varying vec2 vPos;

varying vec2 vTexCoord;

​

uniform float seconds;

uniform float minutes;

uniform float hours;

uniform int click;

​

float sdBox(vec2 p, vec2 b)

{

  vec2 d = abs(p) - b;

  return min(max(d.x,d.y), 0.) + length(max(d, 0.));

}

​

mat2 rotate(float a)

{

  float c = cos(a), s = sin(a);

  return mat2(c, -s, s, c);

}

​

int id = 0;

​

float sdClock(vec2 p)

{

  float smult = 1.0;

  float x = 1e5;

  float y = 1e5;

  float z = 1e5;

  float w = 1e5;

  for (int i = 0; i < 20; i++) {

​

  if (click < 1) {

    p = abs(p)/dot(p, p) - 0.5;

    p *= rotate(seconds);

    p *= 0.5;

    smult *= 0.99;

  }

​

  float secondhand = 0.35*smult;

  vec2 q = p;

  p *= rotate(seconds);

  p.y -= secondhand;

  float b =  sdBox(p, vec2(0.001, secondhand));

  x = min(x,b);

​

  float minutehand = 0.25*smult;

  p = q;

  p *= rotate(minutes);

  p.y -= minutehand;

  b = sdBox(p, vec2(0.001, minutehand));

  y = min(y, b);

  float hourhand = 0.15*smult;

  p = q;

  p *= rotate(hours);

  p.y -= hourhand;

  float c = sdBox(p, vec2(0.004, hourhand));

  z = min(z, c);

  smult *= 0.35;

  }

  float d = 1e5;

  d = min(y, z);

  //d = min(d, w);

  id = x < d ? 1 : 0;

  d = min(d, x);

  return smoothstep(0.0015, 0.001, d);

}

​

void main() {

  vec2 uv = vPos;

  vec2 q = uv;

  float d = 0.;

  uv *= 0.5;

  /*

  for (int i = 0; i < 12; i++) {

    uv = abs(uv)/dot(uv, uv) - 0.5;

    uv *= rotate(seconds);

    uv *= 0.5;

  }

  */

  d = click == 0 ? sdClock(uv) : sdClock(q);

  //id = 0;

  vec3 col = (id == 1) ? vec3(1, 0, 0) : vec3(1);

  gl_FragColor = vec4(d * col, 1.0);

}