Re: [MiNT] XaAES sources for FreeMiNT 1.16.3

[Paul Wratt <paul.wratt@gmail.com>]

On Thu, Dec 10, 2009 at 3:16 AM, Peter Persson <pep.fishmoose@gmail.com> wrote:
>
> On 9 dec 2009, at 16.38, Johan Klockars wrote:
>
>> IMO, it should never be possible for a user program/library to write
>> directly to video memory. In the general case that may not even be
>> physically possible.
>
> In the general case, it is physically possible. At least it includes the Hades, Milan, CTPCI, Videl, SuperVidel, Shifter, TT-Shifter, FireEngine+Radeon, and - if I'm not misinformed - the ACP.
>
> The original TOS has a low level video API (XBIOS). I see no good reason not to keep this approach. Maybe if there was a good alternative - but the VDI does not constitute that alternative. The lack of a good low level API effectively shuts out games and demos completely, which is unfortunate. Accessing video memory directly is something that people want to do. We can either accept that and make a good solution for it - or ignore it - and people will do it anyway, and we'll just end up with lots and lots of compatibility issues.
>
> -- PeP
>
>

isn't one of the main reasons for direct video access the fact that
only one physical workstation can be open with VDI, and yet by default
it abstracts this with a virtual work station. Shouldn't an app be
able to get direct access to the screen, even if in reality this is a
virtual workstation, and it can do what it want as fast or as slow as
it pleases. And isn't it related to a fundamental flaw in VDI's
construction, the fact that is has full control over the actual
hardware screen via a physical workstation (but is limit in some way,
to one physical workstation), shouldn't it be able to manage the
actual virtual to physical, even from another app/control point. (like
a display/desktop manager)

Another way to say this: App says give me a screen, (like console, but
not just text only), or tries traditional memory write (which VDI
intercepts). App is "yay I have full access... (doing stuff)". VDI
says "who is screen manager/director?" in response to positive answer
"this is for you. tell me when you want this onscreen, also let me
know if it is to be "screen hog" and on which monitor (nothing else,
dedicated), or else tell me what size and where do you want it.. "

Hope that is understandable in the context of what VDI currently does
and does not do.

Paul