props: remove specialization, ignore fields, impl for Handle, fix world round tripping

assets/scene/load_scene_example.scn

@@ -1,26 +1,30 @@
 [
-    (
-        entity: 1279729879,
+
+    Entity(
+        id: 1401014920,
         components: [
+
             {
                 "type": "load_scene::Test",
                 "x": 3.0,
                 "y": 4.0,
-            },
-        ],
+            },        ],
     ),
-    (
-        entity: 1639302665,
+    Entity(
+        id: 99763910,
         components: [
+
             {
                 "type": "load_scene::Test",
                 "x": 1.0,
                 "y": 2.0,
             },
+            {
+                "type": "bevy_asset::handle::Handle<bevy_render::mesh::Mesh>",
+                "id": HandleId("edcdd23f-5be5-4dbf-9a6e-9f46b2185570"),
+            },
             {
                 "type": "load_scene::Foo",
                 "value": "hello",
-            },
-        ],
-    ),
-]
+            },        ],
+    ),]

crates/bevy_asset/Cargo.toml

@@ -11,9 +11,11 @@ filesystem_watcher = ["notify"]
 [dependencies]
 bevy_app = { path = "../bevy_app" }
 bevy_core = { path = "../bevy_core" }
+bevy_property = { path = "../bevy_property" }
 legion = { path = "../bevy_legion" }
 
 uuid = { version = "0.8", features = ["v4", "serde"] }
+serde = { version = "1", features = ["derive"] }
 crossbeam-channel = "0.4.2"
 anyhow = "1.0"
 thiserror = "1.0"

crates/bevy_asset/src/assets.rs

@@ -10,13 +10,13 @@ use std::{
     path::{Path, PathBuf},
 };
 
-pub enum AssetEvent<T> {
+pub enum AssetEvent<T: 'static> {
     Created { handle: Handle<T> },
     Modified { handle: Handle<T> },
     Removed { handle: Handle<T> },
 }
 
-pub struct Assets<T> {
+pub struct Assets<T: 'static> {
     assets: HashMap<Handle<T>, T>,
     paths: HashMap<PathBuf, Handle<T>>,
     events: Events<AssetEvent<T>>,

crates/bevy_asset/src/handle.rs

@@ -4,9 +4,11 @@ use std::{
 };
 
 use std::{any::TypeId, marker::PhantomData};
+use serde::{Serialize, Deserialize};
 use uuid::Uuid;
+use bevy_property::{Properties, Property, AsProperties};
 
-#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash, Serialize, Deserialize)]
 pub struct HandleId(pub Uuid);
 pub const DEFAULT_HANDLE_ID: HandleId =
     HandleId(Uuid::from_u128(240940089166493627844978703213080810552));
@@ -17,8 +19,40 @@ impl HandleId {
     }
 }
 
-pub struct Handle<T> {
+impl Property for HandleId {
+    fn any(&self) -> &dyn std::any::Any {
+        self
+    }
+    fn any_mut(&mut self) -> &mut dyn std::any::Any {
+        self
+    }
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+    fn set(&mut self, value: &dyn Property) {
+        let value = value.any();
+        if let Some(prop) = value.downcast_ref::<Self>() {
+            *self = *prop;
+        } else {
+            panic!("prop value is not {}", std::any::type_name::<Self>());
+        }
+    }
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+}
+
+impl AsProperties for HandleId {
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+    
+}
+
+#[derive(Properties)]
+pub struct Handle<T> where T: 'static {
     pub id: HandleId,
+    #[prop(ignore)]
     marker: PhantomData<T>,
 }
 
@@ -137,6 +171,10 @@ impl<T> Clone for Handle<T> {
 }
 impl<T> Copy for Handle<T> {}
 
+// SAFE: T is phantom data and Handle::id is an integer
+unsafe impl<T> Send for Handle<T> {}
+unsafe impl<T> Sync for Handle<T> {}
+
 #[derive(Hash, Copy, Clone, Eq, PartialEq, Debug)]
 pub struct HandleUntyped {
     pub id: HandleId,

crates/bevy_asset/src/load_request.rs

@@ -20,6 +20,7 @@ pub trait AssetLoadRequestHandler: Send + Sync + 'static {
 pub struct ChannelAssetHandler<TLoader, TAsset>
 where
     TLoader: AssetLoader<TAsset>,
+    TAsset: 'static,
 {
     sender: Sender<AssetResult<TAsset>>,
     loader: TLoader,

crates/bevy_asset/src/loader.rs

@@ -30,13 +30,13 @@ pub trait AssetLoader<T>: Send + Sync + 'static {
     }
 }
 
-pub struct AssetResult<T> {
+pub struct AssetResult<T: 'static> {
     pub result: Result<T, AssetLoadError>,
     pub handle: Handle<T>,
     pub path: PathBuf,
 }
 
