Calculating frame rates using std::chrono

20 Oct 2023

programming

In the world of game development and real-time applications, measuring and maintaining a consistent frame rate is crucial for smooth and fluid animations. One way to achieve this is by using the std::chrono library in C++ which provides a high-resolution clock for precise timing.

Let’s dive into how you can calculate frame rates using std::chrono in your C++ program.

Getting Started

First, you need to include the necessary header file for std::chrono:

#include <chrono>

Next, you can define a std::chrono::high_resolution_clock object to measure the time between frames. This clock provides the highest resolution available on your system:

std::chrono::high_resolution_clock clock;

To measure the time at the beginning of a frame, you can store the current time point in a std::chrono::time_point object:

auto start_time = clock.now();

At the end of the frame, you can calculate the elapsed time by subtracting the start time from the current time:

auto end_time = clock.now();
auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end_time - start_time);

Now, to calculate the frame rate, which is measured in frames per second (FPS), you can divide the number of frames by the elapsed time:

double frame_rate = 1000.0 / duration.count(); // Assuming each frame lasts 1 millisecond

You can then display or use the calculated frame rate in your application.

Putting it all together

Here’s a complete example that demonstrates how to calculate the frame rate using std::chrono:

#include <iostream>
#include <chrono>

int main() {
    std::chrono::high_resolution_clock clock;
    auto start_time = clock.now();
    
    // Simulating some work that takes time
    
    auto end_time = clock.now();
    auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end_time - start_time);
    double frame_rate = 1000.0 / duration.count();
    
    std::cout << "Frame rate: " << frame_rate << " FPS\n";
    
    return 0;
}

Conclusion

By leveraging the high-resolution clock provided by std::chrono, you can accurately measure and calculate the frame rate in your C++ program. This allows you to ensure smooth animation and deliver a better user experience in games and real-time applications.

Remember to use the std::chrono library in your code and follow the example demonstrated above to calculate frame rates effectively. Happy coding!

References:

#programming #cpp