Added presentations from EVI 2017

EVI - 2017/EVI 21/EVIray/plane.cpp

@@ -0,0 +1,29 @@
+#include "plane.hpp"
+
+#define TOL 1e-6
+
+using glm::abs;
+using glm::dot;
+
+bool Plane::intersect(Ray & r, float & t) const {
+  float d = dot(r.m_direction, m_normal);
+
+  if (abs(d) > TOL) {
+    t = dot(m_normal, (m_point - r.m_origin)) / d;
+    return t >= 0.0f;
+  }
+
+   return false;
+}
+
+vec3 Plane::normal_at_int(Ray & r, float & t) const {
+  return vec3(m_normal);
+}
+
+vec3 Plane::sample_at_surface() const {
+  return vec3(0.0f);
+}
+
+void Plane::calculate_inv_area() {
+  m_inv_area = 0.0f;
+}