-pub struct AssetChannel<T> {
+pub struct AssetChannel<T: 'static> {
     pub sender: Sender<AssetResult<T>>,
     pub receiver: Receiver<AssetResult<T>>,
 }

crates/bevy_legion/legion_core/src/guid_entity_allocator.rs

@@ -1,11 +1,11 @@
 use crate::entity::Entity;
 use parking_lot::RwLock;
-use std::{collections::HashSet, num::Wrapping, sync::Arc};
+use std::{collections::{VecDeque, HashSet}, num::Wrapping, sync::Arc};
 
 #[derive(Default, Debug, Clone)]
 pub struct GuidEntityAllocator {
     entities: Arc<RwLock<HashSet<Entity>>>,
-    next_ids: Arc<RwLock<Vec<Entity>>>,
+    next_ids: Arc<RwLock<VecDeque<Entity>>>,
 }
 
 impl GuidEntityAllocator {
@@ -18,7 +18,7 @@ impl GuidEntityAllocator {
     /// Allocates a new unused `Entity` ID.
     pub fn create_entity(&self) -> Entity {
         let entity = if !self.next_ids.read().is_empty() {
-            self.next_ids.write().pop().unwrap()
+            self.next_ids.write().pop_front().unwrap()
         } else {
             Entity::new(rand::random::<u32>(), Wrapping(1))
         };

crates/bevy_property/bevy_property_derive/src/lib.rs

@@ -2,10 +2,19 @@ extern crate proc_macro;
 
 mod modules;
 
+use darling::FromMeta;
 use modules::{get_modules, get_path};
 use proc_macro::TokenStream;
 use quote::quote;
-use syn::{parse_macro_input, Data, DataStruct, DeriveInput, Fields};
+use syn::{parse_macro_input, Data, DataStruct, DeriveInput, Field, Fields};
+
+#[derive(FromMeta, Debug, Default)]
+struct PropAttributeArgs {
+    #[darling(default)]
+    pub ignore: Option<bool>,
+}
+
+static PROP_ATTRIBUTE_NAME: &str = "prop";
 
 #[proc_macro_derive(Properties, attributes(prop, module))]
 pub fn derive_properties(input: TokenStream) -> TokenStream {
@@ -17,19 +26,47 @@ pub fn derive_properties(input: TokenStream) -> TokenStream {
         }) => &fields.named,
         _ => panic!("expected a struct with named fields"),
     };
+    let fields_and_args = fields
+        .iter()
+        .map(|f| {
+            (
+                f,
+                f.attrs
+                    .iter()
+                    .find(|a| {
+                        a.path.get_ident().as_ref().unwrap().to_string() == PROP_ATTRIBUTE_NAME
+                    })
+                    .map(|a| {
+                        PropAttributeArgs::from_meta(&a.parse_meta().unwrap())
+                            .unwrap_or_else(|_err| PropAttributeArgs::default())
+                    }),
+            )
+        })
+        .collect::<Vec<(&Field, Option<PropAttributeArgs>)>>();
+    let active_fields = fields_and_args
+        .iter()
+        .filter(|(_field, attrs)| {
+            attrs.is_none()
+                || match attrs.as_ref().unwrap().ignore {
+                    Some(ignore) => !ignore,
+                    None => true,
+                }
+        })
+        .map(|(f, _attr)| *f)
+        .collect::<Vec<&Field>>();
 
     let modules = get_modules(&ast);
     let bevy_property_path = get_path(&modules.bevy_property);
 
