feat(raytracer): add native rt functions to lisp

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lispers"
-description = "lisp interpreter in rust"
+description = "lisp interpreter in rust for raytracing"
 publish = false
 version = "0.1.0"
 
@@ -11,13 +11,17 @@ name = "lispers"
 path = "src/lib.rs"
 
 [[bin]]
-name = "demo"
-path = "src/bin/demo.rs"
+name = "lisp_demo"
+path = "src/bin/lisp_demo.rs"
 
 [[bin]]
 name = "repl"
 path = "src/bin/repl.rs"
 
+[[bin]]
+name = "rt_lisp_demo"
+path = "src/bin/rt_lisp_demo.rs"
+
 [dependencies]
 as-any = "0.3.1"
 futures = "0.3.30"

flake.nix

@@ -63,9 +63,9 @@
         };
       in rec {
         apps = rec {
-          demo = {
+          lisp_demo = {
             type = "app";
-            program = "${packages.default}/bin/demo";
+            program = "${packages.default}/bin/lisp_demo";
           };
           repl = {
             type = "app";
@@ -75,7 +75,11 @@
             type = "app";
             program = "${packages.default}/bin/rt_demo";
           };
-          default = demo;
+          rt_demo_lisp = {
+            type = "app";
+            program = "${packages.default}/bin/rt_demo_lisp";
+          };
+          default = rt_demo_lisp;
         };
         packages = rec {
           lispers = cargoNix.rootCrate.build;

src/bin/rt_demo.rs

@@ -3,10 +3,9 @@ use lispers::raytracer::{
     plane::Checkerboard,
     scene::Scene,
     sphere::Sphere,
-    types::{Color, Light, Material, Point3, Vector3},
+    types::{Color, Light, Material, Point3, RTObjectWrapper, Vector3},
 };
 extern crate nalgebra as na;
-use std::sync::Arc;
 use std::time::Instant;
 
 fn main() {
@@ -23,7 +22,7 @@ fn main() {
         color: Color::new(1.0, 1.0, 1.0),
     });
 
-    scene.add_object(Arc::new(Checkerboard::new(
+    scene.add_object(RTObjectWrapper::new(Box::new(Checkerboard::new(
         Point3::new(0.0, -1.0, 0.0),
         Vector3::new(0.0, 1.0, 0.0),
         Material::new(
@@ -42,9 +41,9 @@ fn main() {
         ),
         0.3,
         Vector3::new(0.0, 0.0, 1.0),
-    )));
+    ))));
 
-    scene.add_object(Arc::new(Sphere::new(
+    scene.add_object(RTObjectWrapper::new(Box::new(Sphere::new(
         Point3::new(-2.0, 0.0, 1.0),
         1.0,
         Material::new(
@@ -54,9 +53,9 @@ fn main() {
             20.0,
             0.3,
         ),
-    )));
+    ))));
 
-    scene.add_object(Arc::new(Sphere::new(
+    scene.add_object(RTObjectWrapper::new(Box::new(Sphere::new(
         Point3::new(0.2, -0.5, -0.2),
         0.5,
         Material::new(
@@ -66,9 +65,9 @@ fn main() {
             20.0,
             0.3,
         ),
-    )));
+    ))));
 
-    scene.add_object(Arc::new(Sphere::new(
+    scene.add_object(RTObjectWrapper::new(Box::new(Sphere::new(
         Point3::new(-0.5, 0.5, -2.0),
         1.5,
         Material::new(
@@ -78,7 +77,7 @@ fn main() {
             20.0,
             0.3,
         ),
-    )));
+    ))));
 
