Trait ExtractComponent

pub trait ExtractComponent: Component {
    type QueryData: ReadOnlyQueryData;
    type QueryFilter: QueryFilter;
    type Out: Bundle;

    // Required method
    fn extract_component(
        item: QueryItem<'_, Self::QueryData>,
    ) -> Option<Self::Out>;
}

Describes how a component gets extracted for rendering.

Therefore the component is transferred from the “app world” into the “render world” in the ExtractSchedule step.

Required Associated Types

type QueryData: ReadOnlyQueryData

ECS ReadOnlyQueryData to fetch the components to extract.

type QueryFilter: QueryFilter

Filters the entities with additional constraints.

type Out: Bundle

The output from extraction.

Returning None based on the queried item will remove the component from the entity in the render world. This can be used, for example, to conditionally extract camera settings in order to disable a rendering feature on the basis of those settings, without removing the component from the entity in the main world.

The output may be different from the queried component. This can be useful for example if only a subset of the fields are useful in the render world.

Out has a Bundle trait bound instead of a Component trait bound in order to allow use cases such as tuples of components as output.

Required Methods

fn extract_component(item: QueryItem<'_, Self::QueryData>) -> Option<Self::Out>

Defines how the component is transferred into the “render world”.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl ExtractComponent for Readback

where Self: Clone,

type QueryData = &'static Readback

type QueryFilter = ()

type Out = Readback

impl ExtractComponent for Msaa

where Self: Clone,

type QueryData = &'static Msaa

type QueryFilter = ()

type Out = Msaa

impl ExtractComponent for CameraMainTextureUsages

where Self: Clone,

type QueryData = &'static CameraMainTextureUsages

type QueryFilter = ()

type Out = CameraMainTextureUsages