bevy_quadtree

bevy_quadtree

A quadtree plugin for Bevy
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About The Project

A quadtree plugin for bevy.

Function:

• Auto update following Changed<GlobalTransform>, all users need to do is querying.
• LooseQuadTree supported.

Features:

• gizmos: show gizmos of the quadtree boundaries.
• sprite: enable CollisionRect and CollisionRotatedRect to track sprite.custom_size.
• multi-quadtree: support multiple quadtrees in one world, see [MultiQuadTreePlugin].

Version:

To align with Bevy, the version is always the same as supported Bevy's version.

Caution

For those who upgrade from version <= 0.15.1-alpha7, pay attention to the new type paramter D in QuadTreePlugin. And shapes now have ID as well. Moreover, the tree memory is pre-allocated, no longer dynamically allocating.

For those who upgrade from version <= 0.15.1-beta.2, X Y type params added to Plugins to set the origin of boundary. The QuadTree's type params is simplified to only ID as well.

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Built With

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Usage

1. Add the plugin to your Cargo.toml:

[dependencies]
bevy_quadtree = { version = "0.16.0" }

2. Add the plugin to your Bevy app:

# #[cfg(feature = "sprite")]
{
# use bevy_app::prelude::*;
# use bevy_transform::prelude::*;
# use bevy_sprite::Sprite;
use bevy_quadtree::{QuadTreePlugin, CollisionCircle, CollisionRect};

fn main() {
    App::new()
        .add_plugins(QuadTreePlugin::<(
                (CollisionCircle, GlobalTransform), (CollisionRect, (GlobalTransform, Sprite)),
            ),
            40, 8, 100, 100, 0, 0, 20, 114514>::default()
        )
        // CollisionCircle follows GlobalTransform, CollisionRect follows Sprite and GlobalTransform
        // at most 40 entities in a node
        // at most 8 levels
        // 100 x 100 world size, center at (0, 0)
        // 20 / 10 = 2.0 = outlet_boundary / inlet_boundary (for loose quadtree)
        // quadtree id 114514
        .run();
}
# }

3. Spawn CollisionShapes as Components:

// in systems
cmds.spawn((
    Sprite {
        color: Color::WHITE,
        custom_size: Some(CUSTOM_SIZE),
        ..Default::default()
    },
    // Spawn collision shape `CollisionRect` with `Sprite`,
    // the plugin will auto-update it following `Changed<GlobalTransform>` and `Changed<Sprite>`
    CollisionRect::from(Rect::from_center_size(pos, CUSTOM_SIZE)),
    Transform::from_xyz(pos.x, pos.y, 1.),
))

4. Query the quadtree like bevy's Or, Not:

// default id 0
type MyQuadTree = QuadTree<114514>;

fn pick(
    mut gizmos: Gizmos,
    btn: Res<ButtonInput<MouseButton>>,
    key: Res<ButtonInput<KeyCode>>,
    quadtree: Res<MyQuadTree>,
    mut start: Local<Option<Vec2>>,
    ...
) {
    if !btn.pressed(MouseButton::Left) {
        *start = None;
        return;
    }
    let world_position = ...;
    let cancel_pick = key.any_pressed([KeyCode::ShiftLeft, KeyCode::ShiftRight]);
    match *start {
        Some(start) => {
            gizmos.rect_2d(
                (start + world_pos) / 2.,
                (start - world_pos).abs(),
                if cancel_pick { RED } else { WHITE },
            );
            let res = if start.x > world_pos.x {
                // left pick
                quadtree.query::<QOr<(Overlap, Contain)>>(&CollisionRect::from(
                    Rect::from_corners(start, world_pos),
                ))
            } else {
                // right pick
                quadtree
                    .query::<Contain>(&CollisionRect::from(Rect::from_corners(start, world_pos)))
            };
            if cancel_pick {
                ...
            } else {
                ...
            }
        }
        None => *start = Some(world_pos),
    }
}

5. However, you may need manually update collision shapes in some cases

xx.observe(
    |trigger: Trigger<TextRefreshEvent>,
     mut q_box: Query<(&mut Sprite, &mut CollisionRect)>| {
        if let Ok((mut s, mut c)) = q_box.get_mut(trigger.entity()) {
            let ev = trigger.event();
            let delta = Vec2::new(ev.width * FONT_WIDTH, (ev.height - 1.) * FONT_HEIGHT);
            s.custom_size = Some(CUSTOM_SIZE + delta);
            // the plugin default only track `Changed<GlobalTransform>`
            // without feature `sprite` enabled, you can also do this way.
            c.set_init_size(CUSTOM_SIZE + delta);
        }
    },
)

See this repo graph for more complete examples.

For more details, please refer to the Documentation

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Roadmap

• Feature

See the open issues for a full list of proposed features (and known issues).

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Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

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License

Distributed under the MIT License. See LICENSE.txt for more information.

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Contact

Louis - 836250617@qq.com

Project Link: https://github.com/kingwingfly/bevy_quadtree

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Acknowledgments

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