mitab_coordsys.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

        if( CSLCount(papszFields) < 5 )
            nDatum = 104; /* WGS84 */

        CSLDestroy( papszFields );
    }
    
    /*-----------------------------------------------------------------
     * We have a "real" datum name.  Try to look it up and get the
     * parameters.  If we don't find it just use WGS84.
     *----------------------------------------------------------------*/
    else 
    {
        int     i;

        for( i = 0; asDatumInfoList[i].nMapInfoDatumID != -1; i++ )
        {
            if( EQUAL(pszWKTDatum,asDatumInfoList[i].pszOGCDatumName) )
            {
                nDatum = asDatumInfoList[i].nMapInfoDatumID;
                break;
            }
        }

        if( nDatum == 0 )
            nDatum = 104; /* WGS84 */
    }

    /*-----------------------------------------------------------------
     * Translate the units
     *----------------------------------------------------------------*/
    const char  *pszMIFUnits = "m";

    if( nProjection == 1 )
        pszMIFUnits = NULL;
    else if( pszLinearUnits == NULL )
        pszMIFUnits = "m";
    else if( dfLinearConv == 1000.0 )
        pszMIFUnits = "km";
    else if( dfLinearConv == 0.0254 || EQUAL(pszLinearUnits,"Inch")
             || EQUAL(pszLinearUnits,"IINCH"))
        pszMIFUnits = "in";
    else if( dfLinearConv == atof(SRS_UL_FOOT_CONV)
             || EQUAL(pszLinearUnits,SRS_UL_FOOT) )
        pszMIFUnits = "ft";
    else if( EQUAL(pszLinearUnits,"YARD") || EQUAL(pszLinearUnits,"IYARD") 
             || dfLinearConv == 0.9144 )
        pszMIFUnits = "yd";
    else if( dfLinearConv == 0.001 )
        pszMIFUnits = "mm";
    else if( dfLinearConv == 0.01 )
        pszMIFUnits = "cm";
    else if( dfLinearConv == 1.0 )
        pszMIFUnits = "m";
    else if( dfLinearConv == atof(SRS_UL_US_FOOT_CONV)
             || EQUAL(pszLinearUnits,SRS_UL_US_FOOT) )
        pszMIFUnits = "survey ft";
    else if( EQUAL(pszLinearUnits,SRS_UL_NAUTICAL_MILE) )
        pszMIFUnits = "nmi";
    else if( EQUAL(pszLinearUnits,SRS_UL_LINK) 
             || EQUAL(pszLinearUnits,"GUNTERLINK") )
        pszMIFUnits = "li";
    else if( EQUAL(pszLinearUnits,SRS_UL_CHAIN) 
             || EQUAL(pszLinearUnits,"GUNTERCHAIN") )
        pszMIFUnits = "ch";
    else if( EQUAL(pszLinearUnits,SRS_UL_ROD) )
        pszMIFUnits = "rd";
    else if( EQUAL(pszLinearUnits,"Mile") 
             || EQUAL(pszLinearUnits,"IMILE") )
        pszMIFUnits = "mi";
    
/* -------------------------------------------------------------------- */
/*      Build coordinate system definition.                             */
/* -------------------------------------------------------------------- */
    char        szCoordSys[256];

    if( nProjection != 0 )
    {
        sprintf( szCoordSys,
                 "Earth Projection %d",
                 nProjection );

    }
    else
        sprintf( szCoordSys,
                 "NonEarth Units" );

/* -------------------------------------------------------------------- */
/*      Append Datum                                                    */
/* -------------------------------------------------------------------- */
    if( nProjection != 0 )
    {
        sprintf( szCoordSys + strlen(szCoordSys),
                 ", %d",
                 nDatum );

        if( nDatum == 999 || nDatum == 9999 )
        {
            sprintf( szCoordSys + strlen(szCoordSys),
                     ", %d, %.15g, %.15g, %.15g",
                     nEllipsoid,
                     adfDatumParm[0], adfDatumParm[1], adfDatumParm[2] );
        }
        
        if( nDatum == 9999 )
        {
            sprintf( szCoordSys + strlen(szCoordSys),
                     ", %.15g, %.15g, %.15g, %.15g, %.15g",
                     adfDatumParm[3], adfDatumParm[4], adfDatumParm[5],
                     adfDatumParm[6], adfDatumParm[7] );
        }
    }

