ram, vertexShader);
  gl.attachShader(program, fragmentShader);
  gl.linkProgram(program);
  var success = gl.getProgramParameter(program, gl.LINK_STATUS);
  if (success) {
    return program;
  }

  console.log(gl.getProgramInfoLog(program));  // eslint-disable-line
  gl.deleteProgram(program);
  return undefined;
}

function main() {
  // Get A WebGL context
  var canvas = document.querySelector("#c");
  var gl = canvas.getContext("webgl2");
  if (!gl) {
    return;
  }

  // create GLSL shaders, upload t