/*
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#ifndef TIMER_H
#define TIMER_H

#include <stdlib.h>

#ifdef WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#else
#include <sys/time.h>

/* RR: Apparently if no BSD or mac, this is missing */ 
#ifndef __USE_BSD
# define timersub(a, b, result)						      \
  do {									      \
    (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;			      \
    (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;			      \
    if ((result)->tv_usec < 0) {					      \
      --(result)->tv_sec;						      \
      (result)->tv_usec += 1000000;					      \
    }									      \
  } while (0)
#endif	/* BSD */


#endif



#ifdef WIN32
double PCFreq = 0.0;
__int64 timerStart = 0;
#else
struct timeval timerStart;
#endif

void StartTimer()
{
#ifdef WIN32
    LARGE_INTEGER li;
    if(!QueryPerformanceFrequency(&li))
        printf("QueryPerformanceFrequency failed!\n");

    PCFreq = (double)li.QuadPart/1000.0;

    QueryPerformanceCounter(&li);
    timerStart = li.QuadPart;
#else
    gettimeofday(&timerStart, NULL);
#endif
}

// time elapsed in ms
double GetTimer()
{
#ifdef WIN32
    LARGE_INTEGER li;
    QueryPerformanceCounter(&li);
    return (double)(li.QuadPart-timerStart)/PCFreq;
#else
    struct timeval timerStop, timerElapsed;
    gettimeofday(&timerStop, NULL);
    timersub(&timerStop, &timerStart, &timerElapsed);
    return timerElapsed.tv_sec*1000.0+timerElapsed.tv_usec/1000.0;
#endif
}

#endif // TIMER_H