     let camera = Camera::new(
         Point3::new(0.0, 0.7, 5.0),

src/bin/rt_lisp_demo.rs

@@ -0,0 +1,46 @@
+use lispers::lisp::environment::EnvironmentLayer;
+use lispers::lisp::prelude::mk_prelude;
+use lispers::lisp::{eval, Environment};
+use lispers::parser::ExpressionStream;
+use lispers::raytracer::lisp::mk_raytrace;
+
+fn main() {
+    let programs = [
+        "(set 'blue (material (color 0 0 1) (color 0 0 1) (color 0 0 0.6) 50 0.25))",
+        "(set 'green (material (color 0 1 0) (color 0 1 0) (color 0 0.6 0) 50 0.25))",
+        "(set 'white (material (color 1 1 1) (color 1 1 1) (color 0.6 0.6 0.6) 100 0.5))",
+        "(set 'black (material (color 0 0 0) (color 0 0 0) (color 0.6 0.6 0.6) 100 0.5))",
+        "(set 's1 (sphere (point 0 1 0) 1 blue))",
+        "(set 's2 (sphere (point 2 0.5 2) 0.5 green))",
+        "(set 'p1 (checkerboard (point 0 0 0) (vector 0 1 0) black white 0.5 (vector 0.5 0 1)))",
+        "(set 'l1 (light (point 3 10 5) (color 1 1 1)))",
+        "(set 'l2 (light (point 2 10 5) (color 1 1 1)))",
+        "(set 'scn (scene (color 0.1 0.1 0.1) '(s1 s2 p1) '(l1 l2)))",
+        "(set 'cam (camera (point 0 3 6) (point 0 0 0) (vector 0 1 0) 40 1920 1080))",
+        "(render cam scn 5 4 \"rt-lisp-demo.png\")",
+    ];
+
+    let mut layer = EnvironmentLayer::new();
+    mk_prelude(&mut layer);
+    mk_raytrace(&mut layer);
+
+    let environment = Environment::from_layer(layer);
+
+    for r in ExpressionStream::from_char_stream(programs.iter().map(|p| p.chars()).flatten()) {
+        match r {
+            Err(err) => {
+                println!("ParserError: {:?}", err);
+                break;
+            }
+            Ok(expr) => {
+                println!("Evaluating: {}", expr.clone());
+                match eval(&environment, expr) {
+                    Ok(e) => println!("=> {}", e),
+                    Err(e) => println!("Error: {}", e),
+                }
+            }
+        }
+    }
+
+    println!("Interpreter Done!");
+}

src/raytracer/camera.rs

@@ -1,3 +1,5 @@
+use std::fmt::Display;
+
 use super::{
     scene::Scene,
     types::{Color, Point3, Ray, Scalar, Vector3},
@@ -6,6 +8,7 @@ use image::RgbImage;
 use rayon::prelude::*;
 
 /// A camera that can render a scene.
+#[derive(Clone, PartialEq, Debug)]
 pub struct Camera {
     /// Position of the camera's eye.
     position: Point3,
@@ -106,3 +109,16 @@ impl Camera {
         img
     }
 }
+
+impl Display for Camera {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Camera {{ position: {}, lower_left: {}, x_dir: {}, y_dir: {}, width: {}, height: {} }}",
+            self.position, self.lower_left, self.x_dir, self.y_dir, self.width, self.height)
+    }
+}
+
+impl PartialOrd for Camera {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}

