Geografic-Information-System/lib/gis/wind_scan.c

/*!
  \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_SP
   - 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 (G_lat_scan(buf, northing))
	    return 1;
	if (!scan_double(buf, northing))
	    return 0;

	return (*northing <= 90.0 && *northing >= -90.0);
    }

    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_SP
   - 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 (G_lon_scan(buf, easting))
	    return 1;
	if (!scan_double(buf, easting))
	    return 0;
	while (*easting > 180.0)
	    *easting -= 360.0;
	while (*easting < -180.0)
	    *easting += 360.0;

	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_SP
   - PROJECTION_LL
   - PROJECTION_OTHER
  
  \param buf buffer containing string resolution
  \param[out] resolution 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 1;
    }

    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 */
}