Directory management in Metapost

Hi,

It seems that Metapost doesn't recognize folder paths, or in command line
terms, doesn't obey the -output-directory. This makes it impossible to call
it on files that are located in different folders.
As an example/illustration of this issue, it restricts the file management
in drawing diagrams in LaTeX (see e.g.
http://tex.stackexchange.com/questions/279009/save-feynman-diagram-files-in-a-subfolder
).

Kind regards,
Tom Vethaak

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http://tug.org/metapost/