map-tool: add command to extract union data

map-tool/src/roblox/cli.rs

@@ -13,6 +13,7 @@ const DOWNLOAD_LIMIT:usize=16;
 pub enum Commands{
 	RobloxToSNF(RobloxToSNFSubcommand),
 	DownloadAssets(DownloadAssetsSubcommand),
+	ExtractUnionData(ExtractUnionData),
 }
 
 #[derive(clap::Args)]
@@ -33,6 +34,13 @@ pub struct DownloadAssetsSubcommand{
 	#[arg(long,group="cookie",required=true)]
 	cookie_file:Option<PathBuf>,
 }
+#[derive(clap::Args)]
+pub struct ExtractUnionData{
+	#[arg(long)]
+	output_folder:PathBuf,
+	#[arg(long)]
+	input_file:PathBuf,
+}
 
 impl Commands{
 	pub async fn run(self)->AResult<()>{
@@ -46,6 +54,7 @@ impl Commands{
 					subcommand.cookie_file,
 				).await?,
 			).await,
+			Commands::ExtractUnionData(subcommand)=>extract_union_data(subcommand.input_file,subcommand.output_folder).await,
 		}
 	}
 }
@@ -347,3 +356,28 @@ pub fn convert_to_snf(dom:rbx_dom_weak::WeakDom)->Result<ConvertOutput,ConvertEr
 		convert_errors,
 	})
 }
+
+async fn extract_union_data(input_file:PathBuf,output_folder:PathBuf)->AResult<()>{
+	let data=tokio::fs::read(&input_file).await?;
+
+	let dom=rbx_binary::from_reader(Cursor::new(data))?;
+	let &[referent]=dom.root().children()else{
+		panic!("Expected one child");
+	};
+	let Some(instance)=dom.get_by_ref(referent)else{
+		panic!("Missing instance");
+	};
+	let output_file=output_folder.join(input_file.file_stem().unwrap());
+	if let Some(rbx_dom_weak::types::Variant::BinaryString(data))=instance.properties.get(&rbx_dom_weak::ustr("PhysicsData")){
+		let mut physics_data_path=output_file.clone();
+		physics_data_path.set_extension("physicsdata");
+		tokio::fs::write(physics_data_path,data).await?;
+	}
+	if let Some(rbx_dom_weak::types::Variant::BinaryString(data))=instance.properties.get(&rbx_dom_weak::ustr("MeshData")){
+		let mut mesh_data_path=output_file.clone();
+		mesh_data_path.set_extension("meshdata");
+		tokio::fs::write(mesh_data_path,data).await?;
+	}
+
+	Ok(())
+}