Test (and slight refactor) of Vector3 normalisation

getNormalised() now implemented in terms of normalise(), rather than separate
code. normalise() now returns the underlying BasicVector3 Element type rather
than coercing everything to float (this would break if we had any
BasicVector3<int> classes and wanted to normalise them, but we don't).

libs/math/Vector3.h

@@ -260,21 +260,15 @@ class BasicVector3
     }
 
     /**
-     * Return a new BasicVector3 equivalent to the normalised version of this
-     * BasicVector3 (scaled by the inverse of its size)
-     */
-    BasicVector3<Element> getNormalised() const {
-        return (*this)/getLength();
-    }
+     * \brief Normalise this vector in-place by scaling by the inverse of its
+     * size.
 
-    /**
-     * Normalise this vector in-place by scaling by the inverse of its size.
-     * Returns the length it had before normalisation.
+     * \return The length of the vector before normalisation.
      */
-    float normalise()
+    Element normalise()
     {
-        float length = getLength();
-        float inverseLength = 1/length;
+        Element length = getLength();
+        Element inverseLength = 1/length;
 
         _v[0] *= inverseLength;
         _v[1] *= inverseLength;
@@ -283,6 +277,14 @@ class BasicVector3
         return length;
     }
 
+    /// Return the result of normalising this vector
+    BasicVector3<Element> getNormalised() const
+    {
+        BasicVector3<Element> copy = *this;
+        copy.normalise();
+        return copy;
+    }
+
     // Returns a vector with the reciprocal values of each component
     BasicVector3<Element> getInversed() {
         return BasicVector3<Element>(

test/math/Vector3.cpp

@@ -38,6 +38,20 @@ TEST(MathTest, VectorLength)
     EXPECT_NEAR(v3.getLength(), sqrt(3*3 + 4*4 + 5*5), 1E-6);
 }
 
+TEST(MathTest, NormaliseVector3)
+{
+    Vector3 v(10, 5, 4);
+    Vector3 vN = v.getNormalised();
+
+    // getNormalised should return correct result and not change the original
+    EXPECT_EQ(vN, v * 1.0/v.getLength());
+    EXPECT_NE(vN, v);
+
+    // Normalise in place gives same result
+    v.normalise();
+    EXPECT_EQ(v, vN);
+}
+
 TEST(MathTest, Vector3IsPacked)
 {
     Vector3 vec(256, -10, 10000);