December 2020 - ntg-context - NTG Mailing Lists

new font trickery
by Hans Hagen 23 Dec '20

23 Dec '20

Hi, I finally decided to start an experiment that I had on my todo list for a while: dynamically scaling fonts. Below is an example of usage (plus some comment). In that example some 2*200 different font sizes are used which in mkiv demands 400 font definitions. This costs time and memory. The example below runs (on my old laptop) in less than 2 seconds and only uses two instances. I bet that our CJK users will love it. I post it because: (1) I need to discuss the impact with Wolfgang ... how do we integrate this. We can for instance define some sizes (\tfa \tfb ...) differently. (2) I want to see if average performance improves on huge documents with many fonts / sizes (that is for Massimiliano to test). (3) Are there side effects? It does work for math (rather neat trickery) but maybe we need an additional configration for that. (4) I considered several variants but for now use a low level \glyphscale command that takes a number (in goodl old tex tradition a scale of 1.0 is entered as 1000). (5) The implementation can be improved a bit (performance wise). There is a bit more overhead involved but usually I can compensate that. (6) It will not be backported to MKIV so one can only test in LMTX. it's a bit of a mix between engine and context features. (7) There can be bugs (unforseen side effects, or typos in the somewhat quick patches in the source). Consider it an experiment, but so far I'm rather satisfied, Hans %%%% EXAMPLE %%%% \setuplayout[middle] \setupbodyfont[pagella,10pt] \setupalign[verytolerant,stretch] \setupwhitespace[big] \starttext \startbuffer \definescaledfont[bfe][scale=2000,style=bf] \setuphead[chapter][style=\bfe] \dostepwiserecurse {10} {2020} {10} { \title{Here we go #1!} \start \glyphscale#1\relax \setupinterlinespace \samplefile{ward}% \bf \samplefile{ward} \par \stop \page } \stopbuffer \getbuffer \title{Scaled fonts} Although \CONTEXT\ is quite efficient with fonts there is always room for improvement. However, after years of finetuning the font mechanisms there was not that much room left. This made me think of a different approach to scaling. Nowadays fonts seldom come in design sizes. Also, in \CONTEXT\ \MKIV\ and therefore \LMTX\ we always had so called dynamic features: apply additional features locally, although that comes with a small penalty in performance, it saves additional font instances. It is a good approach for the occasional small stretch of glyphs, like small capped logos and such. We now can also do dynamic font scaling, which means that we don't need to define a new font instance when the same feature set is used. Or course in addition to this features one can still use the dynamic features. This means that for instance chapter titling can use the bodyfont instance and just apply additional scaling. Although for a normal run the number of loaded fonts is normally small, and the number of instances also isn't that impressive it can happen in a large document that you end up with a few dozen. That number can now be reduced to half a dozen. Of course there can be side effects, whcich is why it's currently tagged as experimental. There is also a small performance hit because we now need to track it but that is gained back because we load less fonts and have less glyph runs. It even works in math, although there some different trickery is needed. \typebuffer \stoptext ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

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cow-font
by Peter Münster 23 Dec '20

23 Dec '20

Hi, How could I make use of the cow-font please? I've tried this test-file: --8<---------------cut here---------------start------------->8--- \setupbodyfont[cow] \starttext test \stoptext --8<---------------cut here---------------end--------------->8--- But the page is empty. With version 2017.08.29 it worked well... TIA for any help, -- Peter

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issue with \cite in ConTeXt ver: 2020.12.22 22:14 LMTX fmt: 2020.12.22
by Alan Bowen 22 Dec '20

22 Dec '20

\cite no longer works as expected MWE: \startsetups[tightspace] \spaceskip 0.5\interwordspace plus.5\interwordstretch minus \interwordshrink \stopsetups \def\dostartbibitem[#1][#2]% {\doifsomethingelse{#2}% {\startBibItem[reference={#1},title={#2}]}% {\startBibItem[reference={#1},title={#1}]}% } \def\startbibitem{\dodoubleempty\dostartbibitem} \def\stopbibitem{\stopBibItem} \definedescription[BibItem][ width=broad, margin=1.5pc, indenting={no}, indentnext=no, alternative=hanging, hang=1, headcommand=\gobbleoneargument, align=right, before={\directsetup{tightspace}\bgroup\language[packed]}, after={\egroup}, ] \definereferenceformat [cite] [type=title,left={},right={}] \definereferenceformat [bibpage] [type=page] starttext Now \cite[test 2020] on page \page \startbibitem[test 2020] \input ward \stopbibitem \stoptext Instead of “Now test 2020 on page”, I get “Now 248>BibItem:referencetext on page” and no sign of an internal link. Alan

