Sun-1515494315033.frag

// Author: Yvan SRAKA
// Title: Sun

#ifdef GL_ES
precision mediump float;
#endif

uniform vec2 u_resolution;
uniform float u_time;

void main(void) {
  float t = cos(u_time);
  float u = gl_FragCoord.x / u_resolution.x;
  float v = gl_FragCoord.y / u_resolution.y;
  float d = sqrt(pow(gl_FragCoord.x - u_resolution.x/2., 2.) +
                 pow(gl_FragCoord.y - u_resolution.y/2., 2.)) + t*50.;

  gl_FragColor =
    (d < 100. + t*50. ? vec4(1., v, u, 1.) :
    (d < 125. + t*40. ? vec4(.8 + .1*t, v*.8, u*.8, .8) :
    (d < 150. + t*30. ? vec4(.6 + .2*t, v*.6, u*.6, .6) :
    (d < 175. + t*20. ? vec4(.4 + .3*t, v*.4, u*.4, .4) :
    (d < 200. + t*10. ? vec4(.2 + .4*t, v*.2, u*.2, .2) :
     vec4(.1*t, .1*v, .1*u, .1))))));
}