SDL Interface Development

[Eric McDonald <mcdonald at phy dot cmich dot edu>]

Hello Xconq developers,

  Today I was thinking about everything that still needs to be done on 
the SDL interface. It would seem that much work must be done in terms of 
things such as widget implementation: a scrollable text box for 
messages, list boxes, drop-down boxes, checkboxes, radio buttons for 
setup and preferences screens, etc.... I have had these bits of work in 
mind every since I took up development of the SDL interface, and have 
not entirely been looking forward to it. (If I was developing an 
SDL-based GUI toolkit for the sake of developing one, it would be a 
different story. Indeed, it would be somewhat appealing.)

  With the help of a powerful scrying tool known as Google, I have 
apparently discovered an easy way out: ParaGUI, 
http://www.bms-austria.com/projects/paragui/
It looks to have most every GUI element that I would want and it would 
undoubtedly shave _months_ off the development of the SDL interface.
However, like most things, this comes at a price.

  The price is twofold:
(1) The ParaGUI API is in C++. This means that Xconq's SDL interface 
would have to be converted to C++ and things going to and from the 
kernel would have to be carefully declared extern "C". I am tempted to 
say this is worth the trouble. I realize that this would break Xconq's 
tendency toward C89 compliance. However, the "damage" would be limited 
to a single user interface, and the kernel should escape unscathed.
(2) ParaGUI has a number of dependencies: Freetype, zlib, libpng, and 
Expat. None of these should be a problem on most modern Linux 
distributions. On Windows, these all are available, thanks in part to 
the Gimp on Win32 project and other reasons. However, any required DLL's 
would have to be bundled with the Windows installer thereby increasing 
its size, perhaps significantly. Some of the space could probably be won 
back once we get to a point where the Tcl/Tk interface no longer needs 
to be provided. Also, I could provide a separate complete install and 
upgrade install. Of course, anyone wishing to do SDL interface 
development on the Win32 platform would have to seek out the necessary 
libraries and headers and install them. Documentation could help aid 
that quest, but the extra work could still be considered an extra 
hurdle. On non-Linux, non-Win32 platforms some compilation of the 
necessary libs would probably be required.

  A while back ago, we considered SDL_Pango for handling of 
international and exotic text. Pango (which SDL_Pango obviously 
requires) is not without dependencies either. So I think point (2) is 
something worth considering. How much should Xconq be able to stand 
alone? And how much should we cave in to rapid development at the 
expense of raising the hacker "cost of entry", so to speak?

  One last note, I am not saying that moving to ParaGUI is without 
work. Probably a widget would have to be created to contain the main map 
and minimap. But, it looks like we get things like themes (font sets, 
background images and gradients) quite easily, and this is something we 
all wanted from/expect of the interface.

Eric

P.S. ParaGUI appears to have been around for over two years now, and is 
still being maintained and developed, and so I don't fear much in the 
way of stagnation.
P.P.S. Here are some ParaGUI screenshots:
http://www.bms-austria.com/projects/paragui/index.php?module=photoshare&func=showimages&fid=1
http://www.freelords.org/screenshots.php
http://www.project-axis.net/pages/screenshots/screens-v03.shtml
http://www.project-axis.net/artbin/screens/snapshot37.png
http://www.project-axis.net/artbin/screens/snapshot36.png