Add builder pattern to a few core types.

Add a From<[3;Float]> impl for Color to make things nicer.

rtchallenge/Cargo.lock

@@ -130,7 +130,7 @@ dependencies = [
  "ansi_term",
  "atty",
  "bitflags",
- "strsim",
+ "strsim 0.8.0",
  "textwrap",
  "unicode-width",
  "vec_map",
@@ -259,6 +259,41 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "darling"
+version = "0.12.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f2c43f534ea4b0b049015d00269734195e6d3f0f6635cb692251aca6f9f8b3c"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.12.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e91455b86830a1c21799d94524df0845183fa55bafd9aa137b01c7d1065fa36"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim 0.10.0",
+ "syn",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.12.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29b5acf0dea37a7f66f7b25d2c5e93fd46f8f6968b1a5d7a3e02e97768afc95a"
+dependencies = [
+ "darling_core",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "deflate"
 version = "0.8.6"
@@ -269,6 +304,37 @@ dependencies = [
  "byteorder",
 ]
 
+[[package]]
+name = "derive_builder"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d13202debe11181040ae9063d739fa32cfcaaebe2275fe387703460ae2365b30"
+dependencies = [
+ "derive_builder_macro",
+]
+
+[[package]]
+name = "derive_builder_core"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66e616858f6187ed828df7c64a6d71720d83767a7f19740b2d1b6fe6327b36e5"
+dependencies = [
+ "darling",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "derive_builder_macro"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58a94ace95092c5acb1e97a7e846b310cfbd499652f72297da7493f618a98d73"
+dependencies = [
+ "derive_builder_core",
+ "syn",
+]
+
 [[package]]
 name = "either"
 version = "1.6.1"
@@ -308,6 +374,12 @@ dependencies = [
  "backtrace",
 ]
 
+[[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
 [[package]]
 name = "getrandom"
 version = "0.2.3"
@@ -349,6 +421,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
 [[package]]
 name = "itertools"
 version = "0.9.0"
@@ -662,6 +740,7 @@ dependencies = [
  "anyhow",
  "core_affinity",
  "criterion",
+ "derive_builder",
  "enum-utils",
  "num_cpus",
  "png",
@@ -773,6 +852,12 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
+[[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
 [[package]]
 name = "structopt"
 version = "0.3.22"

rtchallenge/Cargo.toml

@@ -15,6 +15,7 @@ float-as-double = []
 anyhow = "1.0.41"
 core_affinity = "0.5.10"
 criterion = "0.3.4"
+derive_builder = "0.10.2"
 enum-utils = "0.1.2"
 num_cpus = "1.13.0"
 png = "0.16.8"

rtchallenge/src/lights.rs

@@ -1,8 +1,12 @@
+use derive_builder::Builder;
+
 use crate::tuples::{Color, Tuple};
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Builder, Clone, Debug, Default, PartialEq)]
+#[builder(default)]
 pub struct PointLight {
     pub position: Tuple,
+    #[builder(setter(into))]
     pub intensity: Color,
 }
 

rtchallenge/src/materials.rs

@@ -1,11 +1,16 @@
+use derive_builder::Builder;
+
 use crate::{
     lights::PointLight,
     tuples::Color,
     tuples::{dot, reflect, Tuple},
     Float, BLACK, WHITE,
 };
-#[derive(Debug, PartialEq, Clone)]
+
+#[derive(Builder, Debug, PartialEq, Clone)]
+#[builder(default)]
 pub struct Material {
+    #[builder(setter(into))]
     pub color: Color,
     pub ambient: Float,
     pub diffuse: Float,

rtchallenge/src/shapes.rs

@@ -1,5 +1,7 @@
 use std::sync::{Arc, Mutex};
 
+use derive_builder::Builder;
+
 use crate::{
     intersections::Intersections, materials::Material, matrices::Matrix4x4, rays::Ray,
     tuples::Tuple,
@@ -20,6 +22,12 @@ pub enum Geometry {
     Plane,
 }
 
+impl Default for Geometry {
+    fn default() -> Geometry {
+        Geometry::Sphere
+    }
+}
+
 impl PartialEq for Geometry {
     fn eq(&self, rhs: &Geometry) -> bool {
         use Geometry::*;
@@ -35,7 +43,8 @@ impl PartialEq for Geometry {
 /// Shape represents visible objects.  A signal instance of Shape can generically represent one of
 /// many different shapes based on the value of it's geometry field.  Users chose the shape by
 /// calling the appropriate constructor, i.e. [Shape::sphere].
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Builder, Debug, Clone, PartialEq)]
+#[builder(default)]
 pub struct Shape {
     transform: Matrix4x4,
     inverse_transform: Matrix4x4,
@@ -43,6 +52,17 @@ pub struct Shape {
     geometry: Geometry,
 }
 
+impl Default for Shape {
+    fn default() -> Shape {
+        Shape {
+            transform: Matrix4x4::identity(),
+            inverse_transform: Matrix4x4::identity(),
+            material: Material::default(),
+            geometry: Geometry::default(),
+        }
+    }
+}
+
 impl Shape {
     /// Create a test shape useful for debugging.
     ///

rtchallenge/src/tuples.rs

@@ -161,17 +161,29 @@ pub fn cross(a: Tuple, b: Tuple) -> Tuple {
     )
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, Default)]
 pub struct Color {
     pub red: Float,
     pub green: Float,
     pub blue: Float,
 }
+
 impl Color {
     pub const fn new(red: Float, green: Float, blue: Float) -> Color {
         Color { red, green, blue }
     }
 }
+
+impl From<[Float; 3]> for Color {
+    fn from(rgb: [Float; 3]) -> Self {
+        Color {
+            red: rgb[0],
+            green: rgb[1],
+            blue: rgb[2],
+        }
+    }
+}
+
 impl PartialEq for Color {
     fn eq(&self, rhs: &Color) -> bool {
         ((self.red - rhs.red).abs() < EPSILON)
@@ -179,6 +191,7 @@ impl PartialEq for Color {
             && ((self.blue - rhs.blue).abs() < EPSILON)
     }
 }
+
 impl Add for Color {
     type Output = Self;
     fn add(self, other: Self) -> Self {
@@ -222,6 +235,7 @@ impl Mul<Color> for Float {
         }
     }
 }
+
 impl Mul<Color> for Color {
     type Output = Color;
     fn mul(self, rhs: Color) -> Self::Output {
@@ -243,6 +257,7 @@ impl Neg for Color {
         }
     }
 }
+
 impl Sub for Color {
     type Output = Self;
     fn sub(self, other: Self) -> Self {