Re: wxWidgets terminal : new round

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

Petr Mikulik a =E9crit :

>> I am happy to provide an updated patch for the wxWidgets terminal,=20
>> which goes, as
>> usually, a little further !
>
> It doesn't ./configure:
> (...)

Thanks for the report. It's a line corresponding to a macro coming from=20
pkg-config. I suppose that my version of pkg-config handles it=20
differently. I will add a assign_some_variable_to_something to cope with =
it.

> Ad cairo and pango: they also need package pixman.

As for cairo 1.0 and maybe earlier versions, libpixman has been merged=20
with cairo. Maybe I should ask for cairo>=3D1.0.

>
> All that is OK for the very fresh linuxes (i.e., I will have to=20
> upgrade my SUSE 9.2 boxes), but what about other wx platforms (Mac,=20
> Win, OS/2)? Will it be easy to install all of these dependencies?=20
> Cannot be all that done using the base wxWidgets? From a brief look=20
> the cairo is like the wx library, but it supports less platforms --=20
> isn't this a duplicate?

I have discussed it a little with Bastian Maerkisch off-list, and I will=20
try to explain my thoughts here :

I admit that I have taken some time before deciding to use those=20
libraries. It's a choice based on the balance between functionnality and=20
portability. wxWidgets is well designed to design frames, menus, etc. in=20
a cross-platform way, but is lacking some features as far as drawing is=20
concerned. In particular, text alignment is difficult, because gnuplot=20
aks to justify vertically, and it's not easy to achieve without=20
consistent text extents functions. On the other hand, cairo provides=20
perfect drawing routines, with powerful algorythms for antialiasing for=20
instance (I may seem to insistate an anti-aliasing, but it really makes=20
plots more beautiful), and pango is well-suited for text. Moreover, I=20
have convinced myself that pango and cairo are almost as cross-platform=20
as wxWidgets.

Cairo aims to be a universal drawing library on a lot of platforms. You=20
can convince yourself if you look at mozilla which already uses cairo to=20
handle svg contents in firefox 1.5. Moreover, at this time, I use cairo=20
in a totally cross-platform way, as I draw to an offscreen buffer, and I=20
let wxWidgets do the remaining work to draw to the screen. So we just=20
have to make cairo compile under targetted platforms... It is working=20
with windows, and google seems to say it's also done already by some=20
people on OS/2.

As far as pango is concerned, I am inclined to use it because the text=20
API in cairo is limited, and the doc says it's a "toy". This doc also=20
suggests to use pango. The only platform-dependent code in pango in the=20
way it finds fonts. The rendering is done through cairo directly. Pango=20
is used by gtk+, which is known to work on windows at least (and of=20
course X11). I hope we will be able to make pango also work on OS/2...

As far as "freshness" is concerned, you're right to say that linux users=20
may need some time to have cairo (pango has settled for a longer time)=20
in their distributions. However, by the time you - gnuplot main=20
developpers - decide to make an official release, I think there's no=20
need to worry ;-) Since gnome 2.12 which depends on Cairo 1.0 was=20
released a few weeks ago, Cairo will spread much quicker...

Well, let's talk with concrete figures/examples about platforms. Three=20
days ago, Bastian Maerkisch succeeded to compile the current patch under=20
windows with msvc, with minor tweaks in my code. On my side, I managed=20
to have a working code with pango (the last sf patch uses cairo only),=20
and it suits my needs. So I have switched to windows too, and since=20
yesterday, I have been able to compile and run my code under MinGW with=20
wxWidgets, Cairo and Pango. It's working pretty well, apart from mousing=20
mode since under windows term->waitforinput doesn't seemed to be used...

As a proof ;-), here are screenshots taken from windows XP running the=20
wxWidgets terminal, using Cairo and Pango:

(test) http://tipote.free.fr/wxt_windows1.png
(pm3d) http://tipote.free.fr/wxt_windows2.png

Moreover, here is a zip archive containing gnuplot binary for windows=20
compiled statically with wxWidgets, and dynamically with cairo and=20
pango. Dlls are included so you don't need to add anything : it "should"=20
work out-of-the-box.

(3MB zipped archive) http://tipote.free.fr/Gnuplot4.1.zip

Please note that there's a bug (hopefully not related to my patch) at=20
least on my box : I have to maximize the gnuplot main window, or it will=20
crash when lauching the wxt terminal. I think it's related to debugging=20
strings that I ask to print to stderr, but I don't understand it clearly.=
..

I will appreciate any comment about this scheme.
Thank you very much for your interest in my work.

Best regards,

Timoth=E9e Lecomte