Fontconfig - Nov 2005 - Excluding fonts

On Tue, 2003-03-04 at 13:20, Keith Packard wrote:
> I''m thinking it would be nice to allow people to elide some fonts
from
> their configurations.  It seems like there are a couple of ways:
> 
> 	1)	exclude by path name -- have a regex that matches
> 		filenames and includes/excludes them.
> 
> 	2)	exclude by pattern -- have some match rules that
> 		select fonts by pattern and include/exclude them.
> 
> 1) would allow us to easily eliminate all .pcf.gz fonts from the 
> configuration while 2) would allow us to build "suitcases" if
combined
> with some conditional expressions based on X resources or environment 
> variables.
The Red Hat fontconfig package actually has the attached patch in
it. (I haven''t submitted for obvious total-hack reasons). A way to do
this as a config option would be nice.

While this patch is more like 1), I do actually know the full pathnames
to these fonts, so 2) would work as well, if it is perhaps a little
less robust. (They are from the ghostscript distribution and don''t
render properly with FreeType.)

Regards,
                                          Owen


-------------- next part --------------
--- fontconfig/src/fcdir.c.blacklist	Mon Aug 26 15:57:40 2002
+++ fontconfig/src/fcdir.c	Fri Aug 30 14:59:05 2002
@@ -150,6 +150,40 @@
     return ret;
 }
 
+static FcBool
+FcBlackListed (const char *name)
+{
+    static const char * const black_listed_names[] = {
+	"hrger.pfa",
+	"hrgrr.pfa",
+	"hritr.pfa",
+	"hrpld.pfa",
+	"hrpldi.pfa",
+	"hrplt.pfa",
+	"hrplti.pfa",
+	"hrscc.pfa",
+	"hrscs.pfa",
+	"u003043t.gsf",
+	"u004006t.gsf"
+    };
+
+    int low = 0;
+    int high = sizeof(black_listed_names) / sizeof(black_listed_names[0]) - 1;
+
+    while (low <= high) {
+	int mid = (low + high) / 2;
+	int res = strcmp (name, black_listed_names[mid]);
+	if (res == 0)
+	    return FcTrue;
+	else if (res < 0)
+	    high = mid - 1;
+	else
+	    low = mid + 1;
+    }
+
+    return FcFalse;
+}
+
 #define FC_MAX_FILE_LEN	    4096
 
 FcBool
@@ -201,7 +235,8 @@
     }
     while (ret && (e = readdir (d)))
     {
-	if (e->d_name[0] != ''.'' && strlen (e->d_name)
< FC_MAX_FILE_LEN)
+	if (e->d_name[0] != ''.'' && strlen (e->d_name)
< FC_MAX_FILE_LEN &&
+	    !FcBlackListed (e->d_name))
 	{
 	    strcpy ((char *) base, (char *) e->d_name);
 	    ret = FcFileScan (set, dirs, cache, blanks, file, force);

Around 14 o''clock on Mar 4, Owen Taylor wrote:
> While this patch is more like 1), I do actually know the full pathnames
> to these fonts, so 2) would work as well, if it is perhaps a little
> less robust. (They are from the ghostscript distribution and don''t
> render properly with FreeType.)
So, do you want to blacklist by filename or the contents of the file?

A filename match will be significantly faster than matching the values.
It would also let you skip fonts which freetype can''t even manage to
get
values for.  This seems appropriate for skipping fonts which aren''t 
compatible with the libraries as you have here.  Using a full pathname 
glob would let you exclude certain files wherever they occur in the system:

	*.pcf.gz

would get rid of all compressed bitmap fonts while

	/usr/X11R6/lib/X11/misc*

would eliminate the entire misc directory.  I''d do the matching on 
directory names before scanning which would short-circuit scanning them at 
startup time, reducing memory usage and speeding up application loading.
Managing ~/.fonts.cache might be complicated in this case, but I think we 
could manage even that.

Pattern matching would be quite straightforward, and as the pattern 
includes the filename, it would be a strict superset of the above 
functionality.  It would be quite a bit slower at startup time as
patterns would have to be computed and then discarded.  Again, ~/
.fonts.cache management would be complicated but probably managable.

-keith

I''m thinking it would be nice to allow people to elide some fonts from 
their configurations.  It seems like there are a couple of ways:

	1)	exclude by path name -- have a regex that matches
		filenames and includes/excludes them.

	2)	exclude by pattern -- have some match rules that
		select fonts by pattern and include/exclude them.

1) would allow us to easily eliminate all .pcf.gz fonts from the 
configuration while 2) would allow us to build "suitcases" if combined
with some conditional expressions based on X resources or environment 
variables.

Comments?

-keith