// Fragment shader
precision highp float;

#define PI 3.14159265359
#define PI2 6.28318530718

varying vec2 UV;
varying vec3 v_position;
uniform float time;
uniform float ratio;
uniform vec2 mouse;

float func(float x){
	return 0.4 * cos(x * PI + time * PI2);
}

void main(void){
    float x = UV.x * ratio;
    float y = 2.0 * UV.y - 1.0;

    vec4 col = vec4(0.0);

    for(int i = 0; i < 10; i++){
      if(distance(func(x + float(i)/10.0 + float(i) * x * 0.0),y) < 0.01){
          col.rgb += 1.0;
      }
    }
    col.a = 1.0;

    gl_FragColor = col;
}