On Sun, 8 Jul 2018 11:21:55 +0200
Hans Hagen
the "externalfigure" variant is an old one that had to deal with dimensions in a way that avoids overflows
in a future context (read luatex 1.09+) we go one-pass-mp so we can have a different approach (i never wanted to add a ton of code for images) so there externalfigure will scale proportionally too
ConTeXt running on the luatex experimental branch under development indeed works with one-pass-MP calculations as opposed to the two-pass mechanism that is standard today. For documents with extensive and complicated MP graphics, this yields a huge gain. Hans is at present working out all side-effects (such as recursive MP/TeX/lua calls) and is cleaning up some old ways of doing things that date from mkii. This might seem somewhat minor but is really exciting for those who use a lot of graphics and MetaPost effects. Alan