Re: Keeping HTML Simple & Format negotiation between Browser & Server

frans van hoesel (
Sat, 29 May 1993 14:51:02 +0100 (MDT)

Marc wrote:
> Pei Y. Wei writes:
> > However, one could think of lots of other applications where it would
> > be easier and more appropriate to use area-overlay-buttons. Just look at
> > the numerous HyperCard stackwares that use ``invisible fields'' to
> > implement highly neat effects. This approach, however hard-coded but
> > no more than ``HREF='' is hard-coded, has the benefits of no necessary
> > dependence on a server.
> I agree.

So do I (for what it's worth)

> > An example of invisible/see-thru buttons overlaying an image -- face.gif
> > is visible, and has two invisible area oriented anchors pointing to
> > eyes.gif and mouth.gif respectively. Probably unnecessary, but WIDTH &
> > HEIGHT could be specified to handle scaling. Also, perhaps <FIGA> should
> > simply be <A>. :
> >
> > <FIGURE SRC="" TYPE="image/gif"
> > WIDTH=100 HEIGHT=100>
> > <FIGA HREF="" TYPE="image/gif"
> > x0=20 y0=10 x1=80 y1=30>
> > <FIGA HREF="" TYPE="image/gif"
> > x0=40 y0=70 x1=60 y1=80>
> > <FIGCAP>Spy a face</FIGCAP>
> > </FIGURE>
> Looks good to me. Two comments: my gut feeling is that coordinates
> should be in pixel space, and that if the browser scales the image it
> should readjust any transmitted coordinates to match when the user
> actually selects something. And, I think it should be possible
> to specify more than one rectangle per "FIGA" (e.g...
> <FIGA HREF="" TYPE="image/gif"
> COORDS="40-60,70-80;90-100,120-130">
> ...or something similar).

And if you could add a keyword like TRANSPARENT=0 to specifiy that the
color with index 0 should be transparent I would be even more happy.

This would allow very easy creation of a HREF that is *exactly* only to
mouth and not some collection of rectangles!!!!!

And it's easy for the server too: only one rectangle (the size of the image)
and it only needs a check for the color, if it is not the transparant color,
then follow the link.

It also allows for non-rectangular images inside a document (allthough the
bounding box would be rectangular.

Alternatively, one could send a simple b/w image to specify the
mouth *exactly* and don't use transparant at all

- frans