Added ray-disk intersection and material definition.

disk.hpp

@@ -0,0 +1,40 @@
+#pragma once
+#ifndef DISK_HPP
+#define DISK_HPP
+
+#include <glm/glm.hpp>
+
+#include "plane.hpp"
+
+using glm::vec3;
+using glm::normalize;
+
+class Disk : public Plane {
+public:
+  float m_radius;
+  
+  Disk(): m_radius(1.0f) {
+    rho = 0.0f;
+    m_point = vec3(0.0f);
+    m_normal = vec3(0.0f, 1.0f, 0.0f);
+  }
+
+  Disk(float x, float y, float z, float nx, float ny, float nz, float _r): m_radius(_r) {
+    rho = 0.0f;
+    m_point = vec3(x, y, z);
+    m_normal = normalize(vec3(nx, ny, nz));
+  }
+
+  Disk(vec3 _p, vec3 _n, float _r): m_radius(_r) {
+    rho = 0.0f;
+    m_point = _p;
+    m_normal = normalize(_n);
+  }
+
+  virtual ~Disk() { }
+
+  virtual bool intersect(Ray & r, float & t) const;
+};
+
+
+#endif