static bool Compare(int got, int requested, ref int distance)
{
- if (got < requested)
+ bool valid = true;
+ if (got == 0 && requested != 0)
{
- return false;
+ // mode does not support the requested feature.
+ valid = false;
}
- else
+ else if (got >= requested)
{
+ // mode supports the requested feature,
+ // calculate the distance from an "ideal" mode
+ // that matches this feature exactly.
distance += got - requested;
- return true;
}
+ else
+ {
+ // mode supports the requested feature,
+ // but at a suboptimal level. For example:
+ // - requsted AA = 8x, got 4x
+ // - requested color = 32bpp, got 16bpp
+ // We can still use this mode but only if
+ // no better mode exists.
+ const int penalty = 8;
+ distance += penalty * Math.Abs(got - requested);
+ }
+ return valid;
}
static AccelerationType GetAccelerationType(ref PixelFormatDescriptor pfd)
// Does not appear to be supported by DescribePixelFormat
//flags |= PixelFormatDescriptorFlags.DOUBLEBUFFER;
}
- if (System.Environment.OSVersion.Version.Major >= 6)
+
+ if (System.Environment.OSVersion.Version.Major >= 6 &&
+ requested_acceleration_type != AccelerationType.None)
{
+ // Request a compositor-capable mode when running on
+ // Vista+ and using hardware acceleration. Without this,
+ // some modes will cause the compositor to turn off,
+ // which is very annoying to the user.
+ // Note: compositor-capable modes require hardware
+ // acceleration. Don't set this flag when running
+ // with software acceleration (e.g. over Remote Desktop
+ // as described in bug https://github.com/opentk/opentk/issues/35)
flags |= PixelFormatDescriptorFlags.SUPPORT_COMPOSITION;
}