Adjustment with fix for negative viewbox

[odaki]

Hello again.

My pull request from yesterday does not fully address the fix regarding viewBox with negative values. A few additional fixes are needed.

I checked the G-Code and svg generated using 'automated_testing.py' and it looks fine.

Please check the test results and if everything is fine, please merge my modifications.

• Regenerate G-code for comparison tests on negative viewBox
• Fixed regular expression for viewBox with negative values in linear approximation tests
• Use string literals prefixed with 'r' for regular expressions https://docs.python.org/3/library/re.html

[PadLex]

I'm not able to test it right now but your changes make sense. I'll test everything before creating a new release.

Thank you for your contributions!

[odaki]

Thank you for your quick response.

As for drawing for debug, I have found that inkscape does not display correctly unless laser.py also supports viewBox, so I think it would be better to refactor the viewBox handling in the official release, taking into account the modification of laser.py. Thanks for letting me use your great code. Please keep up the good work.