Hi everyone,
I’ve made great progress creating globes for my diagrams using the data in the
mp-geo package and some ideas from Hans. I have a couple questions about moving
information from Lua to MetaPost. Below is a MWE for illustration. I have two
related questions:
1) Is there a way for MetaPost to grab information from a Lua table? Currently
the MetaPost code calls a Lua function which has a single line returning the
information from the table. Is this necessary, or is these something in
MetaPost that can get a path or color from a Lua table?
2) While I’m having good luck with paths, colors are causing trouble. In the
data set the color information is in strings with French names of the color,
like “rouge.” If I hand this string to MetaPost, MetaPost doesn’t expand it
into a color. It does work if it is a native color, like “red,” but not if it
is a defined color and not if the color is in a Lua variable. Any suggestions?
Thanks!
Gavin
The code below produces four pie shape wedges to show the different results of
handling the color. They should all be red, but the last two are black.
\startMPinclusions
color rouge; % To avoid changing the data files, I need to define
colors in French.
rouge=(1,0,0); % For this MWE, I only define rouge.
color mycolor; % Defining mycolor in MetaPost works great, as shown in
the first shape.
mycolor = rouge;
\stopMPinclusions
\startluacode
myluapath = {{0,0}, {1,0,0,0,1,0.25}, {0.8,0.6,0.95,0.4}, cycle = true}
myluacolor = “red” --% Data files are read by Lua, so the myluacolor will
be a string (in French, but native colors don't work either).
function mp.getpath() --% Is there a way for the MetaPost code to grab the
path directly from the table?
mp.inject.path(myluapath)
end
function mp.getred() --% Returning a string work for native colors.
mp.inject.string("red")
end
function mp.getrouge() --% Returning a string does not work for defined
mp.inject.string("rouge")
end
function mp.getcolor() --% Putting the string in a variable does not work.
mp.inject.string(mycolor)
end
\stopluacode
\starttext
\startMPpage
fill lua.mp.getpath() scaled 2.5cm withcolor mycolor; % MetaPost color
definition works great.
fill lua.mp.getpath() scaled 2.5cm shifted (0, -2cm) withcolor
lua.mp.getred(); % Returning a string work for native colors.
fill lua.mp.getpath() scaled 2.5cm shifted (0, -4cm) withcolor
lua.mp.getrouge(); % Returning a string does not work for defined colors.
fill lua.mp.getpath() scaled 2.5cm shifted (0, -6cm) withcolor
lua.mp.getcolor(); % Putting the string in a variable does not work.
\stopMPpage
\stoptext
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