text: /*=========================================================================
   *
   *  Copyright Insight Software Consortium
   *
   *  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.txt
   *
   *  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.
   *
   *=========================================================================*/
  
  #include <iostream>
  #include <cmath>
  #include "itkMath.h"
  #include "itkRealTimeClock.h"
  #include "itkStdStreamStateSave.h"
  #include "itkTestingMacros.h"
  
  int itkRealTimeClockTest( int, char * [] )
  {
    // Save the format stream variables for std::cout
    // They will be restored when coutState goes out of scope
    // scope.
    itk::StdStreamStateSave coutState(std::cout);
  
    try
      {
  
      // Create an ITK RealTimeClock
      itk::RealTimeClock::Pointer clock = itk::RealTimeClock::New();
      EXERCISE_BASIC_OBJECT_METHODS( clock, RealTimeClock, Object );
  
      std::cout << "Testing itk::RealTimeClock" << std::endl;
      std::cout << "Frequency: " << clock->GetFrequency() << std::endl;
  
      itk::RealTimeStamp timestamps[5];
  
      std::cout << "Printing timestamps got one by one" << std::endl;
  
      for( unsigned int i = 0; i < 5; ++i )
        {
        std::cout << clock->GetRealTimeStamp() << std::endl;
        }
  
      for( unsigned int i = 0; i < 5; ++i )
        {
        timestamps[i] = clock->GetRealTimeStamp();
        }
  
      std::cout << "Printing timestamps buffered" << std::endl;
      for( unsigned int i = 0; i < 5; ++i )
        {
        std::cout << timestamps[i] << std::endl;
        }
  
      // Print out several time stamps
      itk::RealTimeStamp realStamp1 = clock->GetRealTimeStamp();
      itk::RealTimeStamp realStamp2 = clock->GetRealTimeStamp();
      std::cout << "Current Time " << realStamp2 << std::endl;
  
      typedef itk::RealTimeStamp::TimeRepresentationType TimeRepresentationType;
  
      TimeRepresentationType tolerance = 1e6;
  
      for( unsigned int i = 0; i < 10; ++i )
        {
        realStamp1 = realStamp2;
        realStamp2 = clock->GetRealTimeStamp();
        itk::RealTimeInterval difference = realStamp2 - realStamp1;
        itk::RealTimeStamp::TimeRepresentationType seconds1 = realStamp1.GetTimeInSeconds();
        itk::RealTimeStamp::TimeRepresentationType seconds2 = realStamp2.GetTimeInSeconds();
        itk::RealTimeStamp::TimeRepresentationType secondsD = difference.GetTimeInSeconds();
        itk::RealTimeStamp::TimeRepresentationType secondsE = seconds2 - seconds1;
        std::cout << realStamp2 << " - " << realStamp1 << " = ";
        std::cout << secondsD << " = " << secondsE << std::endl;
  
        if( std::abs( secondsD - secondsE ) / secondsE > tolerance )
          {
          std::cerr << "Precision error in time difference" << std::endl;
          std::cerr << "Expected " << secondsE << " seconds " << std::endl;
          std::cerr << "But got  " << secondsD << " seconds " << std::endl;
          return EXIT_FAILURE;
          }
        }
  
      }
    catch(...)
      {
      std::cerr << "Exception caught !!" << std::endl;
      return EXIT_FAILURE;
      }
  
    std::cout << "[PASSED]" << std::endl;
    return EXIT_SUCCESS;
  }
  