-    let field_names = fields
+    let field_names = active_fields
         .iter()
         .map(|field| field.ident.as_ref().unwrap().to_string())
         .collect::<Vec<String>>();
-    let field_idents = fields
+    let field_idents = active_fields
         .iter()
         .map(|field| field.ident.as_ref().unwrap())
         .collect::<Vec<_>>();
-    let field_count = fields.len();
+    let field_count = active_fields.len();
     let field_indices = (0..field_count).collect::<Vec<usize>>();
 
     let generics = ast.generics;

crates/bevy_property/src/lib.rs

@@ -1,5 +1,3 @@
-#![feature(min_specialization)]
-
 mod property;
 mod properties;
 mod dynamic_properties;

crates/bevy_property/src/property.rs

@@ -1,5 +1,4 @@
 use crate::Properties;
-use serde::Serialize;
 use std::any::Any;
 
 pub trait Property: erased_serde::Serialize + Send + Sync + Any + AsProperties + 'static {
@@ -23,12 +22,12 @@ pub trait PropertyVal {
 
 impl PropertyVal for dyn Property {
     #[inline]
-    default fn val<T: 'static>(&self) -> Option<&T> {
+    fn val<T: 'static>(&self) -> Option<&T> {
         self.any().downcast_ref::<T>()
     }
 
     #[inline]
-    default fn set_val<T: 'static>(&mut self, value: T) {
+    fn set_val<T: 'static>(&mut self, value: T) {
         if let Some(prop) = self.any_mut().downcast_mut::<T>() {
             *prop = value;
         } else {
@@ -37,81 +36,83 @@ impl PropertyVal for dyn Property {
     }
 }
 
-// TODO: remove specialization
-impl<T> AsProperties for T
-where
-    T: Clone + Serialize + Send + Sync + Any + 'static,
+impl Property for usize {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
+    fn set(&mut self, value: &dyn Property) {
+        let value = value.any();
+        if let Some(prop) = value.downcast_ref::<Self>() {
+            *self = *prop;
+        } else if let Some(prop) = value.downcast_ref::<u64>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<u32>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<u16>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<u8>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<isize>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<i64>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<i32>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<i16>() {
+            *self = *prop as Self;
+        } else if let Some(prop) = value.downcast_ref::<i8>() {
+            *self = *prop as Self;
+        } else {
+            panic!("prop value is not {}", std::any::type_name::<Self>());
+        }
+    }
+}
+
+impl AsProperties for usize
 {
     fn as_properties(&self) -> Option<&dyn Properties> {
         None
     }
 }
 
-
-impl<T> Property for T
-where
-    T: Clone + Serialize + Send + Sync + Any + 'static,
-{
+impl Property for u64 {
     #[inline]
-    default fn any(&self) -> &dyn Any {
+    fn any(&self) -> &dyn Any {
         self
     }
 
     #[inline]
-    default fn any_mut(&mut self) -> &mut dyn Any {
+    fn any_mut(&mut self) -> &mut dyn Any {
         self
     }
 
     #[inline]
-    default fn clone_prop(&self) -> Box<dyn Property> {
+    fn clone_prop(&self) -> Box<dyn Property> {
         Box::new(self.clone())
     }
 
     #[inline]
-    default fn set(&mut self, value: &dyn Property) {
-        if let Some(prop) = value.any().downcast_ref::<T>() {
-            *self = prop.clone();
-        } else {
-            panic!("prop value is not {}", std::any::type_name::<T>());
-        }
-    }
-
-    #[inline]
-    default fn apply(&mut self, value: &dyn Property) {
+    fn apply(&mut self, value: &dyn Property) {
         self.set(value);
     }
-}
 
-impl Property for usize {
-    fn set(&mut self, value: &dyn Property) {
-        let value = value.any();
-        if let Some(prop) = value.downcast_ref::<Self>() {
-            *self = *prop;
-        } else if let Some(prop) = value.downcast_ref::<u64>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<u32>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<u16>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<u8>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<isize>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<i64>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<i32>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<i16>() {
-            *self = *prop as Self;
-        } else if let Some(prop) = value.downcast_ref::<i8>() {
-            *self = *prop as Self;
-        } else {
-            panic!("prop value is not {}", std::any::type_name::<Self>());
-        }
-    }
-}
-
-impl Property for u64 {
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -140,7 +141,34 @@ impl Property for u64 {
     }
 }
 
+impl AsProperties for u64
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for u32 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -169,7 +197,34 @@ impl Property for u32 {
     }
 }
 
+impl AsProperties for u32
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for u16 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -198,7 +253,34 @@ impl Property for u16 {
     }
 }
 
+impl AsProperties for u16
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for u8 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -227,7 +309,34 @@ impl Property for u8 {
     }
 }
 
+impl AsProperties for u8
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for isize {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -256,7 +365,34 @@ impl Property for isize {
     }
 }
 
+impl AsProperties for isize
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for i64 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -285,7 +421,34 @@ impl Property for i64 {
     }
 }
 
+impl AsProperties for i64
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for i32 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -314,7 +477,34 @@ impl Property for i32 {
     }
 }
 
