shader_type spatial;
uniform int count = 3;
float rand(vec2 n) {
    return fract(sin(dot(n, vec2(12.9898, 4.1414))) * 43758.5453);
}

float noise(vec2 n) {
    vec2 d = vec2(0.0, 1.0);
    vec2 b = floor(n), f = smoothstep(vec2(0.0), vec2(1.0), fract(n));
    return mix(mix(rand(b), rand(b + d.yx), f.x), mix(rand(b + d.xy), rand(b + d.yy), f.x), f.y);
}

float fbm(vec2 n) {
    float total = 0.0, amplitude = 1.0;
    for (int i = 0; i < 7; i++) {
        total += noise(n) * amplitude;
        n += n;
        amplitude *= 0.5;
    }
    return total;
}

float get_line(vec2 t, vec2 uv){

   float ycenter = mix( 0.5, 0.25 + 0.25*fbm( t ), uv.x*4.0);

    float diff = abs(uv.y - ycenter);
    float c = 1.0 - mix(0.0,1.0,diff*20.0);
    return c;
   }

void fragment( )
{
    vec4 col = vec4(0,0,0,1);
    vec2 uv = UV;

    float c = 0.;
    for(int i=1; i <=count; i++){
        vec2 t = uv * vec2(float(i) * 2.0,1.0) - TIME*(3.0+float(i)/2.0);
        float tmp_c = get_line(t, uv);
        if (tmp_c > c){
            c = tmp_c;
           }
    }

    col = vec4(c,c,c*1.2,1.0)*2.0;
    col.a = c;
    ALBEDO = col.rgb;
    ALPHA = col.a;
}