entity archetypes

(for organization and compile time speedups)

examples/entity_builder_comparison.rs

@@ -0,0 +1,191 @@
+use bevy::prelude::*;
+use bevy::ecs::*;
+
+fn main() {
+    AppBuilder::new().add_defaults().setup_world(setup).run();
+}
+
+#[allow(dead_code)]
+fn create_entities_insert_vec(world: &mut World, plane_handle: Handle<Mesh>, cube_handle: Handle<Mesh>) {
+    // plane
+    world.insert(
+        (),
+        vec![(
+            plane_handle.clone(),
+            Material::new(Albedo::Color(math::vec4(0.1, 0.2, 0.1, 1.0))),
+            LocalToWorld::identity(),
+            Translation::new(0.0, 0.0, 0.0),
+        )],
+    );
+
+    // cube
+    world.insert(
+        (),
+        vec![(
+            cube_handle,
+            Material::new(Albedo::Color(math::vec4(0.5, 0.3, 0.3, 1.0))),
+            LocalToWorld::identity(),
+            Translation::new(0.0, 0.0, 1.0),
+        )],
+    );
+
+    // light
+    world.insert(
+        (),
+        vec![(
+            Light {
+                color: wgpu::Color {
+                    r: 0.8,
+                    g: 0.8,
+                    b: 0.5,
+                    a: 1.0,
+                },
+                fov: f32::to_radians(60.0),
+                depth: 0.1..50.0,
+                target_view: None,
+            },
+            LocalToWorld::identity(),
+            Translation::new(4.0, -4.0, 5.0),
+            Rotation::from_euler_angles(0.0, 0.0, 0.0),
+        )],
+    );
+
+    // camera
+    world.insert(
+        (),
+        vec![(
+            Camera::new(CameraType::Projection {
+                fov: std::f32::consts::PI / 4.0,
+                near: 1.0,
+                far: 1000.0,
+                aspect_ratio: 1.0,
+            }),
+            ActiveCamera,
+            LocalToWorld(Mat4::look_at_rh(
+                Vec3::new(3.0, 8.0, 5.0),
+                Vec3::new(0.0, 0.0, 0.0),
+                Vec3::new(0.0, 0.0, 1.0),
+            )),
+        )],
+    );
+}
+
+#[allow(dead_code)]
+fn create_entities_builder_add_component(world: &mut World, plane_handle: Handle<Mesh>, cube_handle: Handle<Mesh>) {
+    world.build()
+        // plane
+        .build_entity()
+            .add(plane_handle.clone())
+            .add(Material::new(Albedo::Color(math::vec4(0.1, 0.2, 0.1, 1.0))))
+            .add(LocalToWorld::identity())
+            .add(Translation::new(0.0, 0.0, 0.0))
+        // cube
+        .build_entity()
+            .add(cube_handle)
+            .add(Material::new(Albedo::Color(math::vec4(0.5, 0.3, 0.3, 1.0))))
+            .add(LocalToWorld::identity())
+            .add(Translation::new(0.0, 0.0, 1.0))
+        // light
+        .build_entity()
+            .add(Light {
+                color: wgpu::Color {
+                    r: 0.8,
+                    g: 0.8,
+                    b: 0.5,
+                    a: 1.0,
+                },
+                fov: f32::to_radians(60.0),
+                depth: 0.1..50.0,
+                target_view: None,
+            })
+            .add(LocalToWorld::identity())
+            .add(Translation::new(4.0, -4.0, 5.0))
+            .add(Rotation::from_euler_angles(0.0, 0.0, 0.0))
+        // camera
+        .build_entity()
+            .add(Camera::new(CameraType::Projection {
+                fov: std::f32::consts::PI / 4.0,
+                near: 1.0,
+                far: 1000.0,
+                aspect_ratio: 1.0,
+            }))
+            .add(ActiveCamera)
+            .add(LocalToWorld(Mat4::look_at_rh(
+                Vec3::new(3.0, 8.0, 5.0),
+                Vec3::new(0.0, 0.0, 0.0),
+                Vec3::new(0.0, 0.0, 1.0),
+            )))
+    .build();
+}
+
+fn create_entities_builder_archetype(world: &mut World, plane_handle: Handle<Mesh>, cube_handle: Handle<Mesh>) {
+    world.build()
+        // plane
+        .build_archetype(Object3dEntity {
+            mesh: plane_handle.clone(),
+            material: Material::new(Albedo::Color(math::vec4(0.1, 0.2, 0.1, 1.0))),
+            local_to_world: LocalToWorld::identity(),
+            translation: Translation::new(0.0, 0.0, 0.0),
+        })
+        // cube
+        .build_archetype(Object3dEntity {
+            mesh: cube_handle,
+            material: Material::new(Albedo::Color(math::vec4(0.5, 0.3, 0.3, 1.0))),
+            local_to_world: LocalToWorld::identity(),
+            translation: Translation::new(0.0, 0.0, 1.0),
+        })
+        // light
+        .build_archetype(LightEntity {
+            light: Light {
+                color: wgpu::Color {
+                    r: 0.8,
+                    g: 0.8,
+                    b: 0.5,
+                    a: 1.0,
+                },
+                fov: f32::to_radians(60.0),
+                depth: 0.1..50.0,
+                target_view: None,
+            },
+            local_to_world: LocalToWorld::identity(),
+            translation: Translation::new(4.0, -4.0, 5.0),
+            rotation: Rotation::from_euler_angles(0.0, 0.0, 0.0),
+        })
+        // camera
+        .build_archetype(CameraEntity {
+            camera: Camera::new(CameraType::Projection {
+                fov: std::f32::consts::PI / 4.0,
+                near: 1.0,
+                far: 1000.0,
+                aspect_ratio: 1.0,
+            }),
+            active_camera: ActiveCamera,
+            local_to_world: LocalToWorld(Mat4::look_at_rh(
+                Vec3::new(3.0, 8.0, 5.0),
+                Vec3::new(0.0, 0.0, 0.0),
+                Vec3::new(0.0, 0.0, 1.0),
+            )),
+        })
+    .build();
+}
+
+fn setup(world: &mut World) {
+    let cube = Mesh::load(MeshType::Cube);
+    let plane = Mesh::load(MeshType::Plane { size: 10.0 });
+
+    let (cube_handle, plane_handle) = {
+        let mut mesh_storage = world.resources.get_mut::<AssetStorage<Mesh>>().unwrap();
+        (mesh_storage.add(cube), mesh_storage.add(plane))
+    };
+
+    // no-archetype precompile: 1.24 sec
+    // archetype precompile: 1.07 sec
+    // create_entities_insert_vec(world, plane_handle, cube_handle);
+
+    // no-archetype precompile: .93
+    // noarchetype precompile: .93
+    // create_entities_builder_add_component(world, plane_handle, cube_handle);
+
+    // archetype precompile: 0.65 
+    create_entities_builder_archetype(world, plane_handle, cube_handle);
+}

