6 // From section 4.3.6 of the GLSL 1.20 spec:
7 // A fragment shader can not write to a varying variable.
9 // From section 7.6 of the GLSL 1.20 spec:
10 // The following varying variables are available to read from in a fragment shader.
12 // varying vec2 gl_PointCoord;
17 gl_PointCoord = vec2(0.0);