Inconsistent placement of fillLabel

[cchaos]

Describe the issue
There doesn't seem to be a consistent placement of labels inside of pie, donut, treemap charts.

Desired behavior
I'd expect them all to appear to be in a consistent place with the consumer able to specify a region like "center", "top left", etc...

Screenshots

[monfera]

There are two kinds of sectors: horizontal for better readability in wider sectors, and radial in case of narrow sectors. There's an iteration that tries to maximize readability via largest fitting font size, up to the maximum allowed font size which is relatively small here.

As your examples show, there's plenty of room for improvement, we should circle back to this. Unfortunately, increasing the consistency of the location, while keeping to the possible font maximization logic is not a quick fix: here the layout is a bit underconstrained as the maximum font size is fairly small, so it's kinda loose in the shape, it'll need a bit of thinking and refinement.

[monfera]

Also, maybe it's possible to classify it as an improvement opportunity rather than a bug, especially that fill text for sunburst, and treemaps in general are new features and our text layout is more refined than what's available in other tools, so the above placement inconsistencies don't feel like a blocker.

[monfera]

Hi @cchaos #652 should address the treemap part of this issue. Having said that, there's opportunity for improvement, maye slightly more or configurable text padding is needed, the current one maxes out the rectangular area for text.

The sunburst part is also not that trivial to do - I think many or most of what you suggest there are fairly straightforward, but need time to implement properly, so it should be subject to planning and prioritization so we work through issues in the best sequence.