Re: default: x11 or wxt?

[<tim...@en...>]

> On Friday 01 September 2006 03:43 am, Richard Henwood wrote:
>> I installed wxt out of curiosity.
>> These are my general, initial impressions and thoughts:
>
>> I didn't work 'out of the box' for me - fonts are tiny.
>
> I too had font problems. Upgrading the support libraries and installing
> fontconfig made it work.  But a user guide to fonts would be a nice
> addition to the documentation.  Unfortunately, I myself only definitive=
ly
> understand fonts for PostScript and libgd.  The other terminal types I
> struggle with just as much as the next guy.

Fonts handling in general is very complicated because it eventually has t=
o
handle many aspects of the problem, and it's not always about "finding th=
e
font file" unfortunately.

Fontconfig is a tool to manage the fonts that are installed on your unix
system. If fontconfig does not know about any font, most graphic apps
including those based on gtk and qt won't work correctly or will choose
some ugly default font.

Pango is a higher level library that takes care of languages, fonts
aspects, characters coverage, and redering. It looks in the fonts
registered in fontconfig to find the one that is best suited to the chain
of utf8 characters that it has to render. This font is the one that
contains most of the characters of the given string (that's the "characte=
r
coverage" of the font) and that respects the style that the user asked fo=
r
(bold, oblique, sans, serif, or more strict requirements such as the font
name directly).

To the end user, there is very little to do on a recent distribution,
since pango and fontconfig have been used for years now.

Of course, in Richard's case, there must be a bug in the way I coded it
for the wxt terminal.

I agree that a general fonts user guide would be nice.

>> It is slower than x11, am I going to run into 'out of memory' problems=
 as
>> as well?
>
> Petr has been saying this also, but to me the response seems snappy
> enough.  It may be slower than x11, but on my machines the difference
> is not enough to matter.  It could again be a question partly of
> newer support libraries, and of course how fast is the CPU it runs
> on.

Richard, you're not going to run out-of-memory, nor will your computer
explode !

The wxt terminal provides anti-aliasing, and that's its unique feature.
Only The aqua terminal for mac is the only other terminal to provide it
too.

For those of you who have not tried its refreshed gnuplot taste yet, here
is a recycled screenshot (wxt on top, x11 on bottom):

http://tipote.free.fr/wxt19.png

Currently (and I should stress on "currently"), this better visual
rendering comes with a little slow-down compared to the x11 terminal. But
cairo (the underlying graphic library) is a fast-improving pease of
software, and you would be amazed to read the mailing list and see how
good is the work done on it, and how cooperative its development is. For
example, these days were proposed improvements from the leading developpe=
r
of the FreeType project (font antialiasing). X and mozilla developpers ar=
e
involved too, . The algorithms currently used by cairo are known to be
suboptimal, and the wxt terminal uses the all-software rendering path. In
the future, we will profit from optimization in cairo as well as hardware
accelerated rendering, providing the state-of-the-art performance for
gnuplot at a low price since cairo and its friend libraries will do the
hard work for us.

In the mean time, if you want to keep x11 the default on top of wxt, it's
not a problem for me. However, in my opinion, the first use of gnuplot fo=
r
new users is mostly drawing 2D curves, and the wxt terminal does that muc=
h
nicer than the X11 terminal, and for no noticeable slowness. When it come=
s
to dense 3D plots or images, I agree that wxt is noticeably slower. I can
add a message in the wxt help, explaining that "native" terminals (win an=
d
x11) can be used instead if performance is an issue.



>> Does gnuplot support alpha channel?
>
> Up until now it only supports an alpha channel in the sense that
> several terminal drivers (png jpeg gif) allow you to specify a
> transparent background.
>
> Adding additional support for transparency is high on my list
> of post-4.2 projects.  You can see a demo of preliminary support
> for transparent fill areas on
>     http://skuld.bmsc.washington.edu/people/merritt/gnuplot/
>
> So far I have it working fully for wxt, and partially for svg,
> png, jpeg, and pdf.  I will need to tap other people's expertise
> in order to extend support to additional terminal types.

Ethan, that's a very nice and valuable work !

Best regards,

Timoth=E9e