Canvas add support for full radial gradient #3
Description
Add support for full radial gradient:
https://learn.microsoft.com/en-us/typography/opentype/spec/colr#radial-gradients
Vello implementation:
https://github.com/linebender/vello/blob/main/vello_shaders/shader/draw_leaf.wgsl#L148
https://github.com/linebender/vello/blob/main/vello_shaders/shader/fine.wgsl#L1077
The corner cases are just crazy. I'm not sure if the complexity is worth it.
During testing, I could not find any example that would not have used other than the simple center + radius radial gradient.