Wrong alpha and moire with semi-transparent colors

[LeaVerou]

This is due to the way arcs are painted overlapping, to prevent moire, which results in more opaque semi-transparent colors which also exhibit moire.

This can be solved by painting the gradient without any alpha information, then making another black-white gradient with the alpha information and using it as a mask via canvas compositing modes.

Putting it here in case someone has time to code it, otherwise it’ll probably have to wait :/