function getShared2DContext() {
  s_ctx = s_ctx || (typeof document !== 'undefined' && document.createElement ? document.createElement("canvas").getContext("2d") : null);
  return s_ctx;
}
Low level texture related functions

You should generally not need to use these functions. They are provided
for those cases where you're doing something out of the ordinary
and you need lower level access.

For backward compatibility they are available at both `twgl.textures` and `twgl`
itself

See {@link module:twgl} for core functions

@module twgl/textures