breaking up into lib file, and made tests less error prone

annoying.sh

@@ -0,0 +1,9 @@
+cargo clippy -- \
+    -Wclippy::all \
+    -Wclippy::restriction \
+    -Wclippy::correctness \
+    -Wclippy::pedantic \
+    -Wclippy::nursery \
+    -Wclippy::cargo \
+    -Wclippy::suspicious \
+    -Wclippy::perf

src/lib.rs

@@ -0,0 +1,211 @@
+use std::f32::consts::PI;
+
+#[derive(Clone, Copy, Debug)]
+struct Point {
+    x: f32,
+    y: f32,
+    z: f32,
+}
+
+impl Point {
+    const fn new(x: f32, y: f32, z: f32) -> Self {
+        Self { x, y, z }
+    }
+    pub fn to_obj_string(self) -> String {
+        format!("v {0} {1} {2}", self.x, self.y, self.z)
+    }
+}
+
+#[derive(Clone)]
+struct Face {
+    points: Vec<Point>,
+    indexes: Vec<u32>,
+}
+
+impl Face {
+    pub fn new(points: Vec<Point>, indexes: Vec<u32>) -> Self {
+        Self { points, indexes }
+    }
+    pub fn to_obj_string(self) -> String {
+        let mut result = String::from("f ");
+
+        result.push_str(
+            &self
+                .indexes
+                .clone()
+                .into_iter()
+                .map(|i: u32| -> String {
+                    format!("-{0}", (self.points.len() as u64 - u64::from(i)))
+                })
+                .collect::<Vec<String>>()
+                .join(" "),
+        );
+        result
+    }
+}
+
+fn vertex_string(points: Vec<Point>) -> String {
+    points
+        .into_iter()
+        .map(Point::to_obj_string)
+        .collect::<Vec<String>>()
+        .join("\n")
+}
+
+
+fn render_obj(points: Vec<Point>, faces: Vec<Face>) -> String {
+    format!(
+        r#"{0}
+{1}
+"#,
+        vertex_string(points.to_vec()),
+        faces
+            .into_iter()
+            .map(Face::to_obj_string)
+            .collect::<Vec<String>>()
+            .join("\n")
+    )
+}
+
+fn sphere(origin: Point, radius: f32, _detail: u32) -> Result<String, String> {
+    // top and bottom point
+    // create vertical "strips" down the sphere,
+    // rotating around the Z axis
+    // Create faces procedurally
+
+    let points = [
+        //top
+        Point::new(origin.x, origin.y + (radius * (2.0 * PI).sin()), origin.z),
+        //bottom
+        Point::new(origin.x, origin.y + (radius * (-2.0 * PI).sin()), origin.z),
+        //north
+        Point::new(origin.x, origin.y, origin.z + (radius * (2.0 * PI).sin())),
+        //south
+        Point::new(origin.x, origin.y, origin.z + (radius * (-2.0 * PI).sin())),
+        //east
+        Point::new(origin.x + (radius * (0.0_f32).cos()), origin.y, origin.z),
+        //west
+        Point::new(origin.x + (radius * (PI).cos()), origin.y, origin.z),
+    ]
+    .to_vec();
+
+    let faces = [
+        // top, north, east
+        Face::new(points.clone(), vec![0, 2, 4]),
+        // top, north, west
+        Face::new(points.clone(), vec![0, 2, 5]),
+        // top, south, east
+        Face::new(points.clone(), vec![0, 3, 4]),
+        // top, south, west
+        Face::new(points.clone(), vec![0, 3, 5]),
+        // bottom, north, east
+        Face::new(points.clone(), vec![1, 2, 4]),
+        // bottom, north, west
+        Face::new(points.clone(), vec![1, 2, 5]),
+        // bottom, south, east
+        Face::new(points.clone(), vec![1, 3, 4]),
+        // bottom, south, west
+        Face::new(points.clone(), vec![1, 3, 5]),
+    ];
+
+    Ok(render_obj(points, faces.to_vec()))
+}
+
+fn cone(origin: Point, _detail: i32, _radius: f32) -> String {
+    let points = [
