Shapes: fixed 2D Capsule transformation.

The test now passes again.

src/Shapes/Capsule.cpp

@@ -36,9 +36,21 @@ using namespace Magnum::Math::Geometry;
 
 namespace Magnum { namespace Shapes {
 
+namespace {
+    template<UnsignedInt dimensions> static typename DimensionTraits<dimensions, Float>::VectorType unitVector();
+
+    template<> inline Vector2 unitVector<2>() {
+        return Vector2(1/Constants::sqrt2());
+    }
+
+    template<> inline Vector3 unitVector<3>() {
+        return Vector3(1/Constants::sqrt3());
+    }
+}
+
 template<UnsignedInt dimensions> Capsule<dimensions> Capsule<dimensions>::transformed(const typename DimensionTraits<dimensions, Float>::MatrixType& matrix) const {
     return Capsule<dimensions>(matrix.transformPoint(_a), matrix.transformPoint(_b),
-        (matrix.rotationScaling()*typename DimensionTraits<dimensions, Float>::VectorType(1/Constants::sqrt3())).length()*_radius);
+        (matrix.rotationScaling()*unitVector<dimensions>()).length()*_radius);
 }
 
 template<UnsignedInt dimensions> bool Capsule<dimensions>::operator%(const Point<dimensions>& other) const {