function texify($string, $dpi = '90', $r = 0.0, $g = 0.0, $b = 0.0, $br = 1.0, $bg = 1.0, $bb = 1.0, $extraprelude = "", $sharpen = FALSE)
{
global $imgfmt;
if ($dpi > 300) {
$dpi = 300;
}
$back = phplatex_colorhex($br, $bg, $bb);
$fore = phplatex_colorhex($r, $g, $b);
# Figure out TeX, either to get the right cache entry or to, you know, compile
# Semi-common (ams) symbol packages are included.
$totex = "\\documentclass[14pt,landscape]{extarticle}\n" . "\\usepackage{color}\n" . "\\usepackage{amsmath}\n\\usepackage{amsfonts}\n\\usepackage{amssymb}\n" . $extraprelude . "\n" . "\\pagestyle{empty}\n" . "\\begin{document}\n" . "\\color[rgb]{" . $r . "," . $g . "," . $b . "}\n" . "\\pagecolor[rgb]{" . $br . "," . $bg . "," . $bb . "}\n" . $string . "\n" . "\\end{document}\n";
$strhash = sha1($totex) . '.' . $dpi;
#file cache entry string: 40-char hash string plus size
$stralt = str_replace("&", "&", preg_replace("/[\"\n]/", "", $string));
#stuck in the alt and title attributes
#May need some extra safety.
$heredir = dirname(__FILE__);
#Experiment: Tries to guess vertical positioning fix that will look short rendered works look natural inside HTML text.
#Only descenders are really a problem since HTML's leeway is upwards.
#TODO: avoid using letters that are part of TeX commands.
# the slash varies per font. In the default CM it is, in Times and others it isn't.
$ascenders = "/(b|d|f|h|i|j|k|l|t|A|B|C|D|E|F|G|H|I|J|L|K|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z|\\[|\\]|\\{|\\}|\\(|\\)|\\/|0|1|2|3|4|5|6|7|8|9|\\#|\\*|\\?|'|\\\\'|\\\\`|\\\\v)/";
$monoliners = "/(a|c|e|m|n|o|r|s|u|v|w|x|z|-|=|\\+|:|.)/";
$descenders = "/(g|j|p|\\/|q|y|Q|,|;|\\[|\\]|\\{|\\}|\\(|\\)|\\#|\\\\LaTeX|\\\\TeX|\\\\c\\{)/";
$deepdescenders = "/(\\[|\\]|\\{|\\}|\\(|\\)|\\int)/";
$ba = preg_match_all($ascenders, $string, $m);
$bm = preg_match_all($monoliners, $string, $m);
$bd = preg_match_all($descenders, $string, $m);
$dd = preg_match_all($deepdescenders, $string, $m);
if ($dd > 0) {
$verticalalign = "vertical-align: -27%";
} else {
if ($bd > 0 && $ba == 0) {
$verticalalign = "vertical-align: -20%";
} else {
if ($bd == 0 && $ba > 0) {
$verticalalign = "vertical-align: -1%";
} else {
if ($bd == 0 && $ba == 0) {
$verticalalign = "vertical-align: -2%";
} else {
$verticalalign = "vertical-align: -19%";
}
}
}
}
# both ascender and regular descender
#check image cache, return link if exists
#the vertical-align is to fix text baseline/descender(/tail) details in and on-average sort of way
if (file_exists($heredir . '/texImages/' . $strhash . '.' . $imgfmt)) {
return '<img style="' . $verticalalign . '" title="' . $stralt . '" alt="LaTeX formula: ' . $stralt . '" src="texImages/' . $strhash . '.' . $imgfmt . '">';
}
#chdir to have superfluous file be created in tmp.
if (chdir("/tmp") === FALSE) {
return false;
}
#I should chech whether file creation is allowed to give a nice error for that problem case
$tfn = tempnam("/tmp", 'PTX');
#file in tmp dir
#write temporary .tex file
if (($tex = fopen($tfn . '.tex', "w")) == FALSE) {
return false;
}
fwrite($tex, $totex);
fclose($tex);
#Run latex to create a .dvi. Try to fix minor errors instead of breaking/pausing on them.