+impl AsProperties for i32
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for i16 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -343,7 +533,34 @@ impl Property for i16 {
     }
 }
 
+impl AsProperties for i16
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for i8 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -372,7 +589,34 @@ impl Property for i8 {
     }
 }
 
+impl AsProperties for i8
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for f32 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -385,7 +629,34 @@ impl Property for f32 {
     }
 }
 
+impl AsProperties for f32
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 impl Property for f64 {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
     fn set(&mut self, value: &dyn Property) {
         let value = value.any();
         if let Some(prop) = value.downcast_ref::<Self>() {
@@ -397,3 +668,46 @@ impl Property for f64 {
         }
     }
 }
+
+impl AsProperties for f64
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
+impl Property for String {
+    #[inline]
+    fn any(&self) -> &dyn Any {
+        self
+    }
+
+    #[inline]
+    fn any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+
+    #[inline]
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+
+    #[inline]
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+
+    fn set(&mut self, value: &dyn Property) {
+        let value = value.any();
+        if let Some(prop) = value.downcast_ref::<Self>() {
+            *self = prop.clone();
+        }
+    }
+}
+
+impl AsProperties for String
+{
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}

crates/bevy_scene/src/lib.rs

@@ -1,7 +1,11 @@
 mod component_registry;
 mod scene;
+mod scene_loader;
+pub mod serde;
+
 pub use component_registry::*;
 pub use scene::*;
+pub use scene_loader::*;
 
 use bevy_app::{AppBuilder, AppPlugin};
 use bevy_asset::AddAsset;

crates/bevy_scene/src/scene.rs

@@ -1,25 +1,19 @@
-use crate::{ComponentRegistry, PropertyTypeRegistryContext};
+use crate::ComponentRegistry;
 use anyhow::Result;
-use bevy_app::FromResources;
-use bevy_asset::AssetLoader;
-use bevy_property::{DynamicProperties, PropertyTypeRegistry, DynamicPropertiesDeserializer};
-use legion::prelude::{Entity, Resources, World};
-use serde::{
-    de::{DeserializeSeed, SeqAccess, Visitor, MapAccess, Error},
-    Serialize,
-    Deserialize
-};
-use std::{cell::RefCell, num::Wrapping, path::Path, rc::Rc};
+use bevy_property::DynamicProperties;
+use legion::prelude::World;
+use serde::Serialize;
+use std::num::Wrapping;
 use thiserror::Error;
 
 #[derive(Default)]
 pub struct Scene {
-    pub entities: Vec<SceneEntity>,
+    pub entities: Vec<Entity>,
 }
 
 #[derive(Serialize)]
-pub struct SceneEntity {
-    pub entity: u32,
+pub struct Entity {
+    pub id: u32,
     pub components: Vec<DynamicProperties>,
 }
 
