Allow scenes to specify their camera

src/main.rs

@@ -30,7 +30,14 @@ mod perlin;
 mod noise;
 mod image_texture;
 
-fn earth() -> HittableList {
+// Image
+const ASPECT_RATIO: f64 = 3.0 / 2.0;
+const IMAGE_WIDTH: usize = 400;
+const IMAGE_HEIGHT: usize = (IMAGE_WIDTH as f64 / ASPECT_RATIO) as usize;
+const SAMPLES_PER_PIXEL: i32 = 100;
+const MAX_DEPTH: i32 = 50;
+
+fn earth() -> (HittableList, Camera) {
     let mut world:HittableList = Vec::new();
     let earth_texture = ImageTexture::new("textures/earthmap.jpg");
     let earth_material = Arc::new(
@@ -40,10 +47,26 @@ fn earth() -> HittableList {
         radius: 2.0,
         material: earth_material
     }));
-    world
+
+    let look_from = Point3::new(13.0, 2.0, 3.0);
+    let look_at = Point3::new(0.0, 0.0, 0.0);
+    let focus_dist = 2.0;
+
+    let cam = Camera::new(
+        look_from,
+        look_at,
+        Vec3::new(0.0, 1.0, 0.0),
+        ASPECT_RATIO,
+        20.0,
+        0.0,
+        focus_dist,
+        0.0,
+        1.0);
+
+    (world, cam)
 }
 
-fn two_spheres() -> HittableList {
+fn two_spheres() -> (HittableList, Camera) {
     let mut world:HittableList = Vec::new();
     let checker = CheckerTexture::colored(
         Color::new(0.2, 0.3, 0.1),
@@ -59,9 +82,25 @@ fn two_spheres() -> HittableList {
         radius: 10.0,
         material: checker_material
     }));
-    world
+
+    let look_from = Point3::new(13.0, 2.0, 3.0);
+    let look_at = Point3::new(0.0, 0.0, 0.0);
+    let focus_dist = 2.0;
+
+    let cam = Camera::new(
+        look_from,
+        look_at,
+        Vec3::new(0.0, 1.0, 0.0),
+        ASPECT_RATIO,
+        20.0,
+        0.0,
+        focus_dist,
+        0.0,
+        1.0);
+
+    (world, cam)
 }
-fn two_perlin_spheres() -> HittableList {
+fn two_perlin_spheres() -> (HittableList, Camera) {
     let mut world:HittableList = Vec::new();
     let noise = NoiseTexture { noise: Perlin::new(), scale: 4.0 };
     let noise_material = Arc::new(Material::Lambertian(Lambertian::textured(Arc::new(noise))));
@@ -75,10 +114,26 @@ fn two_perlin_spheres() -> HittableList {
         radius: 2.0,
         material: noise_material
     }));
-    world
+
+    let look_from = Point3::new(13.0, 2.0, 3.0);
+    let look_at = Point3::new(0.0, 0.0, 0.0);
+    let focus_dist = 2.0;
+
+    let cam = Camera::new(
+        look_from,
+        look_at,
+        Vec3::new(0.0, 1.0, 0.0),
+        ASPECT_RATIO,
+        20.0,
+        0.0,
+        focus_dist,
+        0.0,
+        1.0);
+
+    (world, cam)
 }
 
-fn random_scene() -> HittableList {
+fn random_scene() -> (HittableList, Camera) {
     let mut world: HittableList = Vec::new();
 
     let checker = CheckerTexture::colored(
@@ -155,22 +210,10 @@ fn random_scene() -> HittableList {
         material: material3
     }));
 
-    world
-}
-
-fn main() {
-    // Image
-    const ASPECT_RATIO: f64 = 3.0 / 2.0;
-    const IMAGE_WIDTH: usize = 400;
-    const IMAGE_HEIGHT: usize = (IMAGE_WIDTH as f64 / ASPECT_RATIO) as usize;
-    const SAMPLES_PER_PIXEL: i32 = 1;
-    const MAX_DEPTH: i32 = 50;
-
     let look_from = Point3::new(13.0, 2.0, 3.0);
     let look_at = Point3::new(0.0, 0.0, 0.0);
     let focus_dist = 2.0;
 
-    // Camera
     let cam = Camera::new(
         look_from,
         look_at,
@@ -179,12 +222,16 @@ fn main() {
         20.0,
         0.0,
         focus_dist,
-    0.0,
-    1.0);
+        0.0,
+        1.0);
 
+    (world, cam)
+}
+
+fn main() {
     // World
     let scene: u8 = 2;
-    let world = match scene {
+    let (world, cam) = match scene {
         0 => two_spheres(),
         1 => two_perlin_spheres(),
         2 => earth(),