IPP Mail Archive: Re: IPP> Re: draft-mutz-http-attributes-02.txt

Re: IPP> Re: draft-mutz-http-attributes-02.txt

Robert Herriot (Robert.Herriot@Eng.Sun.COM)
Fri, 6 Jun 1997 12:42:43 -0700

> From masinter@parc.xerox.com Thu Jun 5 19:32:57 1997
>
> > None of these solutions solve the problem of the Printer's
> > resolutions-supported attribute which, hopefully, tells the
> > client exactly what resolutions the Printer supports without
> > any extraneous values and without a complicated structure
> > for the attribute.
>
> I think this is the same problem fax has, though.
> Why would a list of pairs of integers (x-res/y-res)
> or integer & ratio (x-res, aspect ratio) have 'extraneous
> values'? Or be a 'complicated structure'?
>

If there are attributes x-res and y-res, then according to the IPP
model, there must be an x-res-supported and a y-res-supported in the
Printer. Suppose the printer supports 300 and 300x600 and 600 Then
both x-res-supported and y-res-supported have values of 300 and 600.
Then x-res and y-res can have any of the following 4 values 300x300,
300x600, 600x600 and 600x300. The last value is not a legitimate value
according to my original statement.

It may be that resolutions supported by real printers and all future
printers can never have this problem. For example if the values are 300
and 300x600, then x-res-supported is 300 and y-res-supported is 300 and
600. No illegal combinations are possible with these values.

That's the problem I have with the x-res, y-res solution. If you can
show my that this solution cannot lead to unsupported combinations,
then I would agree that a pair of integers is possibly a better solution.

Bob Herriot