​

varying vec2 pos;

​

uniform float millis; 

​

void main() {

  // Just make it white 

  // gl_FragColor = vec4(1.);

  // Single colour

  // gl_FragColor = vec4(1., 0., 1., 1.);

  // 1D gradient

  // gl_FragColor = vec4(pos.x, 0., 1., 1.);

  // 2D gradient

  // gl_FragColor = vec4(pos, 1., 1.);

  // Custom colours using mix

  // vec4 c1 = vec4(0.5, 0.1, 0.9, 1.);

  // vec4 c2 = vec4(0.1, 0.8, 0.7, 1.);

  // vec4 c = mix(c1, c2, pos.x);

  // gl_FragColor = c;

​

  // 2D gradient using mix

  // vec4 tl = vec4(0.5, 0.1, 0.9, 1.);

  // vec4 tr = vec4(0.3, 1., 0.8, 1.);

  // vec4 bl = vec4(0.8, 0.6, 0.1, 1.);

  // vec4 br = vec4(0.7, 0.1, 0.2, 1.);

  // vec4 top = mix(tl, tr, pos.x);

  // vec4 bottom = mix(bl, br, pos.x);

  // vec4 c = mix(bottom, top, pos.y);

  // gl_FragColor = c;

​

  // Repeating pattern

  vec2 newPos = fract(pos * 10.);

  gl_FragColor = vec4(newPos, 1., 1.);

  // Sine waves

  // float c = (sin(pos.x * 16.) + 1.)/ 2.;

  // float c = (sin(pos.x * 16. + millis/1000.) + 1.)/ 2.;

  // gl_FragColor = vec4(c, 0., 1., 1.);

}

​