/* -------------------------------------------------------------------- */
/*      Append units.                                                   */
/* -------------------------------------------------------------------- */
    if( nProjection != 1 && pszMIFUnits != NULL )
    {
        if( nProjection != 0 )
            strcat( szCoordSys, "," );
        
        sprintf( szCoordSys + strlen(szCoordSys),
                 " \"%s\"",
                 pszMIFUnits );
    }

/* -------------------------------------------------------------------- */
/*      Append Projection Parms.                                        */
/* -------------------------------------------------------------------- */
    for( int iParm = 0; iParm < nParmCount; iParm++ )
        sprintf( szCoordSys + strlen(szCoordSys),
                 ", %.15g",
                 parms[iParm] );

/* -------------------------------------------------------------------- */
/*      Report on translation                                           */
/* -------------------------------------------------------------------- */
    char        *pszWKT = NULL;

    poSR->exportToWkt( &pszWKT );
    if( pszWKT != NULL )
    {
        CPLDebug( "MITAB",
                  "This WKT Projection:\n%s\n\ntranslates to:\n%s\n",
                  pszWKT, szCoordSys );
        CPLFree( pszWKT );
    }

    return( CPLStrdup( szCoordSys ) );
}


/************************************************************************/
/*                      MITABExtractCoordSysBounds                      */
/*                                                                      */
/* Return TRUE if MIF coordsys string contains a BOUNDS parameter and   */
/* Set x/y min/max values.                                              */
/************************************************************************/

GBool MITABExtractCoordSysBounds( const char * pszCoordSys,
                                  double &dXMin, double &dYMin,
                                  double &dXMax, double &dYMax )

{
    char        **papszFields;

    if( pszCoordSys == NULL )
        return FALSE;
    
    papszFields = CSLTokenizeStringComplex( pszCoordSys, " ,()", TRUE, FALSE );

    int iBounds = CSLFindString( papszFields, "Bounds" );

    if (iBounds >= 0 && iBounds + 4 < CSLCount(papszFields))
    {
        dXMin = atof(papszFields[++iBounds]);
        dYMin = atof(papszFields[++iBounds]);
        dXMax = atof(papszFields[++iBounds]);
        dYMax = atof(papszFields[++iBounds]);
        CSLDestroy( papszFields );
        return TRUE;
    }

    CSLDestroy( papszFields );
    return FALSE;
}


/**********************************************************************
 *                     MITABCoordSys2TABProjInfo()
 *
 * Convert a MIF COORDSYS string into a TABProjInfo structure.
 *
 * Note that it would have been possible to achieve the same by calling
 * TABFile::SetSpatialRef( MITABCoordSys2SpatialRef() ) but this would 
 * involve lots of manipulations for cases where only a simple conversion
 * is required.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int MITABCoordSys2TABProjInfo(const char * pszCoordSys, TABProjInfo *psProj)

{
    char        **papszFields;

    // Set all fields to zero, equivalent of NonEarth Units "mi"
    memset(psProj, 0, sizeof(TABProjInfo));

    if( pszCoordSys == NULL )
        return -1;
    
    /*-----------------------------------------------------------------
     * Parse the passed string into words.
     *----------------------------------------------------------------*/
    while(*pszCoordSys == ' ') pszCoordSys++;  // Eat leading spaces
    if( EQUALN(pszCoordSys,"CoordSys",8) )
        pszCoordSys += 9;
    
    papszFields = CSLTokenizeStringComplex( pszCoordSys, " ,", TRUE, FALSE );

    /*-----------------------------------------------------------------
     * Clip off Bounds information.
     *----------------------------------------------------------------*/
    int         iBounds = CSLFindString( papszFields, "Bounds" );

    while( iBounds != -1 && papszFields[iBounds] != NULL )
    {
        CPLFree( papszFields[iBounds] );
        papszFields[iBounds] = NULL;
        iBounds++;
    }

