diff options
| -rw-r--r-- | src/main.zig | 63 |
1 files changed, 58 insertions, 5 deletions
diff --git a/src/main.zig b/src/main.zig index fac7648..b18c52b 100644 --- a/src/main.zig +++ b/src/main.zig @@ -173,7 +173,7 @@ const Material = union(MaterialTag) { }; const DiffuseMaterial = struct { - albedo: Color, + albedo: Texture, fn scatter(mat: DiffuseMaterial, r_in: Ray, record: HitRecord, attenuation: *Color, scattered: *Ray, rand: std.rand.Random) bool { var scatter_direction = record.normal.add(randomUnitVector(rand)); @@ -181,7 +181,7 @@ const DiffuseMaterial = struct { scatter_direction = record.normal; } scattered.* = .{ .origin = record.p, .dir = scatter_direction, .time = r_in.time }; - attenuation.* = mat.albedo; + attenuation.* = mat.albedo.value(record.u, record.v, record.p); return true; } }; @@ -319,6 +319,7 @@ const Sphere = struct { } else { record.normal = outward_normal.mul(-1.0); } + Sphere.getSphereUv(outward_normal, &record.u, &record.v); record.material = sphere.material; return true; @@ -336,6 +337,13 @@ const Sphere = struct { return true; } + fn getSphereUv(p: Point3, u: *f64, v: *f64) void { + const phi = math.atan2(f64, -p.z, p.x) + pi; + const theta = math.acos(-p.y); + u.* = phi / (2.0 * pi); + v.* = theta / pi; + } + fn deinit(sphere: *const Sphere, allocator: anytype) void { allocator.destroy(sphere.material); } @@ -632,14 +640,29 @@ const BvhNode = struct { const TextureTag = enum { solid, + checker, }; const Texture = union(TextureTag) { solid: SolidTexture, + checker: CheckerTexture, + + fn makeSolid(color: Color) Texture { + return .{ .solid = .{ .color = color } }; + } + + fn makeChecker(allocator: std.mem.Allocator, odd: Color, even: Color) !Texture { + return .{ .checker = try CheckerTexture.init( + allocator, + Texture.makeSolid(odd), + Texture.makeSolid(even), + ) }; + } fn value(tx: Texture, u: f64, v: f64, p: Vec3) Color { return switch (tx) { TextureTag.solid => |solidTx| solidTx.value(u, v, p), + TextureTag.checker => |checkerTx| checkerTx.value(u, v, p), }; } }; @@ -655,6 +678,34 @@ const SolidTexture = struct { } }; +const CheckerTexture = struct { + allocator: std.mem.Allocator, + odd: *const Texture, + even: *const Texture, + + fn init(allocator: std.mem.Allocator, odd: Texture, even: Texture) !CheckerTexture { + var odd_ = try allocator.create(Texture); + var even_ = try allocator.create(Texture); + odd_.* = odd; + even_.* = even; + return .{ + .allocator = allocator, + .odd = odd_, + .even = even_, + }; + } + + fn deinit(tx: CheckerTexture) void { + tx.allocator.destroy(tx.even); + tx.allocator.destroy(tx.odd); + } + + fn value(tx: CheckerTexture, u: f64, v: f64, p: Vec3) Color { + const sines = @sin(10 * p.x) * @sin(10 * p.y) * @sin(10 * p.z); + return if (sines < 0) tx.odd.value(u, v, p) else tx.even.value(u, v, p); + } +}; + const Camera = struct { origin: Point3, horizontal: Vec3, @@ -755,9 +806,11 @@ fn generateRandomScene(rand: std.rand.Random, allocator: anytype) !Hittable { var mat2 = try allocator.create(Material); var mat3 = try allocator.create(Material); - mat_ground.* = .{ .diffuse = .{ .albedo = rgb(0.5, 0.5, 0.5) } }; + const checker = try Texture.makeChecker(allocator, rgb(0.2, 0.3, 0.1), rgb(0.9, 0.9, 0.9)); + + mat_ground.* = .{ .diffuse = .{ .albedo = checker } }; mat1.* = .{ .dielectric = .{ .ir = 1.5 } }; - mat2.* = .{ .diffuse = .{ .albedo = rgb(0.4, 0.2, 0.1) } }; + mat2.* = .{ .diffuse = .{ .albedo = .{ .solid = .{ .color = rgb(0.4, 0.2, 0.1) } } } }; mat3.* = .{ .metal = .{ .albedo = rgb(0.7, 0.6, 0.5), .fuzz = 0.0 } }; try hittable_objects.append(makeSphere(.{ .x = 0, .y = -1000, .z = 0 }, 1000, mat_ground)); @@ -784,7 +837,7 @@ fn generateRandomScene(rand: std.rand.Random, allocator: anytype) !Hittable { if (choose_mat < 0.8) { // diffuse const albedo = Color.random01(rand).mulV(Color.random01(rand)); - mat_sphere.* = .{ .diffuse = .{ .albedo = albedo } }; + mat_sphere.* = .{ .diffuse = .{ .albedo = .{ .solid = .{ .color = albedo } } } }; const center1 = center.add(.{ .x = 0, .y = randomReal(rand, 0, 0.5), .z = 0 }); try hittable_objects.append(.{ .movingSphere = .{ .center0 = center, |