#bevy #leafwing

leafwing_abilities

A convenient, well-tested ability management suite. Built for the Bevy game engine.

7 releases (breaking)

new 0.7.0 Feb 24, 2024
0.6.0 Nov 16, 2023
0.5.0 Aug 28, 2023
0.4.0 Mar 8, 2023
0.1.1 Oct 18, 2022

#478 in Game dev

Download history 24/week @ 2023-11-04 53/week @ 2023-11-11 53/week @ 2023-11-18 35/week @ 2023-11-25 23/week @ 2023-12-02 6/week @ 2023-12-09 22/week @ 2023-12-16 18/week @ 2023-12-23 12/week @ 2023-12-30 11/week @ 2024-01-06 8/week @ 2024-01-13 11/week @ 2024-01-20 19/week @ 2024-01-27 6/week @ 2024-02-03 30/week @ 2024-02-10 135/week @ 2024-02-17

190 downloads per month

MIT/Apache

91KB
1.5K SLoC

About

A fully-featured set of tools for managing abilities in Bevy. This crate is meant to be used with Leafwing Input Manager, which converts inputs into actions.

Some of those actions will be abilities! Abilities are intended for gameplay use, and follow complex but relatively standardized logic about how they might be used.

use bevy::prelude::*;
use bevy::reflect::Reflect;
use leafwing_abilities::prelude::*;
use leafwing_abilities::premade_pools::mana::{ManaPool, Mana};
use leafwing_abilities::premade_pools::life::{LifePool, Life};
use leafwing_input_manager::prelude::*;

// We're modelling https://leagueoflegends.fandom.com/wiki/Zyra/LoL
// to show off this crate's features!
#[derive(Actionlike, Abilitylike, Clone, Copy, Hash, PartialEq, Eq, Reflect)]
pub enum ZyraAbility {
    GardenOfThorns,
    DeadlySpines,
    RampantGrowth,
    GraspingRoots,
    Stranglethorns,
}

impl ZyraAbility {
    /// You could use the `strum` crate to derive this automatically!
    fn variants() -> Vec<ZyraAbility> {
        use ZyraAbility::*;
        vec![GardenOfThorns, DeadlySpines, RampantGrowth, GraspingRoots, Stranglethorns]
    }

    fn input_map() -> InputMap<ZyraAbility> {
        use ZyraAbility::*;

        // We can use this `new` idiom, which accepts an iterator of pairs
        InputMap::new([
            (DeadlySpines, KeyCode::KeyQ),
            (RampantGrowth, KeyCode::KeyW),
            (GraspingRoots, KeyCode::KeyE),
            (Stranglethorns, KeyCode::KeyR),
        ])
    }

    // This match pattern is super useful to be sure you've defined an attribute for every variant
    fn cooldown(&self) -> Cooldown {
        use ZyraAbility::*;

        let seconds: f32 = match *self {
            GardenOfThorns => 13.0,
            DeadlySpines => 7.0,
            RampantGrowth => 18.0,
            GraspingRoots => 12.0,
            Stranglethorns => 110.0,
        };

        Cooldown::from_secs(seconds)
    }

    fn cooldowns() -> CooldownState<ZyraAbility> {
        let mut cooldowns = CooldownState::default();

        // Now, we can loop over all the variants to populate our struct
        for ability in ZyraAbility::variants() {
            cooldowns.set(ability, ability.cooldown());
        }

        cooldowns
    }

    fn charges() -> ChargeState<ZyraAbility> {
        // The builder API can be very convenient when you only need to set a couple of values
        ChargeState::default()
            .set(ZyraAbility::RampantGrowth, Charges::replenish_one(2))
            .build()
    }

    fn mana_costs() -> AbilityCosts<ZyraAbility, ManaPool> {
        use ZyraAbility::*;
        AbilityCosts::new([
            (DeadlySpines, Mana(70.)),
            (GraspingRoots, Mana(70.)),
            (Stranglethorns, Mana(100.)),
        ])
    }
}

/// Marker component for this champion
#[derive(Component)]
struct Zyra;

#[derive(Bundle)]
struct ZyraBundle {
    champion: Zyra,
    life_pool: LifePool,
    input_manager_bundle: InputManagerBundle<ZyraAbility>,
    abilities_bundle: AbilitiesBundle<ZyraAbility>,
    mana_bundle: PoolBundle<ZyraAbility, ManaPool>,
}

impl Default for ZyraBundle {
    fn default() -> Self {
        ZyraBundle {
            champion: Zyra,
            // Max life, then regen
            life_pool: LifePool::new(Life(574.), Life(574.), (Life(5.5))),
            input_manager_bundle: InputManagerBundle::<ZyraAbility> {
                input_map: ZyraAbility::input_map(),
                ..default()
            },
            abilities_bundle: AbilitiesBundle::<ZyraAbility> {
                cooldowns: ZyraAbility::cooldowns(),
                charges: ZyraAbility::charges(),
            },
            mana_bundle: PoolBundle::<ZyraAbility, ManaPool> {
                pool: ManaPool::new(Mana(418.), Mana(418.), Mana(13.0)),
                ability_costs: ZyraAbility::mana_costs(),
            }
        }
    }
}

Features

  • track and automatically tick cooldowns
  • store multiple charges of abilities
  • Leafwing Studio's trademark #[deny(missing_docs)]

Planned:

  • resource management (health, mana, energy etc)
  • damage
  • cast times
  • range checking

Dependencies

~41–84MB
~1.5M SLoC