How do I do countdown side by side running main loop?

Question

I am making a small console application game in C#. The thing is, you have to run around and collect gold. You have to do it under 1 minute otherwise you die. I made it work the way that I have made an enum including: Runs, Won, Lost, Ends statements. The main loop runs while the game state of the game is: Runs. Something like:

switch (...) {
    case PlayGame:
        Console.Clear();
        GameWorld gameWorld = new GameWorld();

        gameWorld.Update();
        while (gameWorld.GameState == GameState.Runs) {
          gameWorld.PlayerMovement();
          gameWorld.Update();
        }
        break;
    case ...
}

Now everything works fine.. The last thing is, that I have to make this "timer", that would count from 1 to 60 seconds and also print it on the screen at the given coordinates. I tried doing it many different ways. For example I made a method inside the GameWorld class (that is where I have the sort of core of the game) and called it Time. I made a variable Time and assigned the value of 60 to it. Then I made a for loop which set the cursor at the given coordinates, wrote the value which was raising with every loop and set Thread.Sleep(1000); as the last thing .. That basically added 1 to the value every second untill it got to 59. Now the thing is, that when I ran this method at the main loop (while), it counted to 60 seconds first and then it ran anything below it. The same thing was happening when I ran it below all the commands in the while loop. Do you guys have any idea how could I make that "countdown" run side by side with running main loop? Thank you for your answers and time!

Answer 1

While it is possible to start a separate thread to continuously run a timer to have the countdown run side by side, I would just keep track of the start time and print the updated seconds as part of the Update() method (or wherever it makes most sense, possibly a separate method call in the main game loop).

Either the first time Update() is called, when the GameWorld is created or even a new Start() method, store the current time using DateTime.UtcNow and print the 60 where it needs to go. On the next/subsequent updates, get the new current time, find the difference and subtract that from 60 seconds to get the time remaining.

Edit, a little more explanation:

Here is some code to get you started, you can then plug in the calls to Start() and PrintCountdown() where appropriate, I want to let you do as much of the work as I can :).

class GameWorld {
    ...
    DateTime startTime;

    void Start() {
        startTime = DateTime.UtcNow;
    }

    void PrintCountdown() {
        DateTime currentTime = DateTime.UtcNow;
        TimeSpan gameRunTime = currentTime - startTime;
        int timeRemaining = 60 - gameRunTime.TotalSeconds();
        // Whatever code you have to print the countdown time
    }
    ...
}

Edit 2:

As hatchet pointed out, DateTime.UtcNow is much faster thant DateTime.Now. It probably doesn't matter too much for your game, but using DateTime.UtcNow would shave off a few cycle in your game loop.

Answer 2

You could just check the system clock (using DateTime.Now, for example) somewhere and compare it against the starting time of the program, checking for when 60 seconds has elapsed.

Answer 3

You can have a timer which pings you up on specified time intervals and you can handle that event to do your updates. Example

case PlayGame:
        Console.Clear();
        GameWorld gameWorld = new GameWorld();
        gameWorld.Update();

        //Timer to ping you every second
        Timer aTimer = new Timer
        {
            Interval = 1000,    //change this to fit your needs
            Enabled = true
        };
         aTimer.Elapsed+=this.OnTimedEvent;


        while (gameWorld.GameState == GameState.Runs)
        {
            gameWorld.PlayerMovement();
            gameWorld.Update();
        }

Here's the event handler

    private void OnTimedEvent(object sender, ElapsedEventArgs e)
    {
        //updates here?
    }

Answer 4

EDIT: if the scope is to run movement at every second for 60s then using Stopwatch should be the most accurate method. (it will also do a lot of loops...)

        var gameWorld = new GameWorld ();
        var stopwatch = Stopwatch.StartNew ();
        gameWorld.Update();
        for (var n = 0; n < 60;)
        {
            if ((int)(stopwatch.ElapsedMilliseconds / 1000) > n)
            {
                gameWorld.PlayerMovement ();
                gameWorld.Update ();
                ++n;
                Console.WriteLine ("{0}ms elapsed.", stopwatch.ElapsedMilliseconds);
            }
            Thread.Sleep(1);
        }