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-rw-r--r--src/phplatex.php142
-rw-r--r--src/writing/derivative.php16
-rw-r--r--src/writing/images/.gitignore1
-rw-r--r--src/writing/index.php20
-rw-r--r--src/writing/tmp/.gitignore1
5 files changed, 173 insertions, 7 deletions
diff --git a/src/phplatex.php b/src/phplatex.php
new file mode 100644
index 0000000..f8bebeb
--- /dev/null
+++ b/src/phplatex.php
@@ -0,0 +1,142 @@
+<?php
+# Written by scarfboy@gmail.com.
+# Use at your own risk.
+# See README for usage details.
+
+#In case these are elsewhere
+$path_to_latex = '/usr/bin/latex';
+$path_to_dvips = '/usr/bin/dvips';
+$path_to_convert = '/usr/bin/convert';
+
+$imgfmt="png"; # used in extensions, and in parameters to convert. Should be either png or gif.
+
+
+function phplatex_cleantmp($tempfname,$todir) {
+ # removes the various files that probably got created for a specific run, based on the run's filename.
+ global $imgfmt;
+ if (chdir($todir)===FALSE) { return '[directory access error, fix permissions (and empty tmp manually this time)]'; }
+ error_reporting(0); #at least one of these probably will not exist, but disable the error reporting related to that.
+ unlink($tempfname); #the longer/cleaner way would be check for existance for each
+ unlink($tempfname.".tex"); unlink($tempfname.".log");
+ unlink($tempfname.".aux"); unlink($tempfname.".dvi");
+ unlink($tempfname.".ps"); unlink($tempfname.".".$imgfmt);
+ error_reporting(E_ERROR | E_PARSE | E_WARNING | E_NOTICE);
+ #try-catch would have been nice. This is rather overkill too, the way I use it.
+ return '';
+}
+
+function phplatex_colorhex($r,$g,$b) {
+ #there has to be a better way of doing this. It's not even particularly clean.
+ $hex=array("","","");
+ if(strlen($hex[0]=dechex(round(min(255*$r,255))))==1){ $hex[0]="0".$hex[0]; }
+ if(strlen($hex[1]=dechex(round(min(255*$g,255))))==1){ $hex[1]="0".$hex[1]; }
+ if(strlen($hex[2]=dechex(round(min(255*$b,255))))==1){ $hex[2]="0".$hex[2]; }
+ return implode("",$hex);
+}
+
+
+function texify($string,$dpi='90', $r=0.0,$g=0.0,$b=0.0, $br=1.0,$bg=1.0,$bb=1.0,$extraprelude="", $trans=FALSE) {
+ global $imgfmt,$path_to_latex,$path_to_dvips,$path_to_convert;
+ if ($dpi>300) $dpi=300;
+
+ $back = phplatex_colorhex($br,$bg,$bb);
+ $fore = phplatex_colorhex($r,$g,$b);
+
+ # Figure out TeX string, either to get the right cache entry, or to compile
+ # Adds semi-common symbol packages (ams)
+ # used to include ,landscape in documentclass to avoid page wrapping, but it seems this sometimes implies 90 degree rotation
+ $totex = "\\documentclass[14pt]{extarticle}\n".
+ "\\usepackage{color}\n".
+ "\\usepackage{amsmath}\n\\usepackage{amsfonts}\n\\usepackage{amssymb}\n".
+ $extraprelude."\n".
+ "\\pagestyle{empty}\n". #removes header/footer; necessary for trim
+ "\\begin{document}\n".
+ "\\color[rgb]{".$r.",".$g.",".$b."}\n".
+ "\\pagecolor[rgb]{".$br.",".$bg.",".$bb."}\n".
+ $string."\n".
+ "\\end{document}\n";
+ $hashfn = sha1($totex).".".$dpi.".".$fore.".".$back.".".intval($trans); #file cache entry string: 40-char hash string plus size
+ $stralt = str_replace("&","&amp;", preg_replace("/[\"\n]/","",$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.
+ # Some things vary per font, e.g. the slash. In the default CM it is a descender, in Times and others it isn't.
+ # TODO: This can always use more work.
+ # TODO: Avoid using characters that are part of TeX commands.
+ $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)/";
+
+ error_reporting(0);
+ $ba = preg_match_all($ascenders, $string,$m);
+ $bm = preg_match_all($monoliners, $string,$m);
+ $bd = preg_match_all($descenders, $string,$m);
+ $dd = preg_match_all($deepdescenders, $string,$m);
+ error_reporting(E_ERROR | E_PARSE | E_WARNING | E_NOTICE);
+ if ($dd>0) $verticalalign="vertical-align: -25%"; # deep descenders: move down
+ else if ($bd>0 && $ba==0) $verticalalign="vertical-align: -15%"; # descenders: move down
+ else if ($bd==0 && $ba>0) $verticalalign="vertical-align: 0%"; # ascenders only: move up/do nothing?
