RE: Can browsers show text? I don't think so

From: Marco Cimarosti (
Date: Thu Jul 04 2002 - 12:27:35 EDT

Michael Jansson wrote:
> > Marco Cimarosti wrote:
> > > A variant of approach 2) is to support pre-composed Unicode
> > > text, e.g.
> >
> > If I understand what you mean, I totally disagree.
> I am not proposing using PUA or introducing new code points
> to do this. You would still have valid Unicode characters
> in the page (of sorts). The characters would be ordered
> visually though,

That is what I understood. And I still *totally* disagree.

Logical order is not an optional feature of Unicode: it is mandatory.

Transmitting text in visual order is simply not Unicode: it is a hack for
which you'd better chose another name.

> and contain extra information
> to let the user agent (the browser, a.k.a. 'ua') know which
> alternate form to use for a character.

It sounds totally useless: this extra information is already implicitly
contained in the text, and it is called "context".

If the browser (or "ua") contains a properly implemented display engine,
including a proper Bidi Algorithm, this extra information is totally

Whether or not this display engine will use embedded fonts, is a totally
different issue.

> [...] The downside is that you would have visually ordered
> Unicode text.

Sorry. The downside is that it would not be "Unicode".

> This is less than ideal of course, [...]

Much less than ideal, in fact: it is a poor hack.

> > Of course, you do need a "code point" for any glyph, but that
> > would be just
> > an internal "glyph ID": a private convention bound to a
> > certain font format,
> > which would not affect the way the document is encoded and
> > transmitted.
> I don't see why you need code points in this case. A ua can
> easily render text with nothing but glyph index as input,

Of course it can. But I fail to see why you want to call it a "Unicode" ua.

> > Mapping a string of code points to a string of glyph ID's was
> > relatively
> > easy; mapping the other way round proved quite tricky.
> >
> > I still think this backward mapping is possible (or else
> > we'll never see an
> > Indic OCR), but so far haven't succeeded doing it myself.
> It's not impossible, so keep going...

After you showed me the evil such a thing could do in the wrong hands, the
idea suddenly becomes much less appealing!

_ Marco

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