ogr_fromepsg.cpp

在linux环境下

    poSRS->SetNode( "PROJCS", pszPCSName );
    
/* -------------------------------------------------------------------- */
/*      Set GEOGCS.                                                     */
/* -------------------------------------------------------------------- */
    nErr = SetEPSGGeogCS( poSRS, nGCSCode );
    if( nErr != OGRERR_NONE )
        return nErr;

    dfFromGreenwich = poSRS->GetPrimeMeridian();

/* -------------------------------------------------------------------- */
/*      Set linear units.                                               */
/* -------------------------------------------------------------------- */
    if( !EPSGGetUOMLengthInfo( nUOMLength, &pszUOMLengthName, &dfInMeters ) )
        return OGRERR_UNSUPPORTED_SRS;

    poSRS->SetLinearUnits( pszUOMLengthName, dfInMeters );
    poSRS->SetAuthority( "PROJCS|UNIT", "EPSG", nUOMLength );

    CPLFree( pszUOMLengthName );
    CPLFree( pszPCSName );

/* -------------------------------------------------------------------- */
/*      Set projection and parameters.                                  */
/* -------------------------------------------------------------------- */
    if( !EPSGGetProjTRFInfo( nPCSCode, &nProjMethod, anParmIds, adfProjParms ))
        return OGRERR_UNSUPPORTED_SRS;

    switch( nProjMethod )
    {
      case 9801:
      case 9817: /* really LCC near conformal */
        poSRS->SetLCC1SP( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                          OGR_FP( NatOriginScaleFactor ), 
                          OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9802:
        poSRS->SetLCC( OGR_FP( StdParallel1Lat ), OGR_FP( StdParallel2Lat ),
                       OGR_FP( FalseOriginLat ), OGR_FP( FalseOriginLong ),
                       OGR_FP( FalseOriginEasting ), 
                       OGR_FP( FalseOriginNorthing ));
        break;

      case 9803:
        poSRS->SetLCCB( OGR_FP( StdParallel1Lat ), OGR_FP( StdParallel2Lat ),
                        OGR_FP( FalseOriginLat ), OGR_FP( FalseOriginLong ),
                        OGR_FP( FalseOriginEasting ), 
                        OGR_FP( FalseOriginNorthing ));
        break;

      case 9804:
      case 9805: /* NOTE: treats 1SP and 2SP cases the same */
        poSRS->SetMercator( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                            OGR_FP( NatOriginScaleFactor ), 
                            OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9806:
        poSRS->SetCS( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                            OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9807:
        poSRS->SetTM( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                      OGR_FP( NatOriginScaleFactor ), 
                      OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;
        
      case 9808:
        poSRS->SetTMSO( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                        OGR_FP( NatOriginScaleFactor ), 
                        OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;
        
      case 9809:
        poSRS->SetOS( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                      OGR_FP( NatOriginScaleFactor ), 
                      OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9810:
        poSRS->SetPS( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                      OGR_FP( NatOriginScaleFactor ), 
                      OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9811:
        poSRS->SetNZMG( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                        OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9812:
      case 9813:
      case 9814:
        poSRS->SetHOM( OGR_FP( ProjCenterLat ), OGR_FP( ProjCenterLong ),
                       OGR_FP( Azimuth ), 
                       OGR_FP( AngleRectifiedToSkewedGrid ),
                       OGR_FP( InitialLineScaleFactor ),
                       OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );

        poNode = poSRS->GetAttrNode( "PROJECTION" )->GetChild( 0 );
        if( nProjMethod == 9813 )
            poNode->SetValue( SRS_PT_LABORDE_OBLIQUE_MERCATOR );
        break;

      case 9815:
        poSRS->SetHOM( OGR_FP( ProjCenterLat ), OGR_FP( ProjCenterLong ),
                       OGR_FP( Azimuth ), 
                       OGR_FP( AngleRectifiedToSkewedGrid ),
                       OGR_FP( InitialLineScaleFactor ),
                       OGR_FP( ProjCenterEasting ), 
                       OGR_FP( ProjCenterNorthing ) );
        break;

      case 9816:
        poSRS->SetTMG( OGR_FP( FalseOriginLat ), OGR_FP( FalseOriginLong ),
                       OGR_FP( FalseOriginEasting ), 
                       OGR_FP( FalseOriginNorthing ) );
        break;

      case 9818:
        poSRS->SetPolyconic( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                             OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9819:
        poSRS->SetKrovak( OGR_FP( ProjCenterLat ), OGR_FP( ProjCenterLong ),
                          OGR_FP( Azimuth ), 
                          OGR_FP( PseudoStdParallelLat ),
                          OGR_FP( PseudoStdParallelScaleFactor ),
                          OGR_FP( ProjCenterEasting ), 
                          OGR_FP( ProjCenterNorthing ) );
        break;

