Re: [Plplot-devel] plenv() issues

[Joao C. <jc...@fe...>]

On Saturday 09 November 2002 07:54, Maurice LeBrun wrote:
> Joao Cardoso writes:
>  > On Wednesday 06 November 2002 06:17, Maurice LeBrun wrote:
>  > > Alan W. Irwin writes:
>  > >  > On Tue, 5 Nov 2002, [iso-8859-1] Jo=E3o Cardoso wrote:
>  > >  > > What do you think of this problem? Is there a "cure" that doe=
s
>  > >  > > not influence other users?
>  > >  >
>  > >  > How about define plenv0 which does everything but the page adva=
nce?
>  > >  > Then define plenv as the combination of pladv and plenv0.
>  > >  >
>  > >  > I know this adds one more piece of public API that we have to
>  > >  > propagate to all the language interfaces *and* document, but th=
at
>  > >  > is pretty straightforward, and we currently have so many variat=
ions
>  > >  > on our startup commands (think of all the plstart variations), =
and
>  > >  > our advance page commands, that adding another convenient plenv
>  > >  > variation isn't that big a deal IMO.
>  > >  >
>  > >  > Geoffrey and Maurice, is such a solution OK with you?
>  > >
>  > > Sure.  I've never been completely happy with the behavior of plenv=
 in
>  > > this regard either.
>  >
>  > OK, I will work on it soon.
>  >
>  > Do you think that plenv0() should clear the page? I think it should!
>
> Seems reasonable.  There may be some cases where the user doesn't want =
it
> cleared but these are probably rare and not worth API support.
>
> Sigh.. I must admit to some dislike of the proliferation of API calls. =
 I

I agree!=20

> would greatly prefer we handle these kinds of cases through some sort o=
f
> option-setting procedure.  E.g. instead of calling plenv0(...), one wou=
ld
> do:
>
> plsopt("plenv_advance", "0");
> plenv(...)
>
> Then you never need to expand the API (complete with the myriad of lang=
uage
> bindings needed), just add a new option.

Good solution. Now is a bit too late, as I already implemented plenv0().
However, I think that if plsopt("plenv_advance", "0") becomes implemented=
=20
before the next release, then we can drop plenv0().

No user can complain by a feature introduced and removed but that never m=
ade=20
part of a release.=20

>
> I've actually implemented such a scheme for my own libraries, twice now=
,
> once in Fortran and more recently in iTcl.  Because there are times whe=
n
> you want the option to be set forever, I'd use plsdopt(...) to set an
> option permanently (default); plsopt would only take effect until the n=
ext
> new plot. That way you could avoid non-local effects.  It works great.

So lets wait for plsdopt() also. Your ToDo list?

Joao

> Anyway, I've got no time for any of this right now, so for now we're st=
uck
> with the usual addition to the API.
>
>  > As plclear() is not currently working (no driver but the gnome one
>  > supports it) I will also change it, issuing a solid fill with the
>  > background color when the driver does not support clear.
>
> Looks good.