Add random scene.

wtracer.cpp

@@ -28,6 +28,53 @@ Color ray_color(const Ray& r, const Hittable& world, int depth) {
     return (1.0 - t) * Color(1.0, 1.0, 1.0) + t * Color(0.5, 0.7, 1.0);
 }
 
+Hittable_list setup_random_scene() {
+    Hittable_list world;
+
+    const int sph_i = 3;
+
+    auto ground_material = std::make_shared<Lambertian>(Color(0.5, 0.5, 0.5));
+    world.add(std::make_shared<Sphere>(Point3(0, -1000, 0), 1000, ground_material));
+    for (int a = -sph_i; a<sph_i; a++) {
+        for (int b = -sph_i; b<sph_i; b++) {
+            auto choose_mat = random_double();
+            Point3 center(a + 0.9 * (11/sph_i) * random_double(), 0.2, b + 0.9 * (11/sph_i) * random_double());
+
+            if ((center - Point3(4, 0.2, 0)).length() > 0.9) {
+                std::shared_ptr<Material> sphere_material;
+                if (choose_mat < 0.8) {
+                    // diffuse
+                    auto albedo = Color::random() * Color::random();
+                    sphere_material = std::make_shared<Lambertian>(albedo);
+                    world.add(std::make_shared<Sphere>(center, 0.2, sphere_material));
+                } else if (choose_mat < 0.95) {
+                    // metal
+                    auto albedo = Color::random(0.5, 1);
+                    auto fuzz = random_double(0, 0.5);
+
+                    sphere_material = std::make_shared<Metal>(albedo, fuzz);
+                    world.add(std::make_shared<Sphere>(center, 0.2, sphere_material));
+                } else {
+                    // glass
+                    sphere_material = std::make_shared<Dielectric>(1.45);
+                    world.add(std::make_shared<Sphere>(center, 0.2, sphere_material));
+                }
+            }
+        }
+    }
+
+    auto material1 = std::make_shared<Dielectric>(1.45);
+    world.add(std::make_shared<Sphere>(Point3(0, 1, 0), 1.0, material1));
+
+    auto material2 = std::make_shared<Lambertian>(Color(0.4, 0.2, 0.1));
+    world.add(std::make_shared<Sphere>(Point3(-4, 1, 0), 1.0, material2));
+
+    auto material3 = std::make_shared<Metal>(Color(0.7, 0.6, 0.5), 0.0);
+    world.add(std::make_shared<Sphere>(Point3(4, 1, 0), 1.0, material3));
+
+    return world;
+}
+
 int main() {
     const auto aspect_ratio = 16.0 / 9.0;
     //const int image_width = 1280;
@@ -38,24 +85,13 @@ int main() {
     const int samples_per_pixel = 400;
     const int max_depth = 50;
 
-    std::cout << "P3\n" << image_width << " " << image_height << "\n255\n";
+    auto world = setup_random_scene();
 
-    Hittable_list world;
+    Point3 lookfrom(13, 2, 3);
-
+    Point3 lookat(0, 0, 0);
-    world.add(std::make_shared<Sphere>(Point3(0, 0, -1), 0.5, std::make_shared<Lambertian>(Color(0.1, 0.2, 0.5))));
-    world.add(std::make_shared<Sphere>(Point3(0, -100.5, -1), 100, std::make_shared<Lambertian>(Color(0.8, 0.8, 0.0))));
-
-    world.add(std::make_shared<Sphere>(Point3(1, 0, -1), 0.5, std::make_shared<Metal>(Color(0.8, 0.6, 0.2), 0.0)));
-
-
-    world.add(std::make_shared<Sphere>(Point3(-1, 0, -1), 0.5, std::make_shared<Dielectric>(1.45)));
-    world.add(std::make_shared<Sphere>(Point3(-1, 0, -1), -0.45, std::make_shared<Dielectric>(1.45)));
-
-    Point3 lookfrom(3, 3, 2);
-    Point3 lookat(0, 0, -1);
     Vec3 vup(0, 1, 0);
     auto dist_to_focus = (lookfrom - lookat).length();
-    auto aperture = 2.0;
+    auto aperture = 0.1;
 
     Camera cam(lookfrom, lookat, vup, 20, aspect_ratio, aperture, dist_to_focus);
 
@@ -76,6 +112,8 @@ int main() {
         }
     }
     std::cerr << "\nWriting file.\n";
+
+    std::cout << "P3\n" << image_width << " " << image_height << "\n255\n";
     for (int j = image_height - 1; j >= 0; --j) {
         for (int i = 0; i < image_width; ++i) {
             write_color(std::cout, image[i*image_height+j], samples_per_pixel);