bevy_input

Keyboard, mouse, touch, and gamepad input. Defines the events, resources, and per-frame state types other crates write into. Backend-agnostic — bevy_winit and bevy_gilrs populate the events.

Purpose

The crate defines:

• Per-frame button state via ButtonInput<T> (ButtonInput<KeyCode>, ButtonInput<MouseButton>, ButtonInput<GamepadButton>).
• Axis state via Axis<T> (Axis<GamepadAxis>, Axis<MouseScrollAxis>).
• Events for raw input (KeyboardInput, MouseButtonInput, MouseMotion, MouseWheel, TouchInput, GamepadButtonChangedEvent, GamepadAxisChangedEvent, GamepadConnectionEvent).
• Components for connected gamepad entities.
• System sets in PreUpdate so other crates can place themselves before/after input gathering.

Directory layout

crates/bevy_input/src/
├── lib.rs           # InputPlugin
├── button_input.rs  # ButtonInput<T>
├── axis.rs          # Axis<T>
├── keyboard.rs      # KeyboardInput, KeyCode, NativeKey, NativeKeyCode
├── mouse.rs         # MouseButtonInput, MouseMotion, MouseWheel
├── touch.rs         # TouchInput, TouchPhase
├── gamepad.rs       # Gamepad component, GamepadButton, GamepadAxis, etc.
├── gestures.rs      # PinchGesture, RotationGesture, DoubleTap
└── prelude.rs

Key abstractions

Type	File	Description
ButtonInput<T>	crates/bevy_input/src/button_input.rs	pressed, just_pressed, just_released queries.
Axis<T>	crates/bevy_input/src/axis.rs	get(input) returns the current axis value.
KeyCode	crates/bevy_input/src/keyboard.rs	Position-independent key codes (matches winit).
MouseButton, MouseMotion, MouseWheel	crates/bevy_input/src/mouse.rs	Mouse types.
TouchInput, Touches	crates/bevy_input/src/touch.rs	Touch input state and events.
Gamepad, GamepadButton, GamepadAxis	crates/bevy_input/src/gamepad.rs	Gamepad entity components and types.

How it works

1. Backend (bevy_winit, bevy_gilrs) sends events.
2. update_input systems in PreUpdate move just_pressed/just_released flags from the previous frame.
3. User systems read ButtonInput and Axis resources, or read events directly with EventReader<KeyboardInput>.

A Gamepad is an entity, not a resource, so multiple controllers are first-class. Per-pad state (button input, axes) lives in components on that entity.

Integration points

• Depends on: bevy_app, bevy_ecs, bevy_math, bevy_reflect.
• Depended on by: bevy_winit, bevy_gilrs, bevy_picking, bevy_input_focus, bevy_ui, bevy_ui_widgets, …

Entry points for modification

• New input device kind: define types here; populate from a backend crate.
• New key code: keep the KeyCode enum aligned with winit's KeyCode.
• New gesture: gestures.rs.

See also

• bevy_winit, bevy_gilrs — backends.
• bevy_input_focus — keyboard focus routing.
• bevy_picking — pointer events.