#version 100
precision mediump float;
uniform float u_time;
uniform vec2 u_resolution;

void main() {
    vec2 uv = gl_FragCoord.xy / u_resolution.xy;
    float v = 0.0;
    vec2 c = uv * 5.0 - vec2(2.5);
    v += sin((c.x + u_time));
    v += sin((c.y + u_time) / 2.0);
    v += sin((c.x + c.y + u_time) / 2.0);
    c += vec2(sin(u_time / 3.0), cos(u_time / 2.0));
    v += sin(sqrt(c.x * c.x + c.y * c.y + 1.0) + u_time);
    v = v / 2.0; 
    vec3 col = vec3(sin(v * 3.14159), sin(v * 3.14159 + 2.09439), sin(v * 3.14159 + 4.18879));
    gl_FragColor = vec4(col * 0.5 + 0.5, 1.0);
}