src/raytracer/lisp.rs

@@ -0,0 +1,226 @@
+use crate::{
+    lisp::{
+        environment::EnvironmentLayer,
+        eval::{eval, EvalError},
+        expression::ForeignDataWrapper,
+        Environment, Expression,
+    },
+    raytracer::{scene::Scene, types::Light},
+};
+
+use super::{
+    camera::Camera,
+    plane::{Checkerboard, Plane},
+    sphere::Sphere,
+    types::{Color, Material, Point3, RTObjectWrapper, Vector3},
+};
+
+pub fn point(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [x, y, z]: [Expression; 3] = expr.try_into()?;
+
+    let x: f64 = eval(env, x)?.try_into()?;
+    let y: f64 = eval(env, y)?.try_into()?;
+    let z: f64 = eval(env, z)?.try_into()?;
+
+    Ok(ForeignDataWrapper::new(Point3::new(x, y, z)).into())
+}
+
+pub fn vector(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [x, y, z]: [Expression; 3] = expr.try_into()?;
+
+    let x: f64 = eval(env, x)?.try_into()?;
+    let y: f64 = eval(env, y)?.try_into()?;
+    let z: f64 = eval(env, z)?.try_into()?;
+
+    Ok(ForeignDataWrapper::new(Vector3::new(x, y, z)).into())
+}
+
+pub fn color(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [r, g, b]: [Expression; 3] = expr.try_into()?;
+
+    let r: f64 = eval(env, r)?.try_into()?;
+    let g: f64 = eval(env, g)?.try_into()?;
+    let b: f64 = eval(env, b)?.try_into()?;
+
+    Ok(ForeignDataWrapper::new(Color::new(r, g, b)).into())
+}
+
+pub fn light(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [pos, col]: [Expression; 2] = expr.try_into()?;
+
+    let pos: ForeignDataWrapper<Point3> = eval(env, pos)?.try_into()?;
+    let col: ForeignDataWrapper<Color> = eval(env, col)?.try_into()?;
+
+    let pos: Point3 = *pos;
+    let col: Color = *col;
+
+    Ok(ForeignDataWrapper::new(Light::new(pos, col)).into())
+}
+
+pub fn material(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [amb, dif, spe, shi, mir]: [Expression; 5] = expr.try_into()?;
+
+    let amb: ForeignDataWrapper<Color> = eval(env, amb)?.try_into()?;
+    let dif: ForeignDataWrapper<Color> = eval(env, dif)?.try_into()?;
+    let spe: ForeignDataWrapper<Color> = eval(env, spe)?.try_into()?;
+    let shi: f64 = eval(env, shi)?.try_into()?;
+    let mir: f64 = eval(env, mir)?.try_into()?;
+
+    let amb: Color = *amb;
+    let dif: Color = *dif;
+    let spe: Color = *spe;
+
+    Ok(ForeignDataWrapper::new(Material::new(amb, dif, spe, shi, mir)).into())
+}
+
+pub fn sphere(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [pos, rad, mat]: [Expression; 3] = expr.try_into()?;
+
+    let pos: ForeignDataWrapper<Point3> = eval(env, pos)?.try_into()?;
+    let rad: f64 = eval(env, rad)?.try_into()?;
+    let mat: ForeignDataWrapper<Material> = eval(env, mat)?.try_into()?;
+
+    let pos: Point3 = *pos;
+    let mat: Material = *mat;
+
+    Ok(ForeignDataWrapper::new(RTObjectWrapper::from(Sphere::new(pos, rad, mat))).into())
+}
+
+pub fn plane(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [pos, dir, mat]: [Expression; 3] = expr.try_into()?;
+
+    let pos: ForeignDataWrapper<Point3> = eval(env, pos)?.try_into()?;
+    let dir: ForeignDataWrapper<Vector3> = eval(env, dir)?.try_into()?;
+    let mat: ForeignDataWrapper<Material> = eval(env, mat)?.try_into()?;
+
+    let pos: Point3 = *pos;
+    let dir: Vector3 = *dir;
+    let mat: Material = *mat;
+
+    Ok(ForeignDataWrapper::new(RTObjectWrapper::from(Plane::new(pos, dir, mat))).into())
+}
+
+pub fn checkerboard(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [pos, norm, mat1, mat2, sca, up]: [Expression; 6] = expr.try_into()?;
+
+    let pos: ForeignDataWrapper<Point3> = eval(env, pos)?.try_into()?;
+    let norm: ForeignDataWrapper<Vector3> = eval(env, norm)?.try_into()?;
+    let mat1: ForeignDataWrapper<Material> = eval(env, mat1)?.try_into()?;
+    let mat2: ForeignDataWrapper<Material> = eval(env, mat2)?.try_into()?;
+    let sca: f64 = eval(env, sca)?.try_into()?;
+    let up: ForeignDataWrapper<Vector3> = eval(env, up)?.try_into()?;
+
+    let pos: Point3 = *pos;
+    let norm: Vector3 = *norm;
+    let mat1: Material = *mat1;
