New version of bug #13 fix

[kpym]

I have created a new module ellipse where the hard part of the calculation is.
I have reverted my changes to matrix module, because you don't like my copy method ;)

[kpym]

@puzrin Now if rx~=0 or ry~=0 the arc is replaced by a line segment as you suggested, but I can't check if this is consistent with what chrome is doing because if the transform is not reversible, like scale=(0,2) the path is not displayed (even with vector-effect="non-scaling-stroke").
I don't know if this is a good idea to do this...

[puzrin]

It's better to squash into single comit & update codig style to make tests pass (npm test). Also see https://github.com/fontello/svgpath/blob/master/lib/a2c.js#L9 disabled rule, convenient for files with math. Please update coding style to be similar.

The second. I don't see radii correction as in https://github.com/fontello/svgpath/blob/master/lib/a2c.js#L131-L140. That's important. I think, after you try to add those, your signatures can change, because you do no pass size info now ((x2-x1)/2 and (y2-y1)/2).

[puzrin]

Now if rx~=0 or ry~=0 the arc is replaced by a line segment as you suggested, but I can't check if this is consistent with what chrome is doing because if the transform is not reversible

We do not rely on chrome. We follow SVG implementation notes http://www.w3.org/TR/SVG/implnote.html#ArcCorrectionOutOfRangeRadii. It says arc should be replaced with line if rx or ry = 0. It also says in other chapters that arc should be dropped if end point === start point.

[kpym]

It's better to squash into single comit & update codig style to make tests pass (npm test). Also see https://github.com/fontello/svgpath/blob/master/lib/a2c.js#L9 disabled rule, convenient for files with math. Please update coding style to be similar.

Sorry I don't have so much time right now ... I'll move to other things probably.

The second. I don't see radii correction as in https://github.com/fontello/svgpath/blob/master/lib/a2c.js#L131-L140. That's important. I think, after you try to add those, your signatures can change, because you do no pass size info now ((x2-x1)/2 and (y2-y1)/2).

The resulting radii are positif by construction and if they are almost the same they are corrected to be the same (circle case).

if some other corrections should be done, you can probably add them. Thanks.

[puzrin]

No problem. Let's keep it open until we do the rest. That will be complete at the start of nearest week.

[puzrin]

Could you squash this PR to single commit (git rebase --interactive HEAD~6 ...)? I think it's ok to merge

[puzrin]

@kpym could you join all to single commit?

[kpym]

Is it ok now ?

[puzrin]

Yes, thank you for you patience!

Did you checked arc transforms results visually or i should do it for sure?

[kpym]

I have checked a lot, but better you check some also.

[puzrin]

Ok. Can i take 2 days before release or it's urgent?

[kpym]

Nothing is urgent for me ;)