Re: [PATCH] Add function window-line-width

[martin rudalics]

> In general, functions that use only the glyph matrices have a
> significant disadvantage in that they will fail when display is not up
> to date, something that can happen out of control of a Lisp program
> that calls the function.  So I very much prefer window-text-pixel-size
> to an alternative that uses the glyph matrices.  If we find that using
> the glyph matrices is much faster, then I'd prefer to fix
> window-text-pixel-size to use the glyph matrices when possible, and
> otherwise fall back to its current method.  See move-point-visually
> for one example of how this can be done.

Agreed.  Sébastien can you try to show "that using the glyph matrices
is much faster"?

martin