@@ -45,8 +39,8 @@ impl Scene {
                                 component_storage.components(*component_type_id).unwrap();
                             for (index, entity) in component_storage.entities().iter().enumerate() {
                                 if index == entities.len() {
-                                    entities.push(SceneEntity {
-                                        entity: entity.index(),
+                                    entities.push(Entity {
+                                        id: entity.index(),
                                         components: Vec::new(),
                                     })
                                 }
@@ -77,7 +71,7 @@ impl Scene {
         world.entity_allocator.push_next_ids(
             self.entities
                 .iter()
-                .map(|e| Entity::new(e.entity, Wrapping(1))),
+                .map(|e| legion::prelude::Entity::new(e.id, Wrapping(1))),
         );
         for scene_entity in self.entities.iter() {
             // TODO: use EntityEntry when legion refactor is finished
@@ -95,223 +89,3 @@ impl Scene {
         Ok(())
     }
 }
-
-impl Serialize for Scene {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        self.entities.serialize(serializer)
-    }
-}
-
-pub struct SceneDeserializer<'a> {
-    pub property_type_registry: &'a PropertyTypeRegistry,
-    pub current_type_name: Rc<RefCell<Option<String>>>,
-}
-
-impl<'a, 'de> DeserializeSeed<'de> for SceneDeserializer<'a> {
-    type Value = Scene;
-    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
-    where
-        D: serde::Deserializer<'de>,
-    {
-        let mut scene = Scene::default();
-        scene.entities = deserializer.deserialize_seq(SceneEntitySeqVisiter {
-            property_type_registry: self.property_type_registry,
-            current_type_name: self.current_type_name,
-        })?;
-
-        Ok(scene)
-    }
-}
-
-struct SceneEntitySeqVisiter<'a> {
-    pub property_type_registry: &'a PropertyTypeRegistry,
-    pub current_type_name: Rc<RefCell<Option<String>>>,
-}
-
-impl<'a, 'de> Visitor<'de> for SceneEntitySeqVisiter<'a> {
-    type Value = Vec<SceneEntity>;
-    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-        formatter.write_str("list of entities")
-    }
-
-    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
-    where
-        A: SeqAccess<'de>,
-    {
-        let mut entities = Vec::new();
-        while let Some(entity) = seq.next_element_seed(SceneEntityDeserializer {
-            property_type_registry: self.property_type_registry,
-            current_type_name: self.current_type_name.clone(),
-        })? {
-            entities.push(entity);
-        }
-
-        Ok(entities)
-    }
-}
-
-pub struct SceneEntityDeserializer<'a> {
-    pub property_type_registry: &'a PropertyTypeRegistry,
-    pub current_type_name: Rc<RefCell<Option<String>>>,
-}
-
-impl<'a, 'de> DeserializeSeed<'de> for SceneEntityDeserializer<'a> {
-    type Value = SceneEntity;
-    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
-    where
-        D: serde::Deserializer<'de>,
-    {
-        deserializer.deserialize_struct("", &["entity", "components"], SceneEntityVisiter {
-            property_type_registry: self.property_type_registry,
-            current_type_name: self.current_type_name,
-        })
-    }
-}
-
-
-#[derive(Deserialize)]
-#[serde(field_identifier, rename_all = "lowercase")]
-enum EntityField {
-    Entity,
-    Components,
-}
-
-pub const ENTITY_FIELD_ENTITY: &str = "entity";
-pub const ENTITY_FIELD_COMPONENTS: &str = "components";
-
-struct SceneEntityVisiter<'a> {
-    pub property_type_registry: &'a PropertyTypeRegistry,
-    pub current_type_name: Rc<RefCell<Option<String>>>,
-}
-
-impl<'a, 'de> Visitor<'de> for SceneEntityVisiter<'a> {
-    type Value = SceneEntity;
-    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-        formatter.write_str("entities")
-    }
-
-    fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
-    where A: MapAccess<'de> {
-        let mut entity = None;
-        let mut components = None;
-        while let Some(key) = map.next_key()? {
-            match key {
-                EntityField::Entity => {
-                    if entity.is_some() {
-                        return Err(Error::duplicate_field(ENTITY_FIELD_ENTITY));
-                    }
-                    entity = Some(map.next_value::<u32>()?);
-                }
-                EntityField::Components => {
-                    if components.is_some() {
-                        return Err(Error::duplicate_field(ENTITY_FIELD_COMPONENTS));
-                    }
-
-                    components = Some(map.next_value_seed(ComponentVecDeserializer {
-                        current_type_name: self.current_type_name.clone(), 
-                        property_type_registry: self.property_type_registry
-                    })?);
-                }
-            }
-        }
-
-        let entity = entity
-        .as_ref()
-        .ok_or_else(|| Error::missing_field(ENTITY_FIELD_ENTITY))?;
-
-        let components = components
-        .take()
-        .ok_or_else(|| Error::missing_field(ENTITY_FIELD_COMPONENTS))?;
-        Ok(SceneEntity {
-            entity: *entity,
-            components,
-        }) 
-    }
-}
-
-pub struct ComponentVecDeserializer<'a> {
-    pub property_type_registry: &'a PropertyTypeRegistry,
-    pub current_type_name: Rc<RefCell<Option<String>>>,
-}
-
-impl<'a, 'de> DeserializeSeed<'de> for ComponentVecDeserializer<'a> {
-    type Value = Vec<DynamicProperties>;
-    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
-    where
-        D: serde::Deserializer<'de>,
-    {
-        deserializer.deserialize_seq(ComponentSeqVisiter {
-            property_type_registry: self.property_type_registry,
-            current_type_name: self.current_type_name,
-        })
-    }
-}
-
-
-struct ComponentSeqVisiter<'a> {
-    pub property_type_registry: &'a PropertyTypeRegistry,
-    pub current_type_name: Rc<RefCell<Option<String>>>,
-}
-
-impl<'a, 'de> Visitor<'de> for ComponentSeqVisiter<'a> {
-    type Value = Vec<DynamicProperties>;
-    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-        formatter.write_str("list of components")
-    }
-
-    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
-    where
-        A: SeqAccess<'de>,
-    {
-        let mut dynamic_properties = Vec::new();
-        while let Some(entity) = seq.next_element_seed(DynamicPropertiesDeserializer {
-            current_type_name: self.current_type_name.clone(), 
-            property_type_registry: self.property_type_registry
-         })? {
-            dynamic_properties.push(entity);
-        }
-
-        Ok(dynamic_properties)
-    }
-}
-
-
-pub struct SceneLoader {
-    property_type_registry: PropertyTypeRegistryContext,
-}
-impl FromResources for SceneLoader {
-    fn from_resources(resources: &Resources) -> Self {
-        let property_type_registry = resources.get::<PropertyTypeRegistryContext>().unwrap();
-        SceneLoader {
-            property_type_registry: property_type_registry.clone(),
-        }
-    }
-}
-
-impl AssetLoader<Scene> for SceneLoader {
-    fn from_bytes(&self, _asset_path: &Path, bytes: Vec<u8>) -> Result<Scene> {
-        let registry = self.property_type_registry.value.read().unwrap();
-        let mut deserializer = ron::de::Deserializer::from_bytes(&bytes).unwrap();
-        let current_type_name = Rc::new(RefCell::new(None));
-        let scene_deserializer = SceneDeserializer {
-            property_type_registry: &registry,
-            current_type_name: current_type_name.clone(),
-        };
-        let mut callback = |ident: &Option<&[u8]>| {
-            let mut last_type_name = current_type_name.borrow_mut();
-            *last_type_name = ident.map(|i| String::from_utf8(i.to_vec()).unwrap());
-        };
-        deserializer.set_callback(&mut callback);
-
-
-        let scene = scene_deserializer.deserialize(&mut deserializer).unwrap();
-        Ok(scene)
-    }
-    fn extensions(&self) -> &[&str] {
-        static EXTENSIONS: &[&str] = &["scn"];
-        EXTENSIONS
-    }
-}

