Re: redisplay - very long lines

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> I could equally see the argument for displaying as many lines as
>> possible and only increasing line heights when the user scrolls
>> horizontally and the glyph is made visible.

> That'd be horrible, I think: display jumping back and forth as point
> moves horizontally.

This would only happen with truncated lines, not with wrapped
lines, right?  So we (c|sh)ould at least do it for wrapped lines.
That should cover 99.99% of the cases where unbearably long lines make
Emacs too slow (if they're really that long, you probably want to wrap
them rather than truncate them).

[ Also, I'd much rather see occasional jumping than unbearably
  slow display.  In many cases (e.g. unibyte fundamental-mode for binary
  files), the likelihood of varying line height is pretty low. ]


        Stefan