Better framework for asset-driven entities

assets/editor/_.scene

@@ -1,4 +0,0 @@
-entities/camera.entity
-entities/ui_container.entity
-entities/ui_title.entity
-entities/window.entity

assets/editor/entities/camera.entity

@@ -1,5 +0,0 @@
-name "Editor Camera"
-editorTag
-camera target window "window.entity"
-flyCamera
-transform translation 10.0 10.0 10.0 rotation 0.0 0.0 0.0 1.0 scale 1.0 1.0 1.0

assets/editor/entities/ui_container.entity

@@ -1,3 +0,0 @@
-editorTag
-uiNode
-targetCamera "camera.entity"

assets/editor/entities/ui_title.entity

@@ -1,3 +0,0 @@
-editorTag
-uiText "Welcome to the editor" color #ffffff size 12.0
-parent "ui_container.entity"

assets/editor/entities/window.entity

@@ -1,3 +0,0 @@
-editorTag
-name "Editor Window"
-window "Editor" visible false

assets/levels/00/_.scene

@@ -1,2 +0,0 @@
-entities/camera.entity
-entities/van.entity

assets/levels/00/entities/camera.entity

@@ -1,3 +0,0 @@
-name camera
-transform translation 2.0 2.0 0.0 rotation 0.0 0.0 0.0 1.0 scale 1.0 1.0 1.0
-camera

assets/levels/00/entities/van.entity

@@ -1,3 +0,0 @@
-name van
-transform translation 0.0 0.0 0.0 rotation 0.0 0.0 0.0 1.0 scale 1.0 1.0 1.0
-model "models/van.glb" "Scene"

assets/scenes/00.scene

@@ -0,0 +1 @@
+00/a.entity

assets/scenes/00/a.entity

@@ -0,0 +1 @@
+name "Hello world"

src/main.rs

@@ -1,3 +1,5 @@
+#![feature(let_chains)]
+
 /// Camera controller
 pub(crate) mod camera;
 /// ECS scheduling `run_if` conditions
@@ -12,7 +14,6 @@ pub(crate) mod prelude;
 pub(crate) mod save;
 /// Window handling
 pub(crate) mod window;
-
 /// Save file parsing
 pub(crate) mod parser;
 
@@ -26,10 +27,10 @@ fn main() {
             exit_condition: bevy::window::ExitCondition::OnPrimaryClosed,
             ..default()
         }))
-        .add_plugins(camera::CameraPlugin)
-        .add_plugins(editor::EditorPlugin)
-        .add_plugins(menu::MenuPlugin)
+        // .add_plugins(camera::CameraPlugin)
+        // .add_plugins(editor::EditorPlugin)
+        // .add_plugins(menu::MenuPlugin)
+        // .add_plugins(window::WindowPlugin)
         .add_plugins(save::SavePlugin)
-        .add_plugins(window::WindowPlugin)
         .run();
 }

src/parser.rs

@@ -2,14 +2,10 @@ use crate::prelude::*;
 
 #[derive(Error, Debug)]
 pub(crate) enum SaveEntityParseError {
-    #[error("Failed to parse name")]
-    Name,
-    #[error("Failed to parse Transform")]
-    Transform,
+    #[error("Failed to parse `{0}`")]
+    Component(String),
     #[error("Failed to parse Entity")]
     Nom(nom::Err<nom::error::Error<Box<str>>>),
-    #[error("Failed to parse camera")]
-    Camera,
 }
 
 // Convert Nom error to parse error
@@ -22,7 +18,7 @@ impl From<nom::Err<nom::error::Error<&str>>> for SaveEntityParseError {
 
 
 #[derive(Debug, PartialEq)]
-enum Token {
+pub(crate) enum Token {
     Tag(String),
     Str(String),
     Num(f32),
@@ -32,27 +28,35 @@ enum Token {
 /// Simple function to tokenize a string into an array of Token values
 ///
 pub(crate) fn tokenize(line: &str) -> Vec<Token> {
-    line.split(" ")
-        .map(|piece| {
-            if let Ok(n) = piece.parse::<f32>() {
-                Token::Num(n)
-            } else if let Ok((_, (_, s, _))) = tuple((
-                tag::<&str, &str, ()>("\""),
-                take_until1("\""),
-                tag::<&str, &str, ()>("\""),
-            ))(piece)
-            {
-                Token::Str(s.into())
-            } else {
-                Token::Tag(piece.into())
-            }
-        })
-        .collect()
+    let mut l = line;
+    let mut tokens = Vec::new();
+
+    while l.len() > 0 {
+        debug!("Line: {:?}", l);
+        if let Ok((rem, (_, s, _))) = tuple((char::<&str, ()>('"'), take_until("\""), char::<&str, ()>('"')))(l) {
+            debug!("Parsed string {:?}", s);
+            tokens.push(Token::Str(s.into()));
+            l = rem;
+        } else if let Ok((rem, num)) = float::<&str, ()>(l) {
+            debug!("Parsed float {:?}", num);
+            tokens.push(Token::Num(num.into()));
+            l = rem;
+        } else if let Ok((rem, (_, tag, _))) = tuple((space0, alphanumeric1::<&str, ()>, space0))(l) {
+            debug!("Parsed tag {:?}", tag);
+            tokens.push(Token::Tag(tag.into()));
+            l = rem;
+        } else {
+            debug!("Breaking loop");
+            break
+        }
+    }
+
+    tokens
 }
 
