http://pixelshaders.com/editor/#5d000001005a0300000000000000381c88cdaf8125d4569ed1e6e6c09c2fe72b7d489ad9d27ce026c85da1432f9b0a56cbf82b16d7f997abaffdd294666ceebb4d1566bfeab205986af69e507dd6f252b4363278dfa3f6beac1af406cd9c824992c4aa5a4c0ab6599a64b91d4b2c5cd2e584a1048c312c5d6e0acbbc64abd5dd2926c4d3a5cad196fd848f48cf3ad66940dbc7143aa5fef67e8b64c64ca…

Trippy1.frag

precision mediump float;

varying vec2 position;
uniform float time;

const float waves = 19.;

// triangle wave from 0 to 1
float wrap(float n) {
  return abs(mod(n, 2.)-1.)*-3. + 1.;
}

// creates a cosine wave in the plane at a given angle
float wave(float angle, vec2 point) {
  float cth = cos(angle)*2.;
  float sth = sin(angle);
  return (cos (cth*point.x + sth*point.y) + 1.) / 2.;
}

// sum cosine waves at various interfering angles
// wrap values when they exceed 1
float quasi(float interferenceAngle, vec2 point) {
  float sum = 0.;
  for (float i = 0.; i < waves; i++) {
    sum += wave(3.1416*i*interferenceAngle, point);
  }
  return wrap(sum);
}

void main() {
  float b = quasi(time*0.002, (position-0.5)*200.);
  vec4 c1 = vec4(0.0,0.,0.2,1.);
  vec4 c2 = vec4(cos(2.*time),sin(time),abs(sin(time*3.)),1.);
  gl_FragColor = mix(c1,c2,b);
}