/*
 *   GRacer
 *
 *   Copyright (C) 1999 Takashi Matsuda <matsu@users.sourceforge.net>
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#include <unistd.h>
#include <math.h>
#include <lap.h>
#include <stdio.h>

double
gr_get_current_time (void)
{
  struct timeval time;

  gettimeofday (&time, NULL);

  return (double)(time.tv_sec) + 0.000001 * time.tv_usec;
}

void
gr_time_add (struct timeval *dst, struct timeval *src)
{
  int flag = 0;

  if (!dst || !src)
    return;

  dst->tv_usec += src->tv_usec;
  if (dst->tv_usec >= 1000000)
    {
      dst->tv_usec -= 1000000;
      flag = 1;
    }

  dst->tv_sec += src->tv_sec + (flag? 1:0);
}


void
gr_time_sub (struct timeval *dst, struct timeval *src)
{
  int flag = 0;

  if (!dst || !src)
    return;

  dst->tv_usec -= src->tv_usec;
  if (dst->tv_usec < 0)
    {
      flag = 1;
      dst->tv_usec += 1000000;
    }

  dst->tv_sec -= src->tv_sec + (flag? 1:0);
}


void
gr_time_average (struct timeval *dst, struct timeval *src, double f)
{
  double sec;

  if (!dst || !src)
    return;

  sec = (1.0 - f) * dst->tv_sec + f * src->tv_sec;
  dst->tv_sec = sec;
  dst->tv_usec = (1.0 - f) * dst->tv_usec + f * src->tv_usec +
    		 fmod (sec * 1000000, 1000000);
}

#if 0
GrLapRegion
gr_lap_which_region (GrVertex *region, GrVertex *point)
{
}
#endif