+    let mat2: Material = *mat2;
+    let up: Vector3 = *up;
+
+    Ok(
+        ForeignDataWrapper::new(RTObjectWrapper::from(Checkerboard::new(
+            pos, norm, mat1, mat2, sca, up,
+        )))
+        .into(),
+    )
+}
+
+pub fn scene(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [amb, objs, lgts]: [Expression; 3] = expr.try_into()?;
+
+    let amb: ForeignDataWrapper<Color> = eval(env, amb)?.try_into()?;
+    let objs: Vec<Expression> = eval(env, objs)?.try_into()?;
+    let lgts: Vec<Expression> = eval(env, lgts)?.try_into()?;
+
+    let mut scene = Scene::new();
+
+    scene.set_ambient(*amb);
+    for o in objs {
+        let o: ForeignDataWrapper<RTObjectWrapper> = eval(env, o)?.try_into()?;
+        scene.add_object(o.clone());
+    }
+    for l in lgts {
+        let l: ForeignDataWrapper<Light> = eval(env, l)?.try_into()?;
+        scene.add_light(*l);
+    }
+
+    Ok(ForeignDataWrapper::new(scene).into())
+}
+
+pub fn scene_add_object(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [sce, obj]: [Expression; 2] = expr.try_into()?;
+
+    let mut sce: ForeignDataWrapper<Scene> = eval(env, sce)?.try_into()?;
+    let obj: ForeignDataWrapper<RTObjectWrapper> = eval(env, obj)?.try_into()?;
+
+    sce.add_object(obj.clone());
+
+    Ok(sce.into())
+}
+
+pub fn scene_add_light(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [sce, lgt]: [Expression; 2] = expr.try_into()?;
+
+    let mut sce: ForeignDataWrapper<Scene> = eval(env, sce)?.try_into()?;
+    let lgt: ForeignDataWrapper<Light> = eval(env, lgt)?.try_into()?;
+
+    sce.add_light(*lgt);
+
+    Ok(sce.into())
+}
+
+pub fn camera(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [pos, cnt, up, fovy, w, h]: [Expression; 6] = expr.try_into()?;
+
+    let pos: ForeignDataWrapper<Point3> = eval(env, pos)?.try_into()?;
+    let cnt: ForeignDataWrapper<Point3> = eval(env, cnt)?.try_into()?;
+    let up: ForeignDataWrapper<Vector3> = eval(env, up)?.try_into()?;
+    let fovy: f64 = eval(env, fovy)?.try_into()?;
+    let w: i64 = eval(env, w)?.try_into()?;
+    let h: i64 = eval(env, h)?.try_into()?;
+
+    Ok(ForeignDataWrapper::new(Camera::new(*pos, *cnt, *up, fovy, w as usize, h as usize)).into())
+}
+
+pub fn render(env: &Environment, expr: Expression) -> Result<Expression, EvalError> {
+    let [cam, sce, dpt, sbp, out]: [Expression; 5] = expr.try_into()?;
+
+    let cam: ForeignDataWrapper<Camera> = eval(env, cam)?.try_into()?;
+    let sce: ForeignDataWrapper<Scene> = eval(env, sce)?.try_into()?;
+    let dpt: i64 = eval(env, dpt)?.try_into()?;
+    let sbp: i64 = eval(env, sbp)?.try_into()?;
+    let out: String = eval(env, out)?.try_into()?;
+
+    println!("Rendering to {}...", out);
+    let img = cam.render(&sce, dpt as u32, sbp as u32);
+
+    match img.save(out) {
+        Ok(_) => Ok(Expression::Nil),
+        Err(e) => Err(EvalError::RuntimeError(e.to_string())),
+    }
+}
+
+/// Adds the raytracing functions to the given environment layer.
+pub fn mk_raytrace(layer: &mut EnvironmentLayer) {
+    layer.set("point".to_string(), Expression::Function(point));
+    layer.set("vector".to_string(), Expression::Function(vector));
+    layer.set("color".to_string(), Expression::Function(color));
+    layer.set("light".to_string(), Expression::Function(light));
+    layer.set("material".to_string(), Expression::Function(material));
+    layer.set("plane".to_string(), Expression::Function(plane));
+    layer.set(
+        "checkerboard".to_string(),
+        Expression::Function(checkerboard),
+    );
+    layer.set("sphere".to_string(), Expression::Function(sphere));
+    layer.set("scene".to_string(), Expression::Function(scene));
+    layer.set(
+        "scene-add-object".to_string(),
+        Expression::Function(scene_add_object),
+    );
+    layer.set(
+        "scene-add-light".to_string(),
+        Expression::Function(scene_add_light),
+    );
+    layer.set("camera".to_string(), Expression::Function(camera));
+    layer.set("render".to_string(), Expression::Function(render));
+}

