From 6b05f4e005149b71ce31485d2fe1bee6d9842950 Mon Sep 17 00:00:00 2001
From: eudoxia <uplink@distress.network>
Date: Wed, 10 Nov 2021 16:50:31 -0500
Subject: switched math rendering backend to KaTeX (deprecates svgtex.sh)

---
 md.sh     | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 svgtex.sh | 51 -----------------------------------------
 2 files changed, 70 insertions(+), 60 deletions(-)
 delete mode 100755 svgtex.sh

diff --git a/md.sh b/md.sh
index 3e44052..79cc580 100755
--- a/md.sh
+++ b/md.sh
@@ -38,7 +38,7 @@ OUT="$1/index.html"
 [ $(which lowdown) ] ||	{ printf "%s \tFATAL: lowdown not found\n" "[->]" ; exit 1 ; }
 
 cat md-header > $OUT
-lowdown -Thtml $IN >> $OUT
+lowdown -Thtml --html-no-owasp $IN >> $OUT
 cat md-footer >> $OUT
 printf "[ok] \tinitial assembly\n"
 
@@ -89,23 +89,21 @@ sed '/^<!--title:/d' -i'' $OUT ;
 printf "[ok] \tsitemap\n" ;
 fi
 
-[ "$(grep -n '<p><img' $OUT)" ] && {
-
-grep -n '<p><img' $OUT | \
+[ "$(grep -n '<p><img' $OUT)" ] && {	# skip if no figures found
+# escaping backslashes with '@', to be unescaped later:
+grep -n '<p><img' $OUT | sed 's/\\/@/g' | \
 while IFS='' read -r data ; do
 	LINE=$(echo $data | cut -f 1 -d :) ;	# extract line number
 	FILE=$(echo $data | cut -f 2 -d \") ;	# extract file path
 	CAPT=$(echo $data | cut -f 4 -d \") ;	# extract image caption
 
-	if [ "$CAPT" = "#tex" ] ; then 		# for tex figures: only remove caption and containers
-		sed "${LINE}s;.*;<figure><img src=\"${FILE}\" alt=\"\"></figure>;" -i'' $OUT ;
-		printf "[ok] \ttex figure at line %s\n" "$LINE" ;
+	if [ "$FILE" = "%tex" ] ; then 		# for tex figures (to be caught and rendered later)
+		sed "${LINE}s;.*;<figure><%tex \"${CAPT}\" /></figure>;" -i'' $OUT ;
 	else
 		sed "${LINE}s;.*;<figure><a href=\"${FILE}\"><img src=\"${FILE}\" alt=\"\"></a><figcaption><p>${CAPT}</p></figcaption></figure>;" -i'' $OUT ;
 		printf "[ok] \timage at line %s\n" "$LINE" ;
 	fi
 done
-
 }
 
 
@@ -143,7 +141,7 @@ cat $tmp | while IFS='' read -r data ; do
 	fi ;
 	if [ "$HEADER" = "</ul>" ] ; then
 		IDLINE="" ;
-	fi ;
+	fi ;	# TODO use case expr instead
 	if [ "$IDLINE" ] ; then
 		sed "${IDLINE}s;id=\".*\">.*</h;id=\"${ID}\">${HEADER}</h;" -i'' $OUT ;
 		printf "\tassembled header: %s\n" "$(echo $HEADER | unesc)" ;
@@ -167,6 +165,64 @@ printf "[ok] \ttable of contents\n"
 }
 
