[Vm-dev] pb with primitive #primitiveScreenDepth on Linux ?

[Bert Freudenberg]

On Tue, Jan 31, 2017 at 10:44 AM, Christophe Demarey <
christophe.demarey at inria.fr> wrote:

>
> Hello,
>
> With Pavel, we discovered a strange behavior of the primitive
> #primitiveScreenDepth on Linux. It returns a value of 24 bits per pixel
> (True colors) that looks valid but not supported (at least by Pharo).
>
> DisplayScreen actualScreenDepth "(calling the primitive screenDepth)"
>         => 32 on OS X [OK]
>         => 24 on Linux [KO]
>
> Also, it is not consistent with the primitive 91
>
> DisplayScreen new supportsDisplayDepth: DisplayScreen actualScreenDepth
>         => true on OS X
>         => false on Linux
>
> There are some safeguard image-side but it would be great if someone could
> check that vm side.
>

That seems wrong indeed, since BitBlt can only handle power-of-two depths
currently. It should answer 32 or -32 in this case.

Actually ... is there a difference in pixel layout for 32 bit MSB vs LSB
forms? A quick test in SqueakJS suggests there isn't.

- Bert -
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