Re: Line spacing (was Re: Some complaints about HTML 4.0)

David Perrell (
Thu, 17 Jul 1997 13:58:58 -0700

Message-Id: <>
From: "David Perrell" <>
To: "Jim Wise" <>
Cc: <>
Subject: Re: Line spacing (was Re: Some complaints about HTML 4.0)
Date: Thu, 17 Jul 1997 13:58:58 -0700

Jim Wise wrote:
> No, they aren't.  The problem here is that character rendering is
> context dependent.  Spacing will differ based on the prior and next
> characters, for example, and many environments will replace some
> character pairs with ligatures.  And this is just for latin type. 
> scripts, especially mideastern scripts, have much more in depth
> context-sensitive rendering changes.  (Different rendering of a
> character whether it appears at the end of a word or not, for

I consider what you describe as preprocessing that must be completed
before any layout can take place. After the preprocessing, you're left
with a stream of character glyphs, each with its own metrics adjusted
in accordance with the special relationships you describe.

At this point you can consider a glyph the same as any replaced, inline
element, with intrinsic dimensions and zero margins. 

David Perrell