[ENH] maximumSupportedDisplayDepth

Duane Maxwell dmaxwell at san.rr.com
Fri Jan 11 06:10:39 UTC 2002


> I should point out although 16 and 32 bit depth is offered to day on
> most new macs, you will find on older machines 32 bit might not
> technically be available because of VRAM sizes, let alone going back
> 10 years to find machines that only support 256 colors. This is not a
> problem, if you set the squeak depth to 32 then quickdraw (or the
> video driver?) remaps those 32bit color values to 16 or 8. I believe
> the new primitive that lurks to allow you to change the screen
> resolution and depth will resize the screen and set the depth to the
> best fit based on the target screen which is the one that holds most
> of the squeak window for those who have multiple screens. So asking
> for 32bit might actually not get you 32bit because the hardware
> doesn't support it, but Squeak certainly will think it's in 32bit
> mode.

Which reminds me that in the UNIX version under X, the 8-bit color table in
the VM is different than the one in Squeak, which means you get a very poor
rendering of the display if both Squeak and the display are both set to
8-bit.

We fixed this at exobox (it's about an hour's work to reproduce the
algorithm Squeak uses in C for the VM), but I can't find the code. Tim?

-- Duane





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