From 08484306fd5360f40bc68eccc9364c874ceabf8d Mon Sep 17 00:00:00 2001
From: Matthew Gordon <matthew.scott.gordon@gmail.com>
Date: Sat, 21 Dec 2019 10:42:52 -0500
Subject: [PATCH] Move load_obj() into submudule

---
 src/mesh.rs | 152 ++++++++++++++++++++++++++++------------------------
 1 file changed, 82 insertions(+), 70 deletions(-)

diff --git a/src/mesh.rs b/src/mesh.rs
index 546c527..43bed56 100644
--- a/src/mesh.rs
+++ b/src/mesh.rs
@@ -1,19 +1,15 @@
-use nalgebra::{convert, Point3, RealField, Vector2, Vector3};
-use obj::{IndexTuple, Obj, SimplePolygon};
+use nalgebra::{Point3, RealField, Vector2, Vector3};
 
 use super::materials::Material;
 use super::raycasting::{Intersect, IntersectionInfo, Ray};
 
-use alga::general::SupersetOf;
-use std::io::Result;
-use std::path::Path;
 use std::sync::Arc;
 
 #[derive(Debug)]
 pub struct Triangle<T: RealField> {
     pub vertices: [Point3<T>; 3],
     pub normals: [Vector3<T>; 3],
-    pub material: Arc<dyn Material<T> >,
+    pub material: Arc<dyn Material<T>>,
 }
 
 impl<T: RealField> Intersect<T> for Triangle<T> {
@@ -81,75 +77,91 @@ impl<T: RealField> Intersect<T> for Triangle<T> {
     }
 }
 
-fn get_vertex_and_normal<T: RealField>(
-    index_tuple: &IndexTuple,
-    vertex_positions: &Vec<[f32; 3]>,
-    normal_positions: &Vec<[f32; 3]>,
-) -> (Point3<T>, Vector3<T>)
-where
-    T: SupersetOf<f32>,
-{
-    let &IndexTuple(vertex_index, _, maybe_normal_index) = index_tuple;
-    let vertex: Point3<T> = convert(Point3::from_slice(&vertex_positions[vertex_index]));
-    let normal = match maybe_normal_index {
-        Some(normal_index) => convert(Vector3::from_row_slice(&normal_positions[normal_index])),
-        None => Vector3::zeros(),
-    };
-    (vertex, normal)
-}
+mod wavefront_obj {
+    use crate::materials::Material;
 
-fn get_triangles<T: RealField>(
-    polygon: &SimplePolygon,
-    vertex_positions: &Vec<[f32; 3]>,
-    normal_positions: &Vec<[f32; 3]>,
-    material: Arc<dyn Material<T>>,
-) -> Vec<Triangle<T>>
-where
-    T: SupersetOf<f32>,
-{
-    if let Some(v0_index) = polygon.iter().next() {
-        let (v0_vertex, v0_normal) =
-            get_vertex_and_normal(v0_index, &vertex_positions, &normal_positions);
-        polygon
+    use super::Triangle;
+
+    use alga::general::SupersetOf;
+    use nalgebra::{convert, Point3, RealField, Vector3};
+    use obj::{IndexTuple, Obj, SimplePolygon};
+
+    use std::io::Result;
+    use std::path::Path;
+    use std::sync::Arc;
+
+    fn get_vertex_and_normal<T: RealField>(
+        index_tuple: &IndexTuple,
+        vertex_positions: &Vec<[f32; 3]>,
+        normal_positions: &Vec<[f32; 3]>,
+    ) -> (Point3<T>, Vector3<T>)
+    where
+        T: SupersetOf<f32>,
+    {
+        let &IndexTuple(vertex_index, _, maybe_normal_index) = index_tuple;
+        let vertex: Point3<T> = convert(Point3::from_slice(&vertex_positions[vertex_index]));
+        let normal = match maybe_normal_index {
+            Some(normal_index) => convert(Vector3::from_row_slice(&normal_positions[normal_index])),
+            None => Vector3::zeros(),
+        };
+        (vertex, normal)
+    }
+
+    fn get_triangles<T: RealField>(
+        polygon: &SimplePolygon,
+        vertex_positions: &Vec<[f32; 3]>,
+        normal_positions: &Vec<[f32; 3]>,
+        material: Arc<dyn Material<T>>,
+    ) -> Vec<Triangle<T>>
+    where
+        T: SupersetOf<f32>,
+    {
+        if let Some(v0_index) = polygon.iter().next() {
+            let (v0_vertex, v0_normal) =
+                get_vertex_and_normal(v0_index, &vertex_positions, &normal_positions);
+            polygon
+                .iter()
+                .skip(1)
+                .zip(polygon.iter().skip(2))
+                .map(|(v1_index, v2_index)| {
+                    let (v1_vertex, v1_normal) =
+                        get_vertex_and_normal(v1_index, &vertex_positions, &normal_positions);
+                    let (v2_vertex, v2_normal) =
+                        get_vertex_and_normal(v2_index, &vertex_positions, &normal_positions);
+                    let vertices = [v0_vertex, v1_vertex, v2_vertex];
+                    let normals = [v0_normal, v1_normal, v2_normal];
+                    Triangle {
+                        vertices,
+                        normals,
+                        material: material.clone(),
+                    }
+                })
+                .collect()
+        } else {
+            vec![]
+        }
+    }
+
+    pub fn load_obj<T: RealField>(
+        filename: &Path,
+        material: Arc<dyn Material<T>>,
+    ) -> Result<Vec<Triangle<T>>>
+    where
+        T: SupersetOf<f32>,
+    {
+        let obj = Obj::<SimplePolygon>::load(filename)?;
+
+        Ok(obj
+            .objects
             .iter()
-            .skip(1)
-            .zip(polygon.iter().skip(2))
-            .map(|(v1_index, v2_index)| {
-                let (v1_vertex, v1_normal) =
-                    get_vertex_and_normal(v1_index, &vertex_positions, &normal_positions);
-                let (v2_vertex, v2_normal) =
-                    get_vertex_and_normal(v2_index, &vertex_positions, &normal_positions);
-                let vertices = [v0_vertex, v1_vertex, v2_vertex];
-                let normals = [v0_normal, v1_normal, v2_normal];
-                Triangle {
-                    vertices,
-                    normals,
-                    material: material.clone(),
-                }
-            })
-            .collect()
-    } else {
-        vec![]
+            .flat_map(|object| object.groups.iter())
+            .flat_map(|group| group.polys.iter())
+            .flat_map(|poly| get_triangles(poly, &obj.position, &obj.normal, material.clone()))
+            .collect())
     }
 }
 
-pub fn load_obj<T: RealField>(
-    filename: &Path,
-    material: Arc<dyn Material<T>>,
-) -> Result<Vec<Triangle<T>>>
-where
-    T: SupersetOf<f32>,
-{
-    let obj = Obj::<SimplePolygon>::load(filename)?;
-
-    Ok(obj
-        .objects
-        .iter()
-        .flat_map(|object| object.groups.iter())
-        .flat_map(|group| group.polys.iter())
-        .flat_map(|poly| get_triangles(poly, &obj.position, &obj.normal, material.clone()))
-        .collect())
-}
+pub use wavefront_obj::load_obj;
 
 fn indices_with_index_of_largest_element_last<T: RealField>(v: &Vector3<T>) -> [usize; 3] {
     if v.x > v.y {