Test WebGL extensions with the collector

[captainbrosset]

The following 2 WebGL extensions appear unsupported in Edge, while they're supported in Chrome:

• api.EXT_shader_texture_lod
• api.EXT_frag_depth

I asked @Elchi3 if these were tested by the collector or not. If not, it would be good to add support for them. I'm guessing the data is just incorrect in BCD (I'm asking folks on the Edge team to confirm this).

Here's @Elchi3 's response from our chat earlier:

It think the collector doesn't test it but it could probably use https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/getSupportedExtensions.
There is https://webglreport.com/ that also reports supported WebGL extensions.
Would be good to file an issue about this!

[captainbrosset]

For what it's worth, I tested this in Edge:

var canvas = document.createElement("canvas");
document.body.appendChild(canvas);
var gl = canvas.getContext("webgl");

gl.getExtension("EXT_frag_depth"); // returns an EXTFragDepth
gl.getExtension("EXT_shader_texture_lod"); // returns an EXTShaderTextureLOD

So, both extensions seem to work. But I don't know much about WebGL, so I don't know if the above test is enough. And, this might also be OS and/or device dependent.

[foolip]

There actually are generated tests for WebGL extensions, thanks to @queengooborg:
https://mdn-bcd-collector.gooborg.com/tests/api/EXT_shader_texture_lod
https://mdn-bcd-collector.gooborg.com/tests/api/EXT_frag_depth

@captainbrosset do you see support on Edge on Windows with these tests?

[captainbrosset]

That's what I see now (Windows 11, Version 137.0.3249.0 (Official build) canary (arm64)):

For https://mdn-bcd-collector.gooborg.com/tests/api/EXT_shader_texture_lod

For https://mdn-bcd-collector.gooborg.com/tests/api/EXT_frag_depth:

[captainbrosset]

For info, I see the same result in Chrome (Version 136.0.7089.0 (Official Build) canary (arm64)):

[captainbrosset]

I tried running the code from #2267 (comment) in a worker, and it worked fine. No errors.
Could this be a collector bug?

[captainbrosset]

Just talked to an engineer on my team who works on WebGL and learned a couple of things about the extensions mentioned here:

• If you use WebGL2, then you don't need either of these extensions because the functionality comes by default.
• Edge has no downsteam WebGL deltas so we should report the same support as Chrome.

Also, in general, http://www.browserleaks.com/webgl will tell you which extensions the browser supports.

So, part of this issue should be fixed on BCD directly. But I suspect the collector also needs a fix, based on the test results shown in previous messages.