Fix bug when trying to create a rotation matrix with a zero angle.

src/adaptors/rotmat.rs

@@ -36,6 +36,10 @@ pub fn rotmat2<N: Copy + Trigonometric + Neg<N>>(angle: N) -> Rotmat<Mat2<N>>
 
 pub fn rotmat3<N: Copy + Trigonometric + DivisionRing + Algebraic>
 (axisangle: Vec3<N>) -> Rotmat<Mat3<N>>
+{
+  if axisangle.sqnorm().is_zero()
+  { One::one() }
+  else
   {
     let mut axis  = axisangle;
     let angle     = axis.normalize();
@@ -65,6 +69,7 @@ pub fn rotmat3<N: Copy + Trigonometric + DivisionRing + Algebraic>
         (sqz + (_1 - sqz) * cos) ] )
     }
   }
+}
 
 impl<N: Trigonometric + DivisionRing + Copy>
 Rotation<Vec1<N>> for Rotmat<Mat2<N>>

src/tests/mat.rs

@@ -15,7 +15,7 @@ use traits::transpose::Transpose;
 #[test]
 use vec::Vec1;
 #[test]
-use mat::{Mat1, Mat2, Mat3};
+use mat::{Mat1, Mat2, Mat3, Mat4, Mat5, Mat6};
 #[test]
 use adaptors::rotmat::Rotmat;
 
@@ -42,10 +42,17 @@ fn test_inv_mat2()
 fn test_inv_mat3()
 { test_inv_mat_impl!(Mat3<f64>); }
 
-// FIXME: ICE
+#[test]
-// #[test]
+fn test_inv_mat4()
-// fn test_inv_nmat()
+{ test_inv_mat_impl!(Mat4<f64>); }
-// { test_inv_mat_impl!(NMat<d7, f64>); }
+
+#[test]
+fn test_inv_mat5()
+{ test_inv_mat_impl!(Mat5<f64>); }
+
+#[test]
+fn test_inv_mat6()
+{ test_inv_mat_impl!(Mat6<f64>); }
 
 #[test]
 fn test_rotation2()