mirror of
https://github.com/bevyengine/bevy
synced 2025-01-02 08:18:59 +00:00
55ca7fc88e
# Objective Fixes #4884. `ComponentTicks` stores both added and changed ticks contiguously in the same 8 bytes. This is convenient when passing around both together, but causes half the bytes fetched from memory for the purposes of change detection to effectively go unused. This is inefficient when most queries (no filter, mutating *something*) only write out to the changed ticks. ## Solution Split the storage for change detection ticks into two separate `Vec`s inside `Column`. Fetch only what is needed during iteration. This also potentially also removes one blocker from autovectorization of dense queries. EDIT: This is confirmed to enable autovectorization of dense queries in `for_each` and `par_for_each` where possible. Unfortunately `iter` has other blockers that prevent it. ### TODO - [x] Microbenchmark - [x] Check if this allows query iteration to autovectorize simple loops. - [x] Clean up all of the spurious tuples now littered throughout the API ### Open Questions - ~~Is `Mut::is_added` absolutely necessary? Can we not just use `Added` or `ChangeTrackers`?~~ It's optimized out if unused. - ~~Does the fetch of the added ticks get optimized out if not used?~~ Yes it is. --- ## Changelog Added: `Tick`, a wrapper around a single change detection tick. Added: `Column::get_added_ticks` Added: `Column::get_column_ticks` Added: `SparseSet::get_added_ticks` Added: `SparseSet::get_column_ticks` Changed: `Column` now stores added and changed ticks separately internally. Changed: Most APIs returning `&UnsafeCell<ComponentTicks>` now returns `TickCells` instead, which contains two separate `&UnsafeCell<Tick>` for either component ticks. Changed: `Query::for_each(_mut)`, `Query::par_for_each(_mut)` will now leverage autovectorization to speed up query iteration where possible. ## Migration Guide TODO |
||
|---|---|---|
| .. | ||
| blob_vec.rs | ||
| mod.rs | ||
| resource.rs | ||
| sparse_set.rs | ||
| table.rs | ||