316 lines
11 KiB
Rust
316 lines
11 KiB
Rust
use std::{collections::VecDeque, ops::{Deref, DerefMut}};
|
|
|
|
use lyra_ecs::{query::Entities, relation::ChildOf, Bundle, Component, Entity, World};
|
|
|
|
// So we can use lyra_ecs::Component derive macro
|
|
pub(crate) mod lyra_engine {
|
|
pub(crate) mod ecs {
|
|
pub use lyra_ecs::*;
|
|
}
|
|
}
|
|
|
|
mod node;
|
|
use lyra_math::{Transform, Vec3};
|
|
pub use node::*;
|
|
|
|
/// A flag spawned on all scene node entities
|
|
#[derive(Component)]
|
|
pub struct SceneNodeFlag;
|
|
|
|
/// A flag spawned on only the scene root node
|
|
#[derive(Component)]
|
|
pub struct SceneNodeRoot;
|
|
|
|
enum MutCow<'a, T> {
|
|
Mut(&'a mut T),
|
|
Owned(T),
|
|
}
|
|
|
|
impl<'a, T> Deref for MutCow<'a, T> {
|
|
type Target = T;
|
|
|
|
fn deref(&self) -> &Self::Target {
|
|
match self {
|
|
MutCow::Mut(t) => t,
|
|
MutCow::Owned(t) => t,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, T> DerefMut for MutCow<'a, T> {
|
|
fn deref_mut(&mut self) -> &mut Self::Target {
|
|
match self {
|
|
MutCow::Mut(t) => t,
|
|
MutCow::Owned(t) => t,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A SceneGraph is a Graph of nodes that represents the hierarchy of a scene.
|
|
///
|
|
/// This SceneGraph is special in the sense that it is literally just an ECS world with methods
|
|
/// implemented for it that make it easier to use for a SceneGraph.
|
|
//#[derive(Default)]
|
|
pub struct SceneGraph<'a> {
|
|
pub(crate) world: MutCow<'a, World>,
|
|
root_node: SceneNode,
|
|
}
|
|
|
|
impl<'a> SceneGraph<'a> {
|
|
/// Create a new SceneGraph with its own ECS World.
|
|
pub fn new() -> Self {
|
|
let mut world = World::new();
|
|
|
|
let e = world.spawn((Transform::from_translation(Vec3::new(0.0, 0.0, 0.0)), SceneNodeRoot));
|
|
let root = SceneNode::new(None, e);
|
|
|
|
Self {
|
|
world: MutCow::Owned(world),
|
|
root_node: root
|
|
}
|
|
}
|
|
|
|
/// Retrieve a SceneGraph from an ECS World.
|
|
///
|
|
/// Returns `None` if the `root_entity` was not created from a `SceneGraph` that was later
|
|
/// inserted into another world with [`SceneGraph::into_world`].
|
|
pub fn from_world(world: &'a mut World, root_entity: Entity) -> Option<Self> {
|
|
if world.view_one::<(&SceneNodeRoot, &Transform)>(root_entity).get().is_none() {
|
|
None
|
|
} else {
|
|
Some(Self {
|
|
world: MutCow::Mut(world),
|
|
root_node: SceneNode::new(None, root_entity),
|
|
})
|
|
}
|
|
}
|
|
|
|
/// Create a new SceneGraph inside an existing ECS World.
|
|
pub fn new_from_world(world: &'a mut World) -> Self {
|
|
let root_en = world.spawn((Transform::from_translation(Vec3::new(0.0, 0.0, 0.0)), SceneNodeRoot));
|
|
let root = SceneNode::new(None, root_en);
|
|
|
|
Self {
|
|
world: MutCow::Mut(world),
|
|
root_node: root,
|
|
}
|
|
}
|
|
|
|
/// Consume the SceneGraph, inserting its internal world into the provided world.
|
|
///
|
|
/// The `into` World will contain all nodes of the SceneGraph. You could iterate through the
|
|
/// SceneGraph manually if you'd like. The root entity has a [`SceneNodeRoot`] flag component,
|
|
/// and a Transform component. The children nodes have a [`SceneNodeFlag`] component and a
|
|
/// Transform component. The transforms of the children will be local, you must find its world
|
|
/// transform by traversing up the hierarchy of the scene manually with the `ChildOf` relation.
|
|
///
|
|
/// Returns: the Entity of the root node in the provided world.
|
|
pub fn into_world(mut self, into: &mut World) -> Entity {
|
|
// first insert the root entity into the World.
|
|
let v = self.world.view_one::<&Transform>(self.root_node.entity());
|
|
let pos = *v.get().unwrap();
|
|
let new_root = into.spawn((pos, SceneNodeRoot));
|
|
|
|
// now process the children of the root node.
