More advanced shading patterns

[amigalemming]

Can we have more advanced shading patterns?
Currently, I do not know what PDF shading features fits my needs best. I like to draw a tall rectangle with a bright-dark gradient from left to right to give it a look like a tube. But the tube shall have different colors at the top and the bottom and a smooth gradient between.

[thielema]

See ongoing development here:
https://github.com/thielema/hpdf/tree/expression

[hsyl20]

Great! Feel free to open a PR when it's ready :-)