      case 9820:
        poSRS->SetLAEA( OGR_FP( NatOriginLat ), OGR_FP( NatOriginLong ),
                        OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      case 9821: /* this is the spherical form, and really needs different
                    equations which give different results but PROJ.4 doesn't
                    seem to support the spherical form. */
        poSRS->SetLAEA( OGR_FP( SphericalOriginLat ), 
                        OGR_FP( SphericalOriginLong ),
                        OGR_FP( FalseEasting ), OGR_FP( FalseNorthing ) );
        break;

      default:
        return OGRERR_UNSUPPORTED_SRS;
    }

/* -------------------------------------------------------------------- */
/*      Set overall PCS authority code.                                 */
/* -------------------------------------------------------------------- */
    poSRS->SetAuthority( "PROJCS", "EPSG", nPCSCode );

    return OGRERR_NONE;
}

/************************************************************************/
/*                           importFromEPSG()                           */
/************************************************************************/

/**
 * Initialize SRS based on EPSG GCS or PCS code.
 *
 * This code uses the GeoTIFF cpl_csv services to access the EPSG CSV 
 * data.  If frmts/gtiff/libgeotiff isn't linked in, linking will fail. 
 * If EPSG tables can't be found at runtime, the method will fail.
 *
 * This method is the same as the C function OSRImportFromEPSG().
 *
 * @param nCode a GCS or PCS code from the horizontal coordinate system table.
 * 
 * @return OGRERR_NONE on success, or an error code on failure.
 */

OGRErr OGRSpatialReference::importFromEPSG( int nCode )

{
    OGRErr  eErr;

    bNormInfoSet = FALSE;

/* -------------------------------------------------------------------- */
/*      Clear any existing definition.                                  */
/* -------------------------------------------------------------------- */
    if( GetRoot() != NULL )
    {
        delete poRoot;
        poRoot = NULL;
    }

/* -------------------------------------------------------------------- */
/*      Verify that we can find the required filename(s).               */
/* -------------------------------------------------------------------- */
    if( CSVScanFileByName( CSVFilename( "gcs.csv" ),
                           "COORD_REF_SYS_CODE", 
                           "4269", CC_Integer ) == NULL )
    {
        CPLError( CE_Failure, CPLE_OpenFailed, 
                  "Unable to open EPSG support file %s.\n"
                  "Try setting the GDAL_DATA environment variable to point to the\n"
                  "directory containing EPSG csv files.", 
                  CSVFilename( "gcs.csv" ) );
        return OGRERR_FAILURE;
    }

/* -------------------------------------------------------------------- */
/*      Is this a GeogCS code?   this is inadequate as a criteria       */
/* -------------------------------------------------------------------- */
    if( EPSGGetGCSInfo( nCode, NULL, NULL, NULL, NULL, NULL, NULL ) )
        eErr = SetEPSGGeogCS( this, nCode );
    else
        eErr = SetEPSGProjCS( this, nCode );

    if( eErr == OGRERR_UNSUPPORTED_SRS )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "EPSG PCS/GCS code %d not found in EPSG support files.  Is this a valid\nEPSG coordinate system?", 
                  nCode );
    }

/* -------------------------------------------------------------------- */
/*      Make sure any peculiarities in the ordering are fixed up.       */
/* -------------------------------------------------------------------- */
    if( eErr == OGRERR_NONE )
        eErr = FixupOrdering();

    return eErr;
}

/************************************************************************/
/*                         OSRImportFromEPSG()                          */
/************************************************************************/

OGRErr OSRImportFromEPSG( OGRSpatialReferenceH hSRS, int nCode )

{
    return ((OGRSpatialReference *) hSRS)->importFromEPSG( nCode );
}

/************************************************************************/
/*                           SetStatePlane()                            */
/************************************************************************/

/**
 * Set State Plane projection definition.
 *
 * This will attempt to generate a complete definition of a state plane
 * zone based on generating the entire SRS from the EPSG tables.  If the
 * EPSG tables are unavailable, it will produce a stubbed LOCAL_CS definition
 * and return OGRERR_FAILURE.
 *
 * This method is the same as the C function OSRSetStatePlaneWithUnits().
 *
 * @param nZone State plane zone number, in the USGS numbering scheme (as
 * dinstinct from the Arc/Info and Erdas numbering scheme. 
 *
 * @param bNAD83 TRUE if the NAD83 zone definition should be used or FALSE
 * if the NAD27 zone definition should be used.  
 *
 * @param pszOverrideUnitName Linear unit name to apply overriding the 
 * legal definition for this zone.
 *
 * @param dfOverrideUnit Linear unit conversion factor to apply overriding
 * the legal definition for this zone. 
 * 
 * @return OGRERR_NONE on success, or OGRERR_FAILURE on failure, mostly likely
 * due to the EPSG tables not being accessable. 
 */

