zigrtiow/dev.sh

@@ -1,2 +0,0 @@
-fd zig | entr -c bash -c "zig build test && zig build -Drelease-safe=true &&
-  ./zig-out/bin/zigrtiow | convert ppm:- /tmp/output.png"

zigrtiow/src/hittable.zig

@@ -1,8 +1,6 @@
 const vec = @import("./vec.zig");
 const ray = @import("./ray.zig");
 
-const Material = @import("./material.zig").Material;
-
 const Sphere = @import("./sphere.zig").Sphere;
 const HittableList = @import("./hittable_list.zig").HittableList;
 
@@ -27,7 +25,6 @@ pub const HitRecord = struct {
     normal: Vec3,
     t: f32,
     front_face: bool,
-    material: Material,
 
     pub fn set_face_normal(hr: *HitRecord, r: Ray, outward_normal: Vec3) void {
         hr.front_face = r.direction().dot(outward_normal) < 0;

zigrtiow/src/main.zig

@@ -6,32 +6,27 @@ const vec = @import("./vec.zig");
 const sphere = @import("./sphere.zig");
 const hittable = @import("./hittable.zig");
 const hittable_list = @import("./hittable_list.zig");
-const material = @import("./material.zig");
 
 const Camera = camera.Camera;
 const Color = vec.Color;
 const Hittable = hittable.Hittable;
 const HittableList = hittable_list.HittableList;
-const Labertian = material.Labertian;
-const Metal = material.Metal;
-const Material = material.Material;
 const Point3 = vec.Point3;
 const Ray = ray.Ray;
 const Sphere = sphere.Sphere;
 const Vec3 = vec.Vec3;
-const info = std.log.info;
 const random_in_hemisphere = vec.random_in_hemisphere;
+const info = std.log.info;
 const write_color = color.write_color;
 
 fn ray_color(r: Ray, world: Hittable, depth: isize) Color {
     // If we've exceeded the ray bounce limit, no more light is gathered.
     if (depth <= 0) return Color.init(0, 0, 0);
 
-    if (world.hit(r, 0.0001, std.math.inf(f32))) |hit_rec| {
+    var hit = world.hit(r, 0.0001, std.math.inf(f32));
-        if (hit_rec.material.scatter(r, hit_rec)) |scatter_rec| {
+    if (hit) |rec| {
-            return scatter_rec.attenuation.mul(ray_color(scatter_rec.scattered, world, depth - 1));
+        const target = rec.p.add(rec.normal.add(random_in_hemisphere(rec.normal)));
-        }
+        return ray_color(Ray.init(rec.p, target.sub(rec.p)), world, depth - 1).scale(0.5);
-        return Color.init(0, 0, 0);
     }
     var unit_direction = r.direction().unit();
     const t = 0.5 * (unit_direction.y() + 1);
@@ -48,16 +43,8 @@ pub fn main() anyerror!void {
 
     // World
     var tmp_world = HittableList.init();
-
+    try tmp_world.add(Hittable{ .sphere = Sphere.init(Point3.init(0, 0, -1), 0.5) });
-    const material_ground = Material{ .labertian = Labertian{ .albedo = Color.init(0.8, 0.8, 0.0) } };
+    try tmp_world.add(Hittable{ .sphere = Sphere.init(Point3.init(0, -100.5, -1), 100) });
-    const material_center = Material{ .labertian = Labertian{ .albedo = Color.init(0.7, 0.3, 0.3) } };
-    const material_left = Material{ .metal = Metal{ .albedo = Color.init(0.8, 0.8, 0.8) } };
-    const material_right = Material{ .metal = Metal{ .albedo = Color.init(0.8, 0.6, 0.2) } };
-
-    try tmp_world.add(Hittable{ .sphere = Sphere.init(Point3.init(0, -100.5, -1), 100, material_ground) });
-    try tmp_world.add(Hittable{ .sphere = Sphere.init(Point3.init(0, 0, -1), 0.5, material_center) });
-    try tmp_world.add(Hittable{ .sphere = Sphere.init(Point3.init(-1, 0, -1), 0.5, material_left) });
-    try tmp_world.add(Hittable{ .sphere = Sphere.init(Point3.init(1, 0, -1), 0.5, material_right) });
     const world = Hittable{ .hittable_list = tmp_world };
 
