@Override
            public int length(BufferLayout serializer, Vector4f obj) {
                return 4 * 4;
            }
Serializer that respects the Std140 layout
(https://www.khronos.org/registry/OpenGL/specs/gl/glspec45.core.pdf#page=159)
(www.opengl.org/registry/specs/ARB/uniform_buffer_object.txt)

@author Riccardo Balbo
jme3-core/src/main/java/com/jme3/shader/bufferobject/layout/Std140Layout.java