Relocate world generation function

src/scene.rs

@@ -232,3 +232,85 @@ impl Camera {
     }
 }
 
+pub fn random_scene(srng: &mut SmallRng) -> Hittable {
+    let mat_ground = Material::Lambertian { albedo: Vec3::new(0.5, 0.5, 0.5) };
+    let mut world = Hittable::HittableList { hittables : Vec::<Hittable>::new() };
+    
+    world.push( Hittable::Sphere { center: Vec3::new(0.0, -1000.0, 0.0), radius: 1000.0, material: mat_ground });
+    
+    let distrib_zero_one = Uniform::new(0.0, 1.0);
+    for a in -11..11 {
+        for b in -11..11 {
+            let choose_mat = srng.sample(distrib_zero_one);
+            let center = Vec3 {
+                x: a as f32 + 0.9 * srng.sample(distrib_zero_one),
+                y: 0.2,
+                z: b as f32 + 0.9 * srng.sample(distrib_zero_one),
+            };
+            if (center - Vec3::new(4.0, 0.2, 0.0)).length() > 0.9 {
+
+                if choose_mat < 0.8 {
+                    // diffuse
+                    let albedo = Vec3::rand(srng, distrib_zero_one) * Vec3::rand(srng, distrib_zero_one);
+                    let sphere_material = Material::Lambertian { albedo };
+                    world.push(
+                        Hittable::Sphere {
+                            center,
+                            radius: 0.2,
+                            material: sphere_material,
+                        }
+                    );
+                } else if choose_mat < 0.95 {
+                    // metal
+                    let distr_albedo = Uniform::new(0.5, 1.0);
+                    let distr_fuzz = Uniform::new(0.0, 0.5);
+
+                    let albedo = Vec3::rand(srng, distr_albedo);
+                    let fuzz = srng.sample(distr_fuzz);
+                    let material = Material::Metal { albedo, fuzz };
+                    world.push(
+                        Hittable::Sphere {
+                            center,
+                            radius: 0.2,
+                            material: material,
+                        }
+                    );
+                } else {
+                    // glass
+                    let material = Material::Dielectric { index_refraction: 1.5 };
+                    world.push(
+                        Hittable::Sphere{
+                            center,
+                            radius: 0.2,
+                            material: material,
+                        }
+                    );
+
+                };
+            }
+        }
+    }
+
+    let material1 = Material::Dielectric { index_refraction: 1.5 };
+    world.push( Hittable::Sphere{
+        center: Vec3::new(0.0, 1.0, 0.0),
+        radius: 1.0,
+        material: material1
+    });
+
+    let material2 = Material::Lambertian { albedo: Vec3::new(0.4, 0.2, 0.1) };
+    world.push( Hittable::Sphere {
+        center: Vec3::new(-4.0, 1.0, 0.0),
+        radius: 1.0,
+        material: material2
+    });
+
+    let material3 = Material::Metal { albedo: Vec3::new(0.7, 0.6, 0.5), fuzz: 0.0 };
+    world.push( Hittable::Sphere {
+        center: Vec3::new(4.0, 1.0, 0.0),
+        radius: 1.0,
+        material: material3
+    });
+
+    return world;
+}