1 files changed, 59 insertions, 7 deletions

diff --git a/src/scene.rs b/src/scene.rs
index 34ff877..28a4e6a 100644
--- a/src/scene.rs
+++ b/src/scene.rs
@@ -9,6 +9,7 @@ use crate::{
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Scene {
 	pub name: Box<str>,
+	pub preload_scenes: Box<[usize]>,
 	pub scripts: ResourceRequirements,
 }
 
@@ -28,6 +29,34 @@ pub fn scene_id_by_name(scenes: &[Scene], name: &str) -> Option<usize> {
 	None
 }
 
+pub fn preload_scene(
+	scenes: &[Scene],
+	scripts: &mut ScriptManager,
+	files: &mut FileManager,
+	wasm_runner: &WasmRunner,
+	id: usize,
+) {
+	let scene = &scenes[id];
+	for script in &scene.scripts.required {
+		scripts.preload_script(*script, files, wasm_runner);
+	}
+}
+
+pub fn is_scene_loaded(
+	scenes: &[Scene],
+	scripts: &mut ScriptManager,
+	files: &mut FileManager,
+	id: usize,
+) -> bool {
+	let scene = &scenes[id];
+	scene
+		.scripts
+		.required
+		.iter()
+		.cloned()
+		.all(|script_id| scripts.is_script_loaded(script_id, files))
+}
+
 pub fn switch_scenes(
 	scenes: &[Scene],
 	scripts: &mut ScriptManager,
@@ -36,13 +65,36 @@ pub fn switch_scenes(
 	wasm_runner: &WasmRunner,
 	new: usize,
 ) {
-	let active_scripts = FxHashSet::from_iter(scripts.active_scripts.iter().cloned());
-	let scripts_to_load = &scenes[new].scripts.required;
-	for script in scripts_to_load {
-		if !active_scripts.contains(script) {
-			scripts.activate_script(*script, context, wasm_runner, files);
-		} else {
-			scripts.reset_script(*script, context, wasm_runner, files);
+	let active_scripts = scripts
+		.active_scripts
+		.iter()
+		.cloned()
+		.collect::<Box<[usize]>>();
+	for script_id in &active_scripts {
+		scripts.deactivate_script(*script_id, context, wasm_runner, files);
+	}
+
+	let mut needed_scripts = FxHashSet::default();
+	let scene = &scenes[new];
+	for script_id in &scene.scripts.required {
+		needed_scripts.insert(*script_id);
+		scripts.activate_script(*script_id, context, wasm_runner, files);
+	}
+	for script_id in &scene.scripts.preload {
+		needed_scripts.insert(*script_id);
+		scripts.preload_script(*script_id, files, wasm_runner);
+	}
+	for scene_to_preload in &scene.preload_scenes {
+		let scene_to_preload = &scenes[*scene_to_preload];
+		for script_id in &scene_to_preload.scripts.required {
+			needed_scripts.insert(*script_id);
+			scripts.preload_script(*script_id, files, wasm_runner);
 		}
 	}
+
+	let active_scripts: FxHashSet<usize> = active_scripts.iter().cloned().collect();
+	let unneeded_scripts = active_scripts.difference(&needed_scripts);
+	for script_id in unneeded_scripts {
+		scripts.unload_script(*script_id, files);
+	}
 }