Transparent transforms

main.lua

@@ -2,10 +2,10 @@ 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
 
 function update(delta)
+   print(couch.root:find_node("cube"):get_transform().position[3])
 end

src/gameobject.rs

@@ -54,6 +54,25 @@ pub enum GameObject {
     Mesh(Mesh),
 }
 
+impl GameObject {
+    pub fn get_transform(&self) -> Result<Transform, String> {
+	use GameObject::*;
+	match self {
+	    Camera(camera) => Ok(camera.get_transform()),
+	    Mesh(mesh) => Ok(mesh.get_transform()),
+	    _ => Err("object does not implement \"get_transform\"".to_string())
+	}
+    }
+    pub fn set_transform(&mut self, transform: Transform) -> Result<(), String> {
+	use GameObject::*;
+	match self {
+	    Camera(camera) => { camera.set_transform(transform); Ok(()) }
+	    Mesh(mesh) => { mesh.set_transform(transform); Ok(()) }
+	    _ => Err("object does not implement \"set_transform\"".to_string())
+	}
+    }
+}
+
 #[derive(Clone, Copy)]
 pub struct Transform {
     pub position: glm::Vec3,

src/scripting.rs

@@ -1,7 +1,8 @@
-use crate::gameobject::{ Node, Transform, Spatial };
+use crate::gameobject::{ Node, Transform };
 
 extern crate mlua;
 use mlua::Lua as LuaContext;
+use mlua::Error::RuntimeError as LuaError;
 use mlua::chunk;
 
 use std::rc::Rc;
@@ -18,7 +19,6 @@ pub struct Lua {
 
 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 {
@@ -27,16 +27,47 @@ impl mlua::UserData for Node {
 	    }
 	});
 	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()))
+	    match this.gameobject.get_transform() {
+		Ok(transform) => Ok(transform),
+		Err(msg) => Err(LuaError(msg)),
+	    }
+	});
+	methods.add_method_mut("set_transform", |_, this, transform: Transform| {
+	    match this.gameobject.set_transform(transform) {
+		Ok(()) => Ok(()),
+		Err(msg) => Err(LuaError(msg)),
 	    }
 	});
     }
 }
 
-impl mlua::UserData for Transform {}
+impl<'lua> mlua::ToLua<'lua> for Transform {
+    fn to_lua(self, ctx: &'lua LuaContext) -> mlua::Result<mlua::Value<'lua>> {
+	let table = ctx.create_table().unwrap();
+	table.set("position", <[f32; 3]>::from(self.position))?;
+	table.set("rotation", <[f32; 3]>::from(self.rotation))?;
+	table.set("scale", <[f32; 3]>::from(self.scale))?;
+	mlua::Result::Ok(mlua::Value::Table(table))
+    }
+}
+
+impl<'lua> mlua::FromLua<'lua> for Transform {
+    fn from_lua(lua_value: mlua::Value<'lua>, _: &'lua LuaContext) -> mlua::Result<Self> {
+	match lua_value {
+	    mlua::Value::Table(table) => {
+		let position: [f32; 3] = table.get("position")?;
+		let rotation: [f32; 3] = table.get("rotation")?;
+		let scale: [f32; 3] = table.get("scale")?;
+		Ok(Transform {
+		    position: glm::Vec3::from(position),
+		    rotation: glm::Vec3::from(rotation),
+		    scale: glm::Vec3::from(scale),
+		})
+	    }
+	    _ => Err(LuaError("Could not convert to Transform".to_string())),
+	}
+    }
+}
 
 impl Lua {
     pub fn new(root: Rc<RefCell<Node>>) -> Self {