he letter 'F'.
function setTexcoords(gl) {
  gl.bufferData(
      gl.ARRAY_BUFFER,
      new Float32Array([
        // left column front
        0, 0,
        0, 1,
        1, 0,
        0, 1,
        1, 1,
        1, 0,

        // top rung front
        0, 0,
        0, 1,
        1, 0,
        0, 1,
        1, 1,
        1, 0,

        // middle rung front
        0, 0,
        0, 1,
        1, 0,
        0, 1,
        1, 1,
        1, 0,

        // left column back
        0, 0,
        1, 0,
        0