Quaternion::as_matrix normalise to ensure acos in-range

Author: mohawk2

lib/PDL/Graphics/TriD/Quaternion.pm

@@ -134,6 +134,7 @@ sub rotate {
 
 sub as_matrix {
   my ($this) = @_;
+  $this->normalise;
   my ($rot, $vec) = map PDL->pdl(PDL::float, $_), $this->[0], [@$this[1..3]];
   $rot->inplace->acos; $rot *= 2;
   $vec->inplace->norm;

t/quaternion.t

@@ -66,10 +66,10 @@ is_qua $q4, $q1_q2;
 
 my $q_45_about_111 = PDL::Graphics::TriD::Quaternion->new(cos(PI/8),1,1,1);
 is_pdl $q_45_about_111->as_matrix, float('
- 0.804738 -0.310617  0.505879 0;
- 0.505879 0.804738  -0.310617 0;
--0.310617 0.505879   0.804738 0;
-        0 0          0        1
+-0.038003  0.039506  0.998496 0;
+ 0.998496 -0.038003  0.039506 0;
+ 0.039506  0.998496 -0.038003 0;
+        0         0         0 1
 ');
 
 done_testing;