bevy_pancam

A 2d camera plugin for bevy that works with orthographic cameras.

The motivation is that this could be used for something like a map editor for a 2d game.

Controls

Behaves similarly to common online map applications:

• Click and drag to move the camera
• Scroll to zoom
• Hold keyboard buttons to move the camera

Usage

Add the plugin to your app

App::new()
    .add_plugins((DefaultPlugins, PanCamPlugin::default()))
    .run();

Add the component to an orthographic camera:

commands.spawn((
    Camera2d,
    PanCam::default(),
))

This is enough to get going with sensible defaults.

Alternatively, set the fields of the PanCam component to customize behavior:

commands.spawn((
    Camera2d,
    PanCam {
        grab_buttons: vec![MouseButton::Left, MouseButton::Middle], // which buttons should drag the camera
        move_keys: DirectionKeys {      // the keyboard buttons used to move the camera
            up:    vec![KeyCode::KeyQ], // initalize the struct like this or use the provided methods for
            down:  vec![KeyCode::KeyW], // common key combinations
            left:  vec![KeyCode::KeyE],
            right: vec![KeyCode::KeyR],
        },
        speed: 400., // the speed for the keyboard movement
        enabled: true, // when false, controls are disabled. See toggle example.
        zoom_to_cursor: true, // whether to zoom towards the mouse or the center of the screen
        min_scale: 1., // prevent the camera from zooming too far in
        max_scale: 40., // prevent the camera from zooming too far out
        min_x: f32::NEG_INFINITY, // minimum x position of the camera window
        max_x: f32::INFINITY, // maximum x position of the camera window
        min_y: f32::NEG_INFINITY, // minimum y position of the camera window
        max_y: f32::INFINITY, // maximum y position of the camera window
    },
));

See the simple and toggle examples.

Cargo features

• bevy_egui_<major>_<minor> makes pancam cameras not react when the mouse or keyboard focus is on widgets created with the specific bevy_egui release. The feature is suffixed with the egui version because bevy_egui typically releases multiple breaking versions per Bevy release, and we don't want to be forced to break on every bevy_egui release.

Bevy Version Support

The main branch targets the latest bevy release.

License

bevy_pancam is dual-licensed under either

• MIT License (./LICENSE-MIT or http://opensource.org/licenses/MIT)
• Apache License, Version 2.0 (./LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)

at your option.

Contributions

PRs welcome!