library: render: add Renderer trait

pathtracer/src/render/mod.rs

@@ -1,4 +1,13 @@
 //! Define the different kinds of renderers for use on a given scene.
+use image::RgbImage;
+
+/// Each renderer implements this trait, to be called after being built.
+pub trait Renderer {
+    /// Render the [`Scene`] using the chosen rendering technique.
+    ///
+    /// [`Scene`]: ../scene/scene/struct.Scene.html
+    fn render(&self) -> RgbImage;
+}
 
 mod raytracer;
 pub use raytracer::*;

pathtracer/src/render/raytracer.rs

@@ -1,4 +1,5 @@
 use super::utils::*;
+use super::Renderer;
 use crate::scene::{Object, Scene};
 use crate::{
     core::{LightProperties, LinearColor, ReflTransEnum},
@@ -247,3 +248,9 @@ impl Raytracer {
             .sum()
     }
 }
+
+impl Renderer for Raytracer {
+    fn render(&self) -> RgbImage {
+        self.render()
+    }
+}