There's apparently a bad interaction between Heaven 4.0 and our implementation of ARB_sample_shading, which results in the solid white screen. If you disable that by setting the MESA_EXTENSION_OVERRIDE=-GL_ARB_sample_shading environment variable, then Heaven 4.0 works fine on Mesa 10. I've run it a lot, actually.
Valley 1.0 has a bug where it requests dual source color blending without indicating which outputs are color 0 and color 1. Without that information (which is required by the GL spec), we have to guess, and have a 50/50 chance of getting it right. Apparently, nVidia gets lucky. I have some hacks to work around that, and then Valley works as well.
ohhh, thank you. finally some words that clear up things a bit for me. searched like mad all over the inet and found nothing usefull regarding this issue.
many thanks!!! tried out the heaven demo and it works... slow and choppy on my i3 4330 but it works