engine/examples/free_space/src/game_state.rs

use anyhow::Result;

use ecs::*;
use engine::prelude::*;

use crate::game::Game;

#[derive(Default, Resource)]
pub enum GameState {
    #[default]
    Startup,

    Game(Game),
}

impl GameState {
    pub fn update(world: &mut World) -> Result<bool> {
        let me = world.resources.get_mut_unchecked::<Self>();

        match me {
            GameState::Startup => *me = GameState::Game(Game),
            GameState::Game(game) => game.update(world)?,
        }

        Ok(true)
    }
}

impl EventConsumer for GameState {
    fn event(&mut self, world: &mut World, event: EngineEvent<'_>) -> Result<()> {
        match self {
            GameState::Startup => (),
            GameState::Game(game) => game.event(world, event)?,
        }

        Ok(())
    }
}