Add tests for `::angle_between` and `::rotation_between`.

tests/mat.rs

@@ -2,8 +2,8 @@ extern crate nalgebra as na;
 extern crate rand;
 
 use rand::random;
-use na::{Vec1, Vec3, Mat1, Mat2, Mat3, Mat4, Mat5, Mat6, Rot3, Persp3, PerspMat3, Ortho3, OrthoMat3,
-         DMat, DVec, Row, Col, BaseFloat};
+use na::{Vec1, Vec3, Mat1, Mat2, Mat3, Mat4, Mat5, Mat6, Rot2, Rot3, Persp3, PerspMat3, Ortho3,
+         OrthoMat3, DMat, DVec, Row, Col, BaseFloat};
 
 macro_rules! test_inv_mat_impl(
   ($t: ty) => (
@@ -153,6 +153,48 @@ fn test_inv_rotation3() {
     }
 }
 
+#[test]
+fn test_rot3_rotation_between() {
+    let r1: Rot3<f64> = random();
+    let r2: Rot3<f64> = random();
+
+    let delta = na::rotation_between(&r1, &r2);
+
+    assert!(na::approx_eq(&(delta * r1), &r2))
+}
+
+#[test]
+fn test_rot3_angle_between() {
+    let r1: Rot3<f64> = random();
+    let r2: Rot3<f64> = random();
+
+    let delta = na::rotation_between(&r1, &r2);
+    let delta_angle = na::angle_between(&r1, &r2);
+
+    assert!(na::approx_eq(&na::norm(&na::rotation(&delta)), &delta_angle))
+}
+
+#[test]
+fn test_rot2_rotation_between() {
+    let r1: Rot2<f64> = random();
+    let r2: Rot2<f64> = random();
+
+    let delta = na::rotation_between(&r1, &r2);
+
+    assert!(na::approx_eq(&(delta * r1), &r2))
+}
+
+#[test]
+fn test_rot2_angle_between() {
+    let r1: Rot2<f64> = random();
+    let r2: Rot2<f64> = random();
+
+    let delta = na::rotation_between(&r1, &r2);
+    let delta_angle = na::angle_between(&r1, &r2);
+
+    assert!(na::approx_eq(&na::norm(&na::rotation(&delta)), &delta_angle))
+}
+
 #[test]
 fn test_mean_dmat() {
     let mat = DMat::from_row_vec(

tests/quat.rs

@@ -69,3 +69,24 @@ fn test_quat_euler_angles() {
         assert!(na::approx_eq(&q.to_rot(), &m))
     }
 }
+
+#[test]
+fn test_quat_rotation_between() {
+    let q1: UnitQuat<f64> = random();
+    let q2: UnitQuat<f64> = random();
+
+    let delta = na::rotation_between(&q1, &q2);
+
+    assert!(na::approx_eq(&(delta * q1), &q2))
+}
+
+#[test]
+fn test_quat_angle_between() {
+    let q1: UnitQuat<f64> = random();
+    let q2: UnitQuat<f64> = random();
+
+    let delta = na::rotation_between(&q1, &q2);
+    let delta_angle = na::angle_between(&q1, &q2);
+
+    assert!(na::approx_eq(&na::norm(&na::rotation(&delta)), &delta_angle))
+}

tests/vec.rs

@@ -2,7 +2,7 @@ extern crate nalgebra as na;
 extern crate rand;
 
 use rand::random;
-use na::{Vec0, Vec1, Vec2, Vec3, Vec4, Vec5, Vec6, Mat3, Iterable, IterableMut};
+use na::{Vec0, Vec1, Vec2, Vec3, Vec4, Vec5, Vec6, Mat3, Rot2, Rot3, Iterable, IterableMut};
 
 macro_rules! test_iterator_impl(
     ($t: ty, $n: ty) => (
@@ -317,3 +317,65 @@ fn test_outer_vec3() {
             8.0, 10.0, 12.0,
             12.0, 15.0, 18.0));
 }
+
+
+#[test]
+fn test_vec3_rotation_between() {
+    for _ in (0usize .. 10000) {
+        let v1: Vec3<f64> = random();
+
+        let mut v2: Vec3<f64> = random();
+        v2 = na::normalize(&v2) * na::norm(&v1);
+
+        let rot = na::rotation_between(&v1, &v2);
+
+        assert!(na::approx_eq(&(rot * v1), &v2))
+    }
+}
+
+#[test]
+fn test_vec3_angle_between() {
+    for _ in (0usize .. 10000) {
+        let vec: Vec3<f64> = random();
+        let other: Vec3<f64> = random();
+
+        // Ensure the axis we are using is orthogonal to `vec`.
+        let axis_ang = na::cross(&vec, &other);
+        let ang      = na::norm(&axis_ang);
+        let rot      = Rot3::new(axis_ang);
+
+        let delta = na::angle_between(&vec, &(rot * vec));
+
+        assert!(na::approx_eq(&ang, &delta))
+    }
+}
+
+
+#[test]
+fn test_vec2_rotation_between() {
+    for _ in (0usize .. 10000) {
+        let v1: Vec2<f64> = random();
+
+        let mut v2: Vec2<f64> = random();
+        v2 = na::normalize(&v2) * na::norm(&v1);
+
+        let rot = na::rotation_between(&v1, &v2);
+
+        assert!(na::approx_eq(&(rot * v1), &v2))
+    }
+}
+
+#[test]
+fn test_vec2_angle_between() {
+    for _ in (0usize .. 10000) {
+        let axis_ang: Vec1<f64> = random();
+        let ang = na::norm(&axis_ang);
+
+        let rot: Rot2<f64> = Rot2::new(axis_ang);
+        let vec: Vec2<f64> = random();
+
+        let delta = na::angle_between(&vec, &(rot * vec));
+
+        assert!(na::approx_eq(&ang, &delta))
+    }
+}