#version 330 core

uniform float time;
uniform vec2 resolution;
uniform vec2 mouse;

out vec4 color;

float
plot (vec2 st)
{
  return smoothstep (0.01, 0.0, abs (st.y - st.x));
}

void
main () {
  vec2 st = gl_FragCoord.xy/resolution;

  float y = st.x;

  vec3 c = vec3 (y);

  float pct = plot (st);
  c = (1.0 - pct)*c + pct*vec3 (0.0, 1.0, 0.0);

  color = vec4 (c, 1.0);
}