Abstracted lambertian into material

2 files changed, 47 insertions, 0 deletions

diff --git a/src/material/lambertian.rs b/src/material/lambertian.rs
new file mode 100644
index 0000000..28d15d3
--- /dev/null
+++ b/src/material/lambertian.rs
@@ -0,0 +1,37 @@
+use super::Material;
+use crate::core::{Intersection, Ray, Spectrum};
+use crate::sample::Sampler;
+
+use std::rc::Rc;
+
+pub struct Lambertian {
+    color: Spectrum,
+}
+
+impl Lambertian {
+    pub fn new(c: Spectrum) -> Lambertian {
+        Lambertian {
+            color: c,
+        }
+    }
+
+    pub fn new_rc(c: Spectrum) -> Rc<dyn Material> {
+        Rc::new(Self::new(c))
+    }
+}
+
+impl Material for Lambertian {
+    fn scatter(&self, ray: &Ray, i: &Intersection, sampler: &mut dyn Sampler) -> Option<(Spectrum, Ray)> {
+        let mut newray = Ray {
+            origin: i.p,
+            direction: i.n + sampler.get_unit_vector(),
+        };
+
+        // Make sure that the resulting direction is not (0, 0, 0)
+        if newray.direction.near_zero() {
+            newray.direction = i.n;
+        }
+
+        Some((self.color.clone(), newray))
+    }
+}
diff --git a/src/material/mod.rs b/src/material/mod.rs
new file mode 100644
index 0000000..62cbf9a
--- /dev/null
+++ b/src/material/mod.rs
@@ -0,0 +1,10 @@
+use crate::core::{Ray, Intersection, Spectrum};
+use crate::sample::Sampler;
+
+mod lambertian;
+
+pub use lambertian::Lambertian;
+
+pub trait Material {
+    fn scatter(&self, ray: &Ray, i: &Intersection, sampler: &mut dyn Sampler) -> Option<(Spectrum, Ray)>;
+}