--- loncom/xml/lontexconvert.pm	2005/02/24 09:28:54	1.51
+++ loncom/xml/lontexconvert.pm	2005/02/28 19:08:11	1.62
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # TeX Conversion Module
 #
-# $Id: lontexconvert.pm,v 1.51 2005/02/24 09:28:54 albertel Exp $
+# $Id: lontexconvert.pm,v 1.62 2005/02/28 19:08:11 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -117,12 +117,14 @@ sub convert_real {
     return ($xmlstring,$errorstring);
 }
 
-sub converted {
+sub tth_converted {
     my $texstring=shift;
     my $xmlstring='['.&mt('UNDISPLAYABLE').']';
     if ($Apache::lontexconvert::messedup) {
 	return '['.&mt('TeX unconverted due to previous errors').']';
     }
+    $$texstring ='\\documentstyle{article}'.$$texstring;
+
     eval(<<'ENDCONV');
     ($xmlstring,$errorstring)=&convert_real($texstring)
 ENDCONV
@@ -140,6 +142,58 @@ ENDCONV
     return $xmlstring;
 }
 
+sub clean_out_math_mode {
+    my ($texstring)=@_;
+    $$texstring=~s/(?!\\)\$//g;
+    $$texstring=~s/\\[\)\(\]\[]//g;
+    $$texstring=~s/\\ensuremath//g;
+    return '';
+}
+
+sub displaystyle {
+    my ($texstring)=@_;
+    #has a $$ or \[ or \displaystyle in it, guessinng it's display mode
+    if ($$texstring=~/[^\\]\$\$/ ||
+	$$texstring=~/\\\[/ ||
+	$$texstring=~/\\displaystyle/) { return 1; }
+    return 0;
+}
+
+sub jsMath_converted {
+    my $texstring=shift;
+    my $tag='span';
+    if (&displaystyle($texstring)) { $tag='div'; }
+    &clean_out_math_mode($texstring);
+    return '<'.$tag.' class="math">'.$$texstring.'</'.$tag.'>';
+}
+
+sub mimetex_converted {
+    my $texstring=shift;
+    my $displaystyle=&displaystyle($texstring);
+
+    &clean_out_math_mode($texstring);
+
+    if ($displaystyle) {
+	$$texstring='\\displaystyle \\Large '.$$texstring;
+    }
+    my $result='<img src="/cgi-bin/mimetex.cgi?'.&Apache::lonnet::escape($$texstring).'" />';
+    if ($displaystyle) {
+	$result='<center>'.$result.'</center>';
+    }
+    return $result;
+}
+
+sub converted {
+    if ($ENV{'environment.texengine'} eq 'tth') {
+	return &tth_converted;
+    } elsif ($ENV{'environment.texengine'} eq 'jsMath') {
+	return &jsMath_converted;
+    } elsif ($ENV{'environment.texengine'} eq 'mimetex') {
+	return &mimetex_converted;
+    }
+    return &tth_converted;
+}
+
 # ====================================================================== Footer
 
 sub footer {
@@ -215,7 +269,7 @@ sub msgtexconverted {
 sub algebra {
     use AlgParser;
 
-    my ($string,$target)=@_;
+    my ($string,$target,$style)=@_;
     my $parser = new AlgParserWithImplicitExpand;
     $string=&prepare_algebra($string);
     my $ret = $parser->parse($string);
@@ -225,7 +279,12 @@ sub algebra {
 	$parser->normalize();
 	my $latex=$parser->tolatex();
 	$latex=&postprocess_algebra($latex);
-	$latex='$'.$latex.'$';
+	if ($style eq 'display') {
+	    $latex='$$'.$latex.'$$x';
+	} else {
+	    # style is 'inline'
+	    $latex='\\ensuremath{'.$latex.'}';
+	}
 	if ($target eq 'web' || $target eq 'analyze') {
 	    $result = &converted(\$latex);
 	} else {
@@ -240,7 +299,7 @@ sub prepare_algebra {
     my ($string)=@_;
 
     # makes the decision about what is a minus sign easier supposedly
-    $string =~ s/([\=\>\<\%\!\#] *)-/$1 zeroplace -/g;
+    $string =~ s/(\<\>|\<\=|\>\=[\=\>\<] *)-/$1 zeroplace -/g;
 
     return $string;
 }
@@ -254,11 +313,27 @@ sub postprocess_algebra {
     # sqrt(3,4) -> \sqrt\let{3,4\right}, which is annoying
     $string =~s/\\left\{/\{/g;
     $string =~s/\\right\}/\}/g;
+
+    # remove the extra () in the denominator of a \frac
+    $string =~s/\\frac{(.+?)}{\\left\((.+?)\\right\)}/\\frac{$1}{$2}/gs;
     
     # sqrt(3,4) means the 4 root of 3
-    $string =~s/\\sqrt{([^,]+),([^}]+)}/\\sqrt[$2]{$1}/gs;
+    $string =~s/\\sqrt{([^,]+),([^\}]+)}/\\sqrt[$2]{$1}/gs;
+
+    # log(3,4) means the log base 4 of 3
+    $string =~s/\\log\\left\((.+?),(.+?)\\right\)/\\log_{$2}\\left($1\\right)/gs;
+
+    # log(3,4) means the log base 4 of 3
+    $string =~s/\\((?:sin|cos|tan|sec|csc|cot)(?:h)?)\\left\((.+?),(.+?)\\right\)/\\$1^{$3}\\left($2\\right)/gs;
+
+    # int(3,a,b) integral from a to b of 3
+    $string =~s/\\int\\left\((.+?),(.+?),(.+?)\\right\)/\\int_{$2}^{$3}\\left($1\\right)/gs;
+
+    # int( ... dx) -> ...
+    $string =~s/\\int\\left\((.+?)d[a-z]\\right\)/$1/gs;
 
-    &Apache::lonnet::logthis($string);
+    # 
+    $string =~s/\\lim\\left\((.+?),(.+?),(.+?)\\right\)/\\lim_{$2\\to $3}$1/gs;
     return $string;
 }
 1;