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Snooping around in LMTX: Questions about Lua global variables
by Neven Sajko 22 Dec '20

22 Dec '20

Hello again, While learning about how to drive TeX through Lua, I decided to recursively list all Lua global variables (actually this is traversing the _G table) in the LMTX environment, half to learn more Lua, half for getting to know ConTeXt better. I was quite surprised by the huge size of the environment, a file that contains the listing of all the globals is 42 MB long! I wonder if it would be possible to reduce the exposed globals by replacing some of them by getter and setter-like functions? That seems like it would be much nicer and less error prone - because Lua is so dynamic, polluting the global namespace seems even more dangerous than in C-like languages. I guess it could also be more performant, because Lua would conceivably spend less time managing huge tables. There were also some global variables with suspicious random variation in values between runs of ConTeXt: I ran my Lua script like so multiple times (attached, in case someone is interested in it): context s.lua rm s.tuc s.pdf s.log And I found that the values of some variables unpredictably and randomly vary: The variable resolvers.suffixmap.lua sometimes has the value "scripts", and sometimes "lua". I think this means that files with the file name suffix ".lua" are sometimes classified as general scripts and sometimes as Lua scripts. This seems like it could even be a bug? The variables storage.tofmodules and storage.toftables are also interesting: they vary from run to run like this: tofmodules: 0.175483 0.149536 0.150493 0.150005 toftables: 0.008407 0.008118 0.008395 0.008116 I'd like to know what is their purpose, if it's not to involved to explain? Thanks, Neven

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LMTX, PGF/TikZ absolute positioning
by Jean-Philippe Rey 22 Dec '20

22 Dec '20

Dear list, I have a problem with LMTX when I try to place a tikz drawing at an absolute location on the page. Here is a minimal failing example. ======================= \usemodule[tikz] \starttext \starttikzpicture[remember picture, overlay] \draw (current page.center) circle [radius=20mm]; \stoptikzpicture \stoptext ======================= The error is about \hoffset being undefined (see attached log file). Everything works fine with MkIV. Thank you for any help. -- Jean-Philippe Rey jean-philippe.rey(a)centralesupelec.fr 91192 Gif-sur-Yvette Cedex - France Empreinte PGP : 807A 5B2C 69E4 D4B5 783A 428A 1B5E E83E 261B BF51

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Regarding XML export and EPUB
by Andres Conrado Montoya 22 Dec '20

22 Dec '20

Hello, list. I've been experimenting with the export scripts and the instructions and manuals you can find in: https://wiki.contextgarden.net/XML https://wiki.contextgarden.net/Export https://wiki.contextgarden.net/Epub https://wiki.contextgarden.net/ePub This with the expectation of being able to make an epub file form a context document that epubcheck can accept. I see there is an experimental support for epub, and I have played around with the export options a bit. However, what I would really want to know is. It's possible and if so, how can you map context's elements so they can get translated to specific html tags? I mean, the current export output uses divs with custom attributes and classes, or custom tags; but I would like to map lists to ul, list-items to li, headings to h1, h2, h3, paragraphs to <p> etc. In the manuals I see that you can do the opposite: map xml/html tags to context's elements; I wonder if you can go the other way around, and a good place to start reading about it. Apologies if I missed something obvious. Thank you. -- Andrés Conrado Montoya Andi Kú andresconrado(a)gmail.com http://sesentaycuatro.com http://messier87.com http://chiquitico.org ---------------------------------------- Los fines no justifican los medios, porque la medida verdadera de nuestro carácter está dada por los medios que estamos dispuestos a utilizar, no por los fines que proclamamos. ---------------------------------------- “You develop an instant global consciousness, a people orientation, an intense dissatisfaction with the state of the world, and a compulsion to do something about it. From out there on the moon, international politics look so petty. You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, ‘Look at that, you son of a bitch.’” — Apollo 14 astronaut Edgar Mitchell

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Re: [NTG-context] Polar pgfplots seems to be broken (Aditya Mahajan)
by Gavin 21 Dec '20