 #[test]
 fn test_tokenize() {
-    let line = "foo \"bar\" 1.23 baz \"asdf\" etc";
+    let line = "foo \"bar\" 1.23 baz -3.45 \"asdf\" \"multi word string\" etc";
     assert_eq!(
         tokenize(line),
         vec![
@@ -60,7 +64,9 @@ fn test_tokenize() {
             Token::Str("bar".into()),
             Token::Num(1.23),
             Token::Tag("baz".into()),
+            Token::Num(-3.45),
             Token::Str("asdf".into()),
+            Token::Str("multi word string".into()),
             Token::Tag("etc".into())
         ]
     );
@@ -71,8 +77,6 @@ fn test_tokenize() {
 /// Returns reflected `Transform`
 ///
 pub(crate) fn parse_save_transform(tokens: &Vec<Token>) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
-    let mut transform = Transform::default();
-
     // Tag(Transform),
     //      Tag(Translation), Number, Number, Number
     //      Tag(Rotation), Number, Number, Number, Number
@@ -104,9 +108,11 @@ fn test_parse_transform() {
 /// Returns a reflected `Name`
 ///
 pub(crate) fn parse_save_name(tokens: &Vec<Token>) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
-    todo!("parse_save_name");
-
-    // Err(SaveEntityParseError::Name)
+    if let Some((Token::Tag(t), &[Token::Str(ref s)])) = tokens.split_first() && *t == String::from("name") {
+        Ok(Name::new(s.clone()).clone_value())
+    } else {
+        Err(SaveEntityParseError::Component("Name".into()))
+    }
 }
 
 #[test]
@@ -374,7 +380,7 @@ fn test_save_ui_text() {
 ///
 pub(crate) fn parse_save_tag<T: Component + Reflect + Default>(
     t: &str,
-) -> impl FnOnce(&str) -> Result<Box<dyn Reflect>, SaveEntityParseError> + '_ {
+) -> impl FnOnce(&Vec<Token>) -> Result<Box<dyn Reflect>, SaveEntityParseError> + '_ {
     move |tokens: &Vec<Token>| -> Result<Box<dyn Reflect>, SaveEntityParseError> {
         todo!("parse_save_tag")
     }

src/prelude.rs

@@ -9,14 +9,11 @@ pub(crate) use bevy::{
     render::camera::RenderTarget,
     window::{PrimaryWindow, WindowCloseRequested, WindowRef},
 };
-pub(crate) use nom::character::complete::hex_digit1;
 pub(crate) use nom::{
-    branch::alt,
-    bytes::complete::{tag, take_until1},
-    character::complete::{char, space1},
+    bytes::complete::take_until,
+    character::complete::{char, space0, alphanumeric1},
     number::complete::float,
     sequence::tuple,
-    IResult,
 };
 pub(crate) use std::path::PathBuf;
 pub(crate) use thiserror::Error;

src/save.rs

@@ -10,24 +10,27 @@ impl Plugin for SavePlugin {
             .register_type::<SaveModel>()
             .init_asset::<SaveEntity>()
             .init_asset_loader::<SaveEntityLoader>()
+            .init_asset::<SaveScene>()
             .init_asset_loader::<SaveSceneLoader>()
-            .add_systems(Startup, test_load_entity)
-            .add_systems(
-                Update,
-                spawn_loaded_entities.run_if(on_event::<AssetEvent<SaveEntity>>()),
-            );
+            .add_systems(Startup, load_scenes)
+            .add_systems(Update, spawn_scenes.run_if(on_event::<AssetEvent<SaveEntity>>()))
+            .add_systems(Update, spawn_entities.run_if(any_component_added::<Handle<SaveEntity>>));
     }
 }
 
 #[derive(Asset, TypePath, Default)]
-pub(crate) struct SaveEntity {
-    components: Vec<Box<dyn Reflect>>,
+pub(crate) struct SaveScene {
+    entities: Vec<Handle<SaveEntity>>,
 }
 
