Update Camera's Frustum only when its GlobalTransform or CameraProjection changed (#9092)

# Objective

Update a camera's frustum only when needed.

- Maybe a performance gain from not having to compute frusta when not
needed, at the cost of change detection (?)
- Making "fighting" with `update_frusta` less tedious, see
https://github.com/bevyengine/bevy/issues/9077 and
https://discord.com/channels/691052431525675048/743663924229963868/1127566087966433322

## Solution

Add change detection filter for `GlobalTransform` or `T:
CameraProjection` in `update_frusta`, since those are the cases when the
frustum needs to be updated.

## Note

I don't think a migration guide and changelog are needed, but I'm not
100% sure, I could put something like "if you're fighting against
`update_frusta`, you can do it only when there is a change to
`GlobalTransform` or `CameraProjection` now", what do you think? It's
not really a breaking change with a normal use case.
This commit is contained in:
Sélène Amanita 2023-08-10 01:06:27 +01:00 committed by Carter Anderson
parent c4edbdba5f
commit 9d1a10273c

View file

@ -268,7 +268,10 @@ pub fn calculate_bounds(
}
pub fn update_frusta<T: Component + CameraProjection + Send + Sync + 'static>(
mut views: Query<(&GlobalTransform, &T, &mut Frustum)>,
mut views: Query<
(&GlobalTransform, &T, &mut Frustum),
Or<(Changed<GlobalTransform>, Changed<T>)>,
>,
) {
for (transform, projection, mut frustum) in &mut views {
let view_projection =