background color #25

Author: clementlrd

apps/main.cpp

@@ -44,6 +44,7 @@ int main(int argc, char* argv[]) {
   std::shared_ptr<obj::Camera> cam =
       std::make_shared<obj::Camera>(obj::Camera(scene_config.at("camera")));
   debug("camera created");
+
   obj::Scene scene = obj::Scene(cam);
   debug("empty scene created");
 
@@ -52,6 +53,7 @@ int main(int argc, char* argv[]) {
 
   Image image = Image();
   RenderingEngine r(config);
+  r.set_background(scene_config.at("background").get<std::string>());
 
   // render scene on image
   r.render(image, scene);

apps/scene.json

@@ -8,6 +8,8 @@
     "view_dir": [0, 0, -1]
   },
 
+  "background": "day",
+
   "materials": [
     {
       "name": "white_metal",

include/image.hpp

@@ -8,6 +8,7 @@
 #include <filesystem>
 #include <iostream>
 #include <memory>
+#include <string>
 
 #define INIT_WIDTH 600
 #define INIT_HEIGHT 400
@@ -85,9 +86,11 @@ namespace render {
     int max_bounces;
     double view_distance;
     int sample_per_pixel;
+    std::string _background;
 
   protected:
-    Color send_ray(Ray r, int depth);
+    Color send_ray(Ray, int depth) const;
+    Color background(Ray&) const;
 
   public:
     RenderingEngine(json::Json const&);
@@ -97,6 +100,7 @@ namespace render {
     void add_filter(std::shared_ptr<filters::Filter> f) {
       _filters.push_back(f);
     }
+    void set_background(std::string style) { _background = style; }
   };
 } // namespace render
 

src/display/render.cpp

@@ -14,7 +14,7 @@ using render::RenderingEngine;
  */
 
 RenderingEngine::RenderingEngine(json::Json const& config)
-    : sample_per_pixel(1) {
+    : sample_per_pixel(1), _background("day") {
   max_bounces = config.at("max_bounces").get<int>();
   if (max_bounces < 0)
     throw std::invalid_argument("max_bounces need to be a positive integer");
@@ -79,7 +79,7 @@ void RenderingEngine::apply_filters(Image& image) const {
   }
 }
 
-Color RenderingEngine::send_ray(Ray r, int depth) {
+Color RenderingEngine::send_ray(Ray r, int depth) const {
   hit_record hit;
   // Initialize max time
   hit.t = view_distance;
@@ -103,10 +103,19 @@ Color RenderingEngine::send_ray(Ray r, int depth) {
     return send_ray(new_ray, --depth);
   }
 
+  return background(r);
+}
+
+Color RenderingEngine::background(Ray& r) const {
   double t = 0.5 * (r.dir().y() + 1.0); // normalisation
-  r.apply((1 - t) * maths::Vect3D(1.0, 1.0, 1.0)
-          + t * maths::Vect3D(0.5, 0.7, 1.0));
-  return r.colour(); // Sky color from white to cyan
+  if (_background == "day")             // Sky color from white to cyan
+    r.apply((1 - t) * maths::Vect3D(1) + t * maths::Vect3D(0.5, 0.7, 1.0));
+  else if (_background == "night") {
+    r.apply((1 - t) * maths::Vect3D(0.2, 0.2, 0.2) + t * maths::Vect3D(0));
+  } else if (_background == "dark") {
+    r.apply(maths::Vect3D(0));
+  } else throw std::invalid_argument("background style is not a valid name.");
+  return r.colour();
 }
 
 /*