21 Dec '20

> Date: Mon, 21 Dec 2020 00:51:06 -0500 (EST) > From: Aditya Mahajan <adityam(a)umich.edu> > > On Sun, 20 Dec 2020, Gavin wrote: > >> Hello, >> >> I’m drawing solar system diagrams using the pgfplots module, but the polar library seem to be broken. It looks like it is calling something with a \begin{axis}... command. Here is the error message for a short document, included below. >> >>> tex error > tex error on line 18 in file /Users/Gavin/Documents/Computer/ConTeXt/Polar Plot Experiments/Untitled.tex: ! Undefined control sequence >>> >>> \pgfplots@environment@polaraxis@ [#1]->\begin >>> {axis}[#1,data cs=polar,axis type=polar] >>> l.18 \startpolaraxis[] >>> >>> 16 \startsection[title={Polar Plot}] >>> 17 \starttikzpicture % tikz code >>> 18 >> \startpolaraxis[] >>> 19 \addplot+[mark=none,domain=0:720,samples=600]{sin(4*x)}; >>> 20 \stoppolaraxis >>> 21 \stoptikzpicture >>> 22 \stopsection >>> >>> mtx-context | fatal error: return code: 256 >> >> I’d love a fix or an idea for a work around. > > This is a bug in pgfplots macro pgfplotsdefineaxistype, which uses an explicit \begin{axis} ... \end{axis} instead of the more portable \axis ... \endaxis. Attached is a quick fix, but it has been quite a while since I looked at pgfplots code, so it may be better to post a bug-report on pgfplots mailing list for a proper fix. > > Aditya > > URL: <http://mailman.ntg.nl/pipermail/ntg-context/attachments/20201221/d7278aca/a…> Aditya, Thanks for the quick fix! I will post a bug report on the pgfplots mailing list, including your helpful diagnosis of the problem. Gavin

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Off-topic: Struggles with LPEG grammar
by Mojca Miklavec 21 Dec '20

21 Dec '20

Hi, I'm sorry for being slightly off-topic here, but this list might still be the best place to resolve lpeg-related questions :) 0.) Disclaimer: the challenge that triggered this curiosity came from Advent of Code 2020. In case you are taking part and you wan't to avoid spoilers, please stop reading here! (You have been warned.) https://adventofcode.com/2020/day/19 1.) My question: I don't understand why I cannot get ^1 to work "as advertised". Isn't this supposed to mean "one or more occurences of the pattern"? If I change "lpeg.P('b')" into "lpeg.P('b')^1" in the example below, the strings that match the initial grammar no longer match the modified grammar. (I would naively imagine that the secord pattern would get more rather than less matches.) 2.) Background: Most definitely the task on that page is supposed to be solved in a different way, but many people use Advent of Code as an opportunity to learn a new programming language, and when I read the task description, I wanted to figure out if I could solve it using the cute little lpeg. My initial attempt worked correctly (at least to solve the first puzzle), but then I realized that I cannot easily change the pattern from "matches a letter b" into "matches any number of b-s", and I fail to figure out why. Any hints would be greatly appreciated. Below is a not-so-minimal example. I can certainly try to reduce it further, but I would first like to ask whether I'm doing something obviously wrong by trying to replace r5 = lpeg.P('b') by r5 = lpeg.P('b')^1 in order to allow more than one occurrences of the letter b? My only explanation would be that perhaps "^1" is so greedy that the rest of the pattern doesn't get found. But I don't want to believe that explanation. local lpeg = require "lpeg" --[[ 0: 4 1 5 1: 2 3 | 3 2 2: 4 4 | 5 5 3: 4 5 | 5 4 4: "a" 5: "b" ]]-- local parser = lpeg.P{ "r0"; r0 = lpeg.V"r4" * lpeg.V"r1" * lpeg.V"r5", r1 = lpeg.V"r2" * lpeg.V"r3" + lpeg.V"r3" * lpeg.V"r2", r2 = lpeg.V"r4" * lpeg.V"r4" + lpeg.V"r5" * lpeg.V"r5", r3 = lpeg.V"r4" * lpeg.V"r5" + lpeg.V"r5" * lpeg.V"r4", r4 = lpeg.P('a'), r5 = lpeg.P('b'), } * -1 local parser1 = lpeg.P{ "r0"; r0 = lpeg.V"r4" * lpeg.V"r1" * lpeg.V"r5", r1 = lpeg.V"r2" * lpeg.V"r3" + lpeg.V"r3" * lpeg.V"r2", r2 = lpeg.V"r4" * lpeg.V"r4" + lpeg.V"r5" * lpeg.V"r5", r3 = lpeg.V"r4" * lpeg.V"r5" + lpeg.V"r5" * lpeg.V"r4", r4 = lpeg.P('a'), r5 = lpeg.P('b')^1, -- modified part that doesn't seem to work } * -1 strings = { "ababbb", "bababa", "abbbab", "aaabbb", "aaaabbb", }; local total = 0 local total1 = 0 for _, s in ipairs(strings) do if lpeg.match(parser, s) then total = total + 1 end if lpeg.match(parser1, s) then total = total + 1 end end print('total:', total, total1) In this example, total=2, total1=0. What I don't understand is why total1 is zero. Thank you, Mojca

