[7476] in www-talk@info.cern.ch
Re: Transparent GIFs
daemon@ATHENA.MIT.EDU (Bindo)
Thu Feb 2 04:59:33 1995
Date: Thu, 2 Feb 1995 10:34:30 +0100
Errors-To: listmaster@www0.cern.ch
Reply-To: piu1796@cdc8g5.cdc.polimi.it
From: Bindo <piu1796@cdc8g5.cdc.polimi.it>
To: Multiple recipients of list <www-talk@www0.cern.ch>
> While we're in the GIF neighborhood, is anyone aware of a method to create
> transparent GIF files to be used with a browser to give a layered
> effect??
> Steve Cameron
Well about transparency all has been said (gif89, pbm, etc. etc.)
About layered effect, if you ment just layering the gif on the back drop ok...
BUT! in html3 there is a <OVERLAY .....> element .
Here is a little chunk of the html3-DTD, its the part on FIG (enhanced IMG) and overlays :
Well the DTD isn't really clear how <OVERLAY> works, still ...
BTW if anyone has some pointers to tutorials or something less "Structural-analisis" and
more "Reference-guide" please give a shout :))
(if you want the whole file you can get it at :
<A HREF="http://www.w3.org/hypertext/WWW/MarkUp/html3-dtd.txt">DTD</A> )
BindO
<!--====================== Figures ========================================-->
<!--
The element contains text for use in non-graphical displays. Note that
you can use the shape attribute in anchors to specify hotzones on images.
This provides for local processing of pointer clicks and a unified method
for dealing with graphical and non-graphical displays.
Text is flowed around figures when the figure is left or right aligned.
You can request the browser to move down until there is enough room for
the next element, see the CLEAR and NEED attributes (in %needs)
Figures offer a path towards embedding arbitrary information formats
via some kind of OLE/OpenDoc mechanism.
-->
<!ELEMENT FIG - - (OVERLAY*, CAPTION?, %flow;)>
<!ATTLIST FIG
%attrs;
%needs; -- for control of text flow --
src %URI; #REQUIRED -- URI of document to embed --
%url.link; -- standard link attributes --
%block.align; -- horizontal alignment --
width NUMBER #IMPLIED -- desired width in units --
height NUMBER #IMPLIED -- desired height in units --
hspace NUMBER #IMPLIED -- whitespace above/below fig in units --
vspace NUMBER #IMPLIED -- whitespace to left/right in units --
ismap (ismap) #IMPLIED -- pass clicks to server --
units (em|pixels) pixels -- specifies units as em's or pixels --
>
<!--
Figure overlays can be drawn immediately or held in a
sequence for subsequent display. When combined with local
caching, overlays provide a cheap way of modifying a larger
base image sent as part of a previous page.
-->
<!ELEMENT OVERLAY - O EMPTY -- image overlay -->
<!ATTLIST OVERLAY
seq NUMBER 0 -- display order, 0 is immediate --
src %URI; #REQUIRED -- URI of image overlay --
%url.link; -- standard link attributes --
x %FLOAT; 0 -- offset (0 - 1.0) from left --
y %FLOAT; 0 -- offset (0 - 1.0) from top --
width NUMBER #IMPLIED -- desired width in units --
height NUMBER #IMPLIED -- desired height in units --
units (em|pixels) pixels -- specifies units as em's or pixels --
ismap (ismap) #IMPLIED -- pass clicks to server --
>
