Module prelude

The app prelude.

This includes the most common types in this crate, re-exported for your convenience.

Structs

App

App is the primary API for writing user applications. It automates the setup of a standard lifecycle and provides interface glue for plugins.

First

Runs first in the schedule.

FixedFirst

Runs first in the FixedMain schedule.

FixedLast

The schedule that runs last in FixedMain

FixedPostUpdate

The schedule that runs after the FixedUpdate schedule, for reacting to changes made in the main update logic.

FixedPreUpdate

The schedule that contains logic that must run before FixedUpdate.

FixedUpdate

The schedule that contains most gameplay logic, which runs at a fixed rate rather than every render frame. For logic that should run once per render frame, use the Update schedule instead.

Last

Runs last in the schedule.

Main

The schedule that contains the app logic that is evaluated each tick of App::update().

PostStartup

The schedule that runs once after Startup.

PostUpdate

The schedule that contains logic that must run after Update. For example, synchronizing “local transforms” in a hierarchy to “global” absolute transforms. This enables the PostUpdate transform-sync system to react to “local transform” changes in Update without the Update systems needing to know about (or add scheduler dependencies for) the “global transform sync system”.

PreStartup

The schedule that runs before Startup.

PreUpdate

The schedule that contains logic that must run before Update. For example, a system that reads raw keyboard input OS events into an Events resource. This enables systems in Update to consume the events from the Events resource without actually knowing about (or taking a direct scheduler dependency on) the “os-level keyboard event system”.

RunFixedMainLoop

Runs the FixedMain schedule in a loop according until all relevant elapsed time has been “consumed”.

SpawnScene

The schedule that contains scene spawning.

Startup

The schedule that runs once when the app starts.

SubApp

A secondary application with its own World. These can run independently of each other.

Update

The schedule that contains any app logic that must run once per render frame. For most gameplay logic, consider using FixedUpdate instead.

Enums

AppExit

An event that indicates the App should exit. If one or more of these are present at the end of an update, the runner will end and (maybe) return control to the caller.

RunFixedMainLoopSystem

Set enum for the systems that want to run inside RunFixedMainLoop, but before or after the fixed update logic. Systems in this set will run exactly once per frame, regardless of the number of fixed updates. They will also run under a variable timestep.

Traits

Plugin

A collection of Bevy app logic and configuration.

PluginGroup

Combines multiple Plugins into a single unit.