All accelerated pixelformats give 64 bit accumulation buffer...

OpenGL OpenGL: Advanced Coding
1

why do all pixelformats which are returned by DescribePixelFormat have 64 bits accumulation buffer?

System is:
WinXP Pro
GeForce 2 GTS
28.90

NOTE: I mention the ones whose
PFD_DRAW_TO_WINDOW
PFD_SUPPORT_OPENGL
PFD_DOUBLEBUFFER
are set and
PFD_GENERIC_FORMAT
is not set.

2

Well i know that the accel buffer is not supported in hardware on any consumer card but i do know that the accum buffer requires a 64bit depth because it needs all of that precision to work. There was a post a while back about this, Matt from nvidia was talking about that.

-SirKnight

3

I don’t see how the presence of an accumulation buffer is harmful? (And yes, we can lazily allocate it, so unless you use it, it costs you nothing.)

  • Matt