From bfa3282a3770de3a7fea33e093ea506267533c02 Mon Sep 17 00:00:00 2001
From: Bill Thiede <git@xinu.tv>
Date: Sat, 24 Jul 2021 19:36:32 -0700
Subject: [PATCH] materials: add StripePattern as a Material color option.

---
 rtchallenge/examples/eoc6.rs |   2 +-
 rtchallenge/examples/eoc7.rs |   8 +--
 rtchallenge/examples/eoc8.rs |   8 +--
 rtchallenge/examples/eoc9.rs |  10 ++--
 rtchallenge/src/lib.rs       |   1 +
 rtchallenge/src/materials.rs | 103 ++++++++++++++++++++++++++---------
 rtchallenge/src/patterns.rs  |   2 +-
 rtchallenge/src/world.rs     |   7 ++-
 8 files changed, 96 insertions(+), 45 deletions(-)

diff --git a/rtchallenge/examples/eoc6.rs b/rtchallenge/examples/eoc6.rs
index 41cbba6..5b14e66 100644
--- a/rtchallenge/examples/eoc6.rs
+++ b/rtchallenge/examples/eoc6.rs
@@ -22,7 +22,7 @@ fn main() -> Result<()> {
     let half = wall_size / 2.;
     let mut shape = Shape::sphere();
     shape.material = Material {
-        color: Color::new(1., 0.2, 1.),
+        color: Color::new(1., 0.2, 1.).into(),
         specular: 0.5,
         diffuse: 0.7,
         shininess: 30.,
diff --git a/rtchallenge/examples/eoc7.rs b/rtchallenge/examples/eoc7.rs
index 54118d9..5b813ce 100644
--- a/rtchallenge/examples/eoc7.rs
+++ b/rtchallenge/examples/eoc7.rs
@@ -42,7 +42,7 @@ fn main() -> Result<()> {
     let mut floor = Shape::sphere();
     floor.set_transform(Matrix4x4::scaling(10., 0.01, 10.));
     floor.material = Material {
-        color: Color::new(1., 0.9, 0.9),
+        color: Color::new(1., 0.9, 0.9).into(),
         specular: 0.,
         ..Material::default()
     };
@@ -68,7 +68,7 @@ fn main() -> Result<()> {
     let mut middle = Shape::sphere();
     middle.set_transform(Matrix4x4::translation(-0.5, 1., 0.5));
     middle.material = Material {
-        color: Color::new(0.1, 1., 0.5),
+        color: Color::new(0.1, 1., 0.5).into(),
         diffuse: 0.7,
         specular: 0.3,
         ..Material::default()
@@ -77,7 +77,7 @@ fn main() -> Result<()> {
     let mut right = Shape::sphere();
     right.set_transform(Matrix4x4::translation(1.5, 0.5, -0.5) * Matrix4x4::scaling(0.5, 0.5, 0.5));
     right.material = Material {
-        color: Color::new(0.5, 1., 0.1),
+        color: Color::new(0.5, 1., 0.1).into(),
         diffuse: 0.7,
         specular: 0.3,
         ..Material::default()
@@ -88,7 +88,7 @@ fn main() -> Result<()> {
         Matrix4x4::translation(-1.5, 0.33, -0.75) * Matrix4x4::scaling(0.33, 0.33, 0.33),
     );
     left.material = Material {
-        color: Color::new(1., 0.8, 0.1),
+        color: Color::new(1., 0.8, 0.1).into(),
         diffuse: 0.7,
         specular: 0.3,
         ..Material::default()
diff --git a/rtchallenge/examples/eoc8.rs b/rtchallenge/examples/eoc8.rs
index 4fde11d..6ef89d2 100644
--- a/rtchallenge/examples/eoc8.rs
+++ b/rtchallenge/examples/eoc8.rs
@@ -54,7 +54,7 @@ fn main() -> Result<()> {
     let mut floor = Shape::sphere();
     floor.set_transform(Matrix4x4::scaling(10., 0.01, 10.));
     floor.material = Material {
-        color: Color::new(1., 0.9, 0.9),
+        color: Color::new(1., 0.9, 0.9).into(),
         specular: 0.,
         ..Material::default()
     };
@@ -80,7 +80,7 @@ fn main() -> Result<()> {
     let mut middle = Shape::sphere();
     middle.set_transform(Matrix4x4::translation(-0.5, 1., 0.5));
     middle.material = Material {
-        color: Color::new(0.1, 1., 0.5),
+        color: Color::new(0.1, 1., 0.5).into(),
         diffuse: 0.7,
         specular: 0.3,
         ..Material::default()
@@ -89,7 +89,7 @@ fn main() -> Result<()> {
     let mut right = Shape::sphere();
     right.set_transform(Matrix4x4::translation(1.5, 0.5, -0.5) * Matrix4x4::scaling(0.5, 0.5, 0.5));