    /*-----------------------------------------------------------------
     * Fetch the projection.
     *----------------------------------------------------------------*/
    char        **papszNextField;

    if( CSLCount( papszFields ) >= 3
        && EQUAL(papszFields[0],"Earth")
        && EQUAL(papszFields[1],"Projection") )
    {
        psProj->nProjId = atoi(papszFields[2]);
        papszNextField = papszFields + 3;
    }
    else if (CSLCount( papszFields ) >= 2
             && EQUAL(papszFields[0],"NonEarth") )
    {
        // NonEarth Units "..." Bounds (x, y) (x, y)
        psProj->nProjId = 0;
        papszNextField = papszFields + 2;

        if( papszNextField[0] != NULL && EQUAL(papszNextField[0],"Units") )
            papszNextField++;
    }
    else
    {
        // Invalid projection string ???
        if (CSLCount(papszFields) > 0)
            CPLError(CE_Warning, CPLE_IllegalArg,
                     "Failed parsing CoordSys: '%s'", pszCoordSys);
        CSLDestroy(papszFields);
        return -1;
    }

    /*-----------------------------------------------------------------
     * Fetch the datum information.
     *----------------------------------------------------------------*/
    int         nDatum = 0;

    if( psProj->nProjId != 0 && CSLCount(papszNextField) > 0 )
    {
        nDatum = atoi(papszNextField[0]);
        papszNextField++;
    }

    if( (nDatum == 999 || nDatum == 9999)
        && CSLCount(papszNextField) >= 4 )
    {
        psProj->nEllipsoidId = atoi(papszFields[0]);
        psProj->dDatumShiftX = atof(papszNextField[1]);
        psProj->dDatumShiftY = atof(papszNextField[2]);
        psProj->dDatumShiftZ = atof(papszNextField[3]);
        papszNextField += 4;

        if( nDatum == 9999
            && CSLCount(papszNextField) >= 5 )
        {
            psProj->adDatumParams[0] = atof(papszNextField[0]);
            psProj->adDatumParams[1] = atof(papszNextField[1]);
            psProj->adDatumParams[2] = atof(papszNextField[2]);
            psProj->adDatumParams[3] = atof(papszNextField[3]);
            psProj->adDatumParams[4] = atof(papszNextField[4]);
            papszNextField += 5;
        }
    }
    else if (nDatum != 999 && nDatum != 9999)
    {
    /*-----------------------------------------------------------------
     * Find the datum, and collect it's parameters if possible.
     *----------------------------------------------------------------*/
        int         iDatum;
        MapInfoDatumInfo *psDatumInfo = NULL;
        
        for(iDatum=0; asDatumInfoList[iDatum].nMapInfoDatumID != -1; iDatum++)
        {
            if( asDatumInfoList[iDatum].nMapInfoDatumID == nDatum )
            {
                psDatumInfo = asDatumInfoList + iDatum;
                break;
            }
        }

        if( asDatumInfoList[iDatum].nMapInfoDatumID == -1
            && nDatum != 999 && nDatum != 9999 )
        {
            /* use WGS84 */
            psDatumInfo = asDatumInfoList + 0;
        }

        if( psDatumInfo != NULL )
        {
            psProj->nEllipsoidId = psDatumInfo->nEllipsoid;
            psProj->dDatumShiftX = psDatumInfo->dfShiftX;
            psProj->dDatumShiftY = psDatumInfo->dfShiftY;
            psProj->dDatumShiftZ = psDatumInfo->dfShiftZ;
            psProj->adDatumParams[0] = psDatumInfo->dfDatumParm0;
            psProj->adDatumParams[1] = psDatumInfo->dfDatumParm1;
            psProj->adDatumParams[2] = psDatumInfo->dfDatumParm2;
            psProj->adDatumParams[3] = psDatumInfo->dfDatumParm3;
            psProj->adDatumParams[4] = psDatumInfo->dfDatumParm4;
        }
    }    

    /*-----------------------------------------------------------------
     * Fetch the units string.
     *----------------------------------------------------------------*/
    if( CSLCount(papszNextField) > 0 )
    {
        psProj->nUnitsId = TABUnitIdFromString(papszNextField[0]);
        papszNextField++;
    }

    /*-----------------------------------------------------------------
     * Finally the projection parameters.
     *----------------------------------------------------------------*/
    for(int iParam=0; iParam < 6 && CSLCount(papszNextField) > 0; iParam++)
    {
        psProj->adProjParams[iParam] = atof(papszNextField[0]);
        papszNextField++;         
    }

    return 0;
}