Struct RetainedViewEntity

pub struct RetainedViewEntity {
    pub main_entity: MainEntity,
    pub auxiliary_entity: MainEntity,
    pub subview_index: u32,
}

An identifier for a view that is stable across frames.

We can’t use Entity for this because render world entities aren’t stable, and we can’t use just MainEntity because some main world views extract to multiple render world views. For example, a directional light extracts to one render world view per cascade, and a point light extracts to one render world view per cubemap face. So we pair the main entity with an auxiliary entity and a subview index, which together uniquely identify a view in the render world in a way that’s stable from frame to frame.

Fields

main_entity: MainEntity

The main entity that this view corresponds to.

auxiliary_entity: MainEntity

Another entity associated with the view entity.

This is currently used for shadow cascades. If there are multiple cameras, each camera needs to have its own set of shadow cascades. Thus the light and subview index aren’t themselves enough to uniquely identify a shadow cascade: we need the camera that the cascade is associated with as well. This entity stores that camera.

If not present, this will be MainEntity(Entity::PLACEHOLDER).

subview_index: u32

The index of the view corresponding to the entity.

For example, for point lights that cast shadows, this is the index of the cubemap face (0 through 5 inclusive). For directional lights, this is the index of the cascade.

Implementations

impl RetainedViewEntity

pub fn new( main_entity: MainEntity, auxiliary_entity: Option<MainEntity>, subview_index: u32, ) -> Self

Creates a new RetainedViewEntity from the given main world entity, auxiliary main world entity, and subview index.

See RetainedViewEntity::subview_index for an explanation of what auxiliary_entity and subview_index are.

Trait Implementations

impl Clone for RetainedViewEntity

fn clone(&self) -> RetainedViewEntity

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RetainedViewEntity

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for RetainedViewEntity

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for RetainedViewEntity

fn eq(&self, other: &RetainedViewEntity) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for RetainedViewEntity

impl Eq for RetainedViewEntity

impl StructuralPartialEq for RetainedViewEntity