     // Camera

zigrtiow/src/material.zig

@@ -1,56 +0,0 @@
-const vec = @import("./vec.zig");
-const Ray = @import("./ray.zig").Ray;
-const HitRecord = @import("./hittable.zig").HitRecord;
-
-const Vec3 = vec.Vec3;
-const Color = vec.Color;
-const random_unit_vector = vec.random_unit_vector;
-
-pub const Material = union(enum) {
-    labertian: Labertian,
-    metal: Metal,
-
-    pub fn scatter(material: Material, r_in: Ray, rec: HitRecord) ?ScatterRec {
-        return switch (material) {
-            .labertian => |labertian| labertian.scatter(r_in, rec),
-            .metal => |metal| metal.scatter(r_in, rec),
-        };
-    }
-};
-
-pub const ScatterRec = struct { attenuation: Color, scattered: Ray };
-
-pub const Labertian = struct {
-    albedo: Vec3,
-    pub fn scatter(labertian: Labertian, r_in: Ray, rec: HitRecord) ?ScatterRec {
-        _ = r_in;
-        var scatter_direction = rec.normal.add(random_unit_vector());
-        if (scatter_direction.near_zero()) {
-            scatter_direction = rec.normal;
-        }
-        return ScatterRec{
-            .scattered = Ray.init(rec.p, scatter_direction),
-            .attenuation = labertian.albedo,
-        };
-    }
-};
-
-pub const Metal = struct {
-    albedo: Vec3,
-    pub fn scatter(metal: Metal, r_in: Ray, rec: HitRecord) ?ScatterRec {
-        const reflected = reflect(r_in.direction().unit(), rec.normal);
-        const scattered = Ray.init(rec.p, reflected);
-        const attenuation = metal.albedo;
-        if (scattered.direction().dot(rec.normal) > 0) {
-            return ScatterRec{
-                .scattered = scattered,
-                .attenuation = attenuation,
-            };
-        } else {
-            return null;
-        }
-    }
-    fn reflect(v: Vec3, n: Vec3) Vec3 {
-        return v.sub(n.scale(v.dot(n) * 2));
-    }
-};

zigrtiow/src/sphere.zig

@@ -2,8 +2,6 @@ const vec = @import("./vec.zig");
 const ray = @import("./ray.zig");
 const hittable = @import("./hittable.zig");
 
-const Material = @import("./material.zig").Material;
-
 const Vec3 = vec.Vec3;
 const Point3 = vec.Point3;
 const Ray = ray.Ray;
@@ -12,13 +10,11 @@ const HitRecord = hittable.HitRecord;
 pub const Sphere = struct {
     center: Point3,
     radius: f32,
-    material: Material,
 
-    pub fn init(center: Point3, radius: f32, material: Material) Sphere {
+    pub fn init(center: Point3, radius: f32) Sphere {
         return Sphere{
             .center = center,
             .radius = radius,
-            .material = material,
         };
     }
     pub fn hit(sphere: Sphere, r: Ray, t_min: f32, t_max: f32) ?HitRecord {
@@ -48,7 +44,6 @@ pub const Sphere = struct {
             .p = p,
             .normal = Vec3.init(0, 0, 0),
             .front_face = false,
-            .material = sphere.material,
         };
         hr.set_face_normal(r, outward_normal);
         return hr;

zigrtiow/src/vec.zig

@@ -34,9 +34,6 @@ pub const Vec3 = struct {
     pub fn sub(lhs: Vec3, rhs: Vec3) Vec3 {
         return Vec3{ .v = lhs.v - rhs.v };
     }
-    pub fn mul(lhs: Vec3, rhs: Vec3) Vec3 {
-        return Vec3{ .v = lhs.v * rhs.v };
-    }
     pub fn scale(vec: Vec3, t: f32) Vec3 {
         return Vec3{ .v = vec.v * @splat(3, t) };
     }
@@ -55,12 +52,6 @@ pub const Vec3 = struct {
             rand.float(f32) * 2 - 1,
         );
     }
-    pub fn near_zero(vec: Vec3) bool {
-        // Return true if the vector is close to zero in all dimensions.
-        const s = 1e-8;
-        const e = vec.v;
-        return (@fabs(e[0]) < s) and (@fabs(e[1]) < s) and (@fabs(e[2]) < s);
-    }
 };
 
 pub fn random_in_unit_sphere() Vec3 {