Question

I’m using XNA (C#) to develop a 2D platformer.
I was wondering for the best way to handle holding down a specific button. For example the more you hold down the larger the laser beam gets.

So far, since I’m already using the input mechanism that holds the 2 last states of the Keyboard, I can make an extra check each update cycle to increase the duration. But, this approach is rather limited since it only handles a specific button (fire button i.e.) and it should do the trick, but i was wondering if maybe there’s a more general solution to the problem.

Answer 1

float ElapsedSecondsPerFrame = (float) gametime.Elapsed.TotalSeconds;

KeyFirePressedTime = Keyboard.GetState().IsKeyDown(FireKey) 
                         ? (KeyFirePressedTime + ElapsedSecondsPerFrame ) 
                         : 0;

Generic method

Dictionary<int, float> PressedKeysTime = new ...


void Update(float Elapsed)
{
      List<int> OldPressedKeys = PressedKeysTime.Keys.ToList();
      foreach (int key in Keyboard.GetState().GetPressedKeys.Cast<int>())
      {
           if (!PressedKeysTime.ContainsKey(key)) 
           {
                PressedKeysTime[key] = 0;
           } else {
               OldPressedKeys.Remove(key);
               PressedKeysTime[key] += Elapsed;
           }
      }
      foreach (int keynotpressed in OldPressedKeys) 
          PressedKeysTime.Remove(keynotpressed);

}