wind_scan.c

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/*!
   \file lib/gis/wind_scan.c
 
   \brief GIS Library - Coordinate scanning functions.
 
   (C) 2001-2009, 2011 by the GRASS Development Team
 
   This program is free software under the GNU General Public License
   (>=v2). Read the file COPYING that comes with GRASS for details.
 
   \author Original author CERL
 */
 
#include <stdio.h>
#include <grass/gis.h>
 
static int scan_double(const char *, double *);
 
/*!
   \brief ASCII northing to double.
 
   Converts the ASCII "northing" coordinate string in <i>buf</i> to its
   double representation (into <i>northing</i>).
 
   Supported projection codes (see gis.h):
   - PROJECTION_XY
   - PROJECTION_UTM
   - PROJECTION_LL
   - PROJECTION_OTHER
 
   \param buf buffer hold string northing
   \param[out] northing northing
   \param projection projection code
 
   \return 0 on error
   \return 1 on success
 */
int G_scan_northing(const char *buf, double *northing, int projection)
{
    if (projection == PROJECTION_LL) {
        if (!scan_double(buf, northing))
            return G_lat_scan(buf, northing);
 
        return 1;
    }
 
    return scan_double(buf, northing);
}
 
/*!
   \brief ASCII easting to double.
 
   Converts the ASCII "easting" coordinate string in <i>buf</i> to its
   double representation (into <i>easting</i>).
 
   Supported projection codes (see gis.h):
   - PROJECTION_XY
   - PROJECTION_UTM
   - PROJECTION_LL
   - PROJECTION_OTHER
 
   \param buf buffer containing string easting
   \param[out] easting easting
   \param projection projection code
 
   \return 0 on error
   \return 1 on success
 */
int G_scan_easting(const char *buf, double *easting, int projection)
{
    if (projection == PROJECTION_LL) {
        if (!scan_double(buf, easting))
            return G_lon_scan(buf, easting);
 
        return 1;
    }
 
    return scan_double(buf, easting);
}
 
/*!
   \brief ASCII resolution to double.
 
   Converts the ASCII "resolution" string in <i>buf</i> to its double
   representation (into resolution).
 
   Supported projection codes (see gis.h):
   - PROJECTION_XY
   - PROJECTION_UTM
   - PROJECTION_LL
   - PROJECTION_OTHER
 
   \param buf buffer containing string resolution
   \param[out] res resolution value
   \param projection projection code
 
   \return 0 on error
   \return 1 on success
 */
int G_scan_resolution(const char *buf, double *res, int projection)
{
    if (projection == PROJECTION_LL) {
        if (G_llres_scan(buf, res))
            return (*res > 0.0);
    }
 
    return (scan_double(buf, res) && *res > 0.0);
}
 
static int scan_double(const char *buf, double *value)
{
    char junk[2];
 
    /* use sscanf to convert buf to double
     * make sure value doesn't have other characters after it */
 
    *junk = 0;
    *value = 0.0;
 
    if (sscanf(buf, "%lf%1s", value, junk) == 1 && *junk == 0) {
        while (*buf)
            buf++;
        buf--;
 
        if (*buf >= 'A' && *buf <= 'Z')
            return 0;
        if (*buf >= 'a' && *buf <= 'z')
            return 0;
 
        return 1; /* success */
    }
 
    return 0; /* failure */
}