I'm trying to pass an OpenTK Matrix4 to a shader uniform, but there doesn't seem to be a suitable overload for GL.UniformMatrix4. The overloads accept either `float` or `float[]` or `ref float`. Similarly I can't find a way to convert a Matrix4 instance to a float array - I've seen one sample that uses a ToArray method on the Matrix4, but that doesn't seem to be present in the distribution I'm using.

Sure I'm missing something simple as this is pretty fundamental to being able to pass a model/view/projection matrix to a shader.

I'm using the version of OpenTK shipping with the lastest version of MonoTouch.