Some Macros

You can't trick the borrow checker, by putting references into another struct

src/geometry.rs

@@ -0,0 +1,72 @@
+use crate::math::{Point3, Vector3};
+
+pub struct Plane<T> {
+    point: Point3<T>,
+    normal: Vector3<T>,
+}
+
+impl<T> Plane<T> {
+    pub fn new(point: Point3<T>, normal: Vector3<T>) -> Plane<T> {
+        Plane { point, normal }
+    }
+}
+
+pub struct Line<T> {
+    point: Point3<T>,
+    direction: Vector3<T>,
+}
+
+pub struct Sphere<T> {
+    point: Point3<T>,
+    radius: T,
+}
+
+impl<T> Sphere<T> {
+    pub fn new(point: Point3<T>, radius: T) -> Sphere<T> {
+        Sphere { point, radius }
+    }
+}
+
+pub enum Geometry<T> {
+    Sphere(Sphere<T>),
+    Plane(Plane<T>),
+    Line(Line<T>),
+}
+
+impl<T> Geometry<T> {
+    pub fn draw(&self) {
+        match self {
+            Geometry::Sphere(_) => {
+                println!("Drawing Sphere!");
+            }
+            Geometry::Line(_) => {
+                println!("Drawing Line!");
+            }
+            Geometry::Plane(_) => {
+                println!("Drawing Plane!");
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn new_plane() {
+        let p = Point3::new(1.0, 2.0, 3.0);
+        let n = Vector3::new(4.0, 5.0, 6.0);
+
+        let plane = Plane::new(p, n);
+
+        assert_eq!(plane.point, p);
+        assert_eq!(plane.normal, n);
+    }
+
+    #[test]
+    #[should_panic]
+    fn foo() {
+        panic!("This code panics!");
+    }
+}

src/lib.rs

@@ -0,0 +1,2 @@
+pub mod geometry;
+pub mod math;

src/main.rs

@@ -1,5 +1,130 @@
-fn main() {
-    for value in (-10..10).rev() {
-        println!("Value: {}", value);
+use hello::geometry::{Geometry, Line, Plane, Sphere};
+use hello::math::{Mat4x4, Point3, Vector3};
+
+use std::rc::Rc;
+
+#[derive(Clone)]
+struct RGB<T> {
+    red: T,
+    green: T,
+    blue: T,
+}
+
+#[derive(Clone)]
+struct Texture<T> {
+    width: usize,
+    height: usize,
+    pixel: Vec<RGB<T>>,
+}
+
+impl Texture<f64> {
+    fn load_texture() -> Texture<f64> {
+        let width = 640;
+        let height = 480;
+
+        let mut pixel = Vec::new();
+
+        for _ in 0..width {
+            for _ in 0..height {
+                pixel.push(RGB {
+                    red: 1.0,
+                    green: 1.0,
+                    blue: 1.0,
+                });
+            }
+        }
+
+        Texture {
+            width,
+            height,
+            pixel,
+        }
     }
 }
+
+struct RenderableGeometry<T> {
+    transform: Mat4x4,
+    geometry: Geometry<T>,
+    texture: Rc<Texture<f64>>,
+}
+
+impl<T> RenderableGeometry<T> {
+    fn new(
+        transform: Mat4x4,
+        geometry: Geometry<T>,
+        texture: Rc<Texture<f64>>,
+    ) -> RenderableGeometry<T> {
+        RenderableGeometry {
+            transform,
+            geometry,
+            texture,
+        }
+    }
+}
+
+trait Renderable {
+    fn render(&self);
+}
+
+impl<T> Renderable for Sphere<T> {
+    fn render(&self) {
+        println!("Rendering Sphere!");
+    }
+}
+
+impl<T> Renderable for Plane<T> {
+    fn render(&self) {
+        println!("Rendering Plane!");
+    }
+}
+
+impl<T> Renderable for Line<T> {
+    fn render(&self) {
+        println!("Rendering Line!");
+    }
+}
+
+fn main() {
+    let tex = Rc::new(Texture::load_texture());
+
+    let sphere = Geometry::Sphere(Sphere::new(Point3::new(0.0, 0.0, 0.0), 1.0));
+    let geometries = vec![sphere];
+
+    for g in geometries {
+        g.draw();
+    }
+
+    let mut renderables: Vec<Box<dyn Renderable>> = Vec::new();
+    renderables.push(Box::new(Sphere::new(Point3::new(0.0, 0.0, 0.0), 1.0)));
+    renderables.push(Box::new(Plane::new(
+        Point3::new(0.0, 0.0, 0.0),
+        Vector3::new(0.0, 1.0, 0.0),
+    )));
+
+    for r in renderables {
+        r.render();
+    }
+
+    let geo1 = RenderableGeometry::new(
+        Mat4x4::ident(),
+        Geometry::Sphere(Sphere::new(Point3::new(0.0, 0.0, 0.0), 1.0)),
+        tex.clone(),
+    );
+
+    let geo2 = RenderableGeometry::new(
+        Mat4x4::ident(),
+        Geometry::Sphere(Sphere::new(Point3::new(-2.0, 0.0, 0.0), 1.0)),
+        tex.clone(),
+    );
+
+    let geo3 = RenderableGeometry::new(
+        Mat4x4::ident(),
+        Geometry::Sphere(Sphere::new(Point3::new(2.0, 0.0, 0.0), 1.0)),
+        tex.clone(),
+    );
+
+    println!("Reference counter = {}", Rc::strong_count(&tex));
+
+    let a = Vector3::new(2.0, 3.0, 1.0);
+    let b = 10.0 * a;
+}

