The RoundSuperellipse parts look good to me! Thank you for the cleanup!

Currently I have most of the libtess stuff commented out and some of the other tessellator stuff may also be commented out while I see what the status of the libtess library and Dart file is. I can convert it, but I wanted to make sure libtess was still being used before I did so.

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Changes reported for pull request #168760 at sha 1201176

unfortunately the libtess stuff is still used, as that library is compiled to a shared library that is used by package:vector_graphics. but it doesn't need to use the impeller path stuff, it could use Skia path: the binary size isn't important as it is not shipped in applications

There are many cases in the goldens where we rendered a ui.Canvas.drawArc call via "pathbuilder.addArc" and that implementation switched from the cubic-based approximation used in impeller::PathBuilder to the conic-based version (more accurate) in DlPathBuilder/SkPath.

There is also a group of diffs that look like the edge conditions on some of the paths were affected (perhaps due to changes in the way that impeller vs. Skia computes bounds).

unfortunately the libtess stuff is still used, as that library is compiled to a shared library that is used by package:vector_graphics. but it doesn't need to use the impeller path stuff, it could use Skia path: the binary size isn't important as it is not shipped in applications

@chinmaygarde suggested that we could remove it from the repo and ship it separately.

Yes, it appears that Skia adds an arc to a path greedily by 90 degree increments until it reaches the last <90 degree tail end - which means that the control points of the conics for those quarter circles will lie outside the "bounds" of the arc if the beginning isn't quadrant aligned.

There is a method on SkPath to compute a tight bounds, but I'd like to avoid using that unless necessary. I can either create a custom ArcPathSource which will generate conics that don't have control points outside the bounds and/or which reports its bounds based on the bounds of the ellipse it inscribes and the start/end points themselves.

The vector graphics compiler will handle the library being missing (https://github.com/flutter/packages/blob/14685811ed39d018b763ec45e8d520f6d82f8073/packages/vector_graphics_compiler/lib/src/_initialize_tessellator_io.dart#L11) but the functionality that relies on that library will stop working.

suggested that we could remove it from the repo and ship it separately.

But from where and when? The easiest place to build this is going to be from flutter/flutter. If its not too much trouble, I'd try to adapt the Skia paths to work in the libtess library. otherwise we can remove it, but lets not add it somewhere else - just get rid of it.

But from where and when? The easiest place to build this is going to be from flutter/flutter. If its not too much trouble, I'd try to adapt the Skia paths to work in the libtess library. otherwise we can remove it, but lets not add it somewhere else - just get rid of it.

It's not as complicated as using Skia. The files can use the path iteration like the rest of Impeller, I just have to do the plumbing...

libtess is back now

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Changes reported for pull request #168760 at sha 4e57cf1

The goldens look as would be expected. This should be ready for review...

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Changes reported for pull request #168760 at sha e5cabad