Ok so sorry to sound stupid, but what files am I dealing with exactly? I looked in the lib folder and all the folders are empty except for a delete.me file. I moved the header files if I recall, but it didn't seem to do anything.

EDIT: Nevermind, I did a new project and it turns out I did install it. But unfortunately it still crashes.

Ok, first, let's get your AGL version as reported by AGL itself. Then, I'll have to ask you to track down where AGL crashes. There might be an AGL bug that only manifests itself on your system. Most of us don't have Intel Integrated Graphics so it's difficult to debug this issue without your help.

Thanks!

Can you step in AllegroGL's win.c, function allegro_gl_win_init() and see where it crashes there?

No. I mean use a debugger (or lots of printfs, whichever you prefer) and try to figure out where is AGL crashing.

So what do I need to include in the parameters to recompile allegrogl? Guys, I'm really sorry that I'm slow, I'm just new to all of this.

I will finish debugging this tomorrow, but for now here are the offending lines (from win.c):

  if (allegro_gl_extensions_GL.ARB_multisample) {
    glSampleCoverageARB(1.0, GL_FALSE);
  }

Apparently, the variable allegro_gl_extensions_GL suggests that the Intel 915series chipset is capable of handling this Open GL extension, but it is not. I suspect that the extensions are being parsed improperly, but I ran out of time to verify this today.

Tomorrow, I will try to find out the root of the problem, but for now, if you comment out the lines I copied above, you can at least get allegrogl to run.

Thank you too! I hope we can find the problem and fix it so AllegroGL can work on these chipsets.

EDIT: I found this snippet of code for X at : http://www.ks.uiuc.edu/Research/vmd/doxygen/OpenGLDisplayDevice_8C-source.html

00058 // determine if all of the ARB multisample extension routines are available
00059 #if defined(GL_ARB_multisample) && defined(GLX_SAMPLES_ARB) && defined(GLX_SAMPLE_BUFFERS_ARB)
00060 #define USEARBMULTISAMPLE 1
00061 #endif

Does this mean we need GLX extensions as well to use it for some chipsets?

And this link might be useful:
http://oss.sgi.com/projects/ogl-sample/registry/ARB/multisample.txt

You probably know this already though..

Hope you can fix this one!

In the file "gl_ext_list.h"
The number "1.3"
AGL_EXT(ARB_multisample, 1.3)
is causing this code; (in "glext.c")

  /* Get extension info for the rest of the lib */
#    define AGL_EXT(name, ver) {                               \
    allegro_gl_extensions_GL.name =                        \ 
          allegro_gl_is_extension_supported("GL_" #name)   \ 
      || (allegro_gl_info.version >= ver && ver > 0);      \ 
  } 
#   include "allegrogl/GLext/gl_ext_list.h"
#   undef AGL_EXT

To set
allegro_gl_extensions_GL.ARB_multisample = 1

However, the extension GL_ARB_multisample is apparently NOT available on this chipset (INTEL 915GM)

subsequently, when allegrogl attempts to use the extension (in "win.c")

  if (allegro_gl_extensions_GL.ARB_multisample) {
    glSampleCoverageARB(1.0, GL_FALSE);
  }

It crashes (and burns).

Two possible solutions:
1. change line in "gl_ext_list.h" to read:
AGL_EXT(ARB_multisample, 1.4)

OR

2. change line in "win.c" to read:

  if (allegro_gl_is_extension_supported("GL_ARB_multisample")){
    glSampleCoverageARB(1.0, GL_FALSE);
  }

We should do Option 3: Detect Intel 915G chipsets and force multisampling to be disabled. We alreday do this for ARB_texture_non_power_of_two.

The fix would be in src/glext.c in function __allegro_gl_manage_extensions(void).

The problem with Option 2 is that it will work in Windows XP and under, but it will not necessarily work properly in Linux or Windows Vista. The extensions string does not need to contain things that are part of the core spec.

What does printf("%s", (const char*)glGetString(GL_VENDOR)); say?

Should GL_ARB_multisample be disabled only for Intel 915G? I've seen AGL working fine on some other Intel chipsets (not sure which ones).

I was wondering if you could point me at any documentation regarding this? I would like to learn more. Most of what I have read in regards to glGetString(GL_EXTENSIONS) merely mentions that it returns "A list of supported GL extensions." If they didn't mean "all supported extensions" it seems like there would be some documentation somewhere explaining which supported extensions would be in this list?

edit I don't doubt you, I just would like to read more about this.