Re: Several suggestions for image support

[no-spam@cua.dk (Kim F. Storm)]

David Kastrup <dak@gnu.org> writes:

> That it does not work.  It only works when the majority of corner
> pixels has the transparent color.  Also it is impossible for an image
> to have, say, both white and transparent color.
> 
> Since transparency is a feature of PNG files, is there any particular
> reason not to just use the information, preferring some heuristic
> hack to it that does not work in all circumstances?

I understand now -- yes it is silly to try to guess something which
is already there.

Would somebody want to work on fixing this?

> 
> > > I would find it important if an image specifier could restrict the
> > > displayed portion of an image.
> > 
> > This might be useful for other reasons, e.g. image panning.
> > Zoom (scaling) would be useful too.
> > 
> 
> It would also mean that I could walk the cursor through _rows_ of the
> preview-latex image instead of having to walk through it all at
> once.  Image scrolling is a different problem: it does not involve
> actually changing the value of point.

That is correct.

Another use of image splitting would be to allow positioning of
multi-line text on the sides of an image; today you can only have
one line of text on the side of an image, no matter how tall that
image is.

One issue I have been thinking about is how to automatically align
those tiling image slices to the position of the first slice (even
when that slice is not visible in the window).  This would be
a very handy way to support having multi-line proportional font
text on the left of a tiled image.

> It would probably be nice to have a way of tiling an image into areas
> with individual property lists (posn-point, keymap,
> mouse-highlighting...).  But that's just phantasizing for the future.

If done properly, that should definitely be part of it.

Let me think some more about it; if it is trivial to do, I will add
it before feature freeze; otherwise it will have to wait for 22.1.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk