Re: [NTG-context] image file resolver in Lua?

On Sun, Feb 04, 2018 at 01:06:08PM +0100, Hans Hagen wrote:

On 2/3/2018 7:57 AM, Rudolf Bahr wrote:

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On Fri, Feb 02, 2018 at 04:17:32PM +0100, Henning Hraban Ramm wrote:

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Am 2018-02-02 um 12:08 schrieb Rudolf Bahr :

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On Fri, Feb 02, 2018 at 08:40:08AM +0100, Henning Hraban Ramm wrote:

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Ahoi,

I’m using a Lua function to calculate image sizes, cropping etc. This snippet:

local filename = figures.current().status.fullname local pic = img.scan{filename = filename}

... works most of the time, but sometimes the "current" image is the previous one, might be because I’m using layers and postponing. So I’d like to use just the same filename as I give to \externalfigure, i.e. without path and extension. How can I address the same file path resolver in my Lua function?

Moin, Hraban,

where could I find something about those lua functions?

Maybe here: http://source.contextgarden.net/tex/context/base/mkiv/grph-inc.lua

The image placement functions I’m using are something Hans and others helped me accomplish during the last meeting; AFAIK there’s no real documentation.

Find attached the lua part. It’s probably more complicated than necessary

I could work around my original problem: I’m using my image with \externalfigure in an invisible place first, so it’s current, and figures.current().status is the right one. :)

Here’s my (convoluted) placement macro:

% image on empty page, caption in margin % usage: % \startpostponing[pagenumber] % \pagefig[reference]{caption}{filename} % \stoppostponing % postponing is important, otherwise the page numbering gets wrong \def\pagefig{\dosingleempty\doPagefig} \def\doPagefig[#1]#2#3{ % calculate image size \startfullpagemakeup \externalfigure[#3][width=1mm] % dummy to set image as current \def\myClipHeight{\ctxlua{ctxClipHeight("#3", \Resolution)}} \def\mystartY{\ctxlua{ctxStartY("#3", \Resolution)}} % image \setlayerframed[bglayer][% frame=off, offset=overlay, x=21mm, y=\mystartY, height=\myClipHeight, width=\textwidth, align=flushleft, ]{% \clip[ width=\textwidth, height=\myClipHeight, hoffset=0mm, voffset=0mm, % i.e. clip bottom! TODO: options! ]{\externalfigure[#3][width=\textwidth]} } \textreference[pre#1]{\myImgHeight} % caption \setlayerframed[bglayer][% frame=off, offset=overlay, linecorrection=on, x=143mm,y=\dimexpr\mystartY + 3pt\relax, height=\myClipHeight, width=\outermarginwidth, align={flushleft,low}, valign=bottom, ]{% \vbox{ \textreference[#1]{\strut #2}\vfill #2 }} \stopfullpagemakeup }

usage example:

\startpostponing[82] \pagefig[alinari-stelzen]{Gebrüder Alinari (Florenz, 19. Jhd.)}{ka34/img/Gebr-Alinari_Kinder_auf_Stelzen} \stoppostponing

Greetlings, Hraban --- http://www.fiee.net http://wiki.contextgarden.net GPG Key ID 1C9B22FD

Moin Hraban!

It's very interesting for me to see, how exactly you calculate the size of images and texts with the help of lua!

Up to now I used to use python and a independend lua to provide some necessary data for context. For instance python invokes graphicsmagick in order to get the size of images. Because it's provided in px and not in pt, so often some further manual work is unavoidable.

Now, since lua and metafun are well integrated into context it suggests itself to use luatex instead of python, though I like this language very much.

Thank you very much, Hraban, for putting your macros and links at my disposal! Not sure what you want top know but a lot of image properties can be checked by prerolling:

\starttext

\getfiguredimensions[t:/sources/cow.pdf]

\starttabulate[|T|T|] \NC \string\figurewidth \NC \figurewidth \NC \NR \NC \string\figureheight \NC \figureheight \NC \NR \NC \string\figurexscale \NC \figurexscale \NC \NR \NC \string\figureyscale \NC \figureyscale \NC \NR \TB \NC \string\figuresize \NC \figuresize \NC \NR \NC \string\figurelabel \NC \figurelabel \NC \NR \NC \string\figurefileoriginal \NC \figurefileoriginal \NC \NR \NC \string\figurefilepage \NC \figurefilepage \NC \NR \NC \string\figurefileoptions \NC \figurefileoptions \NC \NR \NC \string\figurefileconversion\NC \figurefileconversion\NC \NR \NC \string\figurefileresolution\NC \figurefileresolution\NC \NR \NC \string\figurefilecolor \NC \figurefilecolor \NC \NR \NC \string\figurefilearguments \NC \figurefilearguments \NC \NR \NC \string\figurefilecache \NC \figurefilecache \NC \NR \NC \string\figurefileprefix \NC \figurefileprefix \NC \NR \TB \NC \string\figurenaturalwidth \NC \figurenaturalwidth \NC \NR \NC \string\figurenaturalheight \NC \figurenaturalheight \NC \NR \NC \string\figurexresolution \NC \figurexresolution \NC \NR \NC \string\figureyresolution \NC \figureyresolution \NC \NR \NC \string\figureorientation \NC \figureorientation \NC \NR \NC \string\figurerotation \NC \figurerotation \NC \NR \NC \string\figurexsize \NC \figurexsize \NC \NR \NC \string\figureysize \NC \figureysize \NC \NR \NC \string\figurecolordepth \NC \figurecolordepth \NC \NR \NC \string\figuredepth \NC \figuredepth \NC \NR \TB \NC \string\figurefullname \NC \figurefullname \NC \NR \NC \string\noffigurepages \NC \noffigurepages \NC \NR \TB \NC \string\figurefilepath \NC \figurefilepath \NC \NR \NC \string\figurefilename \NC \figurefilename \NC \NR \NC \string\figurefiletype \NC \figurefiletype \NC \NR \stoptabulate

\stoptext

This is very good and useful, thank you, Hans! I need this to set a bunch of family history books with plenty of photos, texts, family trees, journey diaries, scans, index of persons etc. With the help of context+luatex+metafun I'd like to set the pages hopefully without the need of too much manual corrections, i.e in a as far as possible automated way. There is a lot of material, especially nowadays the flood of digital pictures. At the moment I succeed in setting only 2 or 3 such year-books per year. Thanks again for your help, Rudolf