gl.pixelStorei(gl.UNPACK_ALIGNMENT, 1);
  const data = new Uint8Array([
    255, 64, 192,
    0, 192, 0
  ]);

  let texture = gl.createTexture();
  gl.bindTexture(gl.TEXTURE_2D, texture);
  gl.texImage2D(gl.TEXTURE_2D,
                0,
                gl.R8,
                3,
                2,
                0,
                gl.RED,
                gl.UNSIGNED_BYTE,
                data);

    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

  gl.activeTexture(gl.TEXTURE0);
  gl.bindTexture(gl.TEXTURE_2D, texture);

uniform sampler2D u_texture;

void main() {
  vec2 trans = texelFetch(u_texture, ivec2(0, 0), 0);
}