Crate lightyear_inputs_native

Module to handle client inputs

Client inputs are generated by the user and sent to the server. They have to be handled separately from other messages, for several reasons:

• the history of inputs might need to be saved on the client to perform rollback and client-prediction
• we not only send the input for tick T, but we also include the inputs for the last N ticks before T. This redundancy helps ensure that the server isn’t missing any client inputs even if a packet gets lost
• we must provide SystemSets so that the user can order their systems before and after the input handling

Adding a new input type

An input type must be serializable, Reflect, MapEntities, Clone, PartialEq, and Debug.

You can then add the input type by adding the InputPlugin<InputType> to your app.

use lightyear_inputs_native::prelude::*;

#[derive(Serialize, Deserialize, Clone, PartialEq, Reflect, Debug)]
pub enum MyInput {
    Move { x: f32, y: f32 },
    Jump,
    // we need a variant for "no input", to differentiate between "no input" and "missing input packet"
    None,
}

// every input must implement MapEntities
impl MapEntities for MyInput {
    fn map_entities<M: EntityMapper>(&mut self, entity_mapper: &mut M) {
    }
}

let mut app = App::new();
app.add_plugins(InputPlugin::<MyInput>::default());

Sending inputs

There are several steps to use the InputPlugin:

• (optional) read the inputs from an external signal (mouse click or keyboard press, for instance)
• to buffer inputs for each tick. This is done by setting the input value in the ActionState component. That system must run in the WriteClientInputs system set, in the FixedPreUpdate stage.
• handle inputs in your game logic in systems that run in the FixedUpdate schedule. These systems will read the inputs using the ActionState component

Modules

plugin

Plugin to register and handle user inputs.

prelude