[QtonPi] Graphics Banding problems

[Doug Bradbury]

Hello again.
We've been having some trouble with pretty significant banding when
displaying gradients / shader effects.  Even when running the example from
/opt/vc/src/hello_pi/hello_triangle2, I get an image that seems to have
severe banding issues. That is, the transition between colors isn't
smooth/seemless, but rather there appear to be bands as if my bit-depth
configuration was very low.

I don't have a screenshot of the running example, but if you look here:
http://en.wikipedia.org/wiki/File:Colour_banding_example01.png
my rendering looks like the 8-bit gradient.

I've been reading through forums and trying out everything I could find,
but the banding still occurs.

I am on the Raspbian image with QT 5 installaed. I am connected through
HDMI. This happens both with and w/o XWindows. I have tried increasing the
graphics memory by replacing /boot/start.elf with the arm128_start.elf, but
no luck. I also tried editing a configuration file to force 24-bit graphics
(forgot where that was already), but that didn't work either.

Not sure what else to do or where else to look. Any pointers?

Thanks!
Doug Bradbury
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