Re: TWM: truetype support

On Mon, 5 Nov 2007, Eeri Kask wrote:
>>> So, luckily we are now a step closed to the solution:  let's not use
>>> 'fixed' as coded-in-default in twm.c if TWM_USE_XFT is defined, but
>>> '-*-fixed-*-*-*-*-*-*-*-*-*-*-*-*', and neither XListFonts() nor
>>> XftFontOpenXlfd() have any further difficulties!  (Is XListFonts()
>>> supposed to translate font alias names at all?)  This looks a good idea,
>>> in fact this is what you suggested first: let XListFonts() resolve
>>> 'fixed' and then use it.  Now we know how to do that. :-)

>>> (As a backside, we then remove the flexibility in twm to use the
>>> 'fixed'-alias-redirection to an arbitrary font.)

>> First, the X server does not even start if it cannot resolve 'fixed'.  In
>> that case, whether or not `twm` starts is a moot point.

>> Secondly, there are likely to be .twmrc's out there that specify other
>> aliases, such as '7x13' and so on.  Thus, it is important to fall back to a
>> raster font when Xft cannot resolve a font name, whether or not that name is
>> a default.  This makes it unnecessary to change twm's default font names.

> The good news is, Xft is hardly going to fail.

> One can easily put "A quick brown fox jumps over the lazy dog" for
> TitleFont into .twmrc as an amusing proof.  So if XLFD loading fails, we
> will in fact never enter the "fallback" branch in util.c in GetFont().

> But anyways, on our adventurous path to save "fixed" I'll put up a one
> more proposition.   What about the following code fragment at the
> beginning for GetFont() in util.c?   Now "fixed", "variable", "7x13" et
> cetera are fine as font names.   :-)

> ----8<----8<----

> void
> GetFont(MyFont *font)
> {
> #ifdef TWM_USE_XFT
>
>    XFontStruct *xlfd;
>    Atom  atom;
>    char *atom_name;
>
>    if (font->font != NULL) {
> 	XftFontClose (dpy, font->font);
> 	font->font = NULL;
>    }
>
>    /* test if core font: */
>    xlfd = XLoadQueryFont (dpy, font->name);
>    if (xlfd) {
> 	if (XGetFontProperty (xlfd, XA_FONT, &atom) == True) {
> 	    atom_name = XGetAtomName (dpy, atom);
> 	    if (atom_name) {
> 		font->font = XftFontOpenXlfd (dpy, Scr->screen, atom_name);
> 		XFree (atom_name);
> 	    }
> 	}
> 	XFreeFont (dpy, xlfd);
>    }
>
>    /* next, try Xft font: */
>    if (font->font == NULL)
> 	font->font = XftFontOpenName (dpy, Scr->screen, font->name);
>
>    /* fallback: */

>    ....

> ----8<----8<----

At first, I really liked this idea, but I now realize that, because your 
spacing changes (as I have them integrated) are only effective for Xft 
fonts, "Xft'ing" bitmap fonts would change twm's default behaviour.  Thus, 
I'd rather not call XftFontOpenXlfd(), which leaves me with a GetFont() 
function that looks like ...

void
GetFont(MyFont *font)
{
     if (font->fontset != NULL)
         XFreeFontSet(dpy, font->fontset);
     if (font->font != NULL)
         XFreeFont(dpy, font->font);

#ifdef TWM_USE_XFT

     if (font->xftfont != NULL)
         XftFontClose(dpy, font->xftfont);

     font->xftfont = XftFontOpenName(dpy, Scr->screen, font->name);
     if (font->xftfont != NULL) {
         font->height = font->xftfont->ascent + font->xftfont->descent;
         font->y = font->xftfont->ascent;
         font->ascent = font->xftfont->ascent;
         font->descent = font->xftfont->descent;
         return;
     }

#endif /* TWM_USE_XFT */

     if (use_fontset) {
         char **missing_charset_list_return;
         int missing_charset_count_return;
         char *def_string_return;
         XFontSetExtents *font_extents;
         XFontStruct **xfonts;
         int i, ascent, descent, fnum;
         char *basename2, **font_names;

         basename2 = (char *)malloc(strlen(font->name) + 3);
         if (basename2) {
             sprintf(basename2, "%s,*", font->name);
         } else
             basename2 = font->name;

         if( (font->fontset = XCreateFontSet(dpy, basename2,
                                             &missing_charset_list_return,
                                             &missing_charset_count_return,
                                             &def_string_return)) == NULL) {
             fprintf (stderr, "%s:  unable to open fontset \"%s\"\n",
                          ProgramName, font->name);
             exit(1);
         }

         if (basename2 != font->name)
             free(basename2);

         for(i=0; i<missing_charset_count_return; i++){
             printf("%s: warning: font for charset %s is lacking.\n",
                    ProgramName, missing_charset_list_return[i]);
         }

         font_extents = XExtentsOfFontSet(font->fontset);
         fnum = XFontsOfFontSet(font->fontset, &xfonts, &font_names);
         for( i = 0, ascent = 0, descent = 0; i < fnum; i++){
             if (ascent < (*xfonts)->ascent) ascent = (*xfonts)->ascent;
             if (descent < (*xfonts)->descent) descent = (*xfonts)->descent;
             xfonts++;
         }
         font->height = font_extents->max_logical_extent.height;
         font->y = ascent;
         font->ascent = ascent;
         font->descent = descent;
         return;
     }

     if ((font->font = XLoadQueryFont(dpy, font->name)) == NULL)
     {
         char *deffontname = Scr->DefaultFont.name;

         if (deffontname == NULL)
             deffontname = "fixed";

         if ((font->font = XLoadQueryFont(dpy, deffontname)) == NULL)
         {
             fprintf (stderr, "%s:  unable to open fonts \"%s\" or \"%s\"\n",
                      ProgramName, font->name, deffontname);
             exit(1);
         }

     }

     font->height = font->font->ascent + font->font->descent;
     font->y = font->font->ascent;
     font->ascent = font->font->ascent;
     font->descent = font->font->descent;
}

This means that, to use Xft, the user would need to specify a font name 
that is recognized by XftFontOpenName().

In looking over your latest patch sets, I notice a fair amount of activity 
in the Fixes and Appearance ones.  Do you now consider them as finalised? 
What about SloppyFocus?

I'm attaching a diff, against XFree86 CVS source, of those of your changes 
that I have so far integrated.

Lastly, do you intend to update twm's man page?

Thanks.

Marc.

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