1 files changed, 38 insertions, 0 deletions
diff --git a/lib/material.rb b/lib/material.rb
new file mode 100644
index 0000000..c935147
--- /dev/null
+++ b/lib/material.rb
@@ -0,0 +1,38 @@
+class Material
+  def initialize(r, g, b)
+    @albedo = Colour.new(r, g, b)
+  end
+
+  def attenuation
+    @albedo
+  end
+
+  def scatter(ray, record)
+    nil
+  end
+end
+
+class Lambertian < Material
+  def scatter(ray, record)
+    scat = record.normal + Vec3.random_unit
+    scat = rec.normal if scat.near_zero?
+    Ray.new(record.point, scat)
+  end
+end
+
+class Metal < Material
+  def initialize(r, g, b, fuzz)
+    @fuzz = fuzz < 1 ? fuzz : 1
+    super(r, g, b)
+  end
+
+  def scatter(ray, record)
+    refl = ray.direction.reflect(record.normal)
+    refl = refl.unit + (Vec3.random_unit * @fuzz)
+    if refl.dot(record.normal) > 0
+      Ray.new(record.point, refl)
+    else
+      nil
+    end
+  end
+end