src/ecs/archetypes.rs

@@ -0,0 +1,65 @@
+use crate::prelude::*;
+use legion::prelude::*;
+
+
+// builder macro that makes defaults easy? Object3dBuilder { Option<Material> } impl Builder for Object3dBuilder { }
+pub trait EntityArchetype {
+    fn insert(self, world: &mut World) -> Entity;
+    // add_components appears to be missing from World. it will be less efficient without that
+    // fn add_components(self, world: &mut World);
+}
+
+pub struct Object3dEntity {
+    pub mesh: Handle<Mesh>,
+    pub material: Material,
+    pub local_to_world: LocalToWorld,
+    pub translation: Translation,
+}
+
+// TODO: make this a macro
+impl EntityArchetype for Object3dEntity {
+    fn insert(self, world: &mut World) -> Entity {
+        *world.insert((), vec![(
+            self.mesh,
+            self.material,
+            self.local_to_world,
+            self.translation,
+        )]).first().unwrap()
+    }
+}
+
+pub struct LightEntity {
+    pub light: Light,
+    pub local_to_world: LocalToWorld,
+    pub translation: Translation,
+    pub rotation: Rotation,
+}
+
+// TODO: make this a macro
+impl EntityArchetype for LightEntity {
+    fn insert(self, world: &mut World) -> Entity {
+        *world.insert((), vec![(
+            self.light,
+            self.local_to_world,
+            self.translation,
+            self.rotation,
+        )]).first().unwrap()
+    }
+}
+
+pub struct CameraEntity {
+    pub camera: Camera,
+    pub active_camera: ActiveCamera,
+    pub local_to_world: LocalToWorld,
+}
+
+// TODO: make this a macro
+impl EntityArchetype for CameraEntity {
+    fn insert(self, world: &mut World) -> Entity {
+        *world.insert((), vec![(
+            self.camera,
+            self.active_camera,
+            self.local_to_world,
+        )]).first().unwrap()
+    }
+}

src/ecs/entity_builder.rs

@@ -0,0 +1,55 @@
+use crate::ecs::EntityArchetype;
+use legion::prelude::*;
+
+pub trait EntityBuilderSource {
+    fn build(&mut self) -> EntityBuilder;
+}
+
+impl EntityBuilderSource for World {
+    fn build(&mut self) -> EntityBuilder {
+        EntityBuilder {
+            world: self,
+            current_entity: None,
+        }
+    }
+}
+
+pub struct EntityBuilder<'a> {
+    world: &'a mut World,
+    current_entity: Option<Entity>,
+}
+
+impl<'a> EntityBuilder<'a> {
+    pub fn build_entity(mut self) -> Self {
+        let entity = *self.world.insert((), vec![()]).first().unwrap();
+        self.current_entity = Some(entity);
+        self
+    }
+    pub fn build(self) {}
+
+    // note: this is slow and does a full entity copy
+    pub fn add<T>(self, component: T) -> Self
+    where
+        T: legion::storage::Component,
+    {
+        let _ = self
+            .world
+            .add_component(*self.current_entity.as_ref().unwrap(), component);
+        self
+    }
+
+    pub fn tag<T>(self, tag: T) -> Self
+    where
+        T: legion::storage::Tag,
+    {
+        let _ = self
+            .world
+            .add_tag(*self.current_entity.as_ref().unwrap(), tag);
+        self
+    }
+
+    pub fn build_archetype(mut self, entity_archetype: impl EntityArchetype) -> Self {
+        self.current_entity = Some(entity_archetype.insert(self.world));
+        self
+    }
+}

src/ecs/mod.rs

@@ -1,3 +1,9 @@
+mod entity_builder;
+mod archetypes;
+
+pub use entity_builder::*;
+pub use archetypes::*;
+
 use crate::prelude::{Children, Entity, SubWorld, World};
 
 pub fn run_on_hierarchy<T>(