     right.material = Material {
-        color: Color::new(1., 1., 1.),
+        color: Color::new(1., 1., 1.).into(),
         diffuse: 0.7,
         specular: 0.0,
         ..Material::default()
@@ -100,7 +100,7 @@ fn main() -> Result<()> {
         Matrix4x4::translation(-1.5, 0.33, -0.75) * Matrix4x4::scaling(0.33, 0.33, 0.33),
     );
     left.material = Material {
-        color: Color::new(1., 0.8, 0.1),
+        color: Color::new(1., 0.8, 0.1).into(),
         diffuse: 0.7,
         specular: 0.3,
         ..Material::default()
diff --git a/rtchallenge/examples/eoc9.rs b/rtchallenge/examples/eoc9.rs
index b551b5a..2c83822 100644
--- a/rtchallenge/examples/eoc9.rs
+++ b/rtchallenge/examples/eoc9.rs
@@ -59,14 +59,14 @@ fn main() -> Result<()> {
 
     let mut floor = Shape::plane();
     floor.material = Material {
-        color: Color::new(1., 0.2, 0.2),
+        color: Color::new(1., 0.2, 0.2).into(),
         specular: 0.,
         ..Material::default()
     };
     let mut ceiling = Shape::plane();
     ceiling.set_transform(Matrix4x4::translation(0., 6., 0.) * Matrix4x4::rotation_x(PI));
     ceiling.material = Material {
-        color: Color::new(0.6, 0.6, 0.8),
+        color: Color::new(0.6, 0.6, 0.8).into(),
         specular: 0.2,
         ..Material::default()
     };
@@ -74,7 +74,7 @@ fn main() -> Result<()> {
     let mut middle = Shape::sphere();
     middle.set_transform(Matrix4x4::translation(-0.5, 0.5, 0.5));
     middle.material = Material {
-        color: Color::new(0.1, 1., 0.5),
+        color: Color::new(0.1, 1., 0.5).into(),
         diffuse: 0.7,
         specular: 0.3,
         ..Material::default()
@@ -83,7 +83,7 @@ fn main() -> Result<()> {
     let mut right = Shape::sphere();
     right.set_transform(Matrix4x4::translation(1.5, 0.5, -0.5) * Matrix4x4::scaling(0.5, 0.5, 0.5));
     right.material = Material {
-        color: Color::new(1., 1., 1.),
+        color: Color::new(1., 1., 1.).into(),
         diffuse: 0.7,
         specular: 0.0,
         ..Material::default()
@@ -94,7 +94,7 @@ fn main() -> Result<()> {
         Matrix4x4::translation(-1.5, 0.33, -0.75) * Matrix4x4::scaling(0.33, 0.33, 0.33),
     );
     left.material = Material {
-        color: Color::new(1., 0.8, 0.1),
+        color: Color::new(1., 0.8, 0.1).into(),
         diffuse: 0.7,
         specular: 0.3,
         ..Material::default()
diff --git a/rtchallenge/src/lib.rs b/rtchallenge/src/lib.rs
index d6fb53e..63be81c 100644
--- a/rtchallenge/src/lib.rs
+++ b/rtchallenge/src/lib.rs
@@ -45,6 +45,7 @@ pub mod prelude {
         lights::{PointLight, PointLightBuilder},
         materials::{Material, MaterialBuilder},
         matrices::{identity, rotation_x, rotation_y, rotation_z, scaling, shearing, translation},
+        patterns::stripe_pattern,
         shapes::{plane, sphere, test_shape},
         transformations::view_transform,
         tuples::{point, vector, Color},
diff --git a/rtchallenge/src/materials.rs b/rtchallenge/src/materials.rs
index cc29add..1b2c3c0 100644
--- a/rtchallenge/src/materials.rs
+++ b/rtchallenge/src/materials.rs
@@ -2,16 +2,43 @@ use derive_builder::Builder;
 
 use crate::{
     lights::PointLight,
-    tuples::Color,
-    tuples::{dot, reflect, Tuple},
+    patterns::StripePattern,
+    tuples::{dot, reflect, Color, Tuple},
     Float, BLACK, WHITE,
 };
 
+#[derive(Debug, PartialEq, Clone)]
+pub enum ColorMapper {
+    Constant(Color),
+    StripePattern(StripePattern),
+}
+
+/// Creates a [ColorMapper::Constant] from the given [Color]
+impl From<Color> for ColorMapper {
+    fn from(c: Color) -> Self {
+        ColorMapper::Constant(c)
+    }
+}
+
+/// Creates a [ColorMapper::Constant] from the given array.
