by Reinhard Niehoff, edited by Kristian Picon

Some internal changes:

The Tcl scripting library has been completely replaced with the SP library, written exclusively for Extreme Tux Racer. Because of this modification, some modules or methods are now obsolete: the Tcl hash tables, the "list" module etc.

A restrained approach to C++ has been taken. The entire program can be compiled with g++, but there are only a few C++ classes. Most of these classes are implemented for the sake of clarity. For example, when you see the function "Env.DrawFog", you know that this function is declared and defined in the module env.cpp. The global instance Env of the class CEnvironment is available throughout the code. The same with some other classes. And of course, the classes put together data and their functions. This makes the code clearer.

A substantial change has been made to the phys_sim module (now physics.cpp), though most of the functions are left unchanged or with little modification. There is a new class CControl that encapsulates all parameters of the traditional "TControl" structure, as well as the functions of the old phys_sim. All of this belongs together, and this class is really sensible and will simplify the implementation of multiplayer mode. Some functions have been moved to other modules, for example TuxOrientation to tux.cpp or FindCourseNormal to course.cpp. All functions should now have a logical location.

Completely or almost completely rewritten modules

The old modules audio.c and audio_data.c have been replaced with audio.cpp. The old code was, to say the least, too long and convoluted. The same with game_config, and with many parts of other modules. A significant number of modules have not been completely rewritten, but have been altered almost in their practical entirety. For example winsys.cpp. It is shorter and clearer now, and it contains the joystick functions (only a few lines). The module joystick.c has been rendered obsolete.

These are only some examples. Compare the new code with the original code and you will find that more than 60 % is rewritten. That's less than the code of the Bunny Hill rewrite, but the intention of the ETR rewrite was to clean up und clear up the code first, and enhance it with new functions, later.

One effect of the clearance is shorter code. Three examples:

1) In the old code there are 5 modules responsible for the Tux character: tux.c, tux_shadow.c, hier.c, hier_cb.c and hier_util.c That are about 1850 lines in total (okay, 1500 to 1600 lines without comments). The new code contains all the functions in a single module (tux.cpp) with a total of 720 lines.

2) The audio modules. In Tuxracer 0.61 there are 2 modules, audio.c and audio_data.c with 1630 lines in total. The new code contains only 1 module with 300 lines!

3) The old race_select.c consists of 1300 lines; the reworked, new code contains 230 lines - and does at least the same, of course.

Unchanged modules

Some modules are almost unchanged (except the formal style). That doesn't mean that these modules will never be modified. I think, eventually all the code must be completely rewritten. But some tasks are not very urgent or too extensive at the moment. Here the modules which are nearly unchanged:

view.cpp, quadtree.cpp, hud.cpp, trackmarks.cpp and parts of particles.cpp

Comments

I know, a good code should be well-commented. For me, the best commentation is a clear and well-ordered structure. It sounds unbelievable but first I removed all comments in the original code to make it understandable for me. So excuse the lack of comments in the new code. Perhaps, some day ...

BTW

Some people, including the authors of Tuxracer 0.61, prefer the following formal style:

Okay, this isn't very important (there are more important things) for the effectiveness of the code, but I have problems to putting up with this style. Additionally, the accumulation of underscores is bothersome:

All clear? Oh yes, reading the code of other developers is pleasurable, and so I leave you with: have fun with my code ;-)