|
|
Self::traverse_inserting_into(&mut self.world, self.root_node.entity(), new_root, into);
|
|
new_root
|
|
}
|
|
|
|
/// Recursively traverse the `from` world, starting at `node_en`, inserting the
|
|
/// children entity into the world.
|
|
///
|
|
/// Parameters:
|
|
/// * `scene_world` - The world that the SceneGraph exists in
|
|
/// * `scene_en` - The entity of the parent entity inside of the `scene_world`.
|
|
/// * `parent_en` - The entity of the parent entity inside of the `into` world.
|
|
/// * `into` - The world to insert the SceneGraph world into.
|
|
fn traverse_inserting_into(scene_world: &mut World, scene_en: Entity, parent_en: Entity, into: &mut World) {
|
|
let v = scene_world.view::<(Entities, &Transform)>()
|
|
.relates_to::<ChildOf>(scene_en);
|
|
|
|
// unfortunately, the borrow checker exists, and wasn't happy that `scene_world` was
|
|
// immutably borrowed with the view (v), and being mutably borrowed in the
|
|
// recursive call.
|
|
let mut child_entities = VecDeque::new();
|
|
|
|
for ((child_scene_en, pos), _rel) in v.iter() {
|
|
let into_en = into.spawn((*pos, SceneNodeFlag));
|
|
into.add_relation(into_en, ChildOf, parent_en);
|
|
|
|
child_entities.push_back((child_scene_en, into_en));
|
|
}
|
|
|
|
while let Some((child_scene_en, into_en)) = child_entities.pop_front() {
|
|
Self::traverse_inserting_into(scene_world, child_scene_en, into_en, into);
|
|
}
|
|
}
|
|
|
|
/// Adds a node to the root node of the SceneGraph.
|
|
///
|
|
/// The spawned entity will have a `ChildOf` relation targeting the root node, the
|
|
/// `SceneNodeFlag` component is also added to the entity.
|
|
pub fn add_node<B: Bundle>(&mut self, local_transform: Transform, bundle: B) -> SceneNode {
|
|
let node = self.root_node.clone();
|
|
self.add_node_under(&node, local_transform, bundle)
|
|
}
|
|
|
|
/// Add a node under a parent node.
|
|
///
|
|
/// The spawned entity will have a `ChildOf` relation targeting the provided parent node,
|
|
/// the `SceneNodeFlag` component is also added to the entity.
|
|
pub fn add_node_under<B: Bundle>(&mut self, parent: &SceneNode, local_transform: Transform, bundle: B) -> SceneNode {
|
|
world_add_child_node(&mut self.world, parent, local_transform, bundle)
|
|
}
|
|
|
|
pub fn add_empty_node_under(&mut self, parent: &SceneNode, local_transform: Transform) -> SceneNode {
|
|
let e = self.world.spawn((SceneNodeFlag, local_transform));
|
|
self.world.add_relation(e, ChildOf, parent.entity());
|
|
|
|
SceneNode::new(Some(parent.entity()), e)
|
|
}
|
|
|
|
/// Traverses down the SceneGraph, calling `callback` with each SceneNode and its world transform.
|
|
///
|
|
/// The traversal does not include the root scene node.
|
|
pub fn traverse_down<F>(&self, mut callback: F)
|
|
where
|
|
F: FnMut(&SceneNode, Transform),
|
|
{
|
|
self.traverse_down_from(self.root_node.clone(), &mut callback);
|
|
}
|
|
|
|
/// Recursively Traverses down the SceneGraph from a starting node, calling `callback` with each
|
|
/// SceneNode and its world transform.
|
|
fn traverse_down_from<F>(&self, start: SceneNode, callback: &mut F)
|
|
where
|
|
F: FnMut(&SceneNode, Transform),
|
|
{
|
|
let v = self.world.view::<(Entities, &Transform)>()
|
|
.relates_to::<ChildOf>(start.entity());
|
|
|
|
for ((e, _), _rel) in v.iter() {
|
|
let node = SceneNode::new(Some(start.entity()), e);
|
|
let world_pos = node.world_transform(self);
|
|
callback(&node, world_pos);
|
|
|
|
self.traverse_down_from(node, callback);
|
|
}
|
|
}
|
|
|
|
pub fn root_node(&self) -> SceneNode {
|
|
self.root_node.clone()
|
|
}
|
|
}
|
|
|
|
/// Add a node under a parent node.
|
|
///
|
|
/// The spawned entity will have a `ChildOf` relation targeting the provided parent node,
|
|
/// the `SceneNodeFlag` component is also added to the entity.
