A question about fonts
martyj19 at comcast.net
Thu Mar 10 02:16:58 PST 2011
On 03/10/2011 03:14 AM, Andersen, Jan wrote:
> So your problem is that the web browser you are using fails to display
> all the glyphs? That sounds like an issue with that application. I
> would think all main web browsers today would have proper font switching
> support. That is, if the font they are using does not support a
> specific glyph, they will use a different font for that glyph. A
> possible complication could be if there is a font on the system that
> claims to support the glyph but renders it as a "glyph-not-found" shape.
> (I think I have seen that happen.)
> It would probably make sense to take the question to the web browser's
> (That isn't to say that X and related technologies (e.g. fontconfig)
> can't be improved to make it easier for applications to do proper font
> switching, of course.)
> Thanks for helping, Eirik.
> I'm not really sure the problem is the browser as such - the characters that are missing in the browser are also missing in the font when I look at them with Fontforge, and then there is the problem with a large number of them being outside the range of any single font. I suppose this is something you wouldn't really come across much unless you try to do something like what I am doing, where you systematically go through everything. Missing characters I simply fill in when I have time, so the only remaining problem is the sheer size of the set of characters.
> So, I will go away and study fontconfig now. Thanks to everybody for being so patient with me.
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The issue with creating a font that merges everything is more of an intellectual property issue, and a design consistency issue.
Fonts are created by type designers who expect to be paid for their work, and they are covered by copyright. Some cost a good deal of money. It is only by the good graces of a few donations that we are able to have freely available fonts like the Bitstream Vera family (and its large-coverage derivative DejaVu) and the later Liberation and Ubuntu.
So because of the copyrights and design consistency (all the glyphs in a family come from the same design thinking), you can't just pile all the glyphs together into one big file and call it done.
That is why the fonts are kept separate and the Fontconfig layer searches diligently for a fallback through them until it fails completely. Who knows your work might discover a case where it is buggy and failing to find something that is there. In any event you could crosscheck the coverage maps. I hope you will publish your results when you are done.
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