site/www/shaders/trivial.glsl

// is highp wasteful for this shader?
#ifdef GL_FRAGMENT_PRECISION_HIGH
precision highp float;
#else
precision mediump float;
#endif

uniform float uTime;
uniform vec2 uResolution;

void main() {
  vec2 uv = gl_FragCoord.xy / uResolution;

  vec3 col = 0.5 + 0.5 * cos(uTime + uv.xyx + vec3(0, 2, 4));

  gl_FragColor = vec4(col,1.0);
}