Start implementing lua scripting

main.lua

@@ -2,6 +2,7 @@ print("Hello from a lua script!")
 
 function init()
    print("Hello from \"init\"")
+   print(couch.root:find_node("cube"):get_transform())
    couch.debug("init")
    couch.say_hello("dane", "Hi!")
 end

src/gameobject.rs

@@ -2,34 +2,35 @@ use nalgebra_glm as glm;
 
 use crate::model::Model;
 
+use std::rc::Rc;
+use std::cell::RefCell;
+
+pub type NodeRef = Rc<RefCell<Node>>;
+
 pub struct Node {
     pub name: String,
     pub gameobject: GameObject,
-    pub children: Vec<Node>,
+    pub children: Vec<NodeRef>,
 }
 
-pub trait Childbearing<T> {
+pub trait Childbearing<T> { // TODO remove this
     fn add_child(&mut self, name: &str, child: T);
-    fn find_node(&mut self, name: &str) -> Option<&mut Box<T>>;
+}
+
+impl Node {
+    pub fn find_node(&mut self, name: &str) -> Option<NodeRef> {
+	match self.children.iter().find(|node| node.borrow().name == name) {
+	    Some(node) => Some(Rc::clone(node)),
+	    None => None
+	}
+    }
 }
 
 macro_rules! impl_childbearing {
     ($t:ty, $e:path) => {
 	impl Childbearing<$t> for Node {
 	    fn add_child(&mut self, name: &str, child: $t) {
-		self.children.push(Node::new(name.to_string(), $e(Box::new(child))));
-	    }
-	    fn find_node(&mut self, name: &str) -> Option<&mut Box<$t>> {
-		match self.children.iter_mut().find(|node| node.name == name) {
-		    Some(node) => {
-			if let $e(child) = &mut node.gameobject {
-			    Some(child)
-			} else {
-			    None
-			}
-		    },
-		    None => None,
-		}
+		self.children.push(Rc::new(RefCell::new(Node::new(name.to_string(), $e(child)))));
 	    }
 	}
     }
@@ -49,8 +50,8 @@ impl Node {
 
 pub enum GameObject {
     Null,
-    Camera(Box<Camera>),
-    Mesh(Box<Mesh>),
+    Camera(Camera),
+    Mesh(Mesh),
 }
 
 #[derive(Clone, Copy)]

src/main.rs

@@ -1,17 +1,20 @@
 mod device;
+
 mod model;
+use model::Model;
+
 mod scripting;
+use scripting::{ ScriptLang, Lua };
+
 mod gameobject;
+use gameobject::*;
 
 #[macro_use]
 extern crate glium;
 extern crate nalgebra_glm as glm;
 
-use model::Model;
-
-use scripting::{ ScriptLang, Lua };
-
-use gameobject::*;
+use std::rc::Rc;
+use std::cell::RefCell;
 
 fn main() {
     use glium::{glutin, Surface};
@@ -30,18 +33,22 @@ fn main() {
 
     let mut device_manager = crate::device::DeviceManager::new();
 
-    let mut root = Node::new("_root_".to_string(), GameObject::Null);
-    root.add_child("camera", Camera::new());
+    let root = Rc::new(RefCell::new(Node::new("_root_".to_string(), GameObject::Null)));
+    {
+	// Initial scene setup
+	let mut root = root.borrow_mut();
+	root.add_child("camera", Camera::new());
     
-    let mut cube = Mesh::new(Model::new(&display, "Box.glb"));
-    cube.set_transform(gameobject::Transform {
-	position: glm::vec3(0.0, 0.0, -10.0),
-	rotation: glm::vec3(0.0, 15.0_f32.to_radians(), 0.0),
-	scale: glm::vec3(1.0, 1.0, 1.0),
-    });
-    root.add_child("cube", cube);
+	let mut cube = Mesh::new(Model::new(&display, "Box.glb"));
+	cube.set_transform(gameobject::Transform {
+	    position: glm::vec3(0.0, 0.0, -10.0),
+	    rotation: glm::vec3(0.0, 15.0_f32.to_radians(), 0.0),
+	    scale: glm::vec3(1.0, 1.0, 1.0),
+	});
+	root.add_child("cube", cube);
+    }
 	
-    let mut script_lang = Lua::new();
+    let mut script_lang = Lua::new(Rc::clone(&root));
     script_lang.init();
 
     let mut last_draw = std::time::Instant::now();
@@ -77,8 +84,15 @@ fn main() {
 		    .. Default::default()
 		};
 		target.clear_color_and_depth((0.0, 0.0, 0.0, 1.0), 1.0);
-		
-		let cube: &mut Box<Mesh> = root.find_node("cube").unwrap();
+
+		let mut root = root.borrow_mut();
+
+		let cube = root.find_node("cube").unwrap();
+		let mut cube = cube.borrow_mut();
+		let cube: &mut Mesh = match &mut cube.gameobject {
+		    GameObject::Mesh(mesh) => mesh,
+		    _ => panic!("cube is not a mesh"),
+		};
 		let mut transform = cube.get_transform();
 		if device_manager.is_pressed(&device::Key::W) {
 		    transform.position.z += 1.0 * delta;
@@ -101,8 +115,6 @@ fn main() {
 		};
 		cube.model.draw(&mut target, &program, &uniforms, &params);
 
-		let _camera: &mut Box<Camera> = root.find_node("camera").unwrap();
-		
 		target.finish().unwrap();
 	    }
 	    _ => (),

src/scripting.rs

@@ -1,8 +1,12 @@
-extern crate mlua;
+use crate::gameobject::{ Node, Transform, Spatial };
 
+extern crate mlua;
 use mlua::Lua as LuaContext;
 use mlua::chunk;
 
+use std::rc::Rc;
+use std::cell::RefCell;
+
 pub trait ScriptLang {
     fn init(&mut self);
     fn update(&mut self, delta: f32);
@@ -12,12 +16,35 @@ pub struct Lua {
     ctx: LuaContext,
 }
 
+impl mlua::UserData for Node {
+    fn add_methods<'lua, M: mlua::UserDataMethods<'lua, Self>>(methods: &mut M) {
+	use crate::gameobject::GameObject::*;
+	methods.add_method_mut("find_node", |_, this, name: String| {
+	    let child = this.find_node(&name);
+	    match child {
+		Some(child) => Ok(child),
+		None => Err(mlua::Error::RuntimeError("Could not find child".to_string())),
+	    }
+	});
+	methods.add_method("get_transform", |_, this, _: ()| {
+	    match &this.gameobject {
+		Mesh(mesh) => Ok(mesh.get_transform()),
+		Camera(camera) => Ok(camera.get_transform()),
+		_ => Err(mlua::Error::RuntimeError("Node does not implement get_transform".to_string()))
+	    }
+	});
+    }
+}
+
+impl mlua::UserData for Transform {}
+
 impl Lua {
-    pub fn new() -> Self {
+    pub fn new(root: Rc<RefCell<Node>>) -> Self {
 	// Create a lua context, load std libraries
 	let ctx = LuaContext::new();
 	// Create the ``couch'' api
 	let couch = ctx.create_table().unwrap();
+	couch.set("root", ctx.create_userdata(root).unwrap()).unwrap();
 	couch.set("debug", ctx.create_function(debug).unwrap()).unwrap();
 	couch.set("say_hello", ctx.create_function(say_hello).unwrap()).unwrap();
 	// Hook in to globals