math: add a uniform scaling matrix constructor.

src/lol/math/vector.h

@@ -1696,6 +1696,7 @@ template <typename T> struct Mat3
     inline Vec3<T> const& operator[](size_t n) const { return (&v0)[n]; }
 
     /* Helpers for transformation matrices */
+    static Mat3<T> scale(T x);
     static Mat3<T> scale(T x, T y, T z);
     static Mat3<T> scale(Vec3<T> v);
     static Mat3<T> rotate(T angle, T x, T y, T z);
@@ -1832,6 +1833,11 @@ template <typename T> struct Mat4
     static Mat4<T> translate(T x, T y, T z);
     static Mat4<T> translate(Vec3<T> v);
 
+    static inline Mat4<T> scale(T x)
+    {
+        return Mat4<T>(Mat3<T>::scale(x), (T)1);
+    }
+
     static inline Mat4<T> scale(T x, T y, T z)
     {
         return Mat4<T>(Mat3<T>::scale(x, y, z), (T)1);

src/math/vector.cpp

@@ -305,6 +305,17 @@ template<> std::ostream &operator<<(std::ostream &stream, mat4 const &m)
     return stream;
 }
 
+template<> mat3 mat3::scale(float x)
+{
+    mat3 ret(1.0f);
+
+    ret[0][0] = x;
+    ret[1][1] = x;
+    ret[2][2] = x;
+
+    return ret;
+}
+
 template<> mat3 mat3::scale(float x, float y, float z)
 {
     mat3 ret(1.0f);