New feature: Gradient patterns

[andersonhc]

e.g. Fixes #0

Checklist:

• Implement linear and radial gradients (Pattern/Shading)

• Implement a class to handle named resources better

• A unit test is covering the code added

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

• Docstrings have been added

• Documentation created in the docs/ folder

• This PR is ready to be merged

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

[Lucas-C]

Hi @andersonhc 🙂

This is related to #790?

Thank you for tackling this!

And wish you a merry christmas 🎅🎄

[andersonhc]

Hi @andersonhc 🙂

This is related to #790?

Thank you for tackling this!

And wish you a merry christmas 🎅🎄

There are 2 types of patterns on the PDF specs. Type 1 (tiling patterns) are the repetition of images or text and type 2 (shading patterns) are gradients.

I am only implementing gradients for now because I need this feature to proceed with #1305.

I will comment on #790 to detail what has been done and what's missing to implement tiling patterns.

This PR also open a path to implement the LinearGradient and RadialGradient SVG features, we can open a issue for that.

Merry Christmas to you too. Enjoy the holidays.

[Lucas-C]

There are 2 types of patterns on the PDF specs. Type 1 (tiling patterns) are the repetition of images or text and type 2 (shading patterns) are gradients.

I am only implementing gradients for now because I need this feature to proceed with #1305.

I will comment on #790 to detail what has been done and what's missing to implement tiling patterns.

Awesome!
Thank you for the explanation 👍

[Lucas-C]

I rebased this branch onto master.

I made a few comments but I also approved this PR 👍

[andersonhc]

@Lucas-C

FYI:

• I produced a new reference file for test_insert_jpg_jpxdecode because of changes for JPEG2000 images after pillow 11.1.0
• I also had to skip this test on python 3.8 because pillow dropped this version.

[Lucas-C]

Good job on this @andersonhc! 👍

Congrats, really nice addition 🙂

[Lucas-C]

This has been released in https://github.com/py-pdf/fpdf2/releases/tag/2.8.3