crates/bevy_scene/src/scene_loader.rs

@@ -0,0 +1,45 @@
+use crate::{serde::SceneDeserializer, PropertyTypeRegistryContext, Scene};
+use anyhow::Result;
+use bevy_app::FromResources;
+use bevy_asset::AssetLoader;
+use legion::prelude::Resources;
+use serde::de::DeserializeSeed;
+use std::{cell::RefCell, path::Path, rc::Rc};
+
+pub struct SceneLoader {
+    property_type_registry: PropertyTypeRegistryContext,
+}
+impl FromResources for SceneLoader {
+    fn from_resources(resources: &Resources) -> Self {
+        let property_type_registry = resources.get::<PropertyTypeRegistryContext>().unwrap();
+        SceneLoader {
+            property_type_registry: property_type_registry.clone(),
+        }
+    }
+}
+
+impl AssetLoader<Scene> for SceneLoader {
+    fn from_bytes(&self, _asset_path: &Path, bytes: Vec<u8>) -> Result<Scene> {
+        let registry = self.property_type_registry.value.read().unwrap();
+        let mut deserializer = ron::de::Deserializer::from_bytes(&bytes).unwrap();
+        let current_type_name = Rc::new(RefCell::new(None));
+        let scene_deserializer = SceneDeserializer {
+            property_type_registry: &registry,
+            current_type_name: current_type_name.clone(),
+        };
+
+        // this callback is executed whenever an explicit type name is encountered in a map
+        let mut callback = |ident: &Option<&[u8]>| {
+            let mut last_type_name = current_type_name.borrow_mut();
+            *last_type_name = ident.map(|i| String::from_utf8(i.to_vec()).unwrap());
+        };
+        deserializer.set_callback(&mut callback);
+
+        let scene = scene_deserializer.deserialize(&mut deserializer).unwrap();
+        Ok(scene)
+    }
+    fn extensions(&self) -> &[&str] {
+        static EXTENSIONS: &[&str] = &["scn"];
+        EXTENSIONS
+    }
+}