+impl From<[Float; 3]> for ColorMapper {
+    fn from(rgb: [Float; 3]) -> Self {
+        ColorMapper::Constant(rgb.into())
+    }
+}
+
+/// Creates a [ColorMapper::StripePattern] from the given [Color]
+impl From<StripePattern> for ColorMapper {
+    fn from(sp: StripePattern) -> Self {
+        ColorMapper::StripePattern(sp)
+    }
+}
+
 #[derive(Builder, Debug, PartialEq, Clone)]
 #[builder(default)]
 pub struct Material {
     #[builder(setter(into))]
-    pub color: Color,
+    pub color: ColorMapper,
     pub ambient: Float,
     pub diffuse: Float,
     pub specular: Float,
@@ -29,7 +56,7 @@ impl Default for Material {
     /// assert_eq!(
     ///     m,
     ///     Material {
-    ///         color: WHITE,
+    ///         color: WHITE.into(),
     ///         ambient: 0.1,
     ///         diffuse: 0.9,
     ///         specular: 0.9,
@@ -39,7 +66,7 @@ impl Default for Material {
     /// ```
     fn default() -> Material {
         Material {
-            color: WHITE,
+            color: WHITE.into(),
             ambient: 0.1,
             diffuse: 0.9,
             specular: 0.9,
@@ -55,56 +82,74 @@ impl Default for Material {
 /// use rtchallenge::{
 ///     lights::PointLight,
 ///     materials::{lighting, Material},
-///     tuples::{Color, Tuple},
-///     Float, WHITE,
+///     patterns::stripe_pattern,
+///     tuples::{point, vector, Color},
+///     Float, BLACK, WHITE,
 /// };
 ///
 /// let in_shadow = false;
 /// let m = Material::default();
-/// let position = Tuple::point(0., 0., 0.);
+/// let position = point(0., 0., 0.);
 ///
 /// // Lighting with the eye between the light and the surface.
-/// let eyev = Tuple::vector(0., 0., -1.);
-/// let normalv = Tuple::vector(0., 0., -1.);
-/// let light = PointLight::new(Tuple::point(0., 0., -10.), WHITE);
+/// let eyev = vector(0., 0., -1.);
+/// let normalv = vector(0., 0., -1.);
+/// let light = PointLight::new(point(0., 0., -10.), WHITE);
 /// let result = lighting(&m, &light, position, eyev, normalv, in_shadow);
 /// assert_eq!(result, Color::new(1.9, 1.9, 1.9));
 ///
 /// // Lighting with the eye between the light and the surface, eye offset 45°.
-/// let eyev = Tuple::vector(0., (2. as Float).sqrt() / 2., -(2. as Float).sqrt() / 2.);
-/// let normalv = Tuple::vector(0., 0., -1.);
-/// let light = PointLight::new(Tuple::point(0., 0., -10.), WHITE);
+/// let eyev = vector(0., (2. as Float).sqrt() / 2., -(2. as Float).sqrt() / 2.);
+/// let normalv = vector(0., 0., -1.);
+/// let light = PointLight::new(point(0., 0., -10.), WHITE);
 /// let result = lighting(&m, &light, position, eyev, normalv, in_shadow);
 /// assert_eq!(result, WHITE);
 ///
 /// // Lighting with the eye opposite surface, light offset 45°.
-/// let eyev = Tuple::vector(0., 0., -1.);
-/// let normalv = Tuple::vector(0., 0., -1.);
-/// let light = PointLight::new(Tuple::point(0., 10., -10.), WHITE);
+/// let eyev = vector(0., 0., -1.);
+/// let normalv = vector(0., 0., -1.);
+/// let light = PointLight::new(point(0., 10., -10.), WHITE);
 /// let result = lighting(&m, &light, position, eyev, normalv, in_shadow);
 /// assert_eq!(result, Color::new(0.7364, 0.7364, 0.7364));
 ///
 /// // Lighting with the eye in the path of the reflection vector.
-/// let eyev = Tuple::vector(0., -(2.0 as Float).sqrt() / 2., -(2.0 as Float).sqrt() / 2.);
-/// let normalv = Tuple::vector(0., 0., -1.);
-/// let light = PointLight::new(Tuple::point(0., 10., -10.), WHITE);
+/// let eyev = vector(0., -(2.0 as Float).sqrt() / 2., -(2.0 as Float).sqrt() / 2.);
+/// let normalv = vector(0., 0., -1.);
+/// let light = PointLight::new(point(0., 10., -10.), WHITE);
 /// let result = lighting(&m, &light, position, eyev, normalv, in_shadow);
 /// assert_eq!(result, Color::new(1.63639, 1.63639, 1.63639));
 ///
 /// // Lighting with the light behind the surface.
