[Vm-dev] About Cocoa VMs

John McIntosh johnmci at smalltalkconsulting.com
Mon Jul 11 13:29:42 UTC 2011

Ah, no it's an open/GL issue. On the first frame paint it appears to
use un-initialized video memory, which happens to be full of visual
Technically I'd say it's a security issue, but it seems the video
layer doesn't hand you sanitized bytes when asked.

To track it likely you need to look at the timing of the open gl
buffer flush versus the timing of when Squeak has drawn to the

On Mon, Jul 11, 2011 at 9:23 AM, Igor Stasenko <siguctua at gmail.com> wrote:
> On 11 July 2011 15:10, Juan Vuletich <juan at jvuletich.org> wrote:
>> Hi Esteban,
>> Both these work both with Pharo and Cuis on OS X 10.5.8. There is a minor
>> quirk, though. It happens both with Cuis and Pharo: Upon startup, the
>> Display shows garbage with stuff from the current Mac display for a fraction
>> of a second, later it gets fixed. This doesn't happen with Carbon VMs such
>> as Eliot's release of Cog and the 4.2.4 VM from John.
> i suspecting this is related to initialization phase:
>  when image just starts, all forms are compressed, including display
> (see hibernate/unhibernate)
> I think that VM should not attempt to display anything before first
> #beDisplay is sent.
> --
> Best regards,
> Igor Stasenko AKA sig.

John M. McIntosh <johnmci at smalltalkconsulting.com>
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com

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