1 files changed, 24 insertions, 31 deletions

diff --git a/src/main.zig b/src/main.zig
index f72756a..d44bd09 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -328,17 +328,20 @@ const Camera = struct {
     vertical: Vec3,
     lower_left_corner: Point3,
 
-    fn init(vfov: f64, aspect_ratio: f64) Camera {
+    fn init(lookFrom: Point3, lookAt: Point3, vup: Vec3, vfov: f64, aspect_ratio: f64) Camera {
         const theta = deg2rad(vfov);
         const h = @tan(theta / 2);
         const viewport_height = 2.0 * h;
         const viewport_width = aspect_ratio * viewport_height;
-        const focal_length = 1.0;
 
-        const origin = Point3{ .x = 0.0, .y = 0.0, .z = 0.0 };
-        const horizontal = Vec3{ .x = viewport_width, .y = 0.0, .z = 0.0 };
-        const vertical = Vec3{ .x = 0.0, .y = viewport_height, .z = 0.0 };
-        const lower_left_corner = origin.sub(horizontal.div(2.0)).sub(vertical.div(2.0)).sub(Vec3{ .x = 0.0, .y = 0.0, .z = focal_length });
+        const w = lookFrom.sub(lookAt).normalized();
+        const u = vup.cross(w).normalized();
+        const v = w.cross(u);
+
+        const origin = lookFrom;
+        const horizontal = u.mul(viewport_width);
+        const vertical = v.mul(viewport_height);
+        const lower_left_corner = origin.sub(horizontal.div(2.0)).sub(vertical.div(2.0)).sub(w);
 
         return Camera{
             .origin = origin,
@@ -348,8 +351,8 @@ const Camera = struct {
         };
     }
 
-    fn getRay(camera: Camera, u: f64, v: f64) Ray {
-        const dir = camera.lower_left_corner.add(camera.horizontal.mul(u)).add(camera.vertical.mul(v)).sub(camera.origin);
+    fn getRay(camera: Camera, s: f64, t: f64) Ray {
+        const dir = camera.lower_left_corner.add(camera.horizontal.mul(s)).add(camera.vertical.mul(t)).sub(camera.origin);
         return Ray{
             .origin = camera.origin,
             .dir = dir,
@@ -401,36 +404,26 @@ pub fn main() !void {
     const samples_per_pixel = 100;
     const max_depth = 50;
 
-    // World
-    // const material_ground = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 0.8, .y = 0.8, .z = 0.0 } } };
-    // const material_center = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 0.1, .y = 0.2, .z = 0.5 } } };
-    // const material_left = Material{ .dielectric = DielectricMaterial{ .ir = 1.5 } };
-    // const material_right = Material{ .metal = MetalMaterial{ .albedo = Color{ .x = 0.8, .y = 0.6, .z = 0.2 }, .fuzz = 0.0 } };
-    // const sphere1 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 0.0, .y = -100.5, .z = -1.0 }, .radius = 100.0, .material = &material_ground } };
-    // const sphere2 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 0.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_center } };
-    // const sphere3 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = -1.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_left } };
-    // const sphere4 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 1.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_right } };
-    // var hittable_objects = ArrayList(*const Hittable).init(allocator);
-    // try hittable_objects.append(&sphere1);
-    // try hittable_objects.append(&sphere2);
-    // try hittable_objects.append(&sphere3);
-    // try hittable_objects.append(&sphere4);
-    // const world = Hittable{ .list = HittableList{ .objects = hittable_objects } };
-    // defer hittable_objects.deinit();
-
-    const R = @cos(pi / 4.0);
-    const material_left = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 0.0, .y = 0.0, .z = 1.0 } } };
-    const material_right = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 1.0, .y = 0.0, .z = 0.0 } } };
-    const sphere1 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = -R, .y = 0.0, .z = -1.0 }, .radius = R, .material = &material_left } };
-    const sphere2 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = R, .y = 0.0, .z = -1.0 }, .radius = R, .material = &material_right } };
+    const material_ground = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 0.8, .y = 0.8, .z = 0.0 } } };
+    const material_center = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 0.1, .y = 0.2, .z = 0.5 } } };
+    const material_left = Material{ .dielectric = DielectricMaterial{ .ir = 1.5 } };
+    const material_right = Material{ .metal = MetalMaterial{ .albedo = Color{ .x = 0.8, .y = 0.6, .z = 0.2 }, .fuzz = 0.0 } };
+    const sphere1 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 0.0, .y = -100.5, .z = -1.0 }, .radius = 100.0, .material = &material_ground } };
+    const sphere2 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 0.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_center } };
+    const sphere3 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = -1.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_left } };
+    const sphere4 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = -1.0, .y = 0.0, .z = -1.0 }, .radius = -0.45, .material = &material_left } };
+    const sphere5 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 1.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_right } };
     var hittable_objects = ArrayList(*const Hittable).init(allocator);
     try hittable_objects.append(&sphere1);
     try hittable_objects.append(&sphere2);
+    try hittable_objects.append(&sphere3);
+    try hittable_objects.append(&sphere4);
+    try hittable_objects.append(&sphere5);
     const world = Hittable{ .list = HittableList{ .objects = hittable_objects } };
     defer hittable_objects.deinit();
 
     // Camera
-    const camera = Camera.init(90.0, aspect_ratio);
+    const camera = Camera.init(Point3{ .x = -2.0, .y = 2.0, .z = 1.0 }, Point3{ .x = 0.0, .y = 0.0, .z = -1.0 }, Vec3{ .x = 0.0, .y = 1.0, .z = 0.0 }, 20.0, aspect_ratio);
 
     // Render
     const stdout_file = std.io.getStdOut().writer();