src/raytracer/mod.rs

@@ -1,4 +1,5 @@
 pub mod camera;
+pub mod lisp;
 pub mod plane;
 pub mod scene;
 pub mod sphere;

src/raytracer/plane.rs

@@ -3,6 +3,7 @@ use super::types::{Intersect, Material, Point3, Scalar, Vector3};
 extern crate nalgebra as na;
 
 /// An infinite plane in 3D space.
+#[derive(PartialEq, Clone, Debug)]
 pub struct Plane {
     /// The position of the plane.
     position: Point3,
@@ -13,6 +14,7 @@ pub struct Plane {
 }
 
 /// A infinite checkerboard plane in 3D space.
+#[derive(PartialEq, Clone, Debug)]
 pub struct Checkerboard {
     /// The base plane containing the "white" material
     base: Plane,
@@ -65,14 +67,14 @@ impl Checkerboard {
 }
 
 impl Intersect for Plane {
-    fn intersect<'a>(
-        &'a self,
+    fn intersect(
+        &self,
         ray: &super::types::Ray,
     ) -> Option<(
         Point3,
         Vector3,
         super::types::Scalar,
-        &'a super::types::Material,
+        super::types::Material,
     )> {
         let denom = self.normal.dot(&ray.direction);
         if denom != 0.0 {
@@ -81,7 +83,7 @@ impl Intersect for Plane {
 
             if t > 1e-5 {
                 let point = ray.origin + ray.direction * t;
-                return Some((point, self.normal, t, &self.material));
+                return Some((point, self.normal, t, self.material.clone()));
             }
         }
         None
@@ -89,14 +91,14 @@ impl Intersect for Plane {
 }
 
 impl Intersect for Checkerboard {
-    fn intersect<'a>(
-        &'a self,
+    fn intersect(
+        &self,
         ray: &super::types::Ray,
     ) -> Option<(
         Point3,
         Vector3,
         super::types::Scalar,
-        &'a super::types::Material,
+        super::types::Material,
     )> {
         if let Some((point, normal, t, material)) = self.base.intersect(ray) {
             let v3 = point - self.base.position;
@@ -105,12 +107,44 @@ impl Intersect for Checkerboard {
             if ((v2.x / self.scale).round() % 2.0 == 0.0)
                 == ((v2.y / self.scale).round() % 2.0 == 0.0)
             {
-                Some((point, normal, t, material))
+                Some((point, normal, t, material.clone()))
             } else {
-                Some((point, normal, t, &self.material_alt))
+                Some((point, normal, t, self.material_alt.clone()))
             }
         } else {
             None
         }
     }
 }
+
+impl std::fmt::Display for Plane {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "(plane position: {}, normal: {}, material: {})",
+            self.position, self.normal, self.material
+        )
+    }
+}
+
+impl std::fmt::Display for Checkerboard {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "(checkerboard position: {}, normal: {}, material1: {}, material2: {}, scale: {})",
+            self.base.position, self.base.normal, self.base.material, self.material_alt, self.scale
+        )
+    }
+}
+
+impl PartialOrd for Plane {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}
+
+impl PartialOrd for Checkerboard {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}

src/raytracer/scene.rs

@@ -1,21 +1,24 @@
+use std::fmt::Display;
+
 use super::types::Color;
 use super::types::Intersect;
 use super::types::Light;
 use super::types::Material;
 use super::types::Point3;
+use super::types::RTObjectWrapper;
 use super::types::Ray;
 use super::types::Vector3;
 use super::vec::mirror;
 use super::vec::reflect;
-use std::sync::Arc;
 extern crate nalgebra as na;
 
 /// A scene is a collection of objects and lights, and provides a method to trace a ray through the scene.
+#[derive(Debug, PartialEq, Clone)]
 pub struct Scene {
     /// The ambient light of the scene
     ambient: Color,
     /// The objects in the scene
-    objects: Vec<Arc<dyn Intersect + Send + Sync>>,
+    objects: Vec<RTObjectWrapper>,
     /// The lights in the scene
     lights: Vec<Light>,
 }
@@ -36,7 +39,7 @@ impl Scene {
     }
 
