From 2616e326748c6098b2344c6e4689cc3981f4ff3e Mon Sep 17 00:00:00 2001
From: Amatsugu <khamraj@kaisei.app>
Date: Tue, 22 Jul 2025 22:56:57 -0400
Subject: [PATCH] WIP loading meshes for prefabs

---
 engine/prefabs/src/builders.rs | 17 +++++++++++++++++
 engine/prefabs/src/lib.rs      |  1 +
 engine/prefabs/src/prefab.rs   | 19 ++++++++++++++-----
 engine/prefabs/src/tests.rs    | 19 ++++---------------
 4 files changed, 36 insertions(+), 20 deletions(-)
 create mode 100644 engine/prefabs/src/builders.rs

diff --git a/engine/prefabs/src/builders.rs b/engine/prefabs/src/builders.rs
new file mode 100644
index 0000000..4b61888
--- /dev/null
+++ b/engine/prefabs/src/builders.rs
@@ -0,0 +1,17 @@
+use bevy::prelude::*;
+use serde::{Deserialize, Serialize};
+
+use crate::prefab::ComponentBuilder;
+
+#[derive(Serialize, Deserialize, Clone)]
+pub struct PrefabMesh {
+	pub glb_path: String,
+	pub mesh_path: String,
+}
+
+#[typetag::serde]
+impl ComponentBuilder for PrefabMesh {
+	fn build(&self, _entity: &mut EntityCommands, asset_server: &AssetServer) {
+		let glb: Handle<Scene> = asset_server.load(&self.glb_path);
+	}
+}
diff --git a/engine/prefabs/src/lib.rs b/engine/prefabs/src/lib.rs
index 12133ce..690889f 100644
--- a/engine/prefabs/src/lib.rs
+++ b/engine/prefabs/src/lib.rs
@@ -1,5 +1,6 @@
 use bevy::prelude::*;
 
+pub mod builders;
 pub mod components;
 pub mod prefab;
 #[cfg(test)]
diff --git a/engine/prefabs/src/prefab.rs b/engine/prefabs/src/prefab.rs
index 7ef860b..26c63ea 100644
--- a/engine/prefabs/src/prefab.rs
+++ b/engine/prefabs/src/prefab.rs
@@ -1,23 +1,32 @@
 use bevy::{ecs::entity_disabling::Disabled, prelude::*};
 use serde::{Deserialize, Serialize};
 
-#[derive(Serialize, Deserialize)]
+use crate::builders::PrefabMesh;
+
+#[derive(Serialize, Deserialize, Default)]
 pub struct PrefabAsset {
 	pub components: Vec<Box<dyn ComponentBuilder>>,
+	pub children: Vec<PrefabAsset>,
+	pub mesh: Option<PrefabMesh>,
 }
 
 impl PrefabAsset {
-	pub fn build_prefab(&self, commands: &mut Commands) -> Entity {
+	pub fn build_prefab(&self, commands: &mut Commands, asset_server: &AssetServer) -> Entity {
+		let children: Vec<_> = self
+			.children
+			.iter()
+			.map(|c| c.build_prefab(commands, asset_server))
+			.collect();
 		let mut entity = commands.spawn(Disabled);
+		entity.add_children(&children[..]);
 		for builder in &self.components {
-			builder.insert(&mut entity);
+			builder.build(&mut entity, asset_server);
 		}
-
 		return entity.id();
 	}
 }
 
 #[typetag::serde(tag = "type")]
 pub trait ComponentBuilder: Send {
-	fn insert(&self, entity: &mut EntityCommands);
+	fn build(&self, entity: &mut EntityCommands, asset_server: &AssetServer);
 }
diff --git a/engine/prefabs/src/tests.rs b/engine/prefabs/src/tests.rs
index a94489f..0a8a38c 100644
--- a/engine/prefabs/src/tests.rs
+++ b/engine/prefabs/src/tests.rs
@@ -1,7 +1,4 @@
-use bevy::{
-	ecs::{component::Component, system::EntityCommands, world::World},
-	math::Vec3,
-};
+use bevy::prelude::*;
 use serde::{Deserialize, Serialize};
 
 use crate::prefab::{ComponentBuilder, PrefabAsset};
@@ -12,7 +9,7 @@ struct Name {
 }
 #[typetag::serde]
 impl ComponentBuilder for Name {
-	fn insert(&self, _entity: &mut EntityCommands) {
+	fn build(&self, _entity: &mut EntityCommands, _: &AssetServer) {
 		assert_eq!(self.name, "Test".to_string(), "Name");
 	}
 }
@@ -24,7 +21,7 @@ struct Position {
 
 #[typetag::serde]
 impl ComponentBuilder for Position {
-	fn insert(&self, _entity: &mut EntityCommands) {
+	fn build(&self, _entity: &mut EntityCommands, _: &AssetServer) {
 		assert_eq!(self.pos, Vec3::X, "Position");
 	}
 }
@@ -38,6 +35,7 @@ fn round_trip_test() {
 				name: "Test".to_string(),
 			}),
 		],
+		..default()
 	};
 
 	let serialized = ron::to_string(&prefab);
@@ -52,13 +50,4 @@ fn round_trip_test() {
 		prefab.components.len(),
 		"Prefab's components count do not match"
 	);
-
-	let mut world = World::new();
-	let e = world.spawn_empty().id();
-	let mut commands = world.commands();
-	let mut ec = commands.entity(e);
-
-	for component in loaded_asset.components {
-		component.insert(&mut ec);
-	}
 }