3 releases (breaking)
0.3.0 | Aug 4, 2024 |
---|---|
0.2.0 | Mar 15, 2024 |
0.1.0 | Nov 14, 2023 |
#1693 in Game dev
38 downloads per month
19KB
157 lines
bevy_roll_safe
Rollback-safe implementations and utilities for Bevy Engine.
Motivation
Some of Bevy's features can't be used in a rollback context (with crates such as bevy_ggrs
). This is either because they behave non-deterministically, rely on inaccessible local system state, or are tightly coupled to the Main
schedule.
Roadmap
- States
- Basic freely mutable states
-
OnEnter
/OnLeave
/OnTransition
- Sub-States
- Computed states
- Roll-safe events
- FrameCount
- Events
States
Bevy states when added through app.add_state::<FooState>()
have two big problems:
- They happen in the
StateTransition
schedule within theMainSchedule
- If rolled back to the first frame,
OnEnter(InitialState)
is not re-run.
This crate provides an extension method, add_roll_state::<S>(schedule)
, which lets you add a state to the schedule you want, and a resource, InitialStateEntered<S>
which can be rolled back and tracks whether the initial OnEnter
should be run (or re-run on rollbacks to the initial frame).
See the states
example for usage with bevy_ggrs
.
Cargo features
bevy_ggrs
: Enable integration withbevy_ggrs
math_determinism
: Enable cross-platform determinism for operations on Bevy's (glam
) math types.
Bevy Version Support
bevy | bevy_roll_safe |
---|---|
0.14 | 0.3, main |
0.13 | 0.2 |
0.12 | 0.1 |
License
bevy_roll_safe
is dual-licensed under either
- MIT License (./LICENSE-MIT or http://opensource.org/licenses/MIT)
- Apache License, Version 2.0 (./LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
at your option.
Contributions
PRs welcome!
Dependencies
~21–29MB
~455K SLoC