Re: font renderers in gdk

[raster redhat com]

On 27 Jan, Owen Taylor shouted:
->  
->  Christoph Toshok <toshok@Hungry.COM> writes:
->  
->  > struct _GdkFontRendererVtable
->  > {
->  >   gint		(*GetAPIVersion)(GdkFontRenderer *);
->  >   const gchar*	(*GetName)(GdkFontRenderer *);
->  >   const gchar*	(*GetVendor)(GdkFontRenderer *);
->  >   const gchar*	(*GetVersion)(GdkFontRenderer *);
->  >   const gchar*	(*GetBlurb)(GdkFontRenderer *);
->  >   gint		(*CountFonts)(GdkFontRenderer *);
->  >   gint		(*ListFonts)(GdkFontRenderer *, const gchar **font_specs);
->  >   GdkFont*	(*LoadFont)(GdkFontRenderer *, const gchar *font_spec, gint is_fontset);
->  >   void		(*DestroyFont)(GdkFontRenderer *, GdkFont *font);
->  >   void		(*RenderString)(GdkFontRenderer *, GdkDrawable *,
->  > 				GdkFont *font,
->  > 				GdkGC *gc,
->  > 				const gchar *string,
->  > 				gint length, gint x, gint y);
->                                               ^^^^^^^^^^^^^^
->  
->  For antialiased text, "phases" (non-integer coordinates) are essential
->  to get really good results. 
->  
->  And as somebody pointed out, rotation should probably be in here
->  too. (How many people know that X11R6 supports rotated fonts? (but
->  not rotated text strings, unfortunately))

Actually.. I do.. :) but I'm just cray enought to want to know these
things:):) (the matrix XFLD- tranforms - just use a matrix transform on
your font chars - it only affects the chars. You have to draw each by
hand and calculate new co-ordinates - I actually wrote a library to do
this - libFont, but scrapped it and staretd on libFn. I was just way too
unhappy with X's font mechanisms).

->  
->  >   void		(*GetAscentDescent)(GdkFontRenderer *, GdkFont *font, gint *ascent, gint *descent);
->  >   gint		(*GetAdvancement)(GdkFontRenderer *, GdkFont *font, gchar *character, gint length);
->  >   gint		(*GetMaxAdvancement)(GdkFontRenderer *, GdkFont *font);
->  >   gint		(*StringWidth)(GdkFontRenderer *, GdkFont *font,
->  > 			       const gchar *string, gint length);
->  >   gint		(*FontEqual)(GdkFontRenderer *, GdkFont *fonta, GdkFont *fontb);
->  > };
->  
->  [...]
->  
->  > Would you guys be interested in something like this?  Do you think the
->  > Gdk guys would be (are there any gdk guys on this list?)  If anyone is
->  > interested in diff's to the gtk+ tip, let me know.
->  
->  As one "GTK/GDK guy" I'd say that I think people would be interested
->  in this type of thing in GTK (though not exactly immediately).
->  But I'm not sure that keeping the same API and only modifying the
->  internal is the right way to do things. 
->  
->  X's font handling is quite primitive, and if we want to start
->  adding rendering on the client side, we should provide something
->  better. Something things to look at:
->  
->  The two available free engines
->    - t1lib    
->    - FreeType
->  
->  And QuickDraw GX, which by general consensus has the best typographic
->  model ever made publically available.
->  
->  Of course, I don't know if GTK needs to be _that_ good. But it
->  shouldn't be limited by the current X font model.

I agree, but it is a step forward - much better than anything sofar. I
will work on Fnlib for full color font support, others may with to work
on another lib using Freetyp or t1lib for anti-aliased fonts. This is
going to be a big task on its own, so I may wait a while. I have other
issues on my plate at the moment.

->  Regards,
->                                          Owen
->  
->  

-- 
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