[Devel] PCF bitmap width fix (was: Compressed PCF fonts)

[Detlef Würkner]

address@hidden (Keith Packard) wrote:

> PCF "properties" hold the X font property data.  These are arbitrary name->
> value mappings, with the values as either strings or numbers.  The core X 
> protocol defines no particular properties, but the XLFD spec does -- there 
> are lots of them.  Here's the list that the XLFD defines; most of these 
> have the obvious definitions:
> 
> FOUNDRY | FAMILY_NAME | WEIGHT_NAME | SLANT | SETWIDTH_NAME |
> ADD_STYLE_NAME | PIXEL_SIZE | POINT_SIZE | RESOLUTION_X | RESOLUTION_Y |
> SPACING | AVERAGE_WIDTH | CHARSET_REGISTRY | CHARSET_ENCODING | QUAD_WIDTH
            ^^^^^^^^^^^^^
[...]
> 
> A complete specification for these is available in the XFree86 distribution
> (xc/doc/specs/XLFD/xlfd.tbl.ms).

Thanks for the information! Now I could create a patch for the PCF driver
that sets the correct width of the font if available, instead of always
using the same value for width and height. This is useful especially for
calculating the pixel width of monospaced fonts.

----8<----
--- freetype-2.0.7/src/pcf/pcfread.c.ori        Tue Feb  5 13:57:35 2002
+++ freetype-2.0.7/src/pcf/pcfread.c    Tue Feb  5 15:57:24 2002
@@ -982,8 +982,13 @@
       prop = find_property( face, "PIXEL_SIZE" );
       if ( prop != NULL )
       {
-        root->available_sizes->width  = (FT_Short)( prop->value.integer );
         root->available_sizes->height = (FT_Short)( prop->value.integer );
+        prop = find_property( face, "AVERAGE_WIDTH" );
+        if ( prop != NULL )
+          root->available_sizes->width =
+            (FT_Short)( prop->value.integer / 10 );
+        else
+          root->available_sizes->width = root->available_sizes->height;
         
         size_set = 1;
       }
@@ -992,20 +997,25 @@
         prop = find_property( face, "POINT_SIZE" );
         if ( prop != NULL )
         {
-          PCF_Property  xres = 0, yres = 0;
+          PCF_Property  xres, yres, avgw;
 
 
           xres = find_property( face, "RESOLUTION_X" );
           yres = find_property( face, "RESOLUTION_Y" );
-              
-          if ( ( xres != NULL ) && ( yres != NULL ) )
+          avgw = find_property( face, "AVERAGE_WIDTH" );
+
+          if ( ( yres != NULL ) && ( ( xres != NULL ) || ( avgw != NULL ) ) )
           {
-            root->available_sizes->width =
-              (FT_Short)( prop->value.integer *  
-                          xres->value.integer / 720 );
             root->available_sizes->height =
               (FT_Short)( prop->value.integer *  
                           yres->value.integer / 720 ); 
+            if ( avgw != NULL )
+              root->available_sizes->width =
+                (FT_Short)( avgw->value.integer / 10 );
+            else
+              root->available_sizes->width =
+                (FT_Short)( prop->value.integer *  
+                            xres->value.integer / 720 );
                   
             size_set = 1;
           }
----8<----

BTW, http://ftp.xfree86.org/pub/XFree86/4.2.0/binaries/Common/Xfnts.tgz
seems to have a small problem, tested only with
lib/X11/fonts/75dpi/cour???-ISO8859-1.pcf, it seems that
lib/X11/fonts/75dpi/cour?08-ISO8859-1.pcf (the 8 point variants)
are not monospaced?

Ciao, Detlef
-- 
_ // address@hidden
\X/  Detlef Wuerkner, Langgoens/Germany