 
+math() {
+
+# [ $(npx katex -V 2>&1 | grep '404 Not Found') ] && { printf "[warn] \tkatex not found, skipping math rendering\n" ; return ; }
+
+sed '/main.css/a <link rel="stylesheet" href="/css/katex.css">' -i'' $OUT
+
+# display / "block" style:
+grep -n '<figure><%tex' $OUT | \
+while IFS='' read -r data ; do
+	LINE=$(echo "$data" | cut -f 1 -d :) ;
+	EQNBODY=$(echo "$data" | cut -f 2 -d \" ) ;
+	printf "\trendering tex figure at line %s ... " "$LINE" ;
+	
+	tmp=$(mktemp -p /tmp) ;
+	echo "<figure>" > $tmp ;
+	echo "$EQNBODY" | sed 's/@/\\/g' | npx katex -d 2>&1 >> $tmp ;
+	echo "</figure>" >> $tmp ;
+	sed ':a;N;$!ba;s/\n//g' -i'' $tmp ;
+
+	if [ $(grep "KaTeX parse error" $tmp) ] ; then
+		printf "\n[warn] \ttex expression at line %s contained errors, skipping\n" "$LINE" ;
+	else
+		sed "${LINE}d" -i'' $OUT ;
+		sed "$(expr $LINE - 1)r $tmp" -i'' $OUT ;
+		printf "complete\n" ;
+	fi ;
+
+	rm $tmp ;
+done
+
+# inline / "span" style:
+sed 's;<img src="%itex" alt=".*" />;\n&\n;g' -i'' $OUT
+grep -n '<img src="%itex"' $OUT | sed 's/\\/@/g' | \
+while IFS='' read -r data ; do
+	LINE=$(echo "$data" | cut -f 1 -d :) ;
+	EQNBODY=$(echo "$data" | cut -f 4 -d \" ) ;
+	printf "\trendering inline tex figure at line %s ... " "$LINE" ;
+	
+	tmp=$(mktemp -p /tmp) ;
+	echo "$EQNBODY" | sed 's/@/\\/g' | npx katex 2>&1 > $tmp ;
+	sed ':a;N;$!ba;s/\n//g' -i'' $tmp ;
+
+	if [ $(grep "KaTeX parse error" $tmp) ] ; then
+		printf "\n[warn] \tinline tex expression at line %s contained errors, skipping\n" "$LINE" ;
+	else
+		sed "${LINE}d" -i'' $OUT ;
+		sed "$(expr $LINE - 1)r $tmp" -i'' $OUT ;
+		printf "complete\n" ;
+	fi ;
+
+	rm $tmp ;
+done
+
+printf "[ok] \tmath typesetting\n"
+
+}
+
+
 opts=$(grep -e '^opts: ' -m 1 $IN | cut -f 2- -d ' ')
 while [ "$opts" ]; do
 case "$opts" in
@@ -188,6 +244,11 @@ case "$opts" in
 		opts=$(echo $opts | sed 's/[Hh]//g')
 	;;
 
+	(*[Mm]*)
+		math
+		opts=$(echo $opts | sed 's/[Mm]//g')
+	;;
+
 	(*)
 		printf "[warn] \tmetadata: unrecognized option(s) \"%s\"\n" "${opts}" 
 	;;
diff --git a/svgtex.sh b/svgtex.sh
deleted file mode 100755
index 5098954..0000000
--- a/svgtex.sh
+++ /dev/null
@@ -1,51 +0,0 @@
-#!/bin/sh
-set -e
-
-# usage: echo "<equation>" | ./svgtex.sh <output path>
-
-# Copyright 2019-2021 DistressNetwork° <uplink@distress.network>
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-tmp=$(mktemp -p /tmp)
-eqn=$(cat /dev/stdin)
-
-printf "[ok] \teqn: %s\n" "$eqn"
-
-echo "\\\documentclass[10pt,fleqn]{standalone}
-\\\usepackage{standalone,amsmath,amssymb,xcolor}
-\\\begin{document}
-\\\color[HTML]{DDDDDD}" >> $tmp
-
-printf "\\\[ %s \\\]\n" "$eqn" >> $tmp
-
-echo "\\\end{document}" >> $tmp
-
-# now this is where the fun begins
-
-latex -interaction=batchmode $tmp > /dev/null
-
-[ -f tmp.dvi ] || { printf "%s \tFATAL: tex output failed\n" "[->]" ; exit 1 ; } # make sure output exists before continuing
-
-printf "[ok] \ttex finished typesetting\n"
-
-dvisvgm tmp.dvi -f ttf -T S2 > /dev/null 2>&1
-
-printf "[ok] \tconversion to svg\n"
-
-mv tmp.svg $1 # final move to desired path
-
-rm tmp.aux tmp.log tmp.dvi $tmp # cleanup
-
-printf "%s \tbuild complete: %s\n" "[->]" "$1"
-- 
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