OGRErr OGRSpatialReference::SetStatePlane( int nZone, int bNAD83,
                                           const char *pszOverrideUnitName,
                                           double dfOverrideUnit )

{
    int         nAdjustedId;
    int         nPCSCode;
    char        szID[32];

/* -------------------------------------------------------------------- */
/*      Get the index id from stateplane.csv.                           */
/* -------------------------------------------------------------------- */
    if( bNAD83 )
        nAdjustedId = nZone;
    else
        nAdjustedId = nZone + 10000;

/* -------------------------------------------------------------------- */
/*      Turn this into a PCS code.  We assume there will only be one    */
/*      PCS corresponding to each Proj_ code since the proj code        */
/*      already effectively indicates NAD27 or NAD83.                   */
/* -------------------------------------------------------------------- */
    sprintf( szID, "%d", nAdjustedId );
    nPCSCode =
        atoi( CSVGetField( CSVFilename( "stateplane.csv" ),
                           "ID", szID, CC_Integer,
                           "EPSG_PCS_CODE" ) );
    if( nPCSCode < 1 )
    {
        char    szName[128];
        static int bFailureReported = FALSE;

        if( !bFailureReported )
        {
            bFailureReported = TRUE;
            CPLError( CE_Warning, CPLE_OpenFailed, 
                      "Unable to find state plane zone in stateplane.csv,\n"
                      "likely because the GDAL data files cannot be found.  Using\n"
                      "incomplete definition of state plane zone.\n" );
        }

        Clear();
        if( bNAD83 )
        {
            sprintf( szName, "State Plane Zone %d / NAD83", nZone );
            SetLocalCS( szName );
            SetLinearUnits( SRS_UL_METER, 1.0 );
        }
        else
        {
            sprintf( szName, "State Plane Zone %d / NAD27", nZone );
            SetLocalCS( szName );
            SetLinearUnits( SRS_UL_US_FOOT, atof(SRS_UL_US_FOOT_CONV) );
        }

        return OGRERR_FAILURE;
    }

/* -------------------------------------------------------------------- */
/*      Define based on a full EPSG definition of the zone.             */
/* -------------------------------------------------------------------- */
    OGRErr eErr = importFromEPSG( nPCSCode );

    if( eErr != OGRERR_NONE )
        return eErr;

/* -------------------------------------------------------------------- */
/*      Apply units override if required.                               */
/*                                                                      */
/*      We will need to adjust the linear projection parameter to       */
/*      match the provided units, and clear the authority code.         */
/* -------------------------------------------------------------------- */
    if( dfOverrideUnit != 0.0 
        && fabs(dfOverrideUnit - GetLinearUnits()) > 0.0000000001 )
    {
        double dfFalseEasting = GetNormProjParm( SRS_PP_FALSE_EASTING );
        double dfFalseNorthing= GetNormProjParm( SRS_PP_FALSE_NORTHING);
        OGR_SRSNode *poPROJCS;

        SetLinearUnits( pszOverrideUnitName, dfOverrideUnit );
        
        SetNormProjParm( SRS_PP_FALSE_EASTING, dfFalseEasting );
        SetNormProjParm( SRS_PP_FALSE_NORTHING, dfFalseNorthing );

        poPROJCS = GetAttrNode( "PROJCS" );
        if( poPROJCS != NULL && poPROJCS->FindChild( "AUTHORITY" ) != -1 )
        {
            poPROJCS->DestroyChild( poPROJCS->FindChild( "AUTHORITY" ) );
        }
    }

    return OGRERR_NONE;
}

/************************************************************************/
/*                          OSRSetStatePlane()                          */
/************************************************************************/

OGRErr OSRSetStatePlane( OGRSpatialReferenceH hSRS, int nZone, int bNAD83 )

{
    return ((OGRSpatialReference *) hSRS)->SetStatePlane( nZone, bNAD83 );
}

/************************************************************************/
/*                     OSRSetStatePlaneWithUnits()                      */
/************************************************************************/

OGRErr OSRSetStatePlaneWithUnits( OGRSpatialReferenceH hSRS, 
                                  int nZone, int bNAD83,
                                  const char *pszOverrideUnitName,
                                  double dfOverrideUnit )

{
    return ((OGRSpatialReference *) hSRS)->SetStatePlane( nZone, bNAD83,
                                                          pszOverrideUnitName,
                                                          dfOverrideUnit );
}