Re: TODO additions

[Miles Bader <miles@gnu.org>]

On Tue, Oct 29, 2002 at 06:04:56PM +0000, Dave Love wrote:
> I agree that the main use of HTML background images
> is to make pages more-or-less unusable, but that's not the point.

I'm not sure that background images as I implemented them are actually all
that suitable for a typical html browser usage.  The reason is that a typical
web-site background image is `document relative' -- that is, the image is
logically tiled starting from the beginning of the document, and scrolls with
the image, etc.  In emacs, this is very hard to do, because there's no easy
metric one can use to translate a document position (which is all you
reasonably have available in redisplay) into a vertical offset; I guess this
is the same reason that scroll bars sometimes act in surprising ways.

My background image implementation provided several options for the origin of
the image, but they were all things that were easy to calculate in redisplay
-- e.g., window or frame relative.  [The result being that background images
_don't_ scroll with the document, but rather the document scrolls against
them]

It'd be nice to implement the HTML style too, but I'm not sure how.

As far as I could see the main uses of my background images are (1) to make
emacs look really cool (and it does do that), and (2) to provide a better
answer for the constant `can I make emacs transparent' questions on usenet.

-Miles
-- 
I'm beginning to think that life is just one long Yoko Ono album; no rhyme
or reason, just a lot of incoherent shrieks and then it's over.  --Ian Wolff