( "2d20'14.025\"E" );
            nPMCode = 8903;
        }
        else if( EQUAL(pszPM,"bogota") )
        {
            dfFromGreenwich = CPLDMSToDec( "74d04'51.3\"W" );
            nPMCode = 8904;
        }
        else if( EQUAL(pszPM,"madrid") )
        {
            dfFromGreenwich = CPLDMSToDec( "3d41'16.48\"W" );
            nPMCode = 8905;
        }
        else if( EQUAL(pszPM,"rome") )
        {
            dfFromGreenwich = CPLDMSToDec( "12d27'8.4\"E" );
            nPMCode = 8906;
        }
        else if( EQUAL(pszPM,"bern") )
        {
            dfFromGreenwich = CPLDMSToDec( "7d26'22.5\"E" );
            nPMCode = 8907;
        }
        else if( EQUAL(pszPM,"jakarta") )
        {
            dfFromGreenwich = CPLDMSToDec( "106d48'27.79\"E" );
            nPMCode = 8908;
        }
        else if( EQUAL(pszPM,"ferro") )
        {
            dfFromGreenwich = CPLDMSToDec( "17d40'W" );
            nPMCode = 8909;
        }
        else if( EQUAL(pszPM,"brussels") )
        {
            dfFromGreenwich = CPLDMSToDec( "4d22'4.71\"E" );
            nPMCode = 8910;
        }
        else if( EQUAL(pszPM,"stockholm") )
        {
            dfFromGreenwich = CPLDMSToDec( "18d3'29.8\"E" );
            nPMCode = 8911;
        }
        else if( EQUAL(pszPM,"athens") )
        {
            dfFromGreenwich = CPLDMSToDec( "23d42'58.815\"E" );
            nPMCode = 8912;
        }
        else if( EQUAL(pszPM,"oslo") )
        {
            dfFromGreenwich = CPLDMSToDec( "10d43'22.5\"E" );
            nPMCode = 8913;
        }
        else
        {
            dfFromGreenwich = CPLDMSToDec( pszPM );
            pszPM = "unnamed";
        }
    }
    else
        pszPM = "Greenwich";

/* -------------------------------------------------------------------- */
/*      Operate on the basis of the projection name.                    */
/* -------------------------------------------------------------------- */
    const char *pszProj = CSLFetchNameValue(papszNV,"proj");

    if( pszProj == NULL )
    {
        CPLDebug( "OGR_PROJ4", "Can't find +proj= in:\n%s", pszProj4 );
        CSLDestroy( papszNV );
        return OGRERR_CORRUPT_DATA;
    }

    else if( EQUAL(pszProj,"longlat") || EQUAL(pszProj,"latlong") )
    {
    }
    
    else if( EQUAL(pszProj,"bonne") )
    {
        SetBonne( OSR_GDV( papszNV, "lat_1", 0.0 ), 
                  OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
                  OSR_GDV( papszNV, "x_0", 0.0 ), 
                  OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"cass") )
    {
        SetCS( OSR_GDV( papszNV, "lat_0", 0.0 ), 
               OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
               OSR_GDV( papszNV, "x_0", 0.0 ), 
               OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"nzmg") )
    {
        SetNZMG( OSR_GDV( papszNV, "lat_0", -41.0 ), 
                 OSR_GDV( papszNV, "lon_0", 173.0 ) + dfFromGreenwich, 
                 OSR_GDV( papszNV, "x_0", 2510000.0 ), 
                 OSR_GDV( papszNV, "y_0", 6023150.0 ) );
    }

    else if( EQUAL(pszProj,"cea") )
    {
        SetCEA( OSR_GDV( papszNV, "lat_ts", 0.0 ), 
                OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
                OSR_GDV( papszNV, "x_0", 0.0 ), 
                OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"tmerc") )
    {
        SetTM( OSR_GDV( papszNV, "lat_0", 0.0 ), 
               OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
               OSR_GDV( papszNV, "k", 1.0 ), 
               OSR_GDV( papszNV, "x_0", 0.0 ), 
               OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"utm") )
    {
        SetUTM( (int) OSR_GDV( papszNV, "zone", 0.0 ),
                (int) OSR_GDV( papszNV, "south", 1.0 ) );
    }

    else if( EQUAL(pszProj,"merc") /* 2SP form */
             && OSR_GDV(papszNV, "lat_ts", 1000.0) < 999.0 )
    {
        SetMercator2SP( OSR_GDV( papszNV, "lat_ts", 0.0 ), 
                        0.0,
                        OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
                        OSR_GDV( papszNV, "x_0", 0.0 ), 
                        OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"merc") ) /* 1SP form */
    {
        SetMercator( 0.0,
                     OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
                     OSR_GDV( papszNV, "k", 1.0 ), 
                     OSR_GDV( papszNV, "x_0", 0.0 ), 
                     OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"stere") 
             && ABS(OSR_GDV( papszNV, "lat_0", 0.0 ) - 90) < 0.001 )
    {
        SetPS( OSR_GDV( papszNV, "lat_ts", 90.0 ), 
               OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
               OSR_GDV( papszNV, "k", 1.0 ), 
               OSR_GDV( papszNV, "x_0", 0.0 ), 
               OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"stere") 
             && ABS(OSR_GDV( papszNV, "lat_0", 0.0 ) + 90) < 0.001 )
    {
        SetPS( OSR_GDV( papszNV, "lat_ts", -90.0 ), 
               OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
               OSR_GDV( papszNV, "k", 1.0 ), 
               OSR_GDV( papszNV, "x_0", 0.0 ), 
               OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUALN(pszProj,"stere",5) /* mostly sterea */
             && CSLFetchNameValue(papszNV,"k") != NULL )
    {
        SetOS( OSR_GDV( papszNV, "lat_0", 0.0 ), 
               OSR_GDV( papszNV, "lon_0", 0.0 ) + dfFromGreenwich, 
               OSR_GDV( papszNV, "k", 1.0 ), 
               OSR_GDV( papszNV, "x_0", 0.0 ), 
               OSR_GDV( papszNV, "y_0", 0.0 ) );
    }

    else if( EQUAL(pszProj,"stere") )