That means (however unlikely!) that I already fixed at least part of the Canvas3D not working on ATI cards problem.
And the problem was in the wglChoosePixelFormatARB() call I posted yesterday That 4th parameter (0) is called nMaxFormats and described as ‘Specifies the maximum number of pixel formats to be returned’. I am surprised it worked on any system. The nVidia OpenGL drivers are probably more forgiving of mistakes like this.
Bug 411475 filed and patch is in there if you want to take a look. I don’t know what the policies are for checking in stuff that doesn’t affect the Firefox distribution. We’ll see, maybe it will get checked in.
Update: I’ve repackaged the extension and put it into subversion, but I figured maybe someone outside the project wants to give it a try – so here it is. Note that only the Windows version is updated in this one, the Mac and Linux versions are still the old ones.
If you find that any of it doesn’t work, please report bugs somehow (send me mail, for example).
And how both differ from Vista.
The short answer is that the drivers for a Radeon 9250 on both XP and Slackware are equally good, and equally better than on Vista.
Long answer:
One of the first things I did for the Canvas3D project was to try it out on Slackware, which used to be my main Mozilla development environment. And it failed at this part:
if (!wglChoosePixelFormatARB(mGlewDC,
attribs,
fattribs,
0,
NULL,
&numFormats) || numFormats == 0)
Then I tried it in a mostly-working Windows Vista build environment, and it failed a few lines earlier:
if (!WGLEW_ARB_pixel_format || !WGLEW_ARB_pbuffer)
Seing how Linux support is much less important for the project at this point, I forgot about Linux and went on working with Vista. That’s when I figured out that ARB_pixel_format and ARB_pbuffer are not supported on that platform. I assumed it’s because my card is obsolete.
Turns out it wasn’t my card’s fault, it was the fault of the Vista drivers for my card. Cause now that I got fed up with Vista bugs and set up a Mozilla built environment on XP, it turns out on XP I have the same problem I’ve seen on Linux weeks ago.
Another interesting note is that on XP my Radeon 9250 supports all of OpenGL 1.0, 1.2, 1.3; and almost all of 1.4 and 1.5. On Vista it supports all of 1.0 and none of anything else. We’ll see if the situation changes when I get the new cards.
Anyway, I’m back to where I started, but it’s not quite as bad as it sounds, since I gained quite bit of knowledge on the way.
