precision mediump float;

#endif

​

uniform vec2 u_resolution;

uniform float u_time;

​

void main() {

  vec2 coord = (gl_FragCoord.xy * 2.0 - u_resolution) / min(u_resolution.x, u_resolution.y);

​

  coord.x += sin(u_time) + cos(u_time * 2.1);

  coord.y += cos(u_time) + sin(u_time * 1.6);

  float color = 0.0;

  color += 0.1 * (abs(sin(u_time)) + 0.1) / length(coord);

  gl_FragColor = vec4(vec3(color), 1.0);

}