bevy/examples/stress_tests
ickshonpe c5742ff43e
Simplified ui_stack_system (#9889)
# Objective

`ui_stack_system` generates a tree of `StackingContexts` which it then
flattens to get the `UiStack`.

But there's no need to construct a new tree. We can query for nodes with
a global `ZIndex`, add those nodes to the root nodes list and then build
the `UiStack` from a walk of the existing layout tree, ignoring any
branches that have a global `Zindex`.

Fixes #9877

## Solution

Split the `ZIndex` enum into two separate components, `ZIndex` and
`GlobalZIndex`

Query for nodes with a `GlobalZIndex`, add those nodes to the root nodes
list and then build the `UiStack` from a walk of the existing layout
tree, filtering branches by `Without<GlobalZIndex>` so we don't revisit
nodes.

```
cargo run --profile stress-test --features trace_tracy --example many_buttons
```

<img width="672" alt="ui-stack-system-walk-split-enum"
src="https://github.com/bevyengine/bevy/assets/27962798/11e357a5-477f-4804-8ada-c4527c009421">

(Yellow is this PR, red is main)

---

## Changelog
`Zindex`
* The `ZIndex` enum has been split into two separate components `ZIndex`
(which replaces `ZIndex::Local`) and `GlobalZIndex` (which replaces
`ZIndex::Global`). An entity can have both a `ZIndex` and
`GlobalZIndex`, in comparisons `ZIndex` breaks ties if two
`GlobalZIndex` values are equal.

`ui_stack_system`
* Instead of generating a tree of `StackingContexts`, query for nodes
with a `GlobalZIndex`, add those nodes to the root nodes list and then
build the `UiStack` from a walk of the existing layout tree, filtering
branches by `Without<GlobalZIndex` so we don't revisit nodes.

## Migration Guide

The `ZIndex` enum has been split into two separate components `ZIndex`
(which replaces `ZIndex::Local`) and `GlobalZIndex` (which replaces
`ZIndex::Global`). An entity can have both a `ZIndex` and
`GlobalZIndex`, in comparisons `ZIndex` breaks ties if two
`GlobalZindex` values are equal.

---------

Co-authored-by: Gabriel Bourgeois <gabriel.bourgeoisv4si@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: UkoeHB <37489173+UkoeHB@users.noreply.github.com>
2024-09-30 18:43:57 +00:00
..
bevymark.rs Simplified ui_stack_system (#9889) 2024-09-30 18:43:57 +00:00
many_animated_sprites.rs Remove redundant imports (#12817) 2024-04-01 19:59:08 +00:00
many_buttons.rs Have EntityCommands methods consume self for easier chaining (#14897) 2024-08-26 18:24:59 +00:00
many_cubes.rs Fix floating point math (#15239) 2024-09-16 23:28:12 +00:00
many_foxes.rs Simpler lint fixes: makes ci lints work but disables a lint for now (#15376) 2024-09-24 11:42:59 +00:00
many_gizmos.rs Fix floating point math (#15239) 2024-09-16 23:28:12 +00:00
many_glyphs.rs Add the ability to control font smoothing (#15368) 2024-09-23 17:28:25 +00:00
many_lights.rs Fix floating point math (#15239) 2024-09-16 23:28:12 +00:00
many_sprites.rs Remove redundant imports (#12817) 2024-04-01 19:59:08 +00:00
README.md Add a stress test profile (#6901) 2022-12-20 15:59:41 +00:00
text_pipeline.rs Add the ability to control font smoothing (#15368) 2024-09-23 17:28:25 +00:00
transform_hierarchy.rs Migrate bevy_transform to required components (#14964) 2024-09-27 17:06:48 +00:00
warning_string.txt Added performance warning when running stress test examples in debug mode (#5029) 2022-07-13 19:13:46 +00:00

Stress tests

These examples are used to stress test Bevy's performance in various ways. These should be run with the "stress-test" profile to accurately represent performance in production, otherwise they will run in cargo's default "dev" profile which is very slow.

Example Command

cargo run --profile stress-test --example <EXAMPLE>