void mainImage(out vec4 fragColor, in vec2 fragCoord)
{
    vec2 uv = fragCoord.xy / iResolution.xy;

    vec2 p = uv * 2.0 - 1.0;
    p.x *= iResolution.x / iResolution.y;

    vec3 color = vec3(0.0);

    for(int i = 0; i < 7; i++)
    {
        p = abs(p) / dot(p, p) - 0.75;

        float d = length(p);

        color += vec3(
            sin(float(i) + iTime),
            0.4,
            cos(float(i) - iTime)
        ) * exp(-d * 3.0);
    }

    fragColor = vec4(color, 1.0);
}