This is on the roadmap for being fixed.
On Wed, May 2, 2018 at 1:18 PM, Ashley Gullen <email@example.com> wrote:
>>> Multiple visible canvases can be created with the '2d' rendering context,
>>> and an invisible WebGL-rendered canvas drawn to them using
>> Afaik this would be pretty slow as it'll perform a readback to obtain
>> pixel data to put into the 2D canvas buffer does it not?
> It appears to be hardware accelerated in Chrome, but it is indeed slow in
> Firefox and Safari:
> It's slow enough to not really be useful, as in you probably can't hit 30
> FPS if you simply draw the webgl canvas every frame. Not much action on
> either report so far unfortunately.
> The new imagebitmap context might provide another way, but that's not
> implemented outside of Chrome yet.