-/// let eyev = Tuple::vector(0., 0., -1.);
-/// let normalv = Tuple::vector(0., 0., -1.);
-/// let light = PointLight::new(Tuple::point(0., 0., 10.), WHITE);
+/// let eyev = vector(0., 0., -1.);
+/// let normalv = vector(0., 0., -1.);
+/// let light = PointLight::new(point(0., 0., 10.), WHITE);
 /// let result = lighting(&m, &light, position, eyev, normalv, in_shadow);
 /// assert_eq!(result, Color::new(0.1, 0.1, 0.1));
 ///
 /// // Lighting with the surface in shadow.
 /// let in_shadow = true;
-/// let eyev = Tuple::vector(0., 0., -1.);
-/// let normalv = Tuple::vector(0., 0., -1.);
-/// let light = PointLight::new(Tuple::point(0., 0., -10.), WHITE);
+/// let eyev = vector(0., 0., -1.);
+/// let normalv = vector(0., 0., -1.);
+/// let light = PointLight::new(point(0., 0., -10.), WHITE);
 /// let result = lighting(&m, &light, position, eyev, normalv, in_shadow);
 /// assert_eq!(result, Color::new(0.1, 0.1, 0.1));
+///
+/// // Lighting with a pattern applied.
+///
+/// let m = Material {
+///     color: stripe_pattern(WHITE, BLACK).into(),
+///     ambient: 1.,
+///     diffuse: 0.,
+///     specular: 0.,
+///     ..Material::default()
+/// };
+/// let eyev = vector(0., 0., -1.);
+/// let normalv = vector(0., 0., -1.);
+/// let light = PointLight::new(point(0., 0., -10.), WHITE);
+/// let c1 = lighting(&m, &light, point(0.9, 0., 0.), eyev, normalv, false);
+/// let c2 = lighting(&m, &light, point(1.1, 0., 0.), eyev, normalv, false);
+/// assert_eq!(c1, WHITE);
+/// assert_eq!(c2, BLACK);
 /// ```
 pub fn lighting(
     material: &Material,
@@ -115,7 +160,11 @@ pub fn lighting(
     in_shadow: bool,
 ) -> Color {
     // Combine the surface color with the light's color.
-    let effective_color = material.color * light.intensity;
+    let color = match &material.color {
+        ColorMapper::Constant(color) => *color,
+        ColorMapper::StripePattern(pat) => pat.stripe_at(point),
+    };
+    let effective_color = color * light.intensity;
     // Find the direciton of the light source.
     let lightv = (light.position - point).normalize();
     // Compute the ambient distribution.
diff --git a/rtchallenge/src/patterns.rs b/rtchallenge/src/patterns.rs
index ff10686..78e0b06 100644
--- a/rtchallenge/src/patterns.rs
+++ b/rtchallenge/src/patterns.rs
@@ -1,6 +1,6 @@
 use crate::tuples::{Color, Tuple};
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Clone)]
 pub struct StripePattern {
     pub a: Color,
     pub b: Color,
diff --git a/rtchallenge/src/world.rs b/rtchallenge/src/world.rs
index 5db015e..470dde7 100644
--- a/rtchallenge/src/world.rs
+++ b/rtchallenge/src/world.rs
@@ -44,7 +44,7 @@ impl World {
         let light = PointLight::new(Tuple::point(-10., 10., -10.), WHITE);
         let mut s1 = Shape::sphere();
         s1.material = Material {
-            color: Color::new(0.8, 1., 0.6),
+            color: [0.8, 1., 0.6].into(),
             diffuse: 0.7,
             specular: 0.2,
             ..Material::default()
@@ -161,7 +161,7 @@ impl World {
     ///     shapes::Shape,
     ///     tuples::{Color, Tuple},
     ///     world::World,
-    ///     BLACK,
+    ///     BLACK, WHITE,
     /// };
     ///
     /// // The color when a ray misses.
@@ -188,7 +188,8 @@ impl World {
     /// let inner = &w.objects[1];
     /// let r = Ray::new(Tuple::point(0., 0., 0.75), Tuple::vector(0., 0., -1.));
     /// let c = w.color_at(&r);
-    /// assert_eq!(c, inner.material.color);
+    /// // inner.material.color is WHITE
+    /// assert_eq!(c, WHITE);
     /// ```
     pub fn color_at(&self, r: &Ray) -> Color {
         match self.intersect(r).hit() {