bevy_transform/
bundles.rs

1use bevy_ecs::bundle::Bundle;
2
3use crate::prelude::{GlobalTransform, Transform};
4
5/// A [`Bundle`] of the [`Transform`] and [`GlobalTransform`]
6/// [`Component`]s, which describe the position of an entity.
7///
8/// * To place or move an entity, you should set its [`Transform`].
9/// * To get the global transform of an entity, you should get its [`GlobalTransform`].
10/// * For transform hierarchies to work correctly, you must have both a [`Transform`] and a [`GlobalTransform`].
11///   * You may use the [`TransformBundle`] to guarantee this.
12///
13/// ## [`Transform`] and [`GlobalTransform`]
14///
15/// [`Transform`] is the position of an entity relative to its parent position, or the reference
16/// frame if it doesn't have a parent.
17///
18/// [`GlobalTransform`] is the position of an entity relative to the reference frame.
19///
20/// [`GlobalTransform`] is updated from [`Transform`] by systems in the system set
21/// [`TransformPropagate`](TransformSystem::TransformPropagate).
22///
23/// This system runs during [`PostUpdate`]. If you
24/// update the [`Transform`] of an entity in this schedule or after, you will notice a 1 frame lag
25/// before the [`GlobalTransform`] is updated.
26#[derive(Clone, Copy, Debug, Default, Bundle)]
27pub struct TransformBundle {
28    /// The transform of the entity.
29    pub local: Transform,
30    /// The global transform of the entity.
31    pub global: GlobalTransform,
32}
33
34impl TransformBundle {
35    /// An identity [`TransformBundle`] with no translation, rotation, and a scale of 1 on all axes.
36    pub const IDENTITY: Self = TransformBundle {
37        local: Transform::IDENTITY,
38        global: GlobalTransform::IDENTITY,
39    };
40
41    /// Creates a new [`TransformBundle`] from a [`Transform`].
42    ///
43    /// This initializes [`GlobalTransform`] as identity, to be updated later by the
44    /// [`PostUpdate`] schedule.
45    #[inline]
46    pub const fn from_transform(transform: Transform) -> Self {
47        TransformBundle {
48            local: transform,
49            ..Self::IDENTITY
50        }
51    }
52}
53
54impl From<Transform> for TransformBundle {
55    #[inline]
56    fn from(transform: Transform) -> Self {
57        Self::from_transform(transform)
58    }
59}
bevy_transform/bundles.rs

bevy_transform/
bundles.rs
