#ifdef GL_ES
precision mediump float;
#endif

uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;

vec2 random2( vec2 p ) {
    return fract(sin(vec2(dot(p,vec2(127.1,311.7)),dot(p,vec2(269.5,183.3))))*43758.5453);
}

void main() {
    vec2 st = gl_FragCoord.xy/u_resolution.xy;
    st.x *= u_resolution.x/u_resolution.y;
    vec3 color = vec3(161./256., 174./256., 216./256.);

    st *= 100.;

    vec2 i_st = floor(st);
    vec2 f_st = fract(st);

    float m_dist = 1.;

    for (int y= -1; y <= 1; y++) {
        for (int x= -1; x <= 1; x++) {
            vec2 neighbor = vec2(float(x),float(y));
            vec2 point = random2(i_st + neighbor);
            point = 0.5 + 0.5*sin(u_time + 6.2831*point);

            m_dist = min(m_dist, length(neighbor + point - f_st));
        }
    }

    color += 1.-m_dist;
    color += 1.-smoothstep(0.01, .1, m_dist);

    gl_FragColor = vec4(1.-color,1.0);
}