Added image-based lighting with HDR images.

environment.hpp

@@ -0,0 +1,37 @@
+#pragma once
+#ifndef ENVIRONMENT_HPP
+#define ENVIRONMENT_HPP
+
+#include <FreeImage.h>
+#include <glm/vec3.hpp>
+
+#include "ray.hpp"
+
+using glm::vec3;
+
+class Environment {
+public:
+  Environment(const char * tex_file = NULL, bool light_probe = false, vec3 bckg = vec3(1.0f)): m_bckg_color(bckg), m_probe(light_probe) {
+    FREE_IMAGE_FORMAT fif;
+
+    if (tex_file != NULL) {
+      fif = FreeImage_GetFIFFromFilename(tex_file);
+      m_texture = FreeImage_Load(fif, tex_file, 0);
+    } else
+      m_texture = NULL;
+  }
+
+  ~Environment() {
+    if (m_texture != NULL)
+      FreeImage_Unload(m_texture);
+  }
+
+  vec3 get_color(Ray & r);
+
+private:
+  vec3 m_bckg_color;
+  FIBITMAP * m_texture;
+  bool m_probe;
+};
+
+#endif