Re: Several suggestions for image support

[David Kastrup <dak@gnu.org>]

Richard Stallman <rms@gnu.org> writes:

>     > The rule I would propose is the following: always use the
>     > height of the _current_ font at the point of the space or
>     > newline, unless that would exceed the actually available
>     > height (which normally will never fall behind the ascent of
>     > the default font, unless we use text properties on the newline
>     > character).
> 
> Treating spaces and newlines alike could be a good idea since
> filling converts between them.
> 
> What is the "actually available height"?  I am not sure what that
> phrase means.  However, the use of the current font for either
> spaces or newlines seems to be a mistake, because of the case I
> mentioned earlier (more than one line of small text in a paragraph
> of larger text).

I was talking here about the visual appearance of the cursor and
probably the top line of highlighting boxes: for those I think it
appropriate to use the current font height (there is no sense in
having taller or smaller boxes than the characters around them).

The line distance is determined differently: it is constant for a
frame unless that would cause overlapping rows with the actual glyph
dimensions, or unless we change it with special properties on the
newline characters.  Those special properties can also be put on space
and other characters but have no effect there.

At least that's how I understood the last proposals.  It means that if
one wants to have a paragraph with smaller line distance, one can
explicitly cover it with an appropriate property.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum