Crate bevy_simple_state_machine

Bevy Simple State Machine

Plugin for the Bevy Engine which implements a rudimentary animation state machine system.

To use this, you have to add the SimpleStateMachinePlugin to you app

App::new()
    .add_plugins(DefaultPlugins)
    .add_plugins(SimpleStateMachinePlugin::new());

And then insert an AnimationStateMachine component on your entities

fn setup(mut commands: Commands) {
    let starting_state = "idle";
    let my_states_map = HashMap::from([
        ("idle", AnimationState{
            name: "idle".to_string(),
            clip: idle_clip_handle,
            interruptible: true,
        }),
        ("run", AnimationState{
            name: "run".to_string(),
            clip: run_clip_handle,
            interruptible: true,
        }),
    ]);
    let my_states_transitions_vec = vec![
        StateMachineTransition::immediate(
            AnimationStateRef::from_string("idle"),
            AnimationStateRef::from_string("run"),
            StateMachineTrigger::from(|vars| vars["run"].is_bool(true)),
        ),
   ];
    let state_machine_vars = HashMap::from([
        ("run", StateMachineVariableType::Bool(false)),    
    ]);
      
    commands.spawn(SpatialBundle::default())
        .insert(AnimationPlayer::default())
        .insert(AnimationStateMachine::new(
            starting_state,
            my_states_map,
            my_states_transitions_vec,
            state_machine_vars,
        ));
}

And then you can control it changing the values of the state machine variables

state_machine.update_variable("run", StateMachineVariableType::Bool(true));

Currently supported features:

• Custom transition conditions
• Transitions from wildcard state AnyState
• Events emitted on transition end
• Internal state machine variables

Currently, transitions end on the same frame they are triggered.

Structs

AnimationState

AnimationStateMachine state structure

AnimationStateMachine

Main state machine component

SimpleStateMachinePlugin

Plugin that handles all state machine executions

StateMachineTransition

Transition from AnimationState A to AnimationState B

TransitionEndedEvent

Event emitted once a StateMachineTransition has been executed

Enums

AnimationStateRef

Reference to an AnimationState name

StateMachineSet

State machine system label

StateMachineTrigger

Trigger condition for a StateMachineTransition

StateMachineVariableType

State machine variable type

Type Aliases

StateMachineVariables

Internal state machine variables map type