#ifdef GL_ES
    precision mediump float;
#endif

const float PI = 3.14159265;
uniform vec2 u_resolution;
uniform float u_time;

vec3 palette(float t)  {
 vec3 a = vec3(0.5, 0.5, 0.5);
 vec3 b = vec3(1.0, 1.0, 1.0);
 vec3 c = vec3(1.0, 1.0, 1.0);
 vec3 d = vec3(0.0, 0.6666, 0.3333);
 return a + b * cos(6.28318 * (c*t+d));
}
 

mat2 rotate(float angle){
    return mat2(cos(angle), -sin(angle), sin(angle), cos(angle));
}

float polygon(vec2 position, float radius, float sides){
    float a = atan(position.x, position.y);
    float slice = PI * 2.0 / sides;
    return 1. - step(radius, cos(floor(0.5 + a / slice) * slice - a) * length(position));
}


float star(vec2 position, float radius, float sides){
    float a = atan(position.x, position.y);
    float slice = PI * 2. / sides;
    return 1. - step(radius, cos(floor(-2.0 + a / slice) * slice - a));
}


void main() {
    vec2 uv = (gl_FragCoord.xy * 2. - u_resolution.xy) / u_resolution.y;
    vec3 color = vec3(0.08, 0.22, 0.39);
    vec3 mixer = vec3(0.);
    for(float i = 1.; i < 3.; i++){
        vec2 translate = uv;
        translate *= rotate(i*1.4/5.); // + u_time);
        float sides = 11.;
        mixer += vec3(star(translate, 0.06, sides))*vec3(0.5725, 0.8275, 0.9451)*(i*0.7)*0.2;        
    }

    color = mix( color, mixer, 0.5);   
    // color = max(color, polygon(uv, 0.3, 6.)),
    gl_FragColor = vec4(color, 1.0);    
}