Crate bevy_backroll

Expand description

A Bevy plugin that adds support for running Backroll sessions.

Installing the plugin:

use backroll::*;
use bytemuck::*;
use bevy::prelude::*;
use bevy_backroll::*;

// Create your Backroll input type
#[repr(C)]
#[derive(Clone, Copy, Eq, PartialEq, Pod, Zeroable)]
pub struct PlayerInput {
   // Input data...
   pub buttons_pressed: u8,
}

// Create your state. Must implement Clone.
#[derive(Component, Clone)]
pub struct PlayerState {
   pub handle: PlayerHandle,
   pub current_value: u64,
}

// Sample input from the local player's controller.
fn sample_player_input(player: In<PlayerHandle>) -> PlayerInput {
   // Sample input data...
   PlayerInput {
      buttons_pressed: 1,
   }
}

// Use input to advance the game simulation.
fn simulate_game(
  input: Res<GameInput<PlayerInput>>,
  mut query: Query<&mut PlayerState>
) {
   for mut player in query.iter_mut() {
      if let Ok(input) = input.get(player.handle) {
         player.current_value += input.buttons_pressed as u64;
      }
   }
}

fn main() {
    App::new()
        .add_plugin(BackrollPlugin)
        .register_rollback_input(sample_player_input.system())
        .register_rollback_component::<PlayerState>()
        .add_rollback_system(simulate_game)
        .run();
}