 // TODO: SCALABILITY: SaveEntity should maybe be a HashSet or Vec of Box<into Bundle>
 // Then we tell the parse "For each line, run through each of these concrete parsers"
 // If it matches, add it to the set of Box<Bundle>
 // Ironically we basically want DynamicEntity: https://docs.rs/bevy/latest/bevy/scene/struct.DynamicEntity.html
+#[derive(Asset, TypePath, Default)]
+pub(crate) struct SaveEntity {
+    components: Vec<Box<dyn Reflect>>,
+}
 
 impl SaveEntity {
     fn parse(
@@ -38,13 +41,13 @@ impl SaveEntity {
         let mut entity = SaveEntity { ..default() };
         let fns = [
             parse_save_name,
-            parse_save_transform,
-            parse_save_model,
-            parse_save_camera,
-            parse_save_parent,
-            parse_save_window,
-            parse_save_target_camera,
-            parse_save_ui_text,
+            // parse_save_transform,
+            // parse_save_model,
+            // parse_save_camera,
+            // parse_save_parent,
+            // parse_save_window,
+            // parse_save_target_camera,
+            // parse_save_ui_text,
             // parse_save_tag::<EditorTag>("editor_tag"),
         ];
         lines
@@ -55,7 +58,7 @@ impl SaveEntity {
                 let mut good = false;
 
                 // Tokenize the line
-                let tokens = parser::tokenize(line);
+                let tokens = tokenize(line);
 
                 // Run line against all parsers
                 for f in fns {
@@ -123,7 +126,7 @@ impl AssetLoader for SaveEntityLoader {
 struct SaveSceneLoader;
 
 impl AssetLoader for SaveSceneLoader {
-    type Asset = DynamicScene;
+    type Asset = SaveScene;
     type Settings = ();
     type Error = SaveEntityLoaderError;
 
@@ -140,13 +143,14 @@ impl AssetLoader for SaveSceneLoader {
 
         let asset_path = load_context.path().to_path_buf();
         let parent_dir = asset_path.parent().unwrap();
-        let _sub_assets: Vec<Handle<SaveEntity>> = s
+        let entities: Vec<Handle<SaveEntity>> = s
             .lines()
             .map(|line| parent_dir.join(line))
             .map(|path| load_context.load(path))
             .collect();
+        info!("Entities: {:?}", entities);
 
-        Ok(DynamicScene::default())
+        Ok(SaveScene { entities })
     }
 
     fn extensions(&self) -> &[&str] {
@@ -154,16 +158,18 @@ impl AssetLoader for SaveSceneLoader {
     }
 }
 
-fn test_load_entity(loader: Res<AssetServer>, mut commands: Commands) {
-    let _: Handle<DynamicScene> = loader.load("editor/_.scene");
-    let handle: Handle<SaveEntity> = loader.load("levels/00/entities/van.entity");
-    commands.spawn((SpatialBundle { ..default() }, handle));
+/// Testing system for loading a specific scene
+fn load_scenes(loader: Res<AssetServer>, mut commands: Commands) {
+    let handle: Handle<SaveScene> = loader.load("scenes/00.scene");
+    info!("Loading scene {:?}", handle);
+    commands.spawn(handle);
 }
 
-fn spawn_loaded_entities(
-    query: Query<(Entity, &Handle<SaveEntity>)>,
-    mut events: EventReader<AssetEvent<SaveEntity>>,
-    save_entities: Res<Assets<SaveEntity>>,
+/// Spawns scenes with the Handle<Scene> marker
+fn spawn_scenes(
+    query: Query<(Entity, &Handle<SaveScene>)>,
+    mut events: EventReader<AssetEvent<SaveScene>>,
+    save_scenes: Res<Assets<SaveScene>>,
     mut commands: Commands,
 ) {
     events.read().for_each(|event| {
@@ -171,18 +177,44 @@ fn spawn_loaded_entities(
             query
                 .iter()
                 .filter(|(_, handle)| handle.id() == *id)
-                .for_each(|(entity, _handle)| {
-                    let saved = save_entities.get(*id).unwrap();
+                .for_each(|(entity, handle)| {
+                    debug!("Spawning scene {:?} on {:?}", handle, entity);
+
+                    let scene = save_scenes.get(handle).unwrap();
 
                     // Get entity with SaveEntity handle
                     let mut e = commands.entity(entity);
-                    // Clear the entity
+                    // Clear the entity of descendants
                     e.despawn_descendants();
-                    // Populate with reflected components
-                    saved.components.iter().for_each(|dc| {
-                        e.insert_reflect(dc.clone_value());
+                    // Populate with entities
+                    e.with_children(|parent| {
+                        scene.entities.iter().for_each(|this| {
+                            parent.spawn(this.clone());
+                        });
                     });
                 });
         }
     })
 }
+
+/// Spawns entities with the Handle<SaveEntity> component
+fn spawn_entities(
+    events: Query<(Entity, &Handle<SaveEntity>), Added<Handle<SaveEntity>>>,
+    save_entities: Res<Assets<SaveEntity>>,
+    mut commands: Commands,
+) {
+    events.iter().for_each(|(entity, handle)| {
+        debug!("Spawning entity {:?} {:?}", entity, handle);
+
+        // Get a handle on the
+        let mut e = commands.entity(entity);
+
+        // Get the entity asset containing reflected component
+        let save_entity = save_entities.get(handle).unwrap();
+
+        // Add each component to the entity
+        save_entity.components.iter().for_each(|component| {
+            e.insert_reflect(component.clone_value());
+        });
+    });
+}