Remove unnecessary calls to `iter()`/`iter_mut()`.
Mainly updates the use of queries in our code, docs, and examples.
```rust
// From
for _ in list.iter() {
for _ in list.iter_mut() {
// To
for _ in &list {
for _ in &mut list {
```
We already enable the pedantic lint [clippy::explicit_iter_loop](https://rust-lang.github.io/rust-clippy/stable/) inside of Bevy. However, this only warns for a few known types from the standard library.
## Note for reviewers
As you can see the additions and deletions are exactly equal.
Maybe give it a quick skim to check I didn't sneak in a crypto miner, but you don't have to torture yourself by reading every line.
I already experienced enough pain making this PR :)
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
Partially addresses #4291.
Speed up the sort phase for unbatched render phases.
## Solution
Split out one of the optimizations in #4899 and allow implementors of `PhaseItem` to change what kind of sort is used when sorting the items in the phase. This currently includes Stable, Unstable, and Unsorted. Each of these corresponds to `Vec::sort_by_key`, `Vec::sort_unstable_by_key`, and no sorting at all. The default is `Unstable`. The last one can be used as a default if users introduce a preliminary depth prepass.
## Performance
This will not impact the performance of any batched phases, as it is still using a stable sort. 2D's only phase is unchanged. All 3D phases are unbatched currently, and will benefit from this change.
On `many_cubes`, where the primary phase is opaque, this change sees a speed up from 907.02us -> 477.62us, a 47.35% reduction.
## Future Work
There were prior discussions to add support for faster radix sorts in #4291, which in theory should be a `O(n)` instead of a `O(nlog(n))` time. [`voracious`](https://crates.io/crates/voracious_radix_sort) has been proposed, but it seems to be optimize for use cases with more than 30,000 items, which may be atypical for most systems.
Another optimization included in #4899 is to reduce the size of a few of the IDs commonly used in `PhaseItem` implementations to shrink the types to make swapping/sorting faster. Both `CachedPipelineId` and `DrawFunctionId` could be reduced to `u32` instead of `usize`.
Ideally, this should automatically change to use stable sorts when `BatchedPhaseItem` is implemented on the same phase item type, but this requires specialization, which may not land in stable Rust for a short while.
---
## Changelog
Added: `PhaseItem::sort`
## Migration Guide
RenderPhases now default to a unstable sort (via `slice::sort_unstable_by_key`). This can typically improve sort phase performance, but may produce incorrect batching results when implementing `BatchedPhaseItem`. To revert to the older stable sort, manually implement `PhaseItem::sort` to implement a stable sort (i.e. via `slice::sort_by_key`).
Co-authored-by: Federico Rinaldi <gisquerin@gmail.com>
Co-authored-by: Robert Swain <robert.swain@gmail.com>
Co-authored-by: colepoirier <colepoirier@gmail.com>
# Objective
The current 2d rendering is specialized to render sprites, we need a generic way to render 2d items, using meshes and materials like we have for 3d.
## Solution
I cloned a good part of `bevy_pbr` into `bevy_sprite/src/mesh2d`, removed lighting and pbr itself, adapted it to 2d rendering, added a `ColorMaterial`, and modified the sprite rendering to break batches around 2d meshes.
~~The PR is a bit crude; I tried to change as little as I could in both the parts copied from 3d and the current sprite rendering to make reviewing easier. In the future, I expect we could make the sprite rendering a normal 2d material, cleanly integrated with the rest.~~ _edit: see <https://github.com/bevyengine/bevy/pull/3460#issuecomment-1003605194>_
## Remaining work
- ~~don't require mesh normals~~ _out of scope_
- ~~add an example~~ _done_
- support 2d meshes & materials in the UI?
- bikeshed names (I didn't think hard about naming, please check if it's fine)
## Remaining questions
- ~~should we add a depth buffer to 2d now that there are 2d meshes?~~ _let's revisit that when we have an opaque render phase_
- ~~should we add MSAA support to the sprites, or remove it from the 2d meshes?~~ _I added MSAA to sprites since it's really needed for 2d meshes_
- ~~how to customize vertex attributes?~~ _#3120_
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release.
The examples are all ported over and operational with a few exceptions:
* I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure.
* Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example.
* Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority.
