Another week, another #bevymergetrain for the #bevy crew :) As is now tradition, I'm going to go over the community-approved (that means you!) PRs for our #opensource #rust game engine.
Despite cleaning them all out last week, there's apparently another 33 PRs already?? https://github.com/bevyengine/bevy/pulls?q=is%3Aopen+is%3Apr+label%3AS-Ready-For-Final-Review
1. https://github.com/bevyengine/bevy/pull/18916
Ha, minimized windows: the bane of #gamedev. So many divide-by-zero bugs! Today, we're fixing a crash when minimizing a window with custom viewports. We've managed to fix a dozen of these already, so it make sense that this is niche. LGTM, merging :)
Objective Fix a crash when minimizing a window. (#16704) It happens when the window contains Camera with a custom Viewport. Solution Remove ExtractedCamera when the corresponding camera in main wor...
2. https://github.com/bevyengine/bevy/pull/19117
An edge case bug in our asset loading. The `meta_transform` here is "how to modify the asset metadata".
This is incorrect by inspection, so I'm going to merge it. We do badly need more tests for bevy_assets still though: so many edge cases. Maybe we can fuzz?
Solution While poking around NestedLoader I noticed that one code path fails to pass on the loader's meta transform. - .get_or_create_path_handle(path, None) + .get_or_create_path_handle(path, ...
3. https://github.com/bevyengine/bevy/pull/19138
More on_unimplemented custom diagnostics for #rust :D I love this feature so much. Very simple diagnostic (just "this isn't a read-only system"), but should still make a big difference. The type alias is perfectly sensible too.
Merge conflicts, so pinging the OP.
4. https://github.com/bevyengine/bevy/pull/19559
PR description looks reasonable: a code quality / usability fix to how we handle glyph positions. But uh, what the +40k/-17k diff?! Oh, git screwed up :( This needs to be rebased, which should fix the diff. Author has already been pinged, but let me try on Discord...
5. https://github.com/bevyengine/bevy/pull/19586
Oh-ho-ho: improvements to our scrolling example. I'm excited to continue improving our UI examples, since we have the bare bones of a real widget library now: both headless and via bevy_feathers.
This is rebased, so it's time to merge :)
6. https://github.com/bevyengine/bevy/pull/19922
A simple cleanup of our reflection code (which will help a tiny bit with compile times). The interesting bit here is my back-and-forth with nnethercote about why we use squash-on-merge. TL;DR: it's really nice to be able to bisect the history.
Squashing and merging ;)
Objective Follow on fixes for #19876, using active_types instead of active_fields where appropriate. Helps a tiny bit with #19873. Solution Describe the solution used to achieve the objective abov...
7. https://github.com/bevyengine/bevy/pull/19999
More RenderStartup! I really love this set of changes: it makes the ordering of our rendering initialization much more controllable and explicit. And it reduces the stupid "plugin initialization order dependency' woes.
I'm surprised this is negative LOC! LGTM; merging.
Objective Progress towards Use RenderStartup instead of a FromWorld impl whenever possible #19887. Solution For cases that don't need to conditionally add systems, we can just replace FromWo...
8. https://github.com/bevyengine/bevy/pull/20002
And a second RenderStartup PR :D Thank goodness for having at least *some* automated rendering testing now: it makes these changes much more reliable.
Same deal here: merging.
Objective Progress towards Use RenderStartup instead of a FromWorld impl whenever possible #19887. Solution Convert FromWorld impls into systems. Run those systems in RenderStartup. Testing Ra...
9. https://github.com/bevyengine/bevy/pull/20016
A TOCTOU bug in our ECS internals. No, no, not the cryptocurrency scammer! For those with an unconventional background in #programming like myself, TOCTOU means Time of Check Time of Use: a common class of bugs that's caused by the data changing after your check.
Objective Fix ComponentsQueuedRegistrator::queue_register_component does not ensure components are registered only once #20014 Solution Don't make the force_register_ family of functions alw...
10. https://github.com/bevyengine/bevy/pull/20023
Apparently we missed adding release notes for light textures! Well, that's an easy fix, and it's nice we can just make a follow-up PR.
