feat(examples): Port bezier example shaders to GLSL 300 ES

[donmccurdy]

For #7457. Ports remaining GLSL (that I could find in code search, anyway) to GLSL 300. I see some errors when trying to start these examples — should they be working? — but I think that has to do with the examples relying on older deck.gl releases or build configuration.

Changed:

• ✅ examples/experimental/bezier (deck ^8.8.0, tested)
• ❓ showcases/ascii/ascii-layer/ (deck ^6.0.0, unable to test)
• ❓ showcases/wind (deck ^5.1.0, unable to test)

[donmccurdy]

• feat(examples): Port bezier example shaders to GLSL 300 ES #8433 👈
• master

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[felixpalmer]

I came across these as well, but hesitate to change them if they are not working. They are old examples, which as you say were written against an old version of deck. As they are not present on the website, I don't see them as high priority to fix.

Changing the shaders to GLSL 300 without making them work in v9 will mean they are broken in all versions of deck.gl, so perhaps a better option for now is to add a comment stating what version they work against and if someone wants to port them in the future, they can

[felixpalmer]

For the examples which do not work, could you verify which version of deck these were written against (or work with) and add a comment rather than porting the shaders?

[donmccurdy]

Thanks, I've added versions to the description above — the working example uses v8, the broken examples use v6 and v5.

I'm a bit concerned about having chunks of dead code: it is more difficult to know when migration tasks are finished as a result. I'm not sure that comments can help with that problem much. If these examples are available on their respective release branches, and haven't been updated since the v7 release (5 years ago) then I am inclined to suggest they shouldn't be on the master branch going into v9.

[felixpalmer]

I'm a bit concerned about having chunks of dead code

I agree, v5 & 6 are very old. How about you remove the broken examples from this PR and make another PR which just removes them from the codebase, so we give the others a chance to comment?

[donmccurdy]

I've removed the changes to the "ascii" and "wind" showcases from this PR, so now it only affects examples/experimental/bezier, which I've tested. I posted a thread in Slack about removing the showcases/ folder, but haven't gotten replies on that, so inclined to just leave those alone for now.

[coveralls]

coverage: 81.577%. remained the same
when pulling 6f54555 on donmccurdy/glsl300-v9-pt2
into f362eb9 on master.