[HOpenGL] Runtime error when using blending (on windows XP)

[Yann Morvan]

Yes I'm sorry for the lack of details, here is what I could gather.
I am using GHC 6.3 that I compiled from the fptools
distribution that I downloaded from the CVS server whithout specifying any
branch.
It was compiled under windows XP in a cygwin environment, with all the
mingw tools, targeting a mingw environment.
I copied the glut.h from usr/include/GL into usr/local/include/mingw/GL.

Unfortunately I only get a windows XP error window of the type "main.exe
has encountered a problem and needs to close". The error report says the
code of the exception is 0xc0000005 (access violation). I am sorry but I
don't know how to get a more accurate error description.
(I'm reading right now about the -xc RTS option so I might get back to you with a better error).

However the error seems to clearly come from the call to blendEquation,
since the program runs fine when I comment it out.
>From having a look at the binding, my guess is that the call to
hOpenGL_getProcAddress returns a NULL pointer, the reason for that would
be that a configuration problem with the opengl headers and libraries when
I built the package is causing hOpenGL_gpa in HsOpenGL.c to behave oddly.

The thing is I am very confused as to how GHC configures itself when it
comes to the OpenGL headers and libraries. Does it use the headers in
usr/local/include/mingw or usr/include/w32api, does it use the libraries
from lib/w32api, or usr/local/gcc-lib, or the windows dlls, or something
else ?
The opengl32.dll in windows/system32 says it's version 5.1.2600.1106
The registry key for OpenGLDrivers points to atioglxx.dll, I could find 4
on my machine, the one in windows\system32 says it's version 6.14.10.4332,
from Microsoft.

I guess a good start would be to
-know what implementation of OpenGL works best with HOpenGL under windows
-place the corresponding files where fptools will look when configuring
 the build, and prevent it from finding headers that don't match libraries
 and vis versa
-re-build HOpenGL

It would be great if you could help me with the first two steps,
in the meanwhile I'll be trying to figure things out.

	Yann