|
|
pub(crate) fn world_add_child_node<B: Bundle>(world: &mut World, parent: &SceneNode, local_transform: Transform, bundle: B) -> SceneNode {
|
|
let e = world.spawn(bundle);
|
|
world.insert(e, (SceneNodeFlag, local_transform));
|
|
world.add_relation(e, ChildOf, parent.entity());
|
|
|
|
SceneNode::new(Some(parent.entity()), e)
|
|
}
|
|
|
|
#[cfg(test)]
|
|
pub mod tests {
|
|
use lyra_ecs::{query::Entities, relation::ChildOf, Component, World};
|
|
use lyra_math::{Transform, Vec3};
|
|
|
|
use crate::{lyra_engine, SceneGraph, SceneNodeRoot};
|
|
|
|
#[derive(Component)]
|
|
pub struct FakeMesh;
|
|
|
|
#[test]
|
|
fn single_node_hierarchy() {
|
|
let mut scene = SceneGraph::new();
|
|
|
|
let a = scene.add_node(Transform::from_translation(Vec3::new(10.0, 10.0, 10.0)), FakeMesh);
|
|
assert!(a.parent(&scene).unwrap() == scene.root_node);
|
|
}
|
|
|
|
#[test]
|
|
fn double_node_hierarchy() {
|
|
let mut scene = SceneGraph::new();
|
|
|
|
let a = scene.add_node(Transform::from_translation(Vec3::new(10.0, 10.0, 10.0)), FakeMesh);
|
|
assert!(a.parent(&scene).unwrap() == scene.root_node);
|
|
|
|
let b = a.add_node(&mut scene, Transform::from_translation(Vec3::new(50.0, 50.0, 50.0)), FakeMesh);
|
|
assert!(b.parent(&scene).unwrap() == a);
|
|
}
|
|
|
|
#[test]
|
|
fn traverse_down() {
|
|
let v2s = vec![Vec3::new(10.0, 10.0, 10.0), Vec3::new(50.0, 50.0, 50.0)];
|
|
|
|
let mut scene = SceneGraph::new();
|
|
|
|
let a = scene.add_node(Transform::from_translation(v2s[0]), FakeMesh);
|
|
assert!(a.parent(&scene).unwrap() == scene.root_node);
|
|
let b = a.add_node(&mut scene, Transform::from_translation(v2s[1]), FakeMesh);
|
|
assert!(b.parent(&scene).unwrap() == a);
|
|
|
|
let mut idx = 0;
|
|
scene.traverse_down(|_e, pos| {
|
|
if idx == 0 {
|
|
assert_eq!(pos, Transform::from_translation(v2s[idx]));
|
|
} else if idx == 1 {
|
|
let t = v2s.iter().sum();
|
|
assert_eq!(pos, Transform::from_translation(t));
|
|
}
|
|
|
|
idx += 1;
|
|
});
|
|
}
|
|
|
|
/* #[test]
|
|
fn inserting_and_from_world() {
|
|
let v2s = vec![Vec3::new(10.0, 10.0, 10.0), Vec3::new(50.0, 50.0, 50.0)];
|
|
|
|
let mut scene = SceneGraph::new();
|
|
|
|
let a = scene.add_node(Transform::from_translation(v2s[0]), FakeMesh);
|
|
assert!(a.parent(&scene).unwrap() == scene.root_node);
|
|
let b = a.add_node(&mut scene, Transform::from_translation(v2s[1]), FakeMesh);
|
|
assert!(b.parent(&scene).unwrap() == a);
|
|
|
|
let mut other_world = World::new();
|
|
let root = scene.into_world(&mut other_world);
|
|
|
|
// check all of the entities inside of the World
|
|
let (root_pos, _) = other_world.view_one::<(&Transform, &SceneNodeRoot)>(root).get().unwrap();
|
|
assert_eq!(*root_pos, Transform::from_xyz(0.0, 0.0, 0.0));
|
|
|
|
let ((child_en, child_pos), _) = other_world.view::<(Entities, &Transform)>()
|
|
.relates_to::<ChildOf>(root).iter().next().unwrap();
|
|
assert_eq!(*child_pos, Transform::from_translation(v2s[0]));
|
|
|
|
let ((_, childchild_pos), _) = other_world.view::<(Entities, &Transform)>()
|
|
.relates_to::<ChildOf>(child_en).iter().next().unwrap();
|
|
assert_eq!(*childchild_pos, Transform::from_translation(v2s[1]));
|
|
|
|
drop(root_pos);
|
|
drop(child_pos);
|
|
drop(childchild_pos);
|
|
|
|
// Now get the SceneGraph inside the World and use the nice utility tools to traverse it.
|
|
let scene = SceneGraph::from_world(&mut other_world, root)
|
|
.expect("Failed to get SceneGraph from World!");
|
|
|
|
let mut idx = 0;
|
|
scene.traverse_down(|_e, pos| {
|
|
if idx == 0 {
|
|
assert_eq!(pos, Transform::from_translation(v2s[idx]));
|
|
} else if idx == 1 {
|
|
let t = v2s.iter().sum();
|
|
assert_eq!(pos, Transform::from_translation(t));
|
|
}
|
|
|
|
idx += 1;
|
|
});
|
|
} */
|
|
} |