     /// Add an object to the scene
-    pub fn add_object(&mut self, obj: Arc<dyn Intersect + Send + Sync>) {
+    pub fn add_object(&mut self, obj: RTObjectWrapper) {
         self.objects.push(obj);
     }
 
@@ -61,7 +64,7 @@ impl Scene {
         {
             Some((isect_pt, isect_norm, _, material)) => {
                 // Lighting of material at the intersection point
-                let color = self.lighting(-&ray.direction, material, isect_pt, isect_norm);
+                let color = self.lighting(-&ray.direction, &material, isect_pt, isect_norm);
 
                 // Calculate reflections, if the material has mirror properties
                 if material.mirror > 0.0 {
@@ -128,3 +131,21 @@ impl Scene {
         color
     }
 }
+
+impl PartialOrd for Scene {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}
+
+impl Display for Scene {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "(scene ambient: {}, #objects: {}, #lights: {})",
+            self.ambient,
+            self.objects.len(),
+            self.lights.len()
+        )
+    }
+}

src/raytracer/sphere.rs

@@ -3,6 +3,7 @@ use super::types::{Intersect, Material, Point3, Ray, Scalar, Vector3};
 extern crate nalgebra as na;
 
 /// A sphere in 3D space
+#[derive(PartialEq, Clone, Debug)]
 pub struct Sphere {
     /// Center of the sphere
     center: Point3,
@@ -27,7 +28,7 @@ impl Sphere {
 const EPSILON: Scalar = 1e-5;
 
 impl Intersect for Sphere {
-    fn intersect<'a>(&'a self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, &'a Material)> {
+    fn intersect(&self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, Material)> {
         let co = ray.origin - self.center;
 
         let a = ray.direction.dot(&ray.direction);
@@ -55,7 +56,7 @@ impl Intersect for Sphere {
                     isect_pt,
                     (isect_pt - self.center) / self.radius,
                     t,
-                    &self.material,
+                    self.material.clone(),
                 ));
             }
         }
@@ -63,3 +64,19 @@ impl Intersect for Sphere {
         None
     }
 }
+
+impl std::fmt::Display for Sphere {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "(sphere center: {}, radius: {}, material: {})",
+            self.center, self.radius, self.material
+        )
+    }
+}
+
+impl PartialOrd for Sphere {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}

src/raytracer/types.rs

@@ -1,3 +1,7 @@
+use std::fmt::{Debug, Display};
+
+use as_any::AsAny;
+
 extern crate nalgebra as na;
 
 /// The Scalar type to use for raytracing (f32 may result in acne effects)
@@ -16,10 +20,11 @@ pub trait Intersect {
     /// Otherwise the intersection point, a normal vector at the intersection point,
     /// the distance from the ray origin to the intersection point and
     /// the material of the object are returned.
-    fn intersect<'a>(&'a self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, &'a Material)>;
+    fn intersect(&self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, Material)>;
 }
 
 /// A point light source
+#[derive(Clone, Debug, PartialEq, Copy)]
 pub struct Light {
     /// Position of the light source
     pub position: Point3,
@@ -34,6 +39,12 @@ impl Light {
     }
 }
 
+impl PartialOrd for Light {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}
+
 /// A ray with origin and direction
 pub struct Ray {
     /// Ray origin
@@ -50,6 +61,7 @@ impl Ray {
 }
 
