From b9ebc186faae279fa072070d93e8a9a6b1008368 Mon Sep 17 00:00:00 2001
From: Bill Thiede <git@xinu.tv>
Date: Wed, 18 Jan 2023 20:15:06 -0800
Subject: [PATCH] rtiow: add new Scale tranformer.

---
 rtiow/renderer/src/lib.rs            |  1 +
 rtiow/renderer/src/scale.rs          | 53 ++++++++++++++++++++++++++++
 rtiow/renderer/src/scenes/stltest.rs | 23 +++++++-----
 rtiow/renderer/src/triangles.rs      |  8 -----
 4 files changed, 69 insertions(+), 16 deletions(-)
 create mode 100644 rtiow/renderer/src/scale.rs

diff --git a/rtiow/renderer/src/lib.rs b/rtiow/renderer/src/lib.rs
index 622ef2c..d88add8 100644
--- a/rtiow/renderer/src/lib.rs
+++ b/rtiow/renderer/src/lib.rs
@@ -17,6 +17,7 @@ pub mod ray;
 pub mod rect;
 pub mod renderer;
 pub mod rotate;
+pub mod scale;
 pub mod scenes;
 pub mod sphere;
 pub mod texture;
diff --git a/rtiow/renderer/src/scale.rs b/rtiow/renderer/src/scale.rs
new file mode 100644
index 0000000..a59031d
--- /dev/null
+++ b/rtiow/renderer/src/scale.rs
@@ -0,0 +1,53 @@
+use crate::{
+    aabb::AABB,
+    hitable::{Hit, HitRecord},
+    ray::Ray,
+    vec3::Vec3,
+};
+
+#[derive(Debug)]
+pub struct Scale<H>
+where
+    H: Hit,
+{
+    hitable: H,
+    scale: Vec3,
+}
+
+impl<H> Scale<H>
+where
+    H: Hit,
+{
+    pub fn new<V>(hitable: H, scale: V) -> Scale<H>
+    where
+        V: Into<Vec3>,
+    {
+        Scale {
+            hitable,
+            scale: scale.into(),
+        }
+    }
+}
+
+impl<H> Hit for Scale<H>
+where
+    H: Hit,
+{
+    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
+        let moved_r = Ray::new(r.origin / self.scale, r.direction, r.time);
+        if let Some(rec) = self.hitable.hit(moved_r, t_min, t_max) {
+            return Some(HitRecord {
+                p: rec.p * self.scale,
+                ..rec
+            });
+        }
+        None
+    }
+
+    fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
+        if let Some(bbox) = self.hitable.bounding_box(t_min, t_max) {
+            return Some(AABB::new(bbox.min() * self.scale, bbox.max() * self.scale));
+        }
+        None
+    }
+}
diff --git a/rtiow/renderer/src/scenes/stltest.rs b/rtiow/renderer/src/scenes/stltest.rs
index 6f18395..92cbee6 100644
--- a/rtiow/renderer/src/scenes/stltest.rs
+++ b/rtiow/renderer/src/scenes/stltest.rs
@@ -9,9 +9,9 @@ use crate::{
     material::{DiffuseLight, Lambertian, Metal},
     rect::{XYRect, XZRect},
     renderer::{Opt, Scene},
+    scale::Scale,
     sphere::Sphere,
     texture::ConstantTexture,
-    translate::Translate,
     triangles::Triangles,
     vec3::Vec3,
 };
@@ -48,7 +48,7 @@ pub fn new(opt: &Opt) -> Scene {
     let light_size = 50.;
     let light_height = 200.;
     let objects: Vec<Box<dyn Hit>> = vec![
-        // Light from above
+        // Light from above - white
         Box::new(XZRect::new(
             -light_size,
             light_size,
@@ -57,7 +57,7 @@ pub fn new(opt: &Opt) -> Scene {
             light_height,
             DiffuseLight::new(ConstantTexture::new(Vec3::new(15., 15., 15.))),
         )),
-        // Light from back
+        // Light from back - green
         Box::new(XYRect::new(
             -light_size,
             light_size,
@@ -66,7 +66,7 @@ pub fn new(opt: &Opt) -> Scene {
             -light_height,
             DiffuseLight::new(ConstantTexture::new(Vec3::new(1., 15., 1.))),
         )),
-        // Light from front
+        // Light from front - blue
         Box::new(XYRect::new(
             -light_size,
             light_size,
@@ -81,26 +81,33 @@ pub fn new(opt: &Opt) -> Scene {
             1000.,
             Lambertian::new(ground_color),
         )),
+        /*
         // Blue sphere
         Box::new(Sphere::new(
             Vec3::new(-40., 20., 0.),
             20.,
             Lambertian::new(ConstantTexture::new(Vec3::new(0.1, 0.2, 0.5))),
         )),
+         */
         // Shiny sphere
         Box::new(Sphere::new(
-            Vec3::new(40., 20., 0.),
+            Vec3::new(40., 20., -40.),
+            20.,
+            Metal::new(Vec3::new(0.8, 0.8, 0.8), 0.2),
+        )),
+        Box::new(Sphere::new(
+            Vec3::new(-40., 20., 40.),
             20.,
             Metal::new(Vec3::new(0.8, 0.8, 0.8), 0.2),
         )),
         // STL Mesh
-        Box::new(Translate::new(
+        Box::new(Scale::new(
             Triangles::new(
                 &stl_cube,
-                Lambertian::new(ConstantTexture::new(Vec3::new(1., 1.0, 1.0))),
+                Lambertian::new(ConstantTexture::new(Vec3::new(0.6, 0.6, 0.6))),
                 1.,
             ),
-            [-10., 0., 0.],
+            0.5,
         )),
     ];
     let world: Box<dyn Hit> = if opt.use_accel {
diff --git a/rtiow/renderer/src/triangles.rs b/rtiow/renderer/src/triangles.rs
index 62c2b8f..7a5d528 100644
--- a/rtiow/renderer/src/triangles.rs
+++ b/rtiow/renderer/src/triangles.rs
@@ -39,14 +39,6 @@ where
                 let v0 = t.verts[0] * scale_factor;
                 let v1 = t.verts[1] * scale_factor;
                 let v2 = t.verts[2] * scale_factor;
-                assert_eq!(
-                    t.normal,
-                    cross(v1 - v0, v2 - v0).unit_vector(),
-                    "v1 {} v2 {} v3 {}",
-                    v0,
-                    v1,
-                    v2
-                );
                 Triangle {
                     normal: t.normal,
                     verts: [v0, v1, v2],