fsm's Introduction

fsm

License
Introduction
Usage
[Documentation] (#documentation)

License

This work is free. You can redistribute it and/or modify it under the terms of the Do What The Fuck You Want To Public License, Version 2, as published by Sam Hocevar. See the COPYING file for more details.

Introduction

fsm provides a simple finite state machine intended for game development.

To install: $ go get -u github.com/ArturoVM/fsm

Usage

To use fsm, you first need to declare your own constant state types. For example:

// states.go

package main

import "github.com/ArturoVM/fsm"

const (
    StateOne fsm.StateType = iota
    StateTwo
    StateThree
    StateQuit
)

After that, it's only a matter of writing your own states conforming to the fsm.GameState interface (see the documentation for more information) and initializing a package-wide *fsm.StateMachine instance, and you're good to go:

// main.go

package main

import "github.com/ArturoVM/fsm"

type SomeState struct {
   stateType fsm.StateType
}

func (s *SomeState) Init() {
   s.stateType = StateOne
}

func (s *SomeState) Update() {
    // do some complicated logic
}

func (s *SomeState) Draw() {
    // do some drawing
}

func (s *SomeState) Type() fsm.StateType {
    return s.stateType
}

// Game loop

var FSM *fsm.StateMachine // package-wide StateMachine instance

func m_init() {
    FSM = new(fsm.StateMachine)
    var someState SomeState
    FSM.Init(&someState)
}

func update() {
    FSM.Update() // Crucial! See documentation.
    FSM.CurrentState().Update()
}

func draw() {
    FSM.CurrentState().Draw()
}

func main() {
    m_init()
    for FSM.CurrentState().Type() != StateQuit {
        update()
        draw()
    }
}