These are a little rough and will need editing, but that's an expected part of our release workflow. I'm just glad we remembered!
11. https://github.com/bevyengine/bevy/pull/20053
Another missed release note: this time about the faster zstd backend. I think this needs more context about what zstd is and why this is important enough to warrant a release note, but we can hash that out in the final editing process. Sure, merging.
12. https://github.com/bevyengine/bevy/pull/20055
A feature flag fix: you *really* only want to enable dependency features in #rust if you actually need it, because features are additive and cannot be later disabled.
Perfectly reasonable fix: merging. Boy i wish there was better tooling for this though.
Objective Fixes bevy_ui_picking_backend feature can't be disabled #19742 Solution Initially I made it an optional feature on bevy_core_widgets and piped it through to bevy_internal, but then...
13. https://github.com/bevyengine/bevy/pull/20065
A really interesting PR that allows us to move components from one entity to another even if they aren't `Clone`. Intuitively makes a lot of sense, but the details were tricky. Very high quality engineering by eugineerd, and excellent review by urben.
Merging :)
Objective Fix #18079 Solution EntityCloner can now move components that don't have Clone or Reflect implementation. Components with ComponentCloneBehavior::Ignore will not be moved. Components...
> I believe fixing known bugs outweighs [code cleanup] for now.
Good take! This is the way: fix the bugs, add tests, then refactor to something cleaner. I increasingly think that we're sharing too much between moving / cloning components, but I trust them to figure out a solution in the future.
14. https://github.com/bevyengine/bevy/pull/20077
Why is it always edge cases? Rendering features are so tricky to ship because of the complex interaction between features. Good work detecting this bug, and good job fixing it.
We could use more rendering tests to test all these combinations, but merging the fix now.
Fixes objects being lit by environment map light not having the anisotropy effect applied correctly. The contribution of light from the environment map with anisotropy is calculated but immediately...
15. https://github.com/bevyengine/bevy/pull/20082
Shape sampling for rhombuses! Sure, I can see this being useful to someone at some point. Maybe isometric tile-based games? I like that the trait-based design lets us gradually add these methods one at a time while ensuring consistency.
Merging.
16. https://github.com/bevyengine/bevy/pull/20083
Another bug fix from the author before. Clearly a skilled rendering engineer, but they're new around these parts. Neat! Only a partial fix for forward rendering only, but that's better than nothing.
Spinning up a follow-up and merging.
Objective Fix lightmapped materials not respecting the AmbientLight::affects_lightmapped_meshes setting. NOTE: This only makes the setting work on the forward renderer. Making it work on the deferr...
17. https://github.com/bevyengine/bevy/pull/20089
Ah, Jan's work to carefully document how to move your camera when working with a fixed timestep. This is a massive pain in the ass to do right. I wish it was easier to do right, but for now, documenting the arcane arrangement is really nice.
Objective Since I originally wrote this example, many people on Discord have asked me specifically how to handle camera movement in and around fixed timesteps. I had to write that information up ma...
Extremely clear and helpful. Lots of words, but I think it's warranted here.
Interestingly, even when we have a built-in fly cam, I wouldn't replace this! These details are critical to users: we should present them directly, rather than hiding them.
I'm happy with this: let's merge it in :)
18. https://github.com/bevyengine/bevy/pull/20090
Bevy uses the "latest stable" #rust as its MSRV. That means we can use let chains today to clean things up! Oh yeah baby, give me that +17/-34 diff :D
Merging.
19. https://github.com/bevyengine/bevy/pull/20096
Oh nice, some doc tests demonstrating how to use `camera_to_world`. They even mention the timing needed to ensure that transform propagation has taken place! Very terse, I love it. Bevy really is a research project some days, but that extends to API design.
Merging.
Objective Add doc examples to viewport_to_world and viewport_to_world_2d. With Single and let chains these can be very concise now :) Rendered: I changed my mind on how much to limit the decimal ...
20. https://github.com/bevyengine/bevy/pull/20097
A broken link to the shiny new bevy_solari logo. We can't be having that! The link now works: it's merging time :D I love love love tiny PRs: they're so easy to just merge.
21. https://github.com/bevyengine/bevy/pull/20098
Speaking of tiny PRs: slap some const on that function. Yay const floating point arithmetic for making this possible. Merging.
I poked at this for bevy_color the other day, but we need const trait methods to really improve things there :( const fn lighten plz!
22. https://github.com/bevyengine/bevy/pull/20101
Another iteration (within 0.17) on our event trait hierarchy. This time, we're finally killing the shared trait between buffered and observer traits entirely. Cart's on board with this too, so I marked this Blessed.
23. https://github.com/bevyengine/bevy/pull/20104
And a second PR in this vein: automatically deriving the root `Event` trait (shared by both targeted and untargeted observer events). I'm not super-keen on how implicit the "also derive this other trait" pattern is, but I understand Cart's aversion to boilerplate.
Objective Since we are planning to remove the need to derive both Event and EntityEvent in 0.17 either way, I'm choosing to do the easy thing in this PR so we can get the churn out of the way e...
24. https://github.com/bevyengine/bevy/pull/20108
Want to clone some struct and you can't? Tell us why you're trying to do that and then slap some Clone on that struct. I'm pretty sure this particular request is for some cursed meta-scheduling abstraction lol.
I'm fine with that though: let's merge this.
25. https://github.com/bevyengine/bevy/pull/20112
Hang on, GPU memory allocation isn't blocking? What on earth is going on here. This is definitely over my head: I'm going to ask Rob Swain, my fellow maintainer and rendering expert for his help. This whole API feels off, and I'm not confident here.
26. https://github.com/bevyengine/bevy/pull/20118
Ah, this is more my speed of rendering PR: assorted cleanups! These changes all look fine: merging.
We should really be linting for .get_resource + .unwrap: lemme ask the CLI group....
27. https://github.com/bevyengine/bevy/pull/20120
I see folks are making good use of the `HierarchyPropagatePlugin` :D Very nice little feature! We should probably call that out in the release notes. Issue time.
This particular PR just adds some traits to `NotShadowCaster`: trivial and very reasonable. Merging :)
28. https://github.com/bevyengine/bevy/pull/20124
`RenderStartup` again! This time for examples :D Good stuff: it's nice to teach this to users. Merging :)
Objective Progress towards Use RenderStartup instead of a FromWorld impl whenever possible #19887. I am avoiding dealing with the occlusion_culling example since it is kinda annoying to resolve ni...
29. https://github.com/bevyengine/bevy/pull/20126
Another reflection cleanup / compile time optimization PR. TIL that you can rely on default method impls to improve compile times in #rust. I mean, it makes sense! I'd just never connected the dots. Merging :) Thanks for getting nerd-sniped so thoroughly :D
30. https://github.com/bevyengine/bevy/pull/20127
Crosslinks to a little ECS helper: `ComponentIdFor`. I call these sort of documentation crosslinks "bread crumbs" (since you can follow the trail and get gobbled up by a witch), and they're shockingly useful to users. That's level design baby!
Very reasonable; merging.
31. https://github.com/bevyengine/bevy/pull/20130
Math for #gamedev is weird: there's a ton of little tasks that you need to do constantly, but you can't assume your users are particularly good at the fundamentals needed to derive it from scratch. Very happy to have a "closest point to this line segment" method!
This PR is particularly lovely though: it comes with ASCII art comments, tests and clear code. TIL you can use full words for variable names in math code ;)
Thanks: this sort of work really exemplifies how I feel tools should work. Think about the common cases and make them easy. Merging.
And phew! We're done! Looks like my fellow maintainers have snagged a few of the PRs while I was doing this, so our count was off :p
The merge trains are a big time and energy commitment, but I really love doing them. They force me to reflect on each PR, and communicate a lot of silent context.
Thanks for following along, and please don't hesitate to comment and ask follow-up questions! Those are always my favorite <3
If you love these threads too, please consider contributing or donating to #bevy. I am so grateful I can do this as my fulltime job, and never want that to change.
Alice I. Cecile
chantey