[oe] [RFC] Adding screen dimensions to machine configs

[Paul Sokolovsky]

Hello Graeme,

Monday, July 9, 2007, 5:03:38 PM, you wrote:

> On Mon, Jul 09, 2007 at 03:52:45PM +0200, Dr. Michael Lauer wrote:
>> Heh, it's not just Opie. Eventually we may want to ship prerendered png's for
>> UI elements. We better know about the size and dpi of the displays to
>> get sane defaults. There's a whole lot of packages which could use the
>> MACHINE namespace to improve targetting the platforms specifics at
>> build time.
>> 
> I just worry what happens to machines without screens but that can have
> gfx cards added. By the current level of thought behind these variables
> a divide by zero is inevitable.

  Where is division here at all?

> It also triggers my gut feeling of "this is the wrong way to crack the nut"

  Oh, let me say it *again*. *All* software should be made to adapt to
different screen sizes (including small) and other params dynamically,
at runtime. What will we patch today?

>> What makes you worry so much about adding more (imho necessary)
>> information to the MACHINE_ capability namespace?
>> 
> Nothing, but these variables seem little thought out and seem to be being
> rushed into use for one use case (opie backgrounds).

  Background in general to start with. I don't know exactly how
theming is handled for X, but we don't want to ship backgrounds of
800x600 sizes for QVGA devices there too, even if X would scale them.
Or at least, we may want to optimize. Second, I gave 2 usecases, not
1. And other participants gave more (though I can't say if those
usecases would better be handled in runtime right away).

  Otherwise, I indeed use otherwise pretty static (and needing cleanup
anyway) OPIE as a testbed for ideas on how we can minimize device
dependency and improve support and maintainability. I'm sure results
will be worthy more general application.

> And if it is neccessary then it should be the "correct" information,

  Please add correct, sure. There're guidelines for semantics, but
eventually details are up to device maintainer and users.
  
>  like
> for spitz the screen is 480x640 by default. Deal with it in packages that
> wish to use rotation correctly. Not just this value makes it easy for my
> magic background generator.

  Maybe your generator can use fbset right away?

> Maybe a MACHINE_DEFAULT_ROTATION is also needed.

  And many more others! But again, ultimate usefulness of resolution
is too allow to optimize install size (a random background is say 40k,
there's a difference if we install 40k or 5*40k, right). What would we
gain with specifying a default rotation? Only ability to preconfigure
device to be in user-expectable orientation instead of what its LCD
hardware has (which is good aim, btw ;-) ).

> Graeme




-- 
Best regards,
 Paul                            mailto:pmiscml at gmail.com