bevy/crates/bevy_pbr
James Liu bef9bc1844 Reduce branching in TrackedRenderPass (#7053)
# Objective
Speed up the render phase for rendering.

## Solution
 - Follow up #6988 and make the internals of atomic IDs `NonZeroU32`. This niches the `Option`s of the IDs in draw state, which reduces the size and branching behavior when evaluating for equality.
 - Require `&RenderDevice` to get the device's `Limits` when initializing a `TrackedRenderPass` to preallocate the bind groups and vertex buffer state in `DrawState`, this removes the branch on needing to resize those `Vec`s.

## Performance
This produces a similar speed up akin to that of #6885. This shows an approximate 6% speed up in `main_opaque_pass_3d` on `many_foxes` (408.79 us -> 388us). This should be orthogonal to the gains seen there.

![image](https://user-images.githubusercontent.com/3137680/209906239-e430f026-63c2-4b95-957e-a2045b810d79.png)

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## Changelog
Added: `RenderContext::begin_tracked_render_pass`.
Changed: `TrackedRenderPass` now requires a `&RenderDevice` on construction.
Removed: `bevy_render::render_phase::DrawState`. It was not usable in any form outside of `bevy_render`.

## Migration Guide
TODO
2023-01-09 19:24:56 +00:00
..
src Reduce branching in TrackedRenderPass (#7053) 2023-01-09 19:24:56 +00:00
Cargo.toml Release 0.9.0 (#6568) 2022-11-12 20:01:29 +00:00