crates/bevy_scene/src/serde.rs

@@ -0,0 +1,194 @@
+use crate::{Entity, Scene};
+use anyhow::Result;
+use bevy_property::{DynamicProperties, DynamicPropertiesDeserializer, PropertyTypeRegistry};
+use serde::{
+    de::{DeserializeSeed, Error, MapAccess, SeqAccess, Visitor},
+    Deserialize, Serialize,
+};
+use std::{cell::RefCell, rc::Rc};
+
+impl Serialize for Scene {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        self.entities.serialize(serializer)
+    }
+}
+
+pub struct SceneDeserializer<'a> {
+    pub property_type_registry: &'a PropertyTypeRegistry,
+    pub current_type_name: Rc<RefCell<Option<String>>>,
+}
+
+impl<'a, 'de> DeserializeSeed<'de> for SceneDeserializer<'a> {
+    type Value = Scene;
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let mut scene = Scene::default();
+        scene.entities = deserializer.deserialize_seq(SceneEntitySeqVisiter {
+            property_type_registry: self.property_type_registry,
+            current_type_name: self.current_type_name,
+        })?;
+
+        Ok(scene)
+    }
+}
+
+struct SceneEntitySeqVisiter<'a> {
+    pub property_type_registry: &'a PropertyTypeRegistry,
+    pub current_type_name: Rc<RefCell<Option<String>>>,
+}
+
+impl<'a, 'de> Visitor<'de> for SceneEntitySeqVisiter<'a> {
+    type Value = Vec<Entity>;
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        formatter.write_str("list of entities")
+    }
+
+    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+    where
+        A: SeqAccess<'de>,
+    {
+        let mut entities = Vec::new();
+        while let Some(entity) = seq.next_element_seed(SceneEntityDeserializer {
+            property_type_registry: self.property_type_registry,
+            current_type_name: self.current_type_name.clone(),
+        })? {
+            entities.push(entity);
+        }
+
+        Ok(entities)
+    }
+}
+
+pub struct SceneEntityDeserializer<'a> {
+    pub property_type_registry: &'a PropertyTypeRegistry,
+    pub current_type_name: Rc<RefCell<Option<String>>>,
+}
+
+impl<'a, 'de> DeserializeSeed<'de> for SceneEntityDeserializer<'a> {
+    type Value = Entity;
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        deserializer.deserialize_struct(
+            "Entity",
+            &["id", "components"],
+            SceneEntityVisiter {
+                property_type_registry: self.property_type_registry,
+                current_type_name: self.current_type_name,
+            },
+        )
+    }
+}
+
+#[derive(Deserialize)]
+#[serde(field_identifier, rename_all = "lowercase")]
+enum EntityField {
+    Id,
+    Components,
+}
+
+pub const ENTITY_FIELD_ID: &str = "id";
+pub const ENTITY_FIELD_COMPONENTS: &str = "components";
+
+struct SceneEntityVisiter<'a> {
+    pub property_type_registry: &'a PropertyTypeRegistry,
+    pub current_type_name: Rc<RefCell<Option<String>>>,
+}
+
+impl<'a, 'de> Visitor<'de> for SceneEntityVisiter<'a> {
+    type Value = Entity;
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        formatter.write_str("entities")
+    }
+
+    fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+    where
+        A: MapAccess<'de>,
+    {
+        let mut id = None;
+        let mut components = None;
+        while let Some(key) = map.next_key()? {
+            match key {
+                EntityField::Id => {
+                    if id.is_some() {
+                        return Err(Error::duplicate_field(ENTITY_FIELD_ID));
+                    }
+                    id = Some(map.next_value::<u32>()?);
+                }
+                EntityField::Components => {
+                    if components.is_some() {
+                        return Err(Error::duplicate_field(ENTITY_FIELD_COMPONENTS));
+                    }
+
+                    components = Some(map.next_value_seed(ComponentVecDeserializer {
+                        current_type_name: self.current_type_name.clone(),
+                        property_type_registry: self.property_type_registry,
+                    })?);
+                }
+            }
+        }
+
+        let entity = id
+            .as_ref()
+            .ok_or_else(|| Error::missing_field(ENTITY_FIELD_ID))?;
+
+        let components = components
+            .take()
+            .ok_or_else(|| Error::missing_field(ENTITY_FIELD_COMPONENTS))?;
+        Ok(Entity {
+            id: *entity,
+            components,
+        })
+    }
+}
+
+pub struct ComponentVecDeserializer<'a> {
+    pub property_type_registry: &'a PropertyTypeRegistry,
+    pub current_type_name: Rc<RefCell<Option<String>>>,
+}
+
+impl<'a, 'de> DeserializeSeed<'de> for ComponentVecDeserializer<'a> {
+    type Value = Vec<DynamicProperties>;
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        deserializer.deserialize_seq(ComponentSeqVisiter {
+            property_type_registry: self.property_type_registry,
+            current_type_name: self.current_type_name,
+        })
+    }
+}
+
+struct ComponentSeqVisiter<'a> {
+    pub property_type_registry: &'a PropertyTypeRegistry,
+    pub current_type_name: Rc<RefCell<Option<String>>>,
+}
+
+impl<'a, 'de> Visitor<'de> for ComponentSeqVisiter<'a> {
+    type Value = Vec<DynamicProperties>;
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        formatter.write_str("list of components")
+    }
+
+    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+    where
+        A: SeqAccess<'de>,
+    {
+        let mut dynamic_properties = Vec::new();
+        while let Some(entity) = seq.next_element_seed(DynamicPropertiesDeserializer {
+            current_type_name: self.current_type_name.clone(),
+            property_type_registry: self.property_type_registry,
+        })? {
+            dynamic_properties.push(entity);
+        }
+
+        Ok(dynamic_properties)
+    }
+}