exec('latex --interaction=nonstopmode ' . $tfn . '.tex');
if (!file_exists($tfn . ".dvi")) {
phplatex_cleantmp($tfn, $heredir);
return false;
}
exec('dvipng -bg Transparent -q -T tight ' . $tfn . ' -o ' . $tfn . '.' . $imgfmt);
if (!file_exists($tfn . '.' . $imgfmt)) {
phplatex_cleantmp($tfn, $heredir);
return false;
}
#Copy result image to chache.
copy($tfn . '.' . $imgfmt, $heredir . '/texImages/' . $strhash . '.' . $imgfmt);
#Clean up temporary files, and return link to just-created image
phplatex_cleantmp($tfn, $heredir);
return '<img style="' . $verticalalign . '" title="' . $stralt . '" alt="LaTeX formula: ' . $stralt . '" src="texImages/' . $strhash . '.' . $imgfmt . '">';
}
function texify($string, $dpi = '90', $r = 0.0, $g = 0.0, $b = 0.0, $br = 1.0, $bg = 1.0, $bb = 1.0, $extraprelude = "", $sharpen = FALSE)
{
//global $imgfmt,$path_to_latex,$path_to_dvips,$path_to_convert;
// For some reason the globals don't work
$path_to_latex = '/usr/bin/latex';
$path_to_dvips = '/usr/bin/dvips';
$path_to_convert = '/usr/bin/convert';
$imgfmt = "png";
#literally used in extensions, and in parameters to convert. Should be either png or gif.
if ($dpi > 300) {
$dpi = 300;
}
$back = phplatex_colorhex($br, $bg, $bb);
$fore = phplatex_colorhex($r, $g, $b);
# Figure out TeX, either to get the right cache entry or to, you know, compile
# Semi-common (ams) symbol packages are included.
$totex = "\\documentclass[14pt,landscape]{extarticle}\n" . "\\usepackage{color}\n" . "\\usepackage{amsmath}\n\\usepackage{amsfonts}\n\\usepackage{amssymb}\n" . $extraprelude . "\n" . "\\pagestyle{empty}\n" . "\\begin{document}\n" . "\\color[rgb]{" . $r . "," . $g . "," . $b . "}\n" . "\\pagecolor[rgb]{" . $br . "," . $bg . "," . $bb . "}\n" . $string . "\n" . "\\end{document}\n";
$strhash = sha1($totex) . '.' . $dpi;
#file cache entry string: 40-char hash string plus size
$stralt = str_replace("&", "&", preg_replace("/[\"\n]/", "", $string));
#stuck in the alt and title attributes
#May need some extra safety.
$heredir = getcwd();
#Experiment: Tries to adjust vertical positioning, so that rendered TeX text looks natural enough inline with HTML text
#Only descenders are really a problem since HTML's leeway is upwards.
#TODO: This can always use more work.
