Character state machines

Defining a character's temperament and possible actions in the form of a finite state machine is a simple but effective way to simulate emotion, personality, and those subtle quirks that hint at humanity.

In this recipe, we're going to create a pretty simple example in the form of a security guard who gets progressively more or less excitable depending on whether he can hear or see the hero of the game.

Just like a real person might react, the guard doesn't instantly jump into full-blown anger upon the smallest noise, nor does he instantly calm down upon losing sight of the hero.

Getting ready

This recipe requires only an XNA-compatible font of your choosing.

How to do it...

To create your own character state machine:

1. 1. Add a new SpriteFont to your solution, named Text.

2. 2. Create a class to represent the emotional state of a character:

   class StateNode
   {
   public string Id;
   

3. 3. Complete the class by including a list of possible nodes to transit to, along with a method to...