[doc] Document remaining CAIRO_HAS_* macros

I'm sure I had done them all before.  No idea what happened.
Perhaps gtk-doc was not seeing them as missing.

4 files changed, 8 insertions, 4 deletions

diff --git a/doc/public/tmpl/cairo-ft.sgml b/doc/public/tmpl/cairo-ft.sgml
index 0aac4829..68a3fd43 100644
--- a/doc/public/tmpl/cairo-ft.sgml
+++ b/doc/public/tmpl/cairo-ft.sgml
@@ -22,7 +22,8 @@ systems, but can be used on other platforms too.
 
 <!-- ##### MACRO CAIRO_HAS_FT_FONT ##### -->
 <para>
-
+Defined if the FreeType font backend is available.
+This macro can be used to conditionally compile backend-specific code.
 </para>
 
 
diff --git a/doc/public/tmpl/cairo-quartz-fonts.sgml b/doc/public/tmpl/cairo-quartz-fonts.sgml
index 3e7cd4d1..0c6a73f1 100644
--- a/doc/public/tmpl/cairo-quartz-fonts.sgml
+++ b/doc/public/tmpl/cairo-quartz-fonts.sgml
@@ -23,7 +23,8 @@ implementation of the font backend methods.
 
 <!-- ##### MACRO CAIRO_HAS_QUARTZ_FONT ##### -->
 <para>
-
+Defined if the Quartz font backend is available.
+This macro can be used to conditionally compile backend-specific code.
 </para>
 
 
diff --git a/doc/public/tmpl/cairo-quartz.sgml b/doc/public/tmpl/cairo-quartz.sgml
index 78fe8de7..bd3d7681 100644
--- a/doc/public/tmpl/cairo-quartz.sgml
+++ b/doc/public/tmpl/cairo-quartz.sgml
@@ -22,7 +22,8 @@ Apple OS X Quartz rendering system.
 
 <!-- ##### MACRO CAIRO_HAS_QUARTZ_SURFACE ##### -->
 <para>
-
+Defined if the Quartz surface backend is available.
+This macro can be used to conditionally compile backend-specific code.
 </para>
 
 
diff --git a/doc/public/tmpl/cairo-xlib.sgml b/doc/public/tmpl/cairo-xlib.sgml
index 9e33a174..446d4a68 100644
--- a/doc/public/tmpl/cairo-xlib.sgml
+++ b/doc/public/tmpl/cairo-xlib.sgml
@@ -26,7 +26,8 @@ if it is available.
 
 <!-- ##### MACRO CAIRO_HAS_XLIB_SURFACE ##### -->
 <para>
-
+Defined if the Xlib surface backend is available.
+This macro can be used to conditionally compile backend-specific code.
 </para>