1#version 310 es
2precision mediump float;
3precision mediump int;
4
5layout(binding = 0) uniform mediump sampler2D tex;
6layout(binding = 1) uniform Count
7{
8	float count;
9};
10
11layout(location = 0) in highp vec4 vertex;
12layout(location = 0) out vec4 fragColor;
13
14void main() {
15
16	highp float size = 1.0 / float(textureSize(tex, 0).x);
17	float r = 0.0;
18	float d = dFdx(vertex.x);
19	for (float i = 0.0; i < count ; i += 1.0)
20		r += size * d;
21
22	fragColor = vec4(r);
23}
24