bevy_rectray

A minimal 2d layout system (that works in 3d!) for bevy.

Getting Started

First add RectrayPlugin.

app.add_plugins(RectrayPlugin)

Then add RectrayFrame to a parent entity. This effectively creates a 2d rectangular space around the local x and y axis of the entity's Transform.

commands.spawn(
    SpacialBundle {
        ...
    },
    RectrayFrame::from_dimension(Vec2::new(1024., 768.)),
)

To place descendant entities inside the frame, add Transform2D and Dimension next to entities with Transforms.

commands.spawn (
    Transform { .. },
    Transform2D { .. },
    Dimension { .. },
)

Since we only operate on Transform, bevy_rectray works in Transform - Transform2d - Transform sandwich situations.

Integration

bevy_rectray is minimal and does not magically react to changes in bevy components. We take in Transform2D and Dimension and produces Transform and RotatedRect.

Some of those data can come from external sources. For example if you want to make all Sprites take up space of its Image or custom_size, add a system like this manually:

pub fn update_sprite_dimension(
    scaling_factor: Query<&Window, With<PrimaryWindow>>,
    mut query: Query<(&mut Sprite, &Handle<Image>, &mut Dimension)>,
    assets: Res<Assets<Image>>
) {
    let scaling_factor = scaling_factor
         .get_single()
         .map(|x| x.scale_factor())
         .unwrap_or(1.0);
    query.iter_mut().for_each(|(sp, im, mut dimension)| {
        dimension.0 = sp.custom_size.or_else(|| {
            sp.rect.map(|rect| (rect.max - rect.min) * scaling_factor)
                .or_else(|| {
                    assets.get(im)
                        .map(|x|x.size().as_vec2() * scaling_factor)
                })
        }).unwrap_or(Vec2::ZERO)
    })
}

If you want the opposite behavior, you can update the size of a sprite from the outputted RotatedRect::dimension.

Containers

Add RectrayContainerBundle to put child items in a Layout. See module level documentation for details.

Showcase

• Place items on anchors of parents

• Put 3d meshes in a layout

• Place individual words to form a paragraph

Versions

License

Licensed under either of

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

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.