Structures representing game state

1 files changed, 84 insertions, 0 deletions

diff --git a/src/geometry/point.rs b/src/geometry/point.rs
new file mode 100644
index 0000000..c34d00f
--- /dev/null
+++ b/src/geometry/point.rs
@@ -0,0 +1,84 @@
+use crate::geometry::vec::*;
+
+use std::ops::*;
+use num_traits::{NumOps, NumAssignOps};
+use num_traits::pow::Pow;
+use num_traits::real::Real;
+
+macro_rules! impl_point {
+    ($PointN:ident { $($field:ident),+ }, $VecN:ident) => {
+        #[derive(Debug, Default, Clone, Copy, Hash, PartialEq, Eq)]
+        pub struct $PointN<T> {
+            $(pub $field: T),+
+        }
+
+        impl<T> $PointN<T> {
+            pub fn new($($field: T),+) -> $PointN<T> {
+                $PointN { $($field),+ }
+            }
+        }
+
+        impl<T: NumOps + Pow<u8, Output=T> + Copy> $PointN<T> {
+            pub fn distance_squared(self, other: $PointN<T>) -> T {
+                (self - other).magnitude_squared()
+            }
+        }
+
+
+        impl<T: Real + Pow<u8, Output=T>> $PointN<T> {
+            pub fn distance(self, other: $PointN<T>) -> T {
+                (self - other).magnitude()
+            }
+        }
+
+        impl<T: NumOps> Add<$VecN<T>> for $PointN<T> {
+            type Output = Self;
+
+            fn add(self, other: $VecN<T>) -> Self {
+                $PointN {
+                    $($field: self.$field + other.$field),+
+                }
+            }
+        }
+
+        impl<T: NumAssignOps> AddAssign<$VecN<T>> for $PointN<T> {
+            fn add_assign(&mut self, other: $VecN<T>) {
+                $(self.$field += other.$field);+
+            }
+        }
+
+        impl<T: NumOps> Sub for $PointN<T> {
+            type Output = $VecN<T>;
+
+            fn sub(self, other: Self) -> $VecN<T> {
+                $VecN {
+                    $($field: self.$field - other.$field),+
+                }
+            }
+        }
+    }
+}
+
+impl_point!(Point2d { x, y }, Vec2d);
+impl_point!(Point3d { x, y, z }, Vec3d);
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn distance_in_x_dimension_example() {
+        let a = Point2d::new(1., 1.);
+        let b = Point2d::new(3., 1.);
+        assert_eq!(a.distance(b), 2.);
+        assert_eq!(a.distance_squared(b), 4.);
+    }
+
+    #[test]
+    fn distance_in_y_dimension_example() {
+        let a = Point2d::new(1., 1.);
+        let b = Point2d::new(1., 3.);
+        assert_eq!(b.distance(a), 2.);
+        assert_eq!(b.distance_squared(a), 4.);
+    }
+}