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Problem with \Caps
by Joaquín Ataz López 21 Dec '20

21 Dec '20

Good day to everyone. I have a problem that may be very simple to solve, but for which I have not found an answer in the wiki. Until relatively recently I was using the January 2020 version of ConTeXt Standalone, recently I have updated it to the December 18th version, and when I compile a file that I used to compile well, an error is generated because the \Caps macro is not recognized. I can't get the desired effect with \sc, it has to be with \Caps. I have tried to compile it with LMTX but there too is considered that \Caps is an undefined control sequence. -- Joaquín Ataz López Derecho Civil Universidad de Murcia

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Problem with shading in Metafun (LMTX)
by Jairo A. del Rio 21 Dec '20

21 Dec '20

While shading works with MkIV, with LMTX the following breaks: \startMPpage comment("two shades with named colors"); fill fullcircle scaled 5cm withshademethod "circular" withshadecolors ((1,0,0),(0,0,1,0)) ; fill fullcircle scaled 5cm shifted (6cm,0) withshademethod "circular" withcolor (1,0,0,0) shadedinto "blue" ; \stopMPpage The log says: metafun > log > metafun > log > error: Unknown relation will be considered false metafun > log > metapost > log > metapost > log > <to be read again> metapost > log > : metapost > log > <for(100.21985)> if(EXPR0)>temp_any_u: metapost > log > temp_any_u:=(EXPR0);fi ENDFOR metapost > log > max->begingroup.save.temp_any_u;if.pair(EXPR2):pair.temp_any_u.elseif.string(EXPR2): string.temp_any_u.fi ;temp_any_u=(EXPR2)for.i=(TEXT3):if.i>temp_any_u:temp_any_u:=i;fi.endfor metapost > log > .temp_any_u.endgroup metapost > log > mfun_max_radius->...er(EXPR2)-xpart.center(EXPR2))++(ypart.center(EXPR2)-ypart.lrcorner(EXPR2)),(xpart.urcorner(EXPR2)-xpart.center(EXPR2))++(ypart.urcorner(EXPR2)-ypart.center(EXPR2))) metapost > log > endgroup metapost > log > withshademethod->...cimal.center(EXPR0)withprescript"sh_center_b="&ddecimal.center(EXPR0)withprescript"sh_radius_a="&decimal0withprescript"sh_radius_b="&decimal.mfun_max_radius((EXPR0)) metapost > log > fi metapost > log > <to be read again> metapost > log > withprescript metapost > log > withshadecolors->...hprescript"sh_color_a_"&decimal.mfun_shade_step&"="&colordecimals(EXPR0)withprescript"sh_color_b_"&decimal.mfun_shade_step&"="&colordecimals(EXPR1)else:withprescript metapost > log > "sh_color=in... metapost > log > <*> comment("two shades with named colors"); fill fullcircle scaled 5cm withshademethod "circular" withshadecolors ((1,0,0),(0,0,1,0)) metafun > log > metafun > log > Oh dear. I can't decide if the expression above is positive, negative, or zero. So this comparison test won't be 'true'. metafun > log > metapost > log > ; fill fullcircle scaled 5cm shifted (6cm,0) withshademethod "... metapost > log > Hans told me not to use the B tag, so I'm asking first in case I've missed something. Thank you in advance. Best regards, Jairo

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