# Objective
- Fix sprite rendering performance regression since retained render
world changes
- The retained render world changes moved `ExtractedSprites` from using
the highly-optimised `EntityHasher` with an `Entity` to using
`FixedHasher` with `(Entity, MainEntity)`. This was enough to regress
framerate in bevymark by 25%.
## Solution
- Move the render world entity into a member of `ExtractedSprite` and
change `ExtractedSprites` to use `MainEntityHashMap` for its storage
- Disable sprite picking in bevymark
## Testing
M4 Max. `bevymark --waves 100 --per-wave 1000 --benchmark`. main in
yellow vs PR in red:
<img width="590" alt="Screenshot 2025-01-01 at 16 36 22"
src="https://github.com/user-attachments/assets/1e4ed6ec-3811-4abf-8b30-336153737f89"
/>
20.2% median frame time reduction.
<img width="594" alt="Screenshot 2025-01-01 at 16 38 37"
src="https://github.com/user-attachments/assets/157c2022-cda6-4cf2-bc63-d0bc40528cf0"
/>
49.7% median extract_sprites execution time reduction.
Comparing 0.14.2 yellow vs PR red:
<img width="593" alt="Screenshot 2025-01-01 at 16 40 06"
src="https://github.com/user-attachments/assets/abd59b6f-290a-4eb6-8835-ed110af995f3"
/>
~6.1% median frame time reduction.
---
## Migration Guide
- `ExtractedSprites` is now using `MainEntityHashMap` for storage, which
is keyed on `MainEntity`.
- The render world entity corresponding to an `ExtractedSprite` is now
stored in the `render_entity` member of it.
fd330c834f