Pixi.js: WebGL Context Regression

[mcdenhoed]

Hello! I am developing a pixi app which has to create and destroy lots of PIXI canvases. I've been using PIXI 5.0.4 until recently when I tried to upgrade to 5.1.1.

When I destroy a canvas, I use app.destroy() to destroy the WebGL context. If I run the app without refreshing for a while, eventually I get the following message:

scripts.js:1 WARNING: Too many active WebGL contexts. Oldest context will be lost.
e.createContext @ scripts.js:1

In PIXI 5.0.4, this warning is all that happens and PIXI happily creates a new WebGL context when I ask it to.

In PIXI 5.1.0 and above, I get the same warning and then an error:

scripts.js:1 WARNING: Too many active WebGL contexts. Oldest context will be lost.
e.createContext @ scripts.js:1
/main-es2015.js:1 ERROR TypeError: Failed to execute 'shaderSource' on 'WebGL2RenderingContext': parameter 1 is not of type 'WebGLShader'.

After I get this message, I can't create any new WebGL contexts without refreshing the page. I tried reverting my project to use PIXI 5.0.4 and this error went away.

I'm not a WebGL guru, but noticed that #5872 touches on code that's somewhat related.

[ivanpopelyshev]

OK, that's interesting. Please give more info. Is that in chrome or in firefox? Can you make a simple demo please? My telepathy doesn't work properly on that case and there were multiple people that messed with contexts initialization, so we really need the demo and more info.

[mcdenhoed]

Sure! I see this happen in Chrome (75) and Firefox (68).

I made a short example:
v5.1.0: https://pixiplayground.com/#/edit/m2uYajft~ZRxeTrFQbix6
v5.0.4: https://pixiplayground.com/#/edit/4UmnnyPSGRuUHbmAG2cDP

In both browsers v5.0.4 works as expected while v5.1.0 shows the error (wording of it is a bit different in Firefox) after about 16 seconds (once there's more than 16 contexts).

[JetLua]

https://github.com/pixijs/pixi.js/blob/985ce5897d91ec76a6aac60c0c72c78015a1f3f2/packages/core/src/shader/utils/getTestContext.js#L16

Try a fix, maybe there's a better one.

if (context === unknownContext || context.isContextLost())

[wmike1987]

I just updated to 5.1.4 and I'm still experiencing this issue. Any updates on this?

[bigtimebuddy]

@JetLua that's a good solution. Fancy submitting a PR?

[JetLua]

@JetLua that's a good solution. Fancy submitting a PR?

ok, I'll submit a PR.