Help building/running SDL/OpenGL code

[Pieter de Goeje]

On Wednesday 23 December 2009 04:42:28 Richard Mace wrote:
> Incidentally, if there is anyone out there with newer hardware who is
> interested in building the code I am talking about you can find it at:
>
> http://physics.ukzn.ac.za/~richm/courses/phys110/lennard-jones-3d.html
>
> You'll need to change the following lines in the Makefile to get it to
> successfully build under FreeBSD:
> ==================================================
> CFLAGS = -Wall -Wextra -pthread -I/usr/local/include
> -I/usr/local/include/SDL -O3 -march=native
>
> LFLAGS = -Wall -L/usr/local/lib
>
> lennardjones : $(OBJS)
>         $(CC) $(LFLAGS) -o lennardjones $(OBJS) -lSDL -lSDL_gfx -lGLU
> ==================================================
>
> It would be interesting to hear feedback. (Basic controls are: up-arrow add
> heat to crystal; down-arrow cool down gas/crystal. There are a bunch of
> others -- look in main.c). You are welcome to do whatever you wish with my
> code.

Arrr. Same problem here at startup: segfault in glXGetFBConfigAttribSGIX. A 
simple test case is the following:

pyotr at nox:~% cat test.c
int main() {}
pyotr at nox:~% cc -o test test.c -L/usr/local/lib -lSDL -lGL
pyotr at nox:~% ./test
zsh: segmentation fault (core dumped)  ./test

Then I attempted to switch the arguments around...

pyotr at nox:~% cc -o test test.c -L/usr/local/lib -lGL -lSDL
pyotr at nox:~% ./test
pyotr at nox:~%

Voila! (Admittedly much to my surprise ;))

So then I changed the Makefile to use these libraries: -lGLU -lSDL -lSDL_gfx. 
Result: a perfectly working ./lennardjones. The only minor issue is that it 
presented me with exactly one option:

pyotr at nox:~/temp/lennard-jones-gas-3d% ./lennardjones
Current pixel depth: 32
Available Modes
0 =>  3840 x 1200
Select your preferred video mode:

So apparently I prefer mode 0 :D. It run fine (and smooth) though.

It is clear something goes wrong during the runtime linking process, which 
this library order works around. The actual problem is still a mystery to me. 
It might be worthwhile to post a bugreport on the nvnews.net FreeBSD forum.

Best regards,

Pieter de Goeje