Calculating frames per second in a game

Question

What\'s a good algorithm for calculating frames per second in a game? I want to show it as a number in the corner of the screen. If I just look at how long it took to render

Answer 1

Here's how I do it (in Java):

private static long ONE_SECOND = 1000000L * 1000L; //1 second is 1000ms which is 1000000ns

LinkedList frames = new LinkedList<>(); //List of frames within 1 second

public int calcFPS(){
    long time = System.nanoTime(); //Current time in nano seconds
    frames.add(time); //Add this frame to the list
    while(true){
        long f = frames.getFirst(); //Look at the first element in frames
        if(time - f > ONE_SECOND){ //If it was more than 1 second ago
            frames.remove(); //Remove it from the list of frames
        } else break;
        /*If it was within 1 second we know that all other frames in the list
         * are also within 1 second
        */
    }
    return frames.size(); //Return the size of the list
}