Fix to Vector3::cross().

Note that it has been brought up that this code (and other code similar to it) is not necessarily 100% safe, since struct members are not guaranteed to be contiguous. We may change this and other similar cases in a later check-in.

Fixes #573

gameplay/src/Vector3.cpp

@@ -173,7 +173,10 @@ void Vector3::cross(const Vector3& v1, const Vector3& v2, Vector3* dst)
 {
     GP_ASSERT(dst);
 
-    MathUtil::crossVector3((const float*)&v1.x, (const float*)&v2.x, (float*)dst);
+    // NOTE: This code assumes Vector3 struct members are contiguous floats in memory.
+    // We might want to revisit this (and other areas of code that make this assumption)
+    // later to guarantee 100% safety/compatibility.
+    MathUtil::crossVector3(&v1.x, &v2.x, &dst->x);
 }
 
 float Vector3::distance(const Vector3& v) const