8 * Page 35 of the OpenGL ES Shading Language 3.00 spec says:
10 * "Arrays have a fixed number of elements. This can be obtained
11 * by using the length method:
14 * // returns 5 for the above declarations
16 * The return value is a constant signed integral expression. The
17 * precision is determined using the same rules as for literal
26 gl_Position = vec4(a[i].x + a.length());