+        Point::new(origin.x, origin.y + (PI / 3.0).sin(), origin.z),
+        Point::new(origin.x, origin.y, origin.z + 0.0_f32.cos()),
+        Point::new(
+            origin.x + (4.0 * PI / 3.0).sin(),
+            origin.y,
+            (2.0 * -PI / 3.0).cos(),
+        ),
+        Point::new(
+            origin.x + (2.0 * PI / 3.0).sin(),
+            origin.y,
+            (2.0 * -PI / 3.0).cos(),
+        ),
+    ];
+
+    let faces = [
+        Face::new(points.to_vec(), vec![1, 2, 3]),
+        Face::new(points.to_vec(), vec![0, 2, 3]),
+        Face::new(points.to_vec(), vec![0, 1, 3]),
+        Face::new(points.to_vec(), vec![0, 2, 1]),
+    ];
+
+    render_obj(points.to_vec(), faces.to_vec())
+}
+
+fn cuboid(origin: Point, sx: f32, sy: f32, sz: f32) -> Result<String, String> {
+    println!("GENERATING CUBOID");
+    if sx <= 0.0 || sy <= 0.0 || sz <= 0.0 {
+        return Err(
+            String::from("could not generate cuboid, side length less than or equal to zero"),
+        );
+    }
+    let points = [
+        Point::new(origin.x, origin.y + sy, origin.z + sz),
+        Point::new(origin.x, origin.y, origin.z + sz),
+        Point::new(origin.x + sx, origin.y, origin.z + sz),
+        Point::new(origin.x + sx, origin.y + sy, origin.z + sz),
+        Point::new(origin.x, origin.y + sy, origin.z),
+        Point::new(origin.x, origin.y, origin.z),
+        Point::new(origin.x + sx, origin.y, origin.z),
+        Point::new(origin.x + sx, origin.y + sy, origin.z),
+    ];
+
+    let faces = [
+        Face::new(points.to_vec(), vec![0, 1, 2, 3]),
+        Face::new(points.to_vec(), vec![7, 6, 5, 4]),
+        Face::new(points.to_vec(), vec![4, 5, 1, 0]),
+        Face::new(points.to_vec(), vec![3, 7, 4, 0]),
+        Face::new(points.to_vec(), vec![3, 2, 6, 7]),
+        Face::new(points.to_vec(), vec![6, 2, 1, 5]),
+    ];
+
+    Ok(render_obj(points.to_vec(), faces.to_vec()))
+}
+
+fn cube(origin: Point, size: f32) -> Result<String, String> {
+    println!("GENERATING CUBE");
+    if size <= 0.0 {
+        return Err("ERROR: cannot generate cube of size less than zero".to_string());
+    }
+    cuboid(origin, size, size, size)
+}
+
+pub fn compile(data: &str) -> String {
+    let mut result = String::new();
+
+    let lines = data.split('\n');
+    for line in lines {
+        let tokens: Vec<&str> = line.split(' ').collect();
+        match *tokens.first().unwrap() {
+            "cube" => result.push_str(
+                &cube(
+                    Point::new(0.0, 0.0, 0.0),
+                    tokens[1].parse::<f32>().expect("invalid value given"),
+                )
+                .unwrap(),
+            ),
+            "cuboid" => result.push_str(
+                &cuboid(
+                    Point::new(0.0, 0.0, 0.0),
+                    tokens[1].parse::<f32>().expect("non numeric value given"),
+                    tokens[2].parse::<f32>().expect("non numeric value given"),
+                    tokens[3].parse::<f32>().expect("non numeric value given"),
+                )
+                .unwrap(),
+            ),
+            "cone" => result.push_str(&cone(
+                Point::new(0.0, 0.0, 0.0),
+                0,
+                tokens[1].parse::<f32>().expect("non numeric value given"),
+            )),
+            "sphere" => result.push_str(&sphere(Point::new(0.0, 0.0, 0.0), 10.0, 10).unwrap()),
+            &_ => println!("{} not supported", tokens[0]),
+        }
+    }
+    result
+}