Extract renderer into own packege

ray-tracing-material/src/mirror.rs

@@ -0,0 +1,23 @@
+use ray_tracing_core::prelude::*;
+
+pub struct Mirror {
+    color: Color,
+}
+
+impl Mirror {
+    pub fn new(color: Color) -> Self {
+        Self { color }
+    }
+}
+
+impl<R: Rng> Material<R> for Mirror {
+    fn eval(&self, _w_in: Dir3, _w_out: Dir3, _rng: &mut R) -> Color {
+        Color::black()
+    }
+
+    fn sample(&self, w_in: Dir3, _rng: &mut R) -> ray_tracing_core::material::SampleResult {
+        let w_out = (2.0 * Dir3::up() * w_in.y()) - w_in;
+
+        ray_tracing_core::material::SampleResult::new(w_out, self.color)
+    }
+}