Module prelude

Prelude module

Contains all of the most common traits, structures,

Structs

BitSet

A BitSet is a simple set designed to track which indices are placed into it.

ChangeSet

Change set that can be collected from an iterator, and joined on for easy application to components.

DenseVecStorage

Dense vector storage. Has a redirection 2-way table between entities and components, allowing to leave no gaps within the data.

Dispatcher

The dispatcher struct, allowing systems to be executed in parallel.

DispatcherBuilder

Builder for the Dispatcher.

Entity

Entity type, as seen by the user.

EntityBuilder

The entity builder, allowing to build an entity together with its components.

FlaggedStorage

Wrapper storage that tracks modifications, insertions, and removals of components through an EventChannel.

HashMapStorage

HashMap-based storage. Best suited for rare components.

LazyUpdate

Lazy updates can be used for world updates that need to borrow a lot of resources and as such should better be done at the end. They work lazily in the sense that they are dispatched when calling world.maintain().

NullStorage

A null storage type, used for cases where the component doesn’t contain any data and instead works as a simple flag.

Read

Allows to fetch a resource in a system immutably.

ReaderId

A reader ID which represents a subscription to the events pushed to the EventChannel.

Resources

A resource container, which provides methods to access to the contained resources.

StaticAccessor

The static accessor that is used for SystemData.

Storage

A wrapper around the masked storage and the generations vector. Can be used for safe lookup of components, insertions and removes. This is what World::read/write fetches for the user.

VecStorage

Vector storage. Uses a simple Vec. Supposed to have maximum performance for the components mostly present in entities.

World

The World struct contains the component storages and other resources.

Write

Allows to fetch a resource in a system mutably.

Enums

ComponentEvent

Component storage events received from a FlaggedStorage or any storage that implements Tracked.

Traits

Accessor

A trait for accessing read/write multiple resources from a system. This can be used to create dynamic systems that don’t specify what they fetch at compile-time.

Builder

A common trait for EntityBuilder and LazyBuilder, allowing either to be used. Entity is definitely alive, but the components may or may not exist before a call to World::maintain.

Component

Abstract component type. Doesn’t have to be Copy or even Clone.

Join

The purpose of the Join trait is to provide a way to access multiple storages at the same time with the merged bit set.

RunNow

Trait for fetching data and running systems. Automatically implemented for systems.

System

A System, executed with a set of required Resources.

SystemData

A static system data that can specify its dependencies at statically (at compile-time). Most system data is a SystemData, the DynamicSystemData type is only needed for very special setups.

Tracked

UnprotectedStorages that track modifications, insertions, and removals of components.

Type Aliases

Entities

A wrapper for a read Entities resource. Note that this is just Read<Entities>, so you can easily use it in your system:

ReadExpect

Allows to fetch a resource in a system immutably. This will panic if the resource does not exist. Usage of Read or Option<Read> is therefore recommended.

ReadStorage

A storage with read access.

WriteExpect

Allows to fetch a resource in a system mutably. This will panic if the resource does not exist. Usage of Write or Option<Write> is therefore recommended.

WriteStorage

A storage with read and write access.