Add world representation as hittable list

Makefile

@@ -1,4 +1,4 @@
-raytracer: main.cpp vec3.hpp color.hpp ray.hpp hittable.hpp sphere.hpp hittable_list.hpp
+raytracer: main.cpp vec3.hpp color.hpp ray.hpp hittable.hpp sphere.hpp hittable_list.hpp rtweekend.hpp
 	@g++ -g -Wall -Wextra -Wpedantic main.cpp -o raytracer
 
 image: raytracer

hittable_list.hpp

@@ -13,7 +13,8 @@ struct hittable_list : hittable {
     /* Attributes */
     std::vector<shared_ptr<hittable>> objects;
 
-    /* Constructor */
+    /* Constructors */
+    hittable_list () {}
     hittable_list(shared_ptr<hittable> h) { add(h); }
 
     /* Methods */

main.cpp

@@ -1,25 +1,25 @@
 #include <stdio.h>
 #include <stdint.h>
 
-#include "vec3.hpp"
-#include "color.hpp"
-#include "ray.hpp"
+#include "rtweekend.hpp"
 
-color ray_color(const ray& r);
+#include "color.hpp"
+#include "hittable_list.hpp"
+#include "sphere.hpp"
+
+color ray_color(const ray& r, const hittable& world);
 double hit_sphere(const point3& center, double radius, const ray& r);
 
-color ray_color(const ray& r)
+color ray_color(const ray& r, const hittable& world)
 {
-    double t = hit_sphere(point3(0,0,-1), 0.5, r);
-    if (t > 0.0)
+    hit_record rec;
+    if (world.hit(r, 0, INFINITY, rec))
     {
-        vec3 N = normalize(r.at(t) - vec3(0,0,-1));
-        return 0.5*color(N.x+1, N.y+1, N.z+1);
+        return 0.5 * (rec.normal + color(1,1,1));
     }
     vec3 unit_direction = normalize(r.direction);
-    t = 0.5*(unit_direction.y + 1.0);
-    
-    return (1-t) * color(1,1,1) + t*color(0.5, 0.7, 1.0);
+    double t = 0.5 * (unit_direction.y + 1.0);
+    return (1-t) * color(1,1,1) + t*color(0.5,0.7,1.0);
 }
 
 double hit_sphere(const point3& center, double radius, const ray& r)
@@ -43,6 +43,11 @@ int main()
     const int32_t image_width = 400;
     const int32_t image_height = (int32_t) (image_width / aspect_ratio);
 
+    // World
+    hittable_list world;
+    world.add(std::make_shared<sphere>(point3(0,0,-1), 0.5));
+    world.add(std::make_shared<sphere>(point3(0,-100.5,-1), 100));
+
     // Camera
     double viewport_height = 2.0;
     double viewport_width = aspect_ratio * viewport_height;
@@ -65,7 +70,7 @@ int main()
             double u = (double)i / (image_width-1);
             double v = (double)j / (image_height-1);            
             ray r = ray(origin, lower_left_corner + u*horizontal + v*vertical - origin);            
-            color pixel_color = ray_color(r);
+            color pixel_color = ray_color(r, world);
             
             write_color(stdout, pixel_color);
         }        

rtweekend.hpp

@@ -0,0 +1,19 @@
+#ifndef RTWEEKEND_H
+#define RTWEEKEND_H
+
+#include <math.h>
+#include <memory>
+
+/* Utility functions */
+double degrees_to_radians(double d)
+{
+    return d * M_PI / 180;
+}
+
+/* Common internal headers */
+
+#include "ray.hpp"
+#include "vec3.hpp"
+
+
+#endif