concurrent use of MeasureString causes panic about gg

[justinclift]

Gah. This is what I'm hitting too, converting an image sequence generator to use goroutines. 😦

So far, the code only functions - eg without panicing - if I strip out all calls to MeasureString() and DrawString*(), as the DrawString() functions also call MeasureString() internally.

Any idea of a workaround? Leaving things to run single-threaded isn't really an option.

Guessing all the text will have to be moved out of the generated frames permanently though. 😦

[psanford]

We worked around this by using the Context.LoadFontFace() method instead of the package level method.

[justinclift]

Thanks @psanford, I'll give that a go. 😄

[justinclift]

Yep, that works. Awesome stuff @psanford, thank you. 😄

[justinclift]

As a possibly useful data point, another way to work around it is by moving the same gg.LoadFontFace() calls inside the goroutines.

It makes sense upon thinking about it, as both approaches are ensuring each goroutine get's it's own font face to work with. So no collision problems.