 /// A Material used for PHONG shading
+#[derive(Clone, Debug, PartialEq, Copy)]
 pub struct Material {
     /// Ambient color, aka color without direct or indirect light
     pub ambient_color: Color,
@@ -86,3 +98,145 @@ impl Material {
         }
     }
 }
+
+impl PartialOrd for Material {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}
+
+//////// Display traits ////////////////////////////////////////////////////////////////////////////
+
+impl Display for Light {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "(light position: {}, color: {})",
+            self.position, self.color
+        )
+    }
+}
+
+impl Display for Material {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "(material ambient_color: {}, diffuse_color: {}, specular_color: {}, shininess: {}, mirror: {})",
+            self.ambient_color, self.diffuse_color, self.specular_color, self.shininess, self.mirror
+        )
+    }
+}
+
+// RTWrapper ///////////////////////////////////////////////////////////////////////////////////////
+
+/// A trait used for Objects, which can be stored inside of the Scene, are Intersectable and are ForeignData compatible.
+pub trait RTObject: Intersect + Display + Debug + AsAny + Sync + Send + 'static {
+    /// Convert the object to a Box<dyn Any> allowing downcasts to Self
+    fn as_any_box(self: Box<Self>) -> Box<dyn std::any::Any>;
+    /// Explicitly compare the object with another RTObject for object safety
+    fn eq_impl(&self, other: &dyn RTObject) -> bool;
+    /// Explicitly clone the object for object safety
+    fn clone_impl(&self) -> Box<dyn RTObject>;
+}
+
+impl<T: Intersect + Display + Debug + PartialEq + Clone + Sync + Send + 'static> RTObject for T {
+    fn as_any_box(self: Box<Self>) -> Box<dyn std::any::Any> {
+        self
+    }
+    fn eq_impl(&self, other: &dyn RTObject) -> bool {
+        if let Some(other) = other.as_any().downcast_ref::<T>() {
+            self == other
+        } else {
+            false
+        }
+    }
+    fn clone_impl(&self) -> Box<dyn RTObject> {
+        Box::new(self.clone())
+    }
+}
+
+impl PartialEq for dyn RTObject {
+    fn eq(&self, other: &Self) -> bool {
+        self.eq_impl(other)
+    }
+}
+
+/// The RTObjectWrapper is a wrapper around a Box<dyn RTObject> to make it ForeignData compatible
+/// (not depending on the concrete type of the object).
+pub struct RTObjectWrapper(Box<dyn RTObject>);
+
+impl RTObjectWrapper {
+    /// Create a new RTObjectWrapper from a Box<dyn RTObject>
+    pub fn new<T: RTObject>(value: Box<T>) -> RTObjectWrapper {
+        RTObjectWrapper(value)
+    }
+    /// Create a new RTObjectWrapper from a RTObject
+    pub fn from<T: RTObject>(value: T) -> RTObjectWrapper {
+        RTObjectWrapper::new(Box::new(value))
+    }
+    /// Get the inner box as Box<dyn Any> allowing downcasts to the concrete type
+    pub fn as_any_box(self) -> Box<dyn std::any::Any> {
+        self.0.as_any_box()
+    }
+}
+
+impl Clone for RTObjectWrapper {
+    fn clone(&self) -> Self {
+        RTObjectWrapper(self.0.clone_impl())
+    }
+}
+
+impl PartialEq for RTObjectWrapper {
+    fn eq(&self, other: &Self) -> bool {
+        *self.0 == *other.0
+    }
+}
+
+impl Display for RTObjectWrapper {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "RTObjectWrapper({})", self.0)
+    }
+}
+
+impl Debug for RTObjectWrapper {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "RTObjectWrapper({:?})", self.0)
+    }
+}
+
+impl Intersect for RTObjectWrapper {
+    fn intersect(&self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, Material)> {
+        self.0.intersect(ray)
+    }
+}
+
+impl PartialOrd for RTObjectWrapper {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}
+
+#[test]
+fn test_rt_wrapper_expr_conversion() {
+    use super::sphere::Sphere;
+    use crate::lisp::expression::{Expression, ForeignDataWrapper};
+    let sphere = Sphere::new(
+        Point3::new(0.0, 0.0, 0.0),
+        1.0,
+        Material::new(
+            Color::new(0.0, 0.0, 0.0),
+            Color::new(0.0, 0.0, 0.0),
+            Color::new(0.0, 0.0, 0.0),
+            0.0,
+            0.0,
+        ),
+    );
+
+    let sphere = RTObjectWrapper::new(Box::new(sphere));
+
+    let expr: Expression = ForeignDataWrapper::new(sphere.clone()).into();
+
+    let sphere2: ForeignDataWrapper<RTObjectWrapper> = expr.try_into().unwrap();
+
+    assert_eq!(sphere, *sphere2.0);
+}