Add Degrees and Radians as newtypes

[kaka/rust-sdl-test.git] / src / common.rs

diff --git a/src/common.rs b/src/common.rs
index 52b7324..2be427e 100644 (file)
--- a/src/common.rs
+++ b/src/common.rs
@@ -1,4 +1,4 @@
-use std::ops::{Add, AddAssign, Mul};
+use std::ops::{Add, AddAssign, Sub, SubAssign, Mul, MulAssign, Div, DivAssign, Neg};
 
 pub type Nanoseconds = u64;
 
@@ -21,21 +21,89 @@ impl Point2D<f64> {
     }
 }
 
-impl<T: Add<Output = T>> Add for Point2D<T> {
-    type Output = Point2D<T>;
+macro_rules! point_op {
+    ($op:tt, $trait:ident($fn:ident), $trait_assign:ident($fn_assign:ident), $rhs:ident = $Rhs:ty => $x:expr, $y:expr) => {
+        impl<T: $trait<Output = T>> $trait<$Rhs> for Point2D<T> {
+            type Output = Self;
 
-    fn add(self, rhs: Point2D<T>) -> Self::Output {
-        Point2D {
-            x: self.x + rhs.x,
-            y: self.y + rhs.y,
+            fn $fn(self, $rhs: $Rhs) -> Self {
+                Self {
+                    x: self.x $op $x,
+                    y: self.y $op $y,
+                }
+            }
+        }
+
+        impl<T: $trait<Output = T> + Copy> $trait_assign<$Rhs> for Point2D<T> {
+            fn $fn_assign(&mut self, $rhs: $Rhs) {
+                *self = Self {
+                    x: self.x $op $x,
+                    y: self.y $op $y,
+                }
+            }
         }
     }
 }
 
-impl<T: AddAssign> AddAssign for Point2D<T> {
-    fn add_assign(&mut self, rhs: Point2D<T>) {
-        self.x += rhs.x;
-        self.y += rhs.y;
+point_op!(+, Add(add), AddAssign(add_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(/, Div(div), DivAssign(div_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(+, Add(add), AddAssign(add_assign), rhs = (T, T) => rhs.0, rhs.1);
+point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = (T, T) => rhs.0, rhs.1);
+point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = (T, T) => rhs.0, rhs.1);
+point_op!(/, Div(div), DivAssign(div_assign), rhs = (T, T) => rhs.0, rhs.1);
+
+////////// multiply point with scalar //////////////////////////////////////////
+impl<T: Mul<Output = T> + Copy> Mul<T> for Point2D<T> {
+    type Output = Self;
+
+    fn mul(self, rhs: T) -> Self {
+       Self {
+           x: self.x * rhs,
+           y: self.y * rhs,
+       }
+    }
+}
+
+impl<T: Mul<Output = T> + Copy> MulAssign<T> for Point2D<T> {
+    fn mul_assign(&mut self, rhs: T) {
+       *self = Self {
+           x: self.x * rhs,
+           y: self.y * rhs,
+       }
+    }
+}
+
+////////// divide point with scalar ////////////////////////////////////////////
+impl<T: Div<Output = T> + Copy> Div<T> for Point2D<T> {
+    type Output = Self;
+
+    fn div(self, rhs: T) -> Self {
+       Self {
+           x: self.x / rhs,
+           y: self.y / rhs,
+       }
+    }
+}
+
+impl<T: Div<Output = T> + Copy> DivAssign<T> for Point2D<T> {
+    fn div_assign(&mut self, rhs: T) {
+       *self = Self {
+           x: self.x / rhs,
+           y: self.y / rhs,
+       }
+    }
+}
+
+impl<T: Neg<Output = T>> Neg for Point2D<T> {
+    type Output = Self;
+
+    fn neg(self) -> Self {
+       Self {
+           x: -self.x,
+           y: -self.y,
+       }
     }
 }
 
@@ -48,6 +116,41 @@ impl<T> From<(T, T)> for Point2D<T> {
     }
 }
 
+impl From<Degrees> for Point2D<f64> {
+    fn from(item: Degrees) -> Self {
+        Point2D {
+            x: (item.0 * std::f64::consts::PI / 180.0).cos(),
+            y: (item.0 * std::f64::consts::PI / 180.0).sin(),
+        }
+    }
+}
+
+impl From<Radians> for Point2D<f64> {
+    fn from(item: Radians) -> Self {
+        Point2D {
+            x: item.0.cos(),
+            y: item.0.sin(),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Clone, Copy)]
+struct Degrees(f64);
+#[derive(Debug, PartialEq, Clone, Copy)]
+struct Radians(f64);
+
+impl Degrees {
+    fn to_radians(&self) -> Radians {
+       Radians(self.0 * std::f64::consts::PI / 180.0)
+    }
+}
+
+impl Radians {
+    fn to_degrees(&self) -> Degrees {
+       Degrees(self.0 * 180.0 * std::f64::consts::FRAC_1_PI)
+    }
+}
+
 #[macro_export]
 macro_rules! rect {
     ( $x:expr, $y:expr ) => {
@@ -96,6 +199,54 @@ mod tests {
         assert_eq!(a + point!(2, 2), point!(3, 2)); // Add
         a += point!(2, 2); // AddAssign
         assert_eq!(a, point!(3, 2));
+        assert_eq!(point!(1, 0) + (2, 3), point!(3, 3));
+    }
+
+    #[test]
+    fn sub_points() {
+        let mut a = point!(1, 0);
+        assert_eq!(a - point!(2, 2), point!(-1, -2));
+        a -= point!(2, 2);
+        assert_eq!(a, point!(-1, -2));
+        assert_eq!(point!(1, 0) - (2, 3), point!(-1, -3));
+    }
+
+    #[test]
+    fn mul_points() {
+        let mut a = point!(1, 2);
+        assert_eq!(a * 2, point!(2, 4));
+        assert_eq!(a * point!(2, 3), point!(2, 6));
+        a *= 2;
+        assert_eq!(a, point!(2, 4));
+        a *= point!(3, 1);
+        assert_eq!(a, point!(6, 4));
+        assert_eq!(point!(1, 0) * (2, 3), point!(2, 0));
+    }
+
+    #[test]
+    fn div_points() {
+        let mut a = point!(4, 8);
+        assert_eq!(a / 2, point!(2, 4));
+        assert_eq!(a / point!(2, 4), point!(2, 2));
+        a /= 2;
+        assert_eq!(a, point!(2, 4));
+        a /= point!(2, 4);
+        assert_eq!(a, point!(1, 1));
+        assert_eq!(point!(6, 3) / (2, 3), point!(3, 1));
+    }
+
+    #[test]
+    fn neg_point() {
+        assert_eq!(point!(1, 1), -point!(-1, -1));
+    }
+
+    #[test]
+    fn angles() {
+       assert_eq!(Radians(0.0).to_degrees(), Degrees(0.0));
+       assert_eq!(Radians(std::f64::consts::PI).to_degrees(), Degrees(180.0));
+       assert_eq!(Degrees(180.0).to_radians(), Radians(std::f64::consts::PI));
+       assert!((Point2D::from(Degrees(90.0)) - point!(0.0, 1.0)).length() < 0.001);
+       assert!((Point2D::from(Radians(std::f64::consts::FRAC_PI_2)) - point!(0.0, 1.0)).length() < 0.001);
     }
 
     #[test]