CSC 216/s08/clever imaginings
Finite State Machines and the State Pattern
The problem
Finite state machines are abstract models of systems that have a set number of states, inputs, and rules for transitioning from one state to another. Understanding all the parts of a FSM can be difficult, especially in systems that feature a large number of states and transitions. As an interesting application, a Finite State Machine can be used to model the emotional states of an Non-Player Character (NPC) in video games.
Participants and props
Students should work in pairs. In Part 1, one student will act as the FSM, and the other will act as the environment. The student acting as the FSM should reference the following table (which may be printed on a notecard) to determine their reaction to stimuli.
| Compliment | Dull Comment | Insult | |
|---|---|---|---|
| Amicable | Amicable | Neutral | Neutral |
| Neutral | Amicable | Neutral | Agitated |
| Agitated | Neutral | Agitated | Agitated |
The other student should use the following list of generic insults, compliments and dull comments:
| Compliments | Dull Comments | Insults |
|---|---|---|
|
|
|
The script
Part 1: The Finite State Machine
The student issuing stimuli will try to guess the state table used by the FSM student (the FSM student should keep the table concealed). The student acting as the environment will speak compliments, comments and insults to the student representing the FSM, who shall then respond by modifying their body language to express their current state. The following postures may be used to express emotional states:
- Amicable - Establish eye contact and smile with arms relaxed.
- Neutral - Look away with arms relaxed.
- Agitated - Establish eye contact, frown and cross arms.
Once the environment student has recreated the state table of the FSM student, both students should work together to write corresponding methods (in pseudocode) to accurately model the system.