Simple GML State Machine

Simple GML state machine for GameMaker 2.3+

Usage:

Initialize state machine:

stateMachine = new DTG_StateMachine();

Create states:

state = new DTG_State();
// create a state named "start"
stateMachine.add("start",state);

Events:

Code to run when the state machines enters the state: This is called automatically.

state.onEnter = function(obj)
{
    // code here
    // obj references the State() instance    
}

Code to run when the state machines exits the state: This is called automatically

state.onExit = function(obj)
{
    // code here
    // obj references the State() instance    
}

This needs to be added to your step event for the onStep events to fire:

stateMachine.step()

Code to run each step:

state.onStep = function(obj)
{
    // code here
    // obj references the State() instance    
}

This needs to be added to yuour draw event for the onDraw events to fire:

stateMachine.draw()

Code to run each draw event:

state.onDraw = function(obj)
{
    // code here
    // obj references the State() instance    
}

Note: onStep and onDraw are not actually tied to the Gamemaker step or draw events. You can run them in the beginXXXX/endXXXX events.

If you want to use "getFrames()" call, you must call stateMachine.step() in a step event.

Custom events

You can also make custom events

state.addCustom("my_custom_eventname", function(obj) {
    // code here
    // obj references the State() instance    
});

Execute that code later:

stateMachine.custom("my_custom_eventname");

The state machine needs to be in that state in order for this to work.

User data

Each state can save a struct as user data

Adding user data to the current state:

foo = {
    bar: "spam"
};

stateMachine.addUserData(foo);

Retrieving user data from the current state:

userData = stateMachine.getUserData();

userData would then contain the data from the foo struct. This is a copy, not a reference, so it will be independent of the original struct.

Time/Frames since enter state

You can get the amount of time that has passed since the current state has been running.

timeInMicroseconds = stateMachine.getTime(false);

timeInSeconds = stateMachine.getTime(true);

Also the number of frames since the state started.

frames = stateMachine.getFrames()