From 98373a1935fba5bfec2958ce36f37dd18739c495 Mon Sep 17 00:00:00 2001
From: Matthew Gordon <matthew.scott.gordon@gmail.com>
Date: Wed, 13 Nov 2019 17:48:34 -0500
Subject: [PATCH] Add missing file that should have been in earlier commit

---
 src/integrators.rs | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 src/integrators.rs

diff --git a/src/integrators.rs b/src/integrators.rs
new file mode 100644
index 0000000..34781c3
--- /dev/null
+++ b/src/integrators.rs
@@ -0,0 +1,26 @@
+use nalgebra::{RealField, Vector3};
+
+use super::raycasting::IntersectionInfo;
+
+pub trait Integrator<T: RealField> {
+    fn integrate(&self, info: &IntersectionInfo<T>) -> T;
+}
+
+pub struct DirectionalLight<T: RealField> {
+    pub direction: Vector3<T>,
+    pub intensity: T,
+}
+
+pub struct PhongIntegrator<T: RealField> {
+    pub ambient_light: T,
+    pub lights: Vec<DirectionalLight<T>>,
+}
+
+impl<T: RealField> Integrator<T> for PhongIntegrator<T> {
+    fn integrate(&self, info: &IntersectionInfo<T>) -> T {
+        self.lights
+            .iter()
+            .map(|light| light.intensity * light.direction.dot(&info.normal))
+            .fold(self.ambient_light, |a, b| a + b)
+    }
+}