Mirror function

[sebastiantia]

Implements mirror function addressing issue #536

Checklist:

• The GitHub pipeline is OK (green),
  meaning that both pylint (static code analyzer) and black (code formatter) are happy with the changes of this PR.

• A unit test is covering the code added / modified by this PR

• This PR is ready to be merged

• In case of a new feature, docstrings have been added, with also some documentation in the docs/ folder

• A mention of the change is present in CHANGELOG.md

By submitting this pull request, I confirm that my contribution is made under the terms of the GNU LGPL 3.0 license.

[sebastiantia]

@Lucas-C Mirror transformations with .image and .text are working as expected with this implementation, but things get wonky with cells and I haven't dug deep enough to understand whether it is behaving as expected... any advice would be great :)

[Lucas-C]

@allcontributors please add @sebastiantia fro code

[allcontributors]

@Lucas-C

I've put up a pull request to add @sebastiantia! 🎉

[Lucas-C]

things get wonky with cells and I haven't dug deep enough to understand whether it is behaving as expected... any advice would be great :)

The good news is that cells get perfectly well mirrored with your code! 😊

You just need to reset the FPDF.x position before calling FPDF.cell again within with pdf.mirror().
I added code suggestions to your unit test function that should solve the issue you had.

[sebastiantia]

things get wonky with cells and I haven't dug deep enough to understand whether it is behaving as expected... any advice would be great :)

The good news is that cells get perfectly well mirrored with your code! 😊

You just need to reset the FPDF.x position before calling FPDF.cell again within with pdf.mirror(). I added code suggestions to your unit test function that should solve the issue you had.

Ahh that explains it. Thanks for the detailed code suggestions and review :)

[Lucas-C]

I made you some final comments.
Once you have answered / addressed them,
I'll be happy to merge this nicePR!

[codecov]

Codecov Report

Patch coverage: 91.66% and project coverage change: +0.02 🎉

Comparison is base (37fc30f) 93.26% compared to head (b4a19e5) 93.29%.

❗ Current head b4a19e5 differs from pull request most recent head 49f88ef. Consider uploading reports for the commit 49f88ef to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #783      +/-   ##
==========================================
+ Coverage   93.26%   93.29%   +0.02%     
==========================================
  Files          27       27              
  Lines        7324     7348      +24     
  Branches     1328     1329       +1     
==========================================
+ Hits         6831     6855      +24     
- Misses        308      309       +1     
+ Partials      185      184       -1     

Impacted Files	Coverage Δ
fpdf/fpdf.py	92.55% <86.66%> (+0.05%)	⬆️
fpdf/enums.py	98.00% <100.00%> (+0.04%)	⬆️

☔ View full report in Codecov by Sentry.
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[Lucas-C]

Merged!

Thank you very much @sebastiantia for your contribution! 👍

[Lucas-C]

I forgot to recommend having a unit test for the case where angle is a number,
so after mergig this PR I added an extra commit with a few extra changes 😊
e208ab4

The new documention section will appear there in a few minutes:
https://pyfpdf.github.io/fpdf2/Transformations.html#mirror

I hope you enjoyed contributing to fpdf2 @sebastiantia!
You did a really good job.

[sebastiantia]

I forgot to recommend having a unit test for the case where angle is a number, so after mergig this PR I added an extra commit with a few extra changes 😊 e208ab4

The new documention section will appear there in a few minutes: https://pyfpdf.github.io/fpdf2/Transformations.html#mirror

I hope you enjoyed contributing to fpdf2 @sebastiantia! You did a really good job.

Thanks again for all the help and opportunity :)