examples/scene/load_scene.rs

@@ -1,14 +1,18 @@
 use bevy::prelude::*;
 use bevy_scene::ComponentRegistryContext;
 use serde::Serialize;
+use bevy_asset::HandleId;
 
 fn main() {
     App::build()
         .add_default_plugins()
         // Registering components informs Bevy that they exist. This allows them to be used when loading scenes
         // This step is only required if you want to load your components from scene files.
+        // In the future registered components will also be usable from the Bevy editor.
         .register_component::<Test>()
         .register_component::<Foo>()
+        .register_component::<Handle<Mesh>>()
+        .register_property_type::<HandleId>()
         .add_startup_system(load_scene)
         // .add_startup_system(serialize_scene)
         .run();
@@ -25,16 +29,6 @@ struct Foo {
     pub value: String,
 }
 
-#[derive(Serialize)]
-struct Ahh {
-    pub x: Vec<A>,
-}
-
-#[derive(Serialize)]
-struct A {
-    pub x: f32,
-}
-
 fn load_scene(world: &mut World, resources: &mut Resources) {
     let asset_server = resources.get::<AssetServer>().unwrap();
     let mut scenes = resources.get_mut::<Assets<Scene>>().unwrap();
@@ -56,6 +50,7 @@ fn serialize_scene(world: &mut World, resources: &mut Resources) {
             x: 1.0,
             y: 2.0,
         })
+        .add(Handle::<Mesh>::new())
         .add(Foo {
             value: "hello".to_string()
         })
@@ -67,6 +62,9 @@ fn serialize_scene(world: &mut World, resources: &mut Resources) {
     
     let scene = Scene::from_world(world, &component_registry.value.read().unwrap());
     let pretty_config = ron::ser::PrettyConfig::default().with_decimal_floats(true);
-    let ron_string = ron::ser::to_string_pretty(&scene, pretty_config).unwrap();
+    let mut buf = Vec::new();
+    let mut serializer = ron::ser::Serializer::new(&mut buf, Some(pretty_config), true).unwrap();
+    scene.serialize(&mut serializer).unwrap();
+    let ron_string = String::from_utf8(buf).unwrap();
     println!("{}", ron_string);
 }

examples/scene/properties.rs

@@ -1,5 +1,5 @@
 use bevy::prelude::*;
-use bevy_property::ron::deserialize_dynamic_properties;
+use bevy_property::{AsProperties, ron::deserialize_dynamic_properties};
 use bevy_scene::PropertyTypeRegistryContext;
 use serde::{Deserialize, Serialize};
 
@@ -29,6 +29,35 @@ pub struct CustomProperty {
     a: usize,
 }
 
+impl Property for CustomProperty {
+    fn any(&self) -> &dyn std::any::Any {
+        self
+    }
+    fn any_mut(&mut self) -> &mut dyn std::any::Any {
+        self
+    }
+    fn clone_prop(&self) -> Box<dyn Property> {
+        Box::new(self.clone())
+    }
+    fn set(&mut self, value: &dyn Property) {
+        let value = value.any();
+        if let Some(prop) = value.downcast_ref::<Self>() {
+            *self = prop.clone();
+        } else {
+            panic!("prop value is not {}", std::any::type_name::<Self>());
+        }
+    }
+    fn apply(&mut self, value: &dyn Property) {
+        self.set(value);
+    }
+}
+
+impl AsProperties for CustomProperty {
+    fn as_properties(&self) -> Option<&dyn Properties> {
+        None
+    }
+}
+
 fn setup(property_type_registry: Res<PropertyTypeRegistryContext>) {
     let mut test = Test {
         a: 1,