Impl Neg for Point now that it has Mul too

Author: jdahlstrom

core/src/math/point.rs

@@ -2,7 +2,7 @@ use core::{
     array,
     fmt::{Debug, Formatter},
     marker::PhantomData as Pd,
-    ops::{Add, Div, Index, IndexMut, Mul, Sub},
+    ops::{Add, Div, Index, IndexMut, Mul, Neg, Sub},
     ops::{AddAssign, DivAssign, MulAssign, SubAssign},
 };
 
@@ -407,6 +407,17 @@ where
     }
 }
 
+impl<R, Sp> Neg for Point<R, Sp>
+where
+    Self: Mul<f32, Output = Self>,
+{
+    type Output = Self;
+
+    fn neg(self) -> Self {
+        self * -1.0
+    }
+}
+
 impl<R: Copy, Sp, Sc> Mul<Sc> for Point<R, Sp>
 where
     Self: Affine<Diff = Vector<R, Sp>>,