add add_states, more doc

README.md

@@ -1,7 +1,35 @@
 # Description
-TODO
+I wanted to just use a state machine purely in GDscript, as simply as possible, but with states, transitions, hooks, and conditions/triggers to change states
+
+- States: the FSM will always be in a state. It will change to another state with the transitions, following the first transaction, having the current state as a source, that matches the conditions/trigger
+- Transition: a transition will allow the FSM to change from one state to another when, at each update
+  - The transition is fully matched the (optional) trigger has been called
+  - The (optional) conditions has all been met
+  - A transition is composed of
+    - A state source
+    - A state destination
+    - An optional list of conditions
+    - An optional trigger
+- Transition source: in order to reduce the amount of code to type for transitions, there are some helpers. source can be a string (STATE), or it can be an array:
+  - STATE: any known state (the easy one)
+  - "*": all the states (including the destination)
+  - ^STATE: all the states but STATE. e.g. "^hurt" => it will match, for source, all the states except "hurt"
+  - -STATE: remove STATE from the previous states added (when source is an array). e.g. ["*", "-idle", "-hurt"] => it will match, for source, all the states except "idle" and "hurt"
+- Trigger: a transition can be mapped to 0 or 1 trigger. A trigger is emitted by calling the "trigger" method, and the trigger will be treated at the next update and then forgotten
+- Condition: a condition is just the callback of a method returning a boolean. It can be the name of the method, or it can prefixed by "!" to get the reverse boolean
+
+# TODO
+- Maybe optimize the whole thing
+
 # How to use
-- Add a Node2D node named "StateMachine" with the script state_machine.gd
+- Add it to your project : https://docs.godotengine.org/en/stable/tutorials/plugins/editor/installing_plugins.html#enabling-a-plugin
+```
+    mkdir -p addons
+    cd addons
+    git submodule add ssh://git@git.abxy.fr:212/groug/godot_simple_state_machine.git
+```
+
+- Add the custom StateMachine node (name it "StateMachine" for the purpose of the example)
 - Initialize the states, initial state and conditions:
 ```
 	$StateMachine.add_state("idle")

state_machine.gd

@@ -72,6 +72,11 @@ func add_state(name):
 	if _states.count(name) == 0:
 		_states.append(name)
 
+func add_states(states):
+	for state in states:
+		if _states.count(state) == 0:
+			_states.append(state)
+
 func set_init_state(name):
 	_change_state(name)