use bevy::{
ecs::query::QueryItem,
prelude::*,
render::extract_component::{ExtractComponent, ExtractComponentPlugin},
transform::TransformSystem,
};
pub struct TransformPlugin;
impl Plugin for TransformPlugin {
fn build(&self, app: &mut App) {
app.add_plugin(ExtractComponentPlugin::<GlobalTransformQueue>::default())
.add_system_to_stage(
CoreStage::PostUpdate,
previous_transform_system.after(TransformSystem::TransformPropagate),
);
}
}
#[derive(Component, Debug, Clone, Deref, DerefMut)]
pub struct GlobalTransformQueue(pub [Mat4; 2]);
impl ExtractComponent for GlobalTransformQueue {
type Query = &'static Self;
type Filter = ();
fn extract_component(item: QueryItem<Self::Query>) -> Self {
item.clone()
}
}
#[allow(clippy::type_complexity)]
fn previous_transform_system(
mut commands: Commands,
query: Query<(Entity, &GlobalTransform, Option<&GlobalTransformQueue>)>,
) {
for (entity, transform, queue) in &query {
let matrix = transform.compute_matrix();
let queue = match queue {
Some(queue) => GlobalTransformQueue([matrix, queue[0]]),
None => GlobalTransformQueue([matrix; 2]),
};
commands.entity(entity).insert(queue);
}
}