#include "dcltng.h"

float lt_sw2c ( int endianness, unsigned char *bullx, int *ibxptr )

/************************************************************************
 * lt_sw2c                                                              *
 *                                                                      *
 * This routine unpacks a signed integer from the next 4 bytes of a	* 
 * lightning report, where negative values are assumed to be		*
 * represented using the two's complement scheme.			*
 *                                                                      *
 * Input parameters:                                                    *
 *	ENDIANNESS	INT	Byte-ordering scheme within bulletin:	*
 *				  0 = big-endian			*
 *				  1 = little-endian			*
 *	BULLX		CHAR*	Lightning bulletin			*
 *	IBXPTR		INT*	Pointer within BULLX			*
 *                                                                      *
 * Output parameters:							*
 *	IBXPTR		INT*	Updated pointer within BULLX		*
 *	LT_SW2C		FLOAT	Unpacked value				*
 **                                                                     *
 * Log:                                                                 *
 * J. Ator/NCEP		05/15						*
 ***********************************************************************/

#define POW2_32 ( 4294967296 )	/* = 2 to the 32nd power */
#define POW2_31 ( 2147483648 )	/* = 2 to the 31st power */

{
    unsigned int  ui;
    long lint;

    float result;

    ui = lt_word( endianness, bullx, ibxptr );
    if ( ui < POW2_31 ) {
      result = (float) ui; 
    }
    else {
      lint = ( long ) ui;
      lint = lint - POW2_32;
      result = (float) lint; 
    }

    return result;
}