+ else if ($bd==0 && $ba==0) $verticalalign="vertical-align: 0%"; # neither vertical-align: 0%
+ else $verticalalign="vertical-align: -15%"; # both ascender and regular descender
+
+
+ # check if image for that TeX in the cache, return img HTML if it exists
+ if (file_exists($heredir.'/images/'.$hashfn.'.'.$imgfmt))
+ return '<img style="'.$verticalalign.'" title="'.$stralt.'" alt="'.$stralt.'" src="images/'.$hashfn.'.'.$imgfmt.'">';
+
+ # otherwise try to make and store:
+
+ # chdir to have superfluous files be created in just one place, tmp/ (you probably want to occasionally clean this yourself)
+ error_reporting(0); # TODO: fetch current value so we can restore it
+ if (chdir("tmp")===FALSE) { return '[tmp directory access error, please fix permissions]'; } #I should think about some more specific errors, e.g. check whether file creation is allowed
+ error_reporting(E_ERROR | E_PARSE | E_WARNING | E_NOTICE);
+
+ $tfn = tempnam(getcwd(), 'PTX'); # unique base path in tmp dir
+
+ #write temporary .tex file
+ if ( ($tex = fopen($tfn.'.tex', "w"))==FALSE) { return '[tex file access error] '.phplatex_cleantmp($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. Also trim based on corner pixel and set transparent color.
+ $convert_cmd = $path_to_convert;
+ if ($trans) {
+ $convert_cmd .= ' -transparent-color "#'.$back.'" -transparent "#'.$back.'"';
+ }
+ $convert_cmd .= ' -colorspace RGB -density '.$dpi.' -trim +page '.$tfn.'.ps '.$tfn.'.'.$imgfmt;
+
+ exec($convert_cmd);
+ #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, $heredir.'/images/'.$hashfn.'.'.$imgfmt);
+
+ # Clean up temporary files, and return link to just-created image
+ return phplatex_cleantmp($tfn,$heredir).'<img style="'.$verticalalign.'" title="'.$stralt.'" alt="LaTeX formula: '.$stralt.'" src="images/'.$hashfn.'.'.$imgfmt.'">';
+}
+?>
diff --git a/src/writing/derivative.php b/src/writing/derivative.php
new file mode 100644
index 0000000..28bc00d
--- /dev/null
+++ b/src/writing/derivative.php
@@ -0,0 +1,16 @@
+<?php
+$title = "The Calculus of Infinitesimals";
+require($_SERVER["DOCUMENT_ROOT"] . "/head.php");
+require($_SERVER["DOCUMENT_ROOT"] . "/header.php");
+include($_SERVER["DOCUMENT_ROOT"] . "/phplatex.php");
+?>
+<p>
+ <i>Calculus</i> is often used as the complete name of a branch of mathematics dealing with
+ rates of change and very small numbers. In fact, a calculus is a specific discipline
+ or method for the analysis of some set of problems. The fact that the <i>calculus of infinitesimals</i>
+ has come to known in this way is a testament to its importance.
+</p>
+<p>
+ <?php echo(texify("$\\sqrt[3]{2}\$", 160, 0.96,0.96,0.96, 0.118,0.106,0.106, "", TRUE)); ?>
+</p>
+<?php require($_SERVER["DOCUMENT_ROOT"] . "/footer.php"); ?>
diff --git a/src/writing/images/.gitignore b/src/writing/images/.gitignore
new file mode 100644
index 0000000..f935021
--- /dev/null
+++ b/src/writing/images/.gitignore
@@ -0,0 +1 @@
+!.gitignore
diff --git a/src/writing/index.php b/src/writing/index.php
index bba0f99..c354f70 100644
--- a/src/writing/index.php
+++ b/src/writing/index.php
@@ -11,26 +11,32 @@ require($_SERVER["DOCUMENT_ROOT"] . "/header.php");
</p>
<h2>Essays</h2>
<p>
- Moderately structured, opinionated writing. If you're the psychoanalytical type, you may be interested to know
- that I find it much more fun to deconstruct a question than to construct an answer.
+ Moderately structured, opinionated writing.
</p>
<ul>
- <li><h3><a href="cryptography.php">Cryptography</a> /* Because secret messages are cool */</h3></li>
- <li><h3><a href="moralrealism.php">Moral realism</a> /* Because people make a big deal out of murder */</h3></li>
+ <li><h3><a href="cryptography.php">Cryptography</a> - because secret messages are cool</h3></li>
+ <li><h3><a href="moralrealism.php">Moral realism</a> - because people make a big deal out of murder</h3></li>
+</ul>
+<h2>Mathematics</h2>
+<p>
+ My writing in Greek.
+</p>
+<ul>
+ <li><h3><a href="derivative.php">The Calculus of Infinitesimals</a> - an introduction</h3></li>
</ul>
<h2>Manifestos</h2>
<p>
Plural. For future-proofness.
</p>
<ul>
- <li><h3><a href="systemsmanifesto.php">Systems</a> /* A microcosm of reality */</h3></li>
+ <li><h3><a href="systemsmanifesto.php">Systems</a> - a microcosm of reality</h3></li>
</ul>
<h2>Esoterica</h2>
<p>
The fun stuff.
</p>
<ul>
- <li><h3><a href="corrigenda.php">Corrigenda</a> /* Everything I've ever done wrong */</h3></li>
- <li><h3><a href="epiphenomenalism.php">Epiphenomenalism</a> /* You aren't in control */</h3></li>
+ <li><h3><a href="corrigenda.php">Corrigenda</a> - everything I've ever done wrong</h3></li>
+ <li><h3><a href="epiphenomenalism.php">Epiphenomenalism</a> - you aren't in control</h3></li>
</ul>
<?php require($_SERVER["DOCUMENT_ROOT"] . "/footer.php"); ?>
diff --git a/src/writing/tmp/.gitignore b/src/writing/tmp/.gitignore
new file mode 100644
index 0000000..f935021
--- /dev/null
+++ b/src/writing/tmp/.gitignore
@@ -0,0 +1 @@
+!.gitignore
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-07-01 17:39:16 +0000