src/math.rs

@@ -0,0 +1,168 @@
+use std::ops::{Add, Div, Mul, Sub};
+
+macro_rules! create_vector {
+    ($name:ident [$($elem:ident),+] ) => {
+        #[derive(Copy, Clone, PartialEq, Debug)]
+        pub struct $name<T> {
+            $($elem: T,)*
+        }
+
+        impl<T> $name<T> {
+            pub fn new($($elem : T,)*) -> $name<T> {
+                $name { $($elem,)* }
+            }
+        }
+    };
+}
+
+create_vector! { Vector4 [x, y, z, w] }
+create_vector! { Vector3 [x, y, z] }
+create_vector! { Vector2 [x, y] }
+
+impl<T> Add for Vector3<T>
+where
+    T: Add<Output = T>,
+{
+    type Output = Vector3<T>;
+
+    fn add(self, rhs: Vector3<T>) -> Self::Output {
+        Vector3::new(self.x + rhs.x, self.y + rhs.y, self.z + rhs.z)
+    }
+}
+
+impl<T> Sub for Vector3<T>
+where
+    T: Sub<Output = T>,
+{
+    type Output = Vector3<T>;
+
+    fn sub(self, rhs: Vector3<T>) -> Self::Output {
+        Vector3::new(self.x - rhs.x, self.y - rhs.y, self.z - rhs.z)
+    }
+}
+
+impl<T> Mul<T> for Vector3<T>
+where
+    T: Mul<Output = T> + Clone + Copy,
+{
+    type Output = Vector3<T>;
+
+    fn mul(self, rhs: T) -> Self::Output {
+        Vector3::new(self.x * rhs, self.y * rhs, self.z * rhs)
+    }
+}
+
+macro_rules! impl_mul_for_vector3 {
+    ($($type:ty)+) => {
+        $(
+        impl Mul<Vector3<$type>> for $type {
+            type Output = Vector3<$type>;
+
+            fn mul(self, rhs: Vector3<$type>) -> Self::Output {
+                Vector3::new(self * rhs.x, self * rhs.y, self * rhs.z)
+            }
+        })*
+    };
+}
+
+impl_mul_for_vector3! { i32 f32 f64 }
+
+impl<T> Mul for Vector3<T>
+where
+    T: Mul<Output = T> + Add<Output = T>,
+{
+    type Output = T;
+
+    fn mul(self, rhs: Vector3<T>) -> Self::Output {
+        self.x * rhs.x + self.y * rhs.y + self.z * rhs.z
+    }
+}
+
+impl<T> Div<T> for Vector3<T>
+where
+    T: Div<Output = T> + Copy + Clone,
+{
+    type Output = Vector3<T>;
+
+    fn div(self, rhs: T) -> Self::Output {
+        Vector3::new(self.x / rhs, self.y / rhs, self.z / rhs)
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub struct Point3<T> {
+    x: T,
+    y: T,
+    z: T,
+}
+
+impl<T> Point3<T> {
+    pub fn new(x: T, y: T, z: T) -> Point3<T> {
+        Point3 { x, y, z }
+    }
+}
+
+impl<T> Add<Vector3<T>> for Point3<T>
+where
+    T: Add<Output = T>,
+{
+    type Output = Point3<T>;
+
+    fn add(self, rhs: Vector3<T>) -> Self::Output {
+        Point3::new(self.x + rhs.x, self.y + rhs.y, self.z + rhs.z)
+    }
+}
+
+impl<T> Sub for Point3<T>
+where
+    T: Sub<Output = T>,
+{
+    type Output = Vector3<T>;
+
+    fn sub(self, rhs: Point3<T>) -> Self::Output {
+        Vector3::new(self.x - rhs.x, self.y - rhs.y, self.z - rhs.z)
+    }
+}
+
+pub struct Mat4x4 {
+    v: f64,
+}
+
+impl Mat4x4 {
+    pub fn ident() -> Mat4x4 {
+        Mat4x4 { v: 0.0 }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn new_vector3() {
+        let v = Vector3::new(1.0, 2.0, 3.0);
+        assert_eq!(v.x, 1.0);
+        assert_eq!(v.y, 2.0);
+        assert_eq!(v.z, 3.0);
+    }
+
+    #[test]
+    fn add_vector3_to_vector3() {
+        let v1 = Vector3::new(1.0, 2.0, 3.0);
+        let v2 = Vector3::new(4.0, 5.0, 6.0);
+
+        let r = v1 + v2;
+
+        assert_eq!(r.x, 5.0);
+        assert_eq!(r.y, 7.0);
+        assert_eq!(r.z, 9.0);
+    }
+
+    #[test]
+    fn new_point3() {
+        let p = Point3::new(1.0, 2.0, 3.0);
+        assert_eq!(p.x, 1.0);
+        assert_eq!(p.y, 2.0);
+        assert_eq!(p.z, 3.0);
+    }
+}

tests/long_running_tests.rs

@@ -0,0 +1,2 @@
+#[test]
+fn very_long_running_test() {}