[Boost-docs] Inline math phrase and fixed interline spacing in html

Subject: [Boost-docs] Inline math phrase and fixed interline spacing in html
From: Samuel Debionne (debionne_at_[hidden])
Date: 2007-11-20 10:05:30

Hello all,
I'm using QuickBook/BoostBook for my project and finds it very usefull.  
Since it's a scientific computing project, I have a lot of equations in  
the user documentation. So far, I follow the method develloped by John  
Maddock to create the MathML/PNG/SVG equations and it does a great job  
[1]. I use the attached QuickBook template to insert equation,  
inleeqation, informalequation [2].

These eqations are explained in a text paragraph which includes math  
phrases with (a lot of) super/sub scripts. The transformation goes this  
way :

QBK          -> DOCBOOK                       -> HTML
Foo[sub bar] -> Foo<subscript>bar</subscript> -> Foo<sub>bar</sub>

The problem is that html <sub> and <super> makes the interline spacing  
variable... and the document ugly. A solution is to use CSS for sub and  
super script.

QBK          -> DOCBOOK                                             -> HTML
Foo[sub sat] -> Foo<subscript role="math">barsubscript role="math"> ->  
Foo<span class="subscript">bar</span>

I added the following int he customization layer for html (html.xsl) :

<xsl:template match="superscript[@role = 'math']">
   <xsl:param name="content">
     <xsl:call-template name="anchor"/>
     <xsl:call-template name="simple.xlink">
       <xsl:with-param name="content">
         <xsl:apply-templates/>
       </xsl:with-param>
     </xsl:call-template>
   </xsl:param>
   <span class="math-superscript">
     <xsl:copy-of select="$content"/>
   </span>
</xsl:template>

<xsl:template match="subscript[@role = 'math']">
   <xsl:param name="content">
     <xsl:call-template name="anchor"/>
     <xsl:call-template name="simple.xlink">
       <xsl:with-param name="content">
         <xsl:apply-templates/>
       </xsl:with-param>
     </xsl:call-template>
   </xsl:param>
   <span class="math-subscript">
     <xsl:copy-of select="$content"/>
   </span>
</xsl:template>

And in the css :

p
{
     text-align: left;
     font-size: 10pt;
     line-height: 1.5; /* not the greater spacing */
}

.math-superscript
{
        position: relative;
        bottom: 0.5em;
        font-size: 0.8em;
}

.math-subscript
{
        position: relative;
        top: 0.3em;
        font-size: 0.8em;
}

Hoping it could help,
Samuel

[1] I noticed that a much "smoother" PNG file can be obtained directly  
 from MathCast (rather that using Batik) when the Windows XP ClearType  
options is set.
[2] To be added to the upcoming quickbook template library ? Is there any  
place to contribute ?