76d12fa2b3
# Objective Part of https://github.com/bevyengine/bevy/issues/13529 Helps https://github.com/bevyengine/bevy/pull/13533 Splitting up `bevy_transform` makes it easier to selectively include or exclude parts of it in such a way that it's possible to include only a small part with a small dependency tree. ## Solution Make the crate more modular. --------- Signed-off-by: Torstein Grindvik <torstein.grindvik@muybridge.com> Co-authored-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
60 lines
2.1 KiB
Rust
60 lines
2.1 KiB
Rust
use bevy_ecs::bundle::Bundle;
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use crate::prelude::{GlobalTransform, Transform};
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/// A [`Bundle`] of the [`Transform`] and [`GlobalTransform`]
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/// [`Component`]s, which describe the position of an entity.
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///
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/// * To place or move an entity, you should set its [`Transform`].
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/// * To get the global transform of an entity, you should get its [`GlobalTransform`].
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/// * For transform hierarchies to work correctly, you must have both a [`Transform`] and a [`GlobalTransform`].
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/// * You may use the [`TransformBundle`] to guarantee this.
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///
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/// ## [`Transform`] and [`GlobalTransform`]
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///
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/// [`Transform`] is the position of an entity relative to its parent position, or the reference
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/// frame if it doesn't have a parent.
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///
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/// [`GlobalTransform`] is the position of an entity relative to the reference frame.
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///
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/// [`GlobalTransform`] is updated from [`Transform`] by systems in the system set
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/// [`TransformPropagate`](TransformSystem::TransformPropagate).
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///
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/// This system runs during [`PostUpdate`]. If you
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/// update the [`Transform`] of an entity in this schedule or after, you will notice a 1 frame lag
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/// before the [`GlobalTransform`] is updated.
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#[derive(Clone, Copy, Debug, Default, Bundle)]
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pub struct TransformBundle {
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/// The transform of the entity.
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pub local: Transform,
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/// The global transform of the entity.
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pub global: GlobalTransform,
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}
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impl TransformBundle {
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/// An identity [`TransformBundle`] with no translation, rotation, and a scale of 1 on all axes.
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pub const IDENTITY: Self = TransformBundle {
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local: Transform::IDENTITY,
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global: GlobalTransform::IDENTITY,
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};
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/// Creates a new [`TransformBundle`] from a [`Transform`].
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///
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/// This initializes [`GlobalTransform`] as identity, to be updated later by the
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/// [`PostUpdate`] schedule.
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#[inline]
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pub const fn from_transform(transform: Transform) -> Self {
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TransformBundle {
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local: transform,
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..Self::IDENTITY
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}
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}
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}
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impl From<Transform> for TransformBundle {
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#[inline]
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fn from(transform: Transform) -> Self {
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Self::from_transform(transform)
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}
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}
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