Docs: flesh out config options in Usermanual:Install chapter.

diff --git a/docs/usermanual-install-harfbuzz.xml b/docs/usermanual-install-harfbuzz.xml
index f032b88..cd1e2e1 100644 (file)
--- a/docs/usermanual-install-harfbuzz.xml
+++ b/docs/usermanual-install-harfbuzz.xml
@@ -229,6 +229,10 @@
            <para>
              Allow linking with libstdc++. <emphasis>(Default = no)</emphasis>
            </para>
+           <para>
+             This option enables or disables linking HarfBuzz to the
+             system's libstdc++ library.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -236,8 +240,15 @@
          <term>--with-glib</term>
          <listitem>
            <para>
-            Use GLib. <emphasis>(Default = auto)</emphasis>
+            Use <ulink url="https://developer.gnome.org/glib/">GLib</ulink>. <emphasis>(Default = auto)</emphasis>
            </para>         
+           <para>
+             This option enables or disables usage of the GLib
+             library.  The default setting is to check for the
+             presence of GLib and, if it is found, build with
+             GLib support. GLib is native to GNU/Linux systems but is
+             available on other operating system as well.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -245,8 +256,15 @@
          <term>--with-gobject</term>
          <listitem>
            <para>
-             Use GObject. <emphasis>(Default = no)</emphasis>
-           </para>         
+             Use <ulink url="https://developer.gnome.org/gobject/stable/">GObject</ulink>. <emphasis>(Default = no)</emphasis>
+           </para>        
+           <para>
+             This option enables or disables usage of the GObject
+             library. The default setting is to check for the
+             presence of GObject and, if it is found, build with
+             GObject support. GObject is native to GNU/Linux systems but is
+             available on other operating system as well.
+           </para> 
          </listitem>
        </varlistentry>
        
@@ -254,8 +272,14 @@
          <term>--with-cairo</term>
          <listitem>
            <para>
-             Use Cairo. <emphasis>(Default = auto)</emphasis>
-           </para>         
+             Use <ulink url="https://cairographics.org/">Cairo</ulink>. <emphasis>(Default = auto)</emphasis>
+           </para>        
+           <para>
+             This option enables or disables usage of the Cairo
+             graphics-rendering library. The default setting is to
+             check for the presence of Cairo and, if it is found,
+             build with Cairo support.
+           </para> 
          </listitem>
        </varlistentry>
        
@@ -263,8 +287,15 @@
          <term>--with-fontconfig</term>
          <listitem>
            <para>
-             Use Fontconfig. <emphasis>(Default = auto)</emphasis>
+             Use <ulink url="https://www.freedesktop.org/wiki/Software/fontconfig/">Fontconfig</ulink>. <emphasis>(Default = auto)</emphasis>
            </para>         
+           <para>
+             This option enables or disables usage of the Fontconfig
+             library, which provides font-matching functions and
+             provides access to font properties. The default setting
+             is to check for the presence of Fontconfig and, if it is
+             found, build with Fontconfig support.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -272,8 +303,17 @@
          <term>--with-icu</term>
          <listitem>
            <para>
-             Use the ICU library. <emphasis>(Default = auto)</emphasis>
+             Use the <ulink url="http://site.icu-project.org/home">ICU</ulink> library. <emphasis>(Default = auto)</emphasis>
            </para>         
+           <para>
+             This option enables or disables usage of the
+             <emphasis>International Components for
+             Unicode</emphasis> (ICU) library, which provides access
+             to Unicode Character Database (UCD) properties as well
+             as normalization and conversion functions. The default
+             setting is to check for the presence of ICU and, if it
+             is found, build with ICU support.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -281,8 +321,17 @@
          <term>--with-ucdn</term>
          <listitem>
            <para>
-             Use the built-in UCDN library. <emphasis>(Default = auto)</emphasis>
+             Use HarfBuzz's <ulink url="https://github.com/harfbuzz/harfbuzz/tree/master/src/hb-ucdn">built-in UCDN library</ulink>. <emphasis>(Default = auto)</emphasis>
            </para>         
+           <para>
+             The HarfBuzz source tree includes a <emphasis>Unicode
+             Database and Normalization</emphasis> (UCDN) library
+             that provides access to basic character properties in
+             the Unicode Character Database (UCD) as well as low-level
+             normalization functions. HarfBuzz can be built without
+             this UCDN support if the usage of a different UCDN
+             library is desired.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -290,8 +339,13 @@
          <term>--with-graphite2</term>
          <listitem>
            <para>
-             Use the graphite2 library. <emphasis>(Default = no)</emphasis>
+             Use the <ulink url="http://graphite.sil.org/">Graphite2</ulink> library. <emphasis>(Default = no)</emphasis>
            </para>         
+           <para>
+             This option enables or disables usage of the Graphite2
+             library, which provides support for the Graphite shaping
+             model. 
+           </para>
          </listitem>
        </varlistentry>
        
@@ -299,8 +353,14 @@
          <term>--with-freetype</term>
          <listitem>
            <para>
-             Use the FreeType library. <emphasis>(Default = auto)</emphasis>
+             Use the <ulink url="https://www.freetype.org/">FreeType</ulink> library. <emphasis>(Default = auto)</emphasis>
            </para>         
+           <para>
+             This option enables or disables usage of the FreeType
+             font-rendering library. The default setting is to check for the
+             presence of FreeType and, if it is found, build with
+             FreeType support.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -308,8 +368,12 @@
          <term>--with-uniscribe</term>
          <listitem>
            <para>
-             Use the Uniscribe library. <emphasis>(Default = no)</emphasis>
+             Use the <ulink url="https://docs.microsoft.com/en-us/windows/desktop/intl/uniscribe">Uniscribe</ulink> library. <emphasis>(Default = no)</emphasis>
            </para>         
+           <para>
+             This option enables or disables usage of the Uniscribe
+             font-rendering library. Uniscribe is available on Windows systems.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -317,8 +381,12 @@
          <term>--with-directwrite</term>
          <listitem>
            <para>
-             se the DirectWrite library (experimental). <emphasis>(Default = no)</emphasis>
+             Use the <ulink url="https://docs.microsoft.com/en-us/windows/desktop/directwrite/direct-write-portal">DirectWrite</ulink> library (experimental). <emphasis>(Default = no)</emphasis>
            </para>         
+           <para>
+             This option enables or disables usage of the DirectWrite
+             font-rendering library. DirectWrite is available on Windows systems.
+           </para>
          </listitem>
        </varlistentry>
        
@@ -326,20 +394,14 @@
          <term>--with-coretext</term>
          <listitem>
            <para>
-             Use the CoreText library. <emphasis>(Default = no)</emphasis>
+             Use the <ulink url="https://developer.apple.com/documentation/coretext">CoreText</ulink> library. <emphasis>(Default = no)</emphasis>
            </para>         
-         </listitem>
-       </varlistentry>
-       
-       <varlistentry>
-         <term></term>
-         <listitem>
            <para>
-             <emphasis>(Default = no)</emphasis>
-           </para>         
+             This option enables or disables usage of the CoreText
+             library. CoreText is available on macOS and iOS systems.
+           </para>
          </listitem>
-       </varlistentry>
-       
+       </varlistentry> 
       </variablelist>
     </section>