[webkit-dev] drawing LF/CR/etc.

[Mike Emmel]

I'm waiting for the review of the actual gdk code :(



On 6/14/06, Mike Reed <mikerreed at gmail.com> wrote:
> Got it. I just peeked at TOT, and I see the new (for me at least)
> GlyphBuffer and GlyphMap files. Can't wait to sync to the tip...

> On 6/13/06, David Hyatt <hyatt at apple.com> wrote:
> > On Jun 13, 2006, at 8:59 AM, Mike Reed wrote:
> >
> > > Is it correct that the parser didn't strip that, or convert it into a
> > > space?
> >
> > Correct.  The original string must be preserved, since this is
> > relevant both for HTML editing (to not mangle the source) and for CSS
> > white-space, which can be dynamically set at any time to values like
> > "pre" (thus indicating that the whitespace should be preserved).
> >
> > > If so, is my port expected to strip these sorts of characters
> > > each time I measure or draw (hurting performance)?
> >
> > No.  Your port should be hooking in at a lower level than drawText.
> > Font.cpp is completely cross-platform, and you should be using all of
> > it if you can.
> >
> > Check out the files in the win and mac directories under platform to
> > see what methods you have to implement (all the Font*** and Glyph***
> > classes).  Much of the font layer is cross-platform, and there's
> > really only a handful of methods you have to implement.  For simple
> > text, we handle tabs, newlines, etc. for you.  You only have to deal
> > with it for advanced scripts (the ***ComplexText methods).
> >
> > > If I had complete
> > > control over all my fonts, I could wack their cmap tables to ensure
> > > that all control characters mapped to zero-width spaces, but I don't
> > > have the luxury.
> > >
> >
> > That's basically what we do down the fast code path (which is cross-
> > platform).  We have a cached glyph map that is hacked to map newlines
> > and tabs to spaces.  (The map is only used for those characters when
> > the white-space mode indicates they should not be preserved.
> > Otherwise the white-space handling kicks in at a higher level and
> > avoids the glyph map when processing those characters.)
> >
> > dave
> > (hyatt at apple.com)
> >
> >
> _______________________________________________
> webkit-dev mailing list
> webkit-dev at opendarwin.org
> http://www.opendarwin.org/mailman/listinfo/webkit-dev
>