Added camera abstraction.

sampling.hpp

@@ -0,0 +1,16 @@
+#pragma once
+#ifndef SAMPLING_HPP
+#define SAMPLING_HPP
+
+#include <glm/vec3.hpp>
+
+using glm::vec3;
+
+extern const float PDF;
+
+extern float random01();
+extern void create_coords_system(const vec3 &n, vec3 &nt, vec3 &nb);
+extern vec3 sample_hemisphere(const float r1, float r2);
+extern void rotate_sample(vec3 & sample, vec3 & n);
+
+#endif