/*
    Amiga port by Oliver Gantert

    28.04.2000 - fixed some compiler warnings
*/
/*

ORBIT, a freeware space combat simulator
Copyright (C) 1999  Steve Belczyk <steve1@genesis.nred.ma.us>

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 "orbit.h"

double Time ()
{
  static double oldtime=0.0;
  double newtime, elapsed;

  newtime = glutGet (GLUT_ELAPSED_TIME);
  elapsed = newtime - oldtime;
  oldtime = newtime;

  return (elapsed/1000.0);
}

void InitTimer()
/*
 *  Check for and initialize the performance timer
 */
{
  #ifdef WIN32
  /* This gives a compiler warning; not completely sure why */
  if (!QueryPerformanceFrequency (&ticks_per_sec)) exit (0);
  #endif
  last_ticks = 0;
}

int DeltaTime()
/*
 *  Figure out how much time has elapsed since the last time we were called
 */
{
  #ifdef WIN32
  _int64 ticks, elapsed;
  #else
  int ticks, elapsed;
  #endif

  if (paused)
  {
    deltaT = 0.0;
    return 0;
  }

  #ifdef WIN32
  /* This gives a compiler warning; not completely sure why */
  QueryPerformanceCounter (&ticks);
  #else
  ticks = glutGet (GLUT_ELAPSED_TIME);
  #endif

  if (last_ticks == 0)
  {
    deltaT = 0.0;
  }
  else
  {
    elapsed = ticks - last_ticks;
    #ifdef WIN32
    deltaT = ((double) elapsed) / ((double) ticks_per_sec);
    #else
    deltaT = ((double) elapsed) / 1000.0;
    #endif
  }

  /* If more than maximum, slow things down */
  if (deltaT > MAXDELTAT) deltaT = MAXDELTAT;

  absT += deltaT;
  last_ticks = ticks;

  return 0;
}