fix tile debug rendering on satellite tiles

[andrewharvey]

Launch Checklist

• briefly describe the changes in this PR
  closes Tile number can't display on satellite style #2223 by improving the readability of the debug tiles (showTileBoundaries) on satellite tiles.

This change also increases the halo to 2px to improve readability, but I can change this back if you think it's now too bold.

• write tests for all new functionality

I'll update the render test fixtures once we decide if the increase to 2px halo is okay or not.

• manually test the debug page

[ryanhamley]

The debug/tile-overscaled render test is failing now so you'll have to update that. If you want to finish this PR and then pick up #7314 that's fine with me. I won't get to it anytime soon so the help is appreciated.

[tristen]

@andrewharvey thanks for making this change!

This change also increases the halo to 2px to improve readability, but I can change this back if you think it's now too bold.

My 2c: It does feel a bit too bold.

[andrewharvey]

The debug/tile-overscaled render test is failing now so you'll have to update that.

I thought that was because I increased the halo to 2px, but it wasn't, the render test actually helped pickup an error in my code!

I've fixed that now but a new unit test I created for testing the debug tiles on satellite tiles, passes on my local machine but fails on circleci, it doesn't look like I can access circleci's artifacts from the job, so don't know what it's rendering on how it's different...

If you want to finish this PR and then pick up #7314 that's fine with me. I won't get to it anytime soon so the help is appreciated.

Yep I think I'll try to get this one merged first, then I'll try to work in your changes from #7314.

My 2c: It does feel a bit too bold.

That's okay, I've scaled it back to 1px.

[asheemmamoowala]

I've fixed that now but a new unit test I created for testing the debug tiles on satellite tiles, passes on my local machine but fails on circleci, it doesn't look like I can access circleci's artifacts from the job, so don't know what it's rendering on how it's different...

Here's a link to the results: https://45149-8629417-gh.circle-artifacts.com/0/root/mapbox-gl-js/test/integration/render-tests/index.html

[andrewharvey]

Thanks for fixing that @asheemmamoowala, I could never work out why when I generated the fixture locally it looked fine and hence passed locally but for some reason that same test running on CI was different and hence failed. 🤔

[asheemmamoowala]

I could never work out why when I generated the fixture locally it looked fine and hence passed locally

If I remember correctly you run a non-OSX setup. I believe the difference is subtle in the graphics driver and happens to change the output just enough to go past the tolerance for render tests.

[ryanhamley]

This looks good to me. It even looks pretty good on a 4K screen.