Trait bevy::ecs::prelude::System [−]
pub trait System: 'static + Send + Sync {
type In;
type Out;
fn name(&self) -> Cow<'static, str>;
fn new_archetype(&mut self, archetype: &Archetype);
fn component_access(&self) -> &Access<ComponentId>;
fn archetype_component_access(&self) -> &Access<ArchetypeComponentId>;
fn is_send(&self) -> bool;
unsafe fn run_unsafe(&mut self, input: Self::In, world: &World) -> Self::Out;
fn apply_buffers(&mut self, world: &mut World);
fn initialize(&mut self, _world: &mut World);
fn check_change_tick(&mut self, change_tick: u32);
fn run(&mut self, input: Self::In, world: &mut World) -> Self::Out { ... }
}
Expand description
An ECS system that can be added to a Schedule
Systems are functions with all arguments implementing
SystemParam
.
Systems are added to an application using App::add_system(my_system)
or similar methods, and will generally run once per pass of the main loop.
Systems are executed in parallel, in opportunistic order; data access is managed automatically.
It’s possible to specify explicit execution order between specific systems,
see SystemDescriptor
.
Associated Types
type In
type In
The system’s input. See In
for
FunctionSystem
s.
type Out
type Out
The system’s output.
Required methods
fn new_archetype(&mut self, archetype: &Archetype)
fn new_archetype(&mut self, archetype: &Archetype)
Register a new archetype for this system.
fn component_access(&self) -> &Access<ComponentId>
fn component_access(&self) -> &Access<ComponentId>
Returns the system’s component Access
.
fn archetype_component_access(&self) -> &Access<ArchetypeComponentId>
fn archetype_component_access(&self) -> &Access<ArchetypeComponentId>
Returns the system’s archetype component Access
.
unsafe fn run_unsafe(&mut self, input: Self::In, world: &World) -> Self::Out
unsafe fn run_unsafe(&mut self, input: Self::In, world: &World) -> Self::Out
Runs the system with the given input in the world. Unlike System::run
, this function
takes a shared reference to World
and may therefore break Rust’s aliasing rules, making
it unsafe to call.
Safety
This might access world and resources in an unsafe manner. This should only be called in one
of the following contexts:
1. This system is the only system running on the given world across all threads.
2. This system only runs in parallel with other systems that do not conflict with the
System::archetype_component_access()
.
fn apply_buffers(&mut self, world: &mut World)
fn initialize(&mut self, _world: &mut World)
fn initialize(&mut self, _world: &mut World)
Initialize the system.