From b0127ab5dcf506493bbece3771f37354dd89e898 Mon Sep 17 00:00:00 2001
From: Dzmitry Malyshau <kvark@mozilla.com>
Date: Tue, 25 Jul 2017 11:49:27 -0400
Subject: [PATCH] Mint quaternions

---
 src/geometry/quaternion_conversion.rs | 45 +++++++++++++++++++++++++++
 tests/core/conversion.rs              | 17 ++++++++++
 2 files changed, 62 insertions(+)

diff --git a/src/geometry/quaternion_conversion.rs b/src/geometry/quaternion_conversion.rs
index 7ac90eed..9c264180 100644
--- a/src/geometry/quaternion_conversion.rs
+++ b/src/geometry/quaternion_conversion.rs
@@ -5,6 +5,8 @@ use alga::linear::Rotation as AlgaRotation;
 
 use core::{Vector4, Matrix4};
 use core::dimension::U3;
+#[cfg(feature = "mint")]
+use core::storage::Storage;
 use geometry::{Quaternion, UnitQuaternion, Rotation, Isometry, Similarity,
                Transform, SuperTCategoryOf, TAffine, Translation,
                Rotation3, Point3};
@@ -21,6 +23,9 @@ use geometry::{Quaternion, UnitQuaternion, Rotation, Isometry, Similarity,
  * UnitQuaternion -> Transform<U3>
  * UnitQuaternion -> Matrix<U4> (homogeneous)
  *
+ * mint::Quaternion <-> Quaternion
+ * UnitQuaternion -> mint::Quaternion
+ *
  * NOTE:
  * UnitQuaternion -> Quaternion is already provided by: Unit<T> -> T
  */
@@ -166,3 +171,43 @@ impl<N1: Real, N2: Real + SupersetOf<N1>> SubsetOf<Matrix4<N2>> for UnitQuaterni
         Self::from_rotation_matrix(&rot)
     }
 }
+
+#[cfg(feature = "mint")]
+impl<N, S> From<mint::Quaternion<N>> for QuaternionBase<N, S>
+where
+    N: Real,
+    S: OwnedStorage<N, U4, U1>,
+    S::Alloc: OwnedAllocator<N, U4, U1, S>,
+{
+    fn from(q: mint::Quaternion<N>) -> Self {
+        QuaternionBase::new(q.s, q.v.x, q.v.y, q.v.z)
+    }
+}
+
+#[cfg(feature = "mint")]
+impl<N: Real, S: Storage<N, U4, U1>> Into<mint::Quaternion<N>> for QuaternionBase<N, S> {
+    fn into(self) -> mint::Quaternion<N> {
+        mint::Quaternion {
+            v: mint::Vector3 {
+                x: self[0],
+                y: self[1],
+                z: self[2],
+            },
+            s: self[3],
+        }
+    }
+}
+
+#[cfg(feature = "mint")]
+impl<N: Real, S: Storage<N, U4, U1>> Into<mint::Quaternion<N>> for UnitQuaternionBase<N, S> {
+    fn into(self) -> mint::Quaternion<N> {
+        mint::Quaternion {
+            v: mint::Vector3 {
+                x: self[0],
+                y: self[1],
+                z: self[2],
+            },
+            s: self[3],
+        }
+    }
+}
diff --git a/tests/core/conversion.rs b/tests/core/conversion.rs
index 84420569..ca6d23cf 100644
--- a/tests/core/conversion.rs
+++ b/tests/core/conversion.rs
@@ -11,6 +11,8 @@ use na::{
     Matrix6x2, Matrix6x3, Matrix6x4, Matrix6x5,
     Point3, Translation3, Isometry3, Similarity3, Affine3,
     Projective3, Transform3, Rotation3, UnitQuaternion};
+#[cfg(feature = "mint")]
+use na::Quaternion;
 
 
 #[cfg(feature = "arbitrary")]
@@ -283,3 +285,18 @@ mint_vector_conversion!(
     mint_vector_conversion_3,  Vector3,  3;
     mint_vector_conversion_4,  Vector4,  4;
 );
+
+
+#[test]
+fn mint_quaternion_conversions() {
+    let q = Quaternion::new(0.1f64, 0.2, 0.3, 0.4);
+    let mq: mint::Quaternion<f64> = q.into();
+    let q2 = Quaternion::from(mq);
+
+    assert_eq!(mq.v.x, q[0]);
+    assert_eq!(mq.v.y, q[1]);
+    assert_eq!(mq.v.z, q[2]);
+    assert_eq!(mq.s, q[3]);
+
+    assert_eq!(q, q2);
+}