Re: Coons and Tensor-product patch mesh shading in MetaPost

Hans Hagen via ntg-context <[email protected]> Wed, 8 Jul 2026 10:32:12 +0200
Newsgroups	gmane.comp.tex.context
Message-ID	<[email protected]>
On 7/8/2026 9:42 AM, Florent Michel wrote:
> Hi,
> 
> Is there a way to fill a closed path with Coons or Tensor-product 
> shading in MetaPost/MetaFun?
> 
> Apparently they are implemented in luamplib (https://mirrors.mit.edu/ 
> CTAN/macros/luatex/generic/luamplib/luamplib.pdf <https:// 
> mirrors.mit.edu/CTAN/macros/luatex/generic/luamplib/luamplib.pdf> ; see 
> sections 1.2.20 and 1.2.21), but unless I am missing something not in 
> the versions of MetaPost/MetaFun in the LMTX distribution, or at least 
> not in the way described in the luamplib manual.
> 
> (If I understand correctly, luamplib intercepts the relevant keywords in 
> Lua instead of passing them to MetaPost, which could explain the 
> difference. Not sure my understanding is correct, though.)
> 
> One alternative is to use PGFPlots for figures that require these 
> shadings; but I'm wondering if there is a way to use them while 
> benefiting from the close integration of MetaFun with LMTX.

what is a realistic use case, apart from showing that it can be done and 
adding a lot of code

these are somewhat special shading tricks that date from ps times

what y kind of graphic (PGFPlots) do you have in mind ? example?

Hans


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