Re: Display confusion

[Jos H. <jo...@st...>]

On Sat, 27 Jul 2002, Christoph Egger wrote:

> How about separating the display into a logical and a physical
> one?

Nice idea.. but: logical = ggi, physical = kgi ?

Or is there really a card which can do accelleration across multiple heads
? Shouldn't be too hard ... In that case we really have to get back to
basics when taking your proposal serious.

Anyway.. I was thinking:

Now, the kgi core sets up the struct that holds together the chipset,
ramdac, clock data. Wrong.

The chipset driver initializes. It finds one head. It tells kgi it wants
to register the chipset driver for head 1 (or 0, talking in C arrays).
Chipset driver found another head. Registers the driver for head 2.

Ramdac driver initializes: sees there are two chipset drivers, so
initializes and registers two ramdac drivers...

Clock...

Monitor... (ddc driver is multihead capable as soon as chipset driver is
it, other drivers might have to use parameters or something...)

Note: maybe (donnow) it isn't always the chipset driver but for example
the ramdac driver that defines two heads. For example maybe some tv-out
cards that can only display the same as vga out on tv-out.

Some more thinking:

MAYBE kgi shoud have a load time option: merge heads horizontally, merge
heads vertically, split heads. On the fly changing your available displays
is too beautiful to be true imho.

When implemented correctly, this merging shouldn't be too hard: KGI gets a
mode request from user space. Depending on the configuration at boot time,
it sets both heads at (1/2 x , y) (hor. merged), (x, 1/2 y) (vert merged),
or the driver acts like two, so the request is sent to only one of the
heads.

Thinking more... Apple has a beautiful system that allows you to drag and
drop the monitors around each other at any place (crt one 640x480 starting
at x=0,y=0, crt two starting at x=320,y=480, different sizes, etc). But:
that's real software. If we want THAT, the user can separate the heads,
and we can blame the GGI boys if he doesn't get what he want ;)

Hmzz. too bad we don't have some more active coders... KGI could be so
beautiful...

Jos