Rename Point::Vector to Point::Diff

src/point.rs

@@ -79,7 +79,7 @@ impl<S: BaseNum> Point3<S> {
 }
 
 /// Points in a [Euclidean space](https://en.wikipedia.org/wiki/Euclidean_space)
-/// with an associated vector space, `Self::Vector`.
+/// with an associated space of displacement vectors.
 ///
 /// # Point-Vector distinction
 ///
@@ -129,21 +129,21 @@ pub trait Point: Copy + Clone where
     // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     Self: Array<Element = <Self as Point>::Scalar>,
 
-    Self: Add<<Self as Point>::Vector, Output = Self>,
-    Self: Sub<Self, Output = <Self as Point>::Vector>,
+    Self: Add<<Self as Point>::Diff, Output = Self>,
+    Self: Sub<Self, Output = <Self as Point>::Diff>,
 
     Self: Mul<<Self as Point>::Scalar, Output = Self>,
     Self: Div<<Self as Point>::Scalar, Output = Self>,
     Self: Rem<<Self as Point>::Scalar, Output = Self>,
 {
-    /// The associated scalar.
+    /// The associated scalar over which the space is defined.
     ///
-    /// Due to the equality constraints demanded by `Self::Vector`, this is effectively just an
-    /// alias to `Self::Vector::Scalar`.
+    /// Due to the equality constraints demanded by `Self::Diff`, this is effectively just an
+    /// alias to `Self::Diff::Scalar`.
     type Scalar: BaseNum;
 
     /// The associated space of displacement vectors.
-    type Vector: VectorSpace<Scalar = Self::Scalar>;
+    type Diff: VectorSpace<Scalar = Self::Scalar>;
 
     /// The point at the origin of the Euclidean space.
     fn origin() -> Self;
@@ -152,16 +152,16 @@ pub trait Point: Copy + Clone where
     ///
     /// This can be considered equivalent to the addition of the displacement
     /// vector `v` to to `Self::origin()`.
-    fn from_vec(v: Self::Vector) -> Self;
+    fn from_vec(v: Self::Diff) -> Self;
 
     /// Convert a point to a displacement vector.
     ///
     /// This can be seen as equivalent to the displacement vector from
     /// `Self::origin()` to `self`.
-    fn to_vec(self) -> Self::Vector;
+    fn to_vec(self) -> Self::Diff;
 
     /// This is a weird one, but its useful for plane calculations.
-    fn dot(self, v: Self::Vector) -> Self::Scalar;
+    fn dot(self, v: Self::Diff) -> Self::Scalar;
 }
 
 macro_rules! impl_point {
@@ -197,7 +197,7 @@ macro_rules! impl_point {
 
         impl<S: BaseNum> Point for $PointN<S> {
             type Scalar = S;
-            type Vector = $VectorN<S>;
+            type Diff = $VectorN<S>;
 
             #[inline]
             fn origin() -> $PointN<S> {

src/rotation.rs

@@ -35,14 +35,14 @@ pub trait Rotation<P: Point>: PartialEq + Sized where
     fn one() -> Self;
 
     /// Create a rotation to a given direction with an 'up' vector
-    fn look_at(dir: P::Vector, up: P::Vector) -> Self;
+    fn look_at(dir: P::Diff, up: P::Diff) -> Self;
 
     /// Create a shortest rotation to transform vector 'a' into 'b'.
     /// Both given vectors are assumed to have unit length.
-    fn between_vectors(a: P::Vector, b: P::Vector) -> Self;
+    fn between_vectors(a: P::Diff, b: P::Diff) -> Self;
 
     /// Rotate a vector using this rotation.
-    fn rotate_vector(&self, vec: P::Vector) -> P::Vector;
+    fn rotate_vector(&self, vec: P::Diff) -> P::Diff;
 
     /// Rotate a point using this rotation, by converting it to its
     /// representation as a vector.

src/transform.rs

@@ -34,17 +34,17 @@ pub trait Transform<P: Point>: Sized {
 
     /// Create a transformation that rotates a vector to look at `center` from
     /// `eye`, using `up` for orientation.
-    fn look_at(eye: P, center: P, up: P::Vector) -> Self;
+    fn look_at(eye: P, center: P, up: P::Diff) -> Self;
 
     /// Transform a vector using this transform.
-    fn transform_vector(&self, vec: P::Vector) -> P::Vector;
+    fn transform_vector(&self, vec: P::Diff) -> P::Diff;
 
     /// Transform a point using this transform.
     fn transform_point(&self, point: P) -> P;
 
     /// Transform a vector as a point using this transform.
     #[inline]
-    fn transform_as_point(&self, vec: P::Vector) -> P::Vector {
+    fn transform_as_point(&self, vec: P::Diff) -> P::Diff {
         self.transform_point(P::from_vec(vec)).to_vec()
     }
 
@@ -78,23 +78,23 @@ pub struct Decomposed<V: VectorSpace, R> {
     pub disp: V,
 }
 
-impl<P: Point, R: Rotation<P>> Transform<P> for Decomposed<P::Vector, R> where
+impl<P: Point, R: Rotation<P>> Transform<P> for Decomposed<P::Diff, R> where
     // FIXME: Ugly type signatures - blocked by rust-lang/rust#24092
     <P as Point>::Scalar: BaseFloat,
     // FIXME: Investigate why this is needed!
-    <P as Point>::Vector: VectorSpace,
+    <P as Point>::Diff: VectorSpace,
 {
     #[inline]
-    fn one() -> Decomposed<P::Vector, R> {
+    fn one() -> Decomposed<P::Diff, R> {
         Decomposed {
             scale: <P as Point>::Scalar::one(),
             rot: R::one(),
-            disp: P::Vector::zero(),
+            disp: P::Diff::zero(),
         }
     }
 
     #[inline]
-    fn look_at(eye: P, center: P, up: P::Vector) -> Decomposed<P::Vector, R> {
+    fn look_at(eye: P, center: P, up: P::Diff) -> Decomposed<P::Diff, R> {
         let rot = R::look_at(center - eye, up);
         let disp = rot.rotate_vector(P::origin() - eye);
         Decomposed {
@@ -105,7 +105,7 @@ impl<P: Point, R: Rotation<P>> Transform<P> for Decomposed<P::Vector, R> where
     }
 
     #[inline]
-    fn transform_vector(&self, vec: P::Vector) -> P::Vector {
+    fn transform_vector(&self, vec: P::Diff) -> P::Diff {
         self.rot.rotate_vector(vec * self.scale)
     }
 
@@ -114,7 +114,7 @@ impl<P: Point, R: Rotation<P>> Transform<P> for Decomposed<P::Vector, R> where
         self.rot.rotate_point(point * self.scale) + self.disp
     }
 
-    fn concat(&self, other: &Decomposed<P::Vector, R>) -> Decomposed<P::Vector, R> {
+    fn concat(&self, other: &Decomposed<P::Diff, R>) -> Decomposed<P::Diff, R> {
         Decomposed {
             scale: self.scale * other.scale,
             rot: self.rot.concat(&other.rot),
@@ -122,7 +122,7 @@ impl<P: Point, R: Rotation<P>> Transform<P> for Decomposed<P::Vector, R> where
         }
     }
 
-    fn invert(&self) -> Option<Decomposed<P::Vector, R>> {
+    fn invert(&self) -> Option<Decomposed<P::Diff, R>> {
         if self.scale.approx_eq(&<P as Point>::Scalar::zero()) {
             None
         } else {