# Avoid using characters that are part of TeX commands.
# Some things vary per font, e.g. the slash. In the default CM it is a descender, in Times and others it isn't.
$ascenders = "/(b|d|f|h|i|j|k|l|t|A|B|C|D|E|F|G|H|I|J|L|K|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z|\\[|\\]|\\{|\\}|\\(|\\)|\\/|0|1|2|3|4|5|6|7|8|9|\\#|\\*|\\?|'|\\\\'|\\\\`|\\\\v)/";
$monoliners = "/(a|c|e|m|n|o|r|s|u|v|w|x|z|-|=|\\+|:|.)/";
$descenders = "/(g|j|p|\\/|q|y|Q|,|;|\\[|\\]|\\{|\\}|\\(|\\)|\\#|\\\\LaTeX|\\\\TeX|\\\\c\\{)/";
$deepdescenders = "/(\\[|\\]|\\{|\\}|\\(|\\)|\\int)/";
$ba = preg_match_all($ascenders, $string, $m);
$bm = preg_match_all($monoliners, $string, $m);
$bd = preg_match_all($descenders, $string, $m);
$dd = preg_match_all($deepdescenders, $string, $m);
if ($dd > 0) {
$verticalalign = "vertical-align: -25%";
} else {
if ($bd > 0 && $ba == 0) {
$verticalalign = "vertical-align: -15%";
} else {
if ($bd == 0 && $ba > 0) {
$verticalalign = "vertical-align: 0%";
} else {
if ($bd == 0 && $ba == 0) {
$verticalalign = "vertical-align: 0%";
} else {
$verticalalign = "vertical-align: -15%";
}
}
}
}
# both ascender and regular descender
#check image cache, return link if exists
#the vertical-align is to fix text baseline/descender(/tail) details in and on-average sort of way
if (file_exists($heredir . '/images/' . $strhash . '.' . $imgfmt)) {
return '<img style="' . $verticalalign . '" title="' . $stralt . '" alt="' . $stralt . '" src="images/' . $strhash . '.' . $imgfmt . '">';
}
#chdir to have superfluous files be created in tmp. (you stiill have to empty this yourself)
error_reporting(0);
# not checking existence myself, that would be double.
if (chdir("tmp") === FALSE) {
return '[directory access error, fix permissions]';
}
#I should chech whether file creation is allowed to give a nice error for that problem case
error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);
# TODO: set old value
$tfn = tempnam(getcwd(), 'PTX');
#file in tmp dir
#write temporary .tex file
if (($tex = fopen($tfn . '.tex', "w")) == FALSE) {
return '[file access error] ' . phplatex_cleantmp($tfn, $heredir);
}
fwrite($tex, $totex);
fclose($tex);
#Run latex to create a .dvi. Have it try to fix minor errors instead of breaking/pausing on them.
exec($path_to_latex . ' --interaction=nonstopmode ' . $tfn . '.tex');
if (!file_exists($tfn . ".dvi")) {
$log = file_get_contents($tfn . '.log');
#The log always exists, but now it's actually interesting since it'll contain an error
return '[latex error, code follows]<pre>' . $totex . '</pre><p><b>Log file:</b><pre>' . $log . '</pre></p> ' . phplatex_cleantmp($tfn, $heredir);
}
#DVI -> PostScript. Since dvips uses lpr, which may be configured to actually print by default, force writing to a file with -o
exec($path_to_dvips . ' ' . $tfn . '.dvi -o ' . $tfn . '.ps');
if (!file_exists($tfn . '.ps')) {
return '[dvi2ps error] ' . phplatex_cleantmp($tfn, $heredir);
}
#PostScript -> image. Trim based on corner pixel, and set transparent color.
exec($path_to_convert . ' -transparent-color "#' . $back . '" -colorspace RGB -density ' . $dpi . ' -trim +page ' . $tfn . '.ps -transparent "#' . $back . '" ' . $tfn . '.' . $imgfmt);
#Note: +page OR -page +0+0 OR +repage moves the image to the cropped area (kills offset)
#Older code tried: exec('/usr/bin/mogrify -density 90 -trim +page -format $imgfmt '.$tfn.'.ps');
# It seems some versions of convert may not have -trim. Old versions?
if (!file_exists($tfn . '.' . $imgfmt)) {
return '[image convert error] ' . phplatex_cleantmp($tfn, $heredir);
}
#Copy result image to chache.
copy($tfn . '.' . $imgfmt, $heredir . '/images/' . $strhash . '.' . $imgfmt);
#Clean up temporary files, and return link to just-created image
return phplatex_cleantmp($tfn, $heredir) . '<img style="' . $verticalalign . '" title="' . $stralt . '" alt="LaTeX formula: ' . $stralt . '" src="images/' . $strhash . '.' . $imgfmt . '">';
}