big_space_with_trim/CHANGELOG.md

Changelog

UNRELEASED

Updated: Bevy 0.16

Due to changes in bevy, this plugin once again requires you to disable bevy's built-in transform system:

DefaultPlugins.build().disable::<TransformPlugin>(),

Changed: BigSpaceDefaultPlugins plugin group

Instead of adding common plugins individually, they have been grouped into the BigSpaceDefaultPlugins plugin group, similar to the DefaultPlugins plugin group in Bevy.

For example, the hierarchy validation plugin is enabled whenever debug assertions are enabled but can be manually enabled or disabled to override this behavior:

BigSpaceDefaultPlugins
    .build()
    .enable::<BigSpaceValidationPlugin>()

Plugins that are behind feature flags are automatically enabled when their corresponding feature is enabled. For example, you no longer need to manually add the camera controller plugin, you only need to enable the feature and add BigSpaceDefaultPlugins to your app.

This replaces BigSpacePlugin.

The existing plugin structure has been organized into more fine grained plugins, with the addition of the BigSpaceMinimalPlugins composed of BigSpaceCorePlugin and BigSpacePropagationPlugin. These are particularly useful for tests, benchmarks, and serverside applications. Future serverside physics will likely only use the BigSpaceCorePlugin to handle grid cell recentering, and not do any propagation which is only needed for rendering.

Changed: Naming consistency

To avoid common name collisions and improve searchability, names have been standardized:

• FloatingOriginSystem -> BigSpaceSystems
• CameraControllerPlugin -> BigSpaceCameraControllerPlugin
  • CameraController -> BigSpaceCameraController
  • CameraInput -> BigSpaceCameraInput
• TimingStatsPlugin -> BigSpaceTimingStatsPlugin
• FloatingOriginDebugPlugin -> BigSpaceDebugPlugin
• BigSpaceValidationPlugin (new)
• BigSpaceDefaultPlugins (new)
• BigSpaceMinimalPlugins (new)
• BigSpaceCorePlugin (new)
• BigSpacePropagationPlugin (new)

Changed: Default plugin filters

Plugins that accept an optional query filter no longer require specifying the default empty filter tuple turbofish ::<()>:

• GridHashPlugin::<()>::default() -> GridHashPlugin::default()
• GridPartitionPlugin::<()>::default() -> GridPartitionPlugin::default()

To construct a plugin with a custom filter, use the new() method: GridHashPlugin::<With<Player>>::new()

New: no_std Support

Thanks to bushrat011899's efforts upstream and in this crate, it is now possible to use the plugin without the rust standard library. This is particularly useful when targeting embedded or console targets.

v0.9.0 - 2024-12-23

New: GridCell Spatial Hashing

Spatial hashing makes fast spatial queries and neighbor lookups possible. This release adds the GridHashMap, an automatically updated map of the entities in each grid cell. This makes it possible to query things like:

• What other entities are in the same cell as this entity?
• Are these two entities in the same cell?
• What entities are in adjacent grid cells?

This introduces a new component, the GridHash, which is automatically kept up to date, and stores a precomputed hash. This makes the spatial hash map especially fast, because hashing is only done when an entity moves between cells, not every time a hash map lookup is needed.

The map has received a few rounds of optimization passes to make incremental updates and neighbor lookups especially fast. This map does not suffer from hash collisions.

New: Spatial Partitioning

Built on top of the new spatial hashing feature is the GridPartitionMap. This map tracks groups of adjacent grid cells that have at least one entity. Each of these partitions contains many entities, and each partition is independent. That is, entities in partition A are guaranteed to be unable to collide with entities in partition B.

This lays the groundwork for adding physics integrations. Because each partition is a clump of entities independent of all other entities, it should be possible to have independent physics simulations for each partition. Not only will this allow for extreme parallelism, it becomes possible to use 32-bit physics simulations in a 160-bit big_space.

ReferenceFrame Renamed Grid

While revisiting documentation, it became clear that the naming scheme can be confusing and inconsistent. Most notably, it wasn't immediately clear there is a relationship between ReferenceFrame and GridCell. Additionally, there were multiple places where reference frames were clarified to be fixed precision grids.

To clear this up, ReferenceFrame has been renamed Grid. The core spatial types in this library are now:

• Grid: Defines the size of a grid for its child cells.
• GridCell: Cell index of an entity within its parent's grid.
• GridPrecision: Integer precision of a grid.

The newly added types follow this pattern:

• GridHash: The spatial hash of an entity's grid cell.
• GridHashMap: A map for entity, grid cell, and neighbor lookups.
• GridPartition: Group of adjacent grid cells.
• GridPartitionMap: A map for finding independent partitions of entities.

It should now be more clear how all of the Grid types are related to each other.