uniform mediump float med_a;
uniform mediump float med_b;
uniform lowp float low_c;

void main()
{
	// must be computed at mediump since some args are mediump
	lowp float t = (med_a + low_c / med_b);
	// computed at lowp
	lowp vec4 c = clamp(vec4(t), 0.0, 1.0);

	gl_FragColor = c;
}
