ofxStateMachine is intended to help organise code for complex projects. Each state is essentially a mini OF app and you can override setup(), update() and so on in the same way.

To use the class, simply create your state classes that inherits from ofxState. The only function that it is necessary to implement is getName() (this is what you use to change states)...

class MyState : public itg::ofxState<>
{
public:
  string getName();
};

Functions that you can override are similar to those in ofBaseApp with the addition of stateEnter() and stateExit() see ofxState.h

In your OF app declare an instance of the state machine...

itg::ofxStateMachine<> stateMachine;

Add your states to the state machine in your OF app setup() and choose your initial state...

stateMachine.addState<MyState>();
stateMachine.changeState("mystate");

...and your done. Overridden functions such as update(), mousePressed() and so on in the current state will be called automatically.

If you wish to share data between states then pass your data class as a parameter to both your states and the state machine...

itg::ofxStateMachine<MySharedData> stateMachine;

class MyState : public itg::ofxState<MySharedData>

To access shared data from within a state simple call getSharedData()...

void MyState::update()
{
  getSharedData().doStuff();
}

...it can also be accessed from the state machine by calling...

stateMachine.getSharedData();

Changing states is as simple as calling...

changeState("mystate");

...from within a state.

If you are using a version of OF that is older than 0071, you will need to checkout an older version of the addon. Run the following command in the directory that you clone the addon to...

